Romania Rocks

Geology on 35mm film #2 - Soft sediment deformation

2011-01-19T19:56:00.000-08:00

©RomaniaRocks
Soft sediment deformation in the form of a small compressional fold, in the
Olanesti Formation (Eocene). Note the undeformed strata above and below
the fold. The outcrop is located in a road cut, east of the Olt river.

Good examples of soft sediment deformation structures exist in the Eocene section of the Getic Basin in Romania. The photographs give some examples of reverse faults and small compressional folds found in road-cut outcrops to the east of the Olt River.

These features most likely formed in a pro-delta environment, characterized by high sedimentation rates and relatively steep slopes. Because of the high sedimentation rates, water did not expel easily from the recently deposited sediment. This resulted in increased pore pressure immediately after deposition, which lead to displacement and movement of unconsolidated sediment.

©RomaniaRocks
Soft sediment deformation in the form of a small compressional fold.
The strata are Eocene in age and the outcrop is located east of the Olt river.

©RomaniaRocks
Soft sediment deformation in the Eocene strata, Getic Basin.
The section consists of silty mudstone with interbeds of sandstone.
The deformation is in the form of a reverse fault.

Mud cracks revisited

2011-01-09T10:47:00.000-08:00

In a previous post I showed a picture of the desiccation cracks that formed when a little pond on our Brenham property dried out this summer. We visited three months later (yesterday), and found that the cracks in the mud weathered, and now look more like ant mounds. The two pictures, side by side are shown below.

October 14, 2010 ©RomaniaRocks January 8, 2011
Three-month repeat photography of desiccation cracks, Brenham - Texas.

The picture to the left was taken immediately after the water in the pond evaporated; the mud on the bottom of the pond was exposed to the surface, it shrunk and cracked resulting in the polygonal shapes shown in the photo. As the mud continued to dry during the three months of subaerial exposure, it lost its strength and started to crumble, taking the mounded form shown in the picture to the right.

Also very interesting is the fact that this polygonal pattern so characteristic to the desiccation cracks shows up in many places and at a variety of scales in nature, from beer foam, to the skin of a giraffe, to structures found at the nano-particle scales, to patterns found in the Universe. The short video below from University of Nottingham-Sixty Symbols describes very nicely the multi-scale occurrence of the polygonal pattern.

The Danube, New Year, Vienna and Music

2011-01-01T13:29:00.000-08:00

Odd combination one may say, but there is a common thread here. On January 1st every year I watch the New Year's concert from Vienna; it is a family tradition, about which I blogged here one year ago. The concert is centered around music from the Strauss family, and one of the most anticipated pieces every year is the Blue Danube waltz. So there, you now see the connection.

The Danube River ends its "journey" in the Black Sea, where it forms the Danube Delta, which is one of my favorite places in Romania for many reasons: scenery, geology, landscape, people, the food, the culture, and the list could go on.

The Danube Delta (Romania and Ukraine). Image credit - Chelys, via Earth Snapshot.

The Danube Delta overlies two geologic provinces: the Scythian Platform and the Pre-Doborogea Depression. The deltaic sedimentary complex is up to 400m thick and formed during Late Pleistocene - Holocene. The delta consists of three depositional systems: 1) a deltaic plain, which in the picture above is roughly the dark green area, from the first point of bifurcation of the Danube River (marked by the red circle in the photo above), to the shoreline; 2) the delta front parallels the coast and roughly coincides with the area where sediment plumes are visible in the water; and 3) the pro-delta, offshore of the delta-front, in water depths as deep as 50-60m.

In Vienna, on every January 1st, the Blue Danube waltz is the second of the three encore pieces played during the New Year's Concert. The tradition is that the orchestra starts the music, and after the first few measures the audience interrupts with applause. The conductor stops the music, turns towards the audience and wishes everyone a Happy New Year, after which the orchestra resumes the music.

I wish everyone a happy, healthy and prosperous 2011, and I am looking forward to some Champagne and waltz music tonight, including one of my favorites - the Blue Danube Waltz.

Happy New Year!

Romania viewed from above - Carpathians and the Black Sea

2010-12-29T12:10:00.000-08:00

Envisat image showing the deep freeze that affected the southeastern Europe in January 2010.
Image source - European Space Agency

Weather in Europe has been very rough recently, so it looks like the year will end the same as it started: cold! The picture above is from January 25, 2010 and it shows the deep freeze in SE Europe at the time. The Carpathians are visible in the center left, the Danube Delta is seen in the center of the image, at the edge of the Black Sea.

Geology on 35mm film - Conglomerates

2010-12-26T19:03:00.000-08:00

I started going through my old 35mm slide collection representing geological field work from the pre-digital era. Some of these places I will probably not visit again, at least not anytime soon, so I am bringing them to life with the help of a digital scanner.

The Paleocene rocks in the Southern Carpathians foredeep are represented by poorly sorted, massive, clast-supported conglomerates, which onlap the crystalline basement. They consist of angular fragments of schist up to 1m in diameter, as shown in the photo below.

©RomaniaRocks
Calimanesti Conglomerate on Topolog Valley, Southern Carpathians - Romania

The schist fragments are lithologically similar to metamorphic rocks in the Southern Carpathians. The massive conglomerates grade upward into upward-fining cycles of conglomerate and sandstone, each cycle about 8m thick.

©RomaniaRocks
Upward-fining cycles of conglomerate and sandstone.
Calimanesti Conglomerate, Valsan Valley-Romania.

The upward-fining cycles have a clear erosional base, and the lithology of the clasts are more diverse, consisting not only of crystalline rocks, like lower in the section, but also of sandstone and limestone.

©RomaniaRocks

Calimanesti Conglomearte, Valsan Valley - Romania.

Note the erosional base and fining-upward character.

The sandstone at the upper part of each cycle is medium- to very coarse grained and massive, flat-beddd or cross-laminated.

©RomaniaRocks

Calimanesti Conglomerate, Valsan Valley-Romania. Note the erosional base,

large fragments of crystalline rocks and the finning-upward character

The conglomerates described above were deposited by overlapping alluvial fans sourced by the Southern Carpathians. The poorly sorted, angular, coarse textured deposits, with fragments up to one meter in diameter are indicative of debris flow deposits, a common occurrence in alluvial fans. The Paleocene landscape of Romania was probably not too different than the landscape in the photo below, from the Rocky Mountain National Park in Colorado.

©RomaniaRocks

Alluvial fan at the mouth of a canyon in Rocky Mountain National Park, Colorado.

A hike on top of the fan in the Rockies reveals the size and complexity of the fan. I bet a hike in the Paleocene in Romania, on top of the Calimanesti Conglomerate would have been somewhat similar, less the ability to use the humans for scale :)

©RomaniaRocks

Close-up view of the alluvial fan in Rocky Mountain Park, Colorado.

Earth as art #1

2010-12-10T16:29:00.000-08:00

Photo credit - European Space Agency

Fascinating geomorphology in the Arctic tundra combined with modern technology (multitemporal Advanced Synthetic Aperture Radar), gives this amazing image that rivals the most creative human talent.

Rivers, geology and culture (#1) - Arges, Romania

2010-12-05T09:07:00.000-08:00

A river represents the perfect fusion between geology and culture. Rivers are characterizesd, generally speaking, both by erosion and deposition; this is where the geology aspect comes from. Think of the Grand Canyon and you can visualize the results of river erosion through time. Take a canoe down or up a river, stop on the river bank for lunch and look around; the canoe trip and the lunch break will help you witness river processes, deposition and their resulting features.
Rivers are also amazing "cultural centers", in the sense that human settlements usually started along a river. Any major city in Europe for example is associated with a river: Paris-Seine, Vienna-Danube, Frankfurt-Main, Bucharest-Dambovita, Rome-Tiber, and the list could go on... This is where the cultural aspect comes from.
With this post, I am starting a geological-cultural trip along a river, the Arges River in Romania, to be more precise; I imagine I am a rock particle (or a water molecule) originating from the Southern Carpathians and traveling along the Arges River all the way to the Danube. The trip will witness some amazing history (geological and human), culture and landscapes.
The Arges River headwaters are located in the Southern Carpathians, between the two highest mountain peaks in Romania: Moldoveanu and Negoiu.

Google map showing the headwaters of the Arges River, located between Negoiu and Modoveanu, the highest mountain peaks in Romania. Top of the map is towards South.

Geologic sketch of the area around
the Arges River (modified after Mutihac, 1990). Note that only
the geology relevant to the Arges River is represented in color.
Cn2= Serbota crystalline series; Cn1=Fagaras crystalline series;
Pg=Paleogene; m=Miocene; N=Neogene

The Arges River has its headwaters in the metamorphic rocks of the Fagaras Mountains. The views are breathtaking, the weather is harsh and as a result, the few motels and chalets that exist in the area function only during the summer.
The upstream part of the Arges River is probably most famous because it parallels the second highest paved road in Romania - the Transfagarasan. The road was built in early 1970's in response to the Soviet invasion of Czechoslovakia. Ceausescu, the Communist President of Romania at the time, wanted to have quick access across the mountains in case the Soviets attempted a similar move in Romania. The road was built with heavy human (forty people lost their life) and financial sacrifice.
The next posts will take us to the Vidraru lake, then through the most upstream permanent settlements (villages) along the river; this will allow us to explore more geology and culture.

Romania viewed from above - Bucharest

2010-12-04T09:37:00.000-08:00

Synthetic Aperture Radar (SAR) multitemporal colour composite image of south-central Romania with focus on Bucharest. Photo Credit - European Space Agency

Bucharest (Bucuresti in Romanian) is the bright area in the center right. The city lies on the banks of the Dambovita River, and its name comes from Bucur who, depending what legend you take into account, was either a prince, an outlaw, a shepherd or a hunter.
More on Bucharest from the local administration website and the Wiki site. More on Synthetic Aperture Radar here.

Happy Birthday Romania!

2010-11-30T21:11:00.000-08:00

On December 1st Romanians everywhere celebrate the National Day of Romania. To do my part, I put together some of the photos from my trip to Romania this summer. The pictures are from Bucharest, Zarnesti, Piatra Craiului Mountains, Brasov, Bran, Rucar-Bran. The music is composed by Ciprian Porumbescu. This is for "My Romania", with love, and for all of you to enjoy!

PS sorry for the less-than-perfect image quality. Blogger did not let me upload the hi-rez version :(

Romanian National Parks

2010-11-25T14:41:00.000-08:00

On my to-do list in Romania is to hike all of the National Parks. As a note to self, and also to entice others to go and visit these beautiful places, this post provides a map and links to some of the parks. One of the best things about National Parks, in Romania or elsewhere, is the geology associated with the breathtaking views. This post is about some cool places in Romania where you can see awesome geology and experience great landscapes, views and culture.

View Romanian National Parks in a larger map
Apuseni Nature Park (Rom. Parcul Natural Apuseni): best known for the beautiful karst landscape and its numerous caves.
Bicaz Gorge - Hasmas National Park (Rom. Parcul National Cheile Bicazului-Hasmas): best known for the spectacular Bicaz Gorge
Calimani National Park (link in Romanian) (Rom. Parcul National Calimani): located in the Calimani volcanic chain.
Ceahlau National Park (link in Romanian)(Rom. Parcul National Ceahlau): Ceahlau Mountain is also called the Olympus of Romania, because of its significance in the history of the Dacians, the ancestors of the Romanian people. Ceahlau was considered to be the sacred mountain of Zalmoxis, the ancient deity of the Dacians.
Piatra Craiului National Park (Rom. Parcul National Piatra Craiului): one of my favorite places to hike. Beautiful Mesozoic limestone landscape.
Retezat National Park (link in Romanian)(Rom. Parcul National Retezat): best known for the beautiful landscape sculpted by long gone glaciers, it is the park in Romania with the highest number of mountain peaks over 2000m in height.

Your path looks boring? Explore the edges!

2010-11-24T10:31:00.000-08:00

Everyone's research (or career) path looks like this at one point in time or another.
Whether looking ahead ...

... or in the rearview mirror....

... the path may look flat, predictable, and downright boring. When that happens, there are three choices: continue ahead and hope some exciting breakthrough is waiting around the corner (good luck with that!); change course to a more exciting destination (take the train if needed, to get there faster); or go off the beaten path and explore the edges of your own discipline, and in the process listen to the echoes coming from fields outside your own. It is the latter that has the potential to bring the biggest breakthroughs.
Happy trails, and remember: it is the journey that counts.

Geology field notes - Process to product: ripples

2010-11-23T08:41:00.000-08:00

One nice thing about beaches is that you can observe processes and the resulting products at the same location. The video clip and the picture were taken from a beach not far away from my home (ok, about an hour drive...).
In the short movie below, the wave action on the beach creates a water flow that entrains the sand and generates moving bed-forms (ripples) on the bed surface.

The resulting rippled bed surface looks like this.

Ripples on a beach ©RomaniaRocks

If the process continues and net sediment accumulation takes place, the result is a ripple-laminated sand.
Enjoy your next walk on the beach and take your own pictures and video-clips of ripples in the making.

Speleology in Romania - Frasin Aven

2010-11-21T10:04:00.000-08:00

Speleology is what got me into geosciences in the first place, therefore a series of posts on caves of all sorts in Romania is in order.
An aven in caving is a very steep or vertical section in a cave that needs ladders or ropes to ascend and descend. The Frasin Aven (link in Romanian) is located in the Obcina Mare Mountains, which are part of the Eastern Carpathians mountain range.

The Frasin Aven is the northern-most pin on this map; zoom out for better viewing. Locations of other caves in Romania are also indicated on the map.
View Romanian caves in a larger map

The Frasin Aven can be accessed from Frasin village, on the National Highway #71, between Gura Humorului and Campulung Moldovenesc. The aven was discovered in 1975, it has an elevation change of 73.2 meters, which placed it in the 20th place in the world for elevation change for sandstone caves (based on 1989 statistics).

Frasin Aven sketch, after Giurgiu and Muraru, 1977

From a geologic point of view, the aven is located in the Carpathian Fold and Thrust Belt (Tarcau Nappe), and it is developed in Kliwa Sandstone Formation (Oligocene in age). Kliwa is a deep-water siliceous sandstone (98% silica content), and the aven is thought to have formed within a fracture caused either by extension associated with its position on a crest of an anticline, or via detachment and sliding of the sandstone block along its basal contact (the Kliwa Formation consists of a succession of interbedded sandstone and mudstone).

Seismic geomorphology research conference

2010-11-17T19:46:00.000-08:00

If you are in or near Houston-Texas, or can get to Houston in early December, I highly recommend this: the 30th Annual GCSSEPM Foundation Bob F. Perkins Research Conference - "Seismic imaging of depositional and geomorphic systems". With a 3-day full program, the BEG visualization center set up for people to view data volumes, and keynote speakers such as Kurt Marfurt, Sergey Fomel, Henry Posamentier, this will be THE conference on this topic for years to come.
The conference will be held at the Houston Marriott Westchase, on December 5-8, 2010. You may register for the event here.
The conference will cover the entire spectrum of depositional systems, clastics and carbonates, a wide variety of geographical locations, basins and geological settings: incised valleys on the Sunda Shelf, Indonesia; carbonate platform systems in the Browse Basin, Australia; estuarine deposits in the Gulf of Cambay, India; Pleistocene turbidites from NE Nigeria; point-bars in the McMurray Formation, Canada; channel-levee complexes, slope valleys and canyons from East Kalimantan, Indonesia; and much more.
I will be sharing on Twitter and blogging from the conference (hopefully).

Deserts, tectonics, erosion and natural beauty

2010-11-14T07:43:00.000-08:00

©RomaniaRocks

The Arches National Park in Utah is a must see. I was recently in the Moab area for geology-related field work and stopped for a few hours in the park. This was not my first visit, but I enjoyed it as much as the first time. Below is a short account of how, from a geologic point of view, the arches formed.
It started with a "see-of-sand" in Jurassic, about 200 million years ago; at that time the Moab area looked not unlike the Sahara. The desert-like environment persisted for fifty million years or so, and resulted in the accumulation of the two sandstone formations that make the natural beauty of the Arches today: the Navajo and the Entrada. These formations overly a layer of salt, three hundred million years old. The salt has the interesting "habit" of moving when loaded with sediment, just like tooth-paste moves when I load it and squeeze it from the tube. Imagine a brittle layer of sandstone pushed up by a mobile layer of salt from beneath; the sandstone will break along faults just like this:

The faults are enhanced with time by erosion (water, wind etc.), which results in the sandstone fins - intriguing features when viewed from above. Some of the sandstone fins are more resistant than others, and get preserved (at least for a while) as arches, spires, balanced rocks we see today in the park.

©RomaniaRocks

Delicate Arch ©RomaniaRocks

Fluvial and aeolian rocks from the Triassic of Utah

2010-11-07T08:52:00.000-08:00

Rocks are like people...in some ways. You take the same "material" (be it genetic for people, sedimentary for rocks) and place it in different environments, and you will get different results.

©RomaniaRocks

One of the principal goals in sedimentary geology is to identify the environment of deposition by looking at rocks and their characteristics. It is very important to be able to determine if a package of rocks was formed by wave processes pounding on a beach, by river processes, or by gravity flows traveling from submarine canyons to the abyssal plain of oceans. It is important because by doing so, we can understand, for example, past climate (and use it to predict future climate), we can understand the Earth complex systems, we are able to make predictions about the presence (or absence) at a certain location of a certain rock type, etc.

This post shows an example of the difference between fluvial and eolian rocks. Both pictures (above and below) show the eolian Wingate Sandstone, overlying the fluvial Chinle Formation.

©RomaniaRocks

The Wingate Sandstone forms the steep, upper pat of the cliff. It is called an aeolian sandstone because it was deposited by the action of the wind in a desert environment, not unlike what the Sahara desert is today.

The Chinle Formation can be seen immediately below the Windgate, it is more heterogeneous from the point of view of the lithology, consisting of mudstone, sandstone and conglomerate. The Chinle was deposited by rivers flowing on a floodplain.

Immediately after hitting the "Publish post " button I saw "Where does desert sand come from?" talking about the Namib Sand Sea, and posted on the AGU blogosphere site by Vivienne. An appropriate present day analogy for the Wingate of the Triassic.

Geology field notes - Mud cracks

2010-11-01T22:17:00.000-07:00

©RomaniaRocks

When muddy sediment is exposed to the atmosphere and dries up it commonly develops polygonal shape cracks in plan view, V-shaped in cross section.

Landscapes into Rock - Part 4

2010-10-04T14:52:00.000-07:00

This post ends my summary of the Landscapes into Rock conference that took place in London, September 21-23, 2010. Click here for previous posts.

Theme three – Landscapes into Rock – was obviously the central theme of the Conference. It was chaired by Sebastien Castelltort (ETH – Zurich) and Emma Finch (University of Manchester), it had eleven oral presentations and featured a very insightful “keynote of the keynotes” by Mike Leeder (University of East Anglia). Of interest for me was the research by Alex Whittaker et al using regional grain-size trends to derive information on the dynamics of the sediment routing system.

The high-point of the session was the keynote address by Mike Leeder. Mike put forth many interesting and provocative ideas:

the need to fully utilize the sedimentary record to test the landscape evolution models;
the recent advances in speleothem and calcisol research that may provide the ability to isolate climate/vegetation forcing of the eroding landscape;
the understanding of the link between the rate of tectonic evolution and how they induce major changes in the landscape;
teleconection – the link between the eroding landscape and the downslope deposcape.

The fourth (and last) theme – Integrative studies of sediment routing systems and the petroleum systems - was organized by Ian Lunt (Statoil) and Mike Blum (ExxonMobil), and featured two presentation and two keynote speakers – Ole Martinsen (Statoil) and Peter Burgess (Shell and Royal Holloway University of London). For me, the highlight of this session was Peter’s overview of stratigraphic forward modeling in hydrocarbon exploration. Peter noted that stratigraphic forward models (SFM) are more mature but still have a limited predictive power. SFM prove most useful in their ability to quickly create multiple scenarios, to test hypotheses and ideas, to devise numerical experiments that illustrate how depositional systems work and through that to develop new plays and concepts.

On a less-formal side, the conference ended each day with a social hour, which involved a lot of discussion of the ideas presented during the day, accompanied by wine, of course. The discussions were less formal, but certainly not less technical. They were less flashy than the gathering that took place at Dolce & Gabbana one evening, just down the street from the Burlington House (picture below), but the social hour at the Landscapes into Rock conference were certainly more intellectually stimulating -- for me :)

A day on the river

2010-10-03T20:17:00.000-07:00

You are a geologist when you have fun digging trenches to see cross-bedding and when you enjoy photographing mud clasts on a Saturday afternoon.

©RomaniaRocks

I am a geologist, so is my SO, and this weekend we enjoyed a trip along the Trinity River; beautiful weather was a plus, and it made it for a great family outing. We started with our canoe from the bridge across Trinity near Liberty, TX. From here we went north for about 7 km in total (the red line shows our path for the day).

The first stop was on the opposite bank from the meander loop cut-off, indicated by the yellow arrow in the picture above. A point bar with a lot of awesome features, worthy of any Geology 101 class: ripples and dunes...

©RomaniaRocks

... with awesome lineation in the coarse grain fraction oriented parallel to the transport direction (downstream is towards the top of the picture).

More ripples and dunes...

©RomaniaRocks

... mud cracks and the resulting mud-chips waiting for the next bank-full discharge to be washed away....

©RomaniaRocks

... unless of course your teenager will not remove them all by building mud-chip castles.

©RomaniaRocks

The mud cracks on the surface of this point bar developed in low areas, when water level was just above the edge of the depression where the mud accumulated. Eddies formed in these low areas of the point bar, and these eddies brought in and deposited a thin layer of mud. The mud cracks formed later after the water receded and the surface dried out. Similar eddies carrying and depositing fine-grained material (but at a larger scale) were responsible for the deposition of a nice mud-drape on one of the point bars we stopped at further upstream. The picture below shows the river bank with the water flow from right to left, and a protected area entered by an eddie, which deposited a beautiful mud-drape over the extent of the point bar exposure (arrows indicate the extent of the mud drape).

©RomaniaRocks

Well developed cross-bedding may be seen within the point bar succession....

©RomaniaRocks

... and ripple lamination, cross-bedding and wind ripples may be found in the right exposures on the point bars...

©RomaniaRocks

We had a blast: great weather, nice river, good canoeing, and cool sedimentary features. You get the picture :)

Comparative geology - the tale of two rivers

2010-10-03T12:30:00.000-07:00

I recently went on a canoe trip along the Trinity River (our track is shown by the red snaky line in the picture below). We spent the day looking at sedimentary features associated with modern river systems, and by doing so, thinking about processes at work in rivers, and the resulting rock architecture. As geologists, we often study modern environments (like rivers, beaches, deltas etc) to gather clues that help us understand the rocks and the processes that formed them.

The trip to the Trinity (more details in this post) reminded me of the Arges River in Romania; if looked from above, both have a lot in common.

Note that the scale of the two satellite images are similar, so the size of the geomorphic features can be easily compared. The width of the meander belt in the two images is similar. Two abandoned meander loops (red arrows) have similar dimensions and shape. Their paleo meander belts (active sometime in the recent past and still visible on the satellite image) have similar widths (black arrows).

The zoomed satellite photos show that the size of the active channels are similar. The Arges shows better the point bars within the active channel, but this is only because the picture of the Trinity was taken at near bank-full stage, where most of the point-bars are submerged.
These two rivers, although in somewhat different settings, would most likely create a very similar rock succession. I have to take a canoe trip along Arges sometime in the future, and at that point I will have on the ground pictures from the both locations. Until then, wait for the next post on the Trinity, and enjoy the birds-eye view of the two rivers.

Landscapes into Rock - Part 3

2010-09-27T11:24:00.000-07:00

This post continues my summary of the Landscapes into Rock conference that took place in London, September 21-23, 2010. Click here for previous posts.

The second theme of the conference – The Dynamics of the Sediment Routing System – was chaired by Alex Densmore (Durham University) and Ruth Robinson (University of St. Andrews), who assembled a very good mix of nine talks and three keynote speakers: James Syvitski (University of Colorado), Greg Tucker (University of Colorado) and Chris Paola (University of Minesota).

Interesting research of the Golo source-to-sink system was presented by Tor Somme (University of Bergen) et al. One of the interesting conclusions was that channel aggradation may occur both during eustatic highstand and lowstand, and that sediment partitioning along the source to sink continuum may be controlled by internal thresholds rather than external forcing.

The keynote by Greg Tucker (University of Colorado) on rapidly changing landscapes underscored some interesting points:

channel incision rate correlates with characteristic stream power and shear stress;
temporal variability in sediment cover is an important control in long-term bedrock river incision.

Chris Paola’s keynote address on mass balance effects in depositional systems was full of insight, discussing many fascinating concepts:

fractional sediment extraction and the subsidence-driven depositional mass loss
similarity in fining profiles along depositional trends
the use of generalized models/experiments as reference cases of down transport changes, against which field or subsurface cases can be compared

For the benefit of advancing our knowledge and workflows Chris jokingly invoked the need for adhering to the “Republic of Simplicity”, which created a cascade of comments in almost every talk that followed. Others, in return, advocated the “Republic of Complexity” or the “Monarchy of Necesity”, leading to great discussions but also polarized opinions among two camps: those who view the need to approach the Earth’s dynamic systems in all of their complexity, and those who believe that a simplifying approach maybe more appropriate. I certainly subscribe to the simplicity theory, while I choose to remain a citizen of the world and not subscribe to any republic or monarchy :)

Random fluid dynamics thoughts (and videos)

2010-09-26T14:52:00.000-07:00

I was riding my bike this morning along one of the man-made drainage channels in my extended neighborhood. Couldn't help to watch the water flow patterns and make connections between fluid dynamics and fluid/sediment flow patterns in modern environments. The short video below shows the fluid dispersal patterns not dissimilar with what one would see in a river reaching a shoreline and changing flow from confined to unconfined on a gently dipping slope. Note how the fluid dispersal pattern is fan-like, not different from a fan shape in a distributary channel system. There is a sharp change in slope, about half way through the image. Note how the dispersal pattern changes from fan-shape to almost parallel stream lines.

There was something else that caught my attention. To the right of the location in this first video, there was a change in slope, where two concrete slabs came together at an angle. At the same location, water was flowing from two directions, the stream lines joining at almost 90deg angle.

This caused the flow to have its top surface split in two. Are these standing waves? What else are they called and what causes their formation? The change in slope? Flow directions joining at 90deg angle? A combination of both? Watch the video and let me know.

Landscapes into Rock - Part 2

2010-09-25T09:50:00.000-07:00

The Landscapes into Rock conference held in London this past week had four main themes. For more general information about the event, see my previous posts.

The first conference theme was "The Erosional Engine". The session was chaired by Alex Whittaker (Imperial College London) and Andrew Carter (Birkbeck College London) and focused on geomorphology, erosion, sediment flux, burial/exhumation histories. The theme had eight contributions in the form of presentations and two keynote speakers: Niels Hovius from University of Cambridge and Kelin Whipple from University of Arizona. Several posters were also on display.

One of the highlights for me was the talk by Paul Bierman et al (University of Vermont) on their synthesis of the ten-year research in erosion and sediment rates using cosmogenic nuclides, with one big takeaway being the fact that bedrock erosion rates (measured from outcrop along ridgelines) are slower than basin-scale erosion rates inferred from fluvial sediment; the latter integrates processes active across the entire landscapes. Interesting also was the positive correlation between tectonic setting/activity and erosion rates and the documentation of using cosmogenic nuclides as tracers to study processes over 10 to 10^5 years timescale.

The keynote address by Niels Hovius on weathering, erosion and sediment transfer in Taiwan, was another highlight, with a valuable insight into the fact that to get a better understanding of weathering and erosion it is more useful to look at the dynamic forces acting upon a landscape (tectonics, erosion, climate), rather than at the static proxies such as topography or landscape. Both Niels and Paul referred to mountains as being “big piles of sand”, which stirred a big debate during the discussion sessions.

Kelin Whipple’s keynote talk on tectonic and climatic control on erosion rates made some excellent points: at steady state conditions, tectonic is the major control on erosion (not climate). For non-steady state conditions, some generalizations arise regarding the ability to distinguish between the tectonic or climatic forcing, with erosion rates increasing gradually in response to tectonic forcing, versus erosion rates increasing immediately in response to climate forcing.

Landscapes into Rock - Part 1

2010-09-24T17:32:00.000-07:00

Landscape into Rock conference, held in London during 21-23 September, was an extremely insightful event, rich in ideas and very inspiring. The title itself is meant to represent many aspects of sedimentary geology:

the link between surface geologic processes and the resulting rocks;
the source-to-sink continuum of sedimentary processes and depositional systems, and the need to understand and view this continuum with a holistic approach;
the insights that can be captured from short term processes, rates and models and how these insights may be applied to the rock record, which represents a much longer time frame and records controlling factors and rates that may have been very different compared to what we observe today;
what makes stratigraphy and how do we place stratigraphy in the context of Earth’s dynamic systems.

The organizers were Philip Allen (Imperial College London), Paul Bishop (University of Glasgow), Hugh Sinclair (University of Edinburgh) and Robert Gawthorpe (University of Bergen). Through careful planning at many levels they made this conference a success. The event was held at the Burlington House on Picadilly Street.

The conference was held as one plenary session, which for me was great: more focused and less stressful compared to large conferences with many synchronous sessions, which leads to the desire to clone oneself in order to be able to be in several places at once in order to not miss relevant talks.

The talks and posters were grouped in four themes, which took place in succession over the three days. I will cover each theme in a separate blog post (to come over the next few days). Needless to say, I was unable to tweet or blog real time, as internet connection costs an arm and a leg in London.

One side note: during the event, Paul Bierman made everyone aware of the digital archive of Earth surface images that is under development at the University of Vermont. This is a NSF-supported, free archive useful for teaching and learning about geomprphology - enjoy!.

Using crowds to communicate and innovate

2010-09-17T20:01:00.000-07:00

Three pieces of information came together today, they merged and managed to spark some ideas in my prefrontal cortex. First, a note from the organizers of "Landscapes into rocks" conference, which I will attend next week, asking for my permission to record the talk and post it online. This took me by surprise, and of course the first thought was "what a nice and progressive idea". Followed by the next thought "what if I have a stomach ache and give a lousy talk? It will remain forever posted on the web, and I will be forever embarrassed! I better prepare!"
Then, I stumbled upon a blog post by Seth Godin with an insightful title - "Rehearsing is for cowards", where the basic idea is that a well rehearsed talk/presentation will protect "against the downside, the unpredictable and the embarrassing" but will not allow for a potential leap forward. Seth states in his post:

"A well-rehearsed performance will go without a hitch. An explorer seeks the hitches, because hitches are the fissures and chasms that help us leap forward."

The third and final piece that made my day was a TED talk by Chris Anderson on Crowd accelerated innovation. This talk emphasized how internet video allows the communication of ideas beyond the audience that attended an event, and also how it creates a cycle of improvement, through the feedback and the recognition a video post receives.

Dinosaurus Geopark - Hateg, Romania

2010-09-17T14:05:00.000-07:00

The Dinosaurus Geopark (in Romanian - Geoparcul Dinozaurilor Tara Hategului) is located in central Romania in a beautiful area named "Tara Hategului".

Source: IUCN and UNEP. 2009. The World Database on Protected Areas (WDPA). UNEP-WCMC. Cambridge, UK

The European geopark concept is relatively new, was established by UNESCO in 1999 and is defined as:

A territory with a great geological heritage. A territory developing the "Geoturism" in cooperation with its inhabitants. An experimental territory inside a thematic network (detailed definition here).

Hateg Dinosaur Geopark was recognized by UNESCO in 2004 through the effort of two great Romanian geologists, Professor Dan Grigorescu and Lecturer Alexandru Andrasanu, both with the Geology Department, University of Bucharest. Dan Grigorescu was my first stratigraphy professor during my undergraduate studies in Romania; I clearly remember his passion for research, dinosaurs and the Hateg area. The geopark is located between the vilages of Baru Mare to the east, and Zeicani to the west, and is surrounded by some of my favorite mountains (links to webpages in Romanian): Sureanu, Retezat, Poiana Rusca.
The geopark is famous for the assemblages of dwarf dinosaurs, numerous reptile fossil assemblages, karst cave systems and volcanic rock formations. More details on some of the fossil sites and the park in general may be found here. The area is heavy with history, it is indeed the "heart of the Romanian heart", as one historian put it: archeological sites including the Sarmisegetusa Ulpia Traiana fortress, which is the most important Dacian military, political and religious center; some of the oldest churches and monasteries, such as the Densus Church, believed to have been a pagan worship center before becoming a Christian church; medieval and more recent historical sites.

Geology, buildings, cities, architecture

2010-09-07T17:12:00.000-07:00

Stone buildings are forever linked to geology by the architects that created them. And through that, the cities and the human culture they represent are forever linked to geology. I showed in a previous post how the Romanian village of Corbi and its culture is forever linked to geology through the little church carved in stone by the villagers.

During a recent trip to San Antonio, we strolled by the Bexar County Courthouse, a beautiful building designed in 1892 by James Riely Gordon in a Romanesque Revival style.

The courthouse is built from Texas red sandstone (Pecos Sandstone), with a layer of Texas Pink Granite at the base, all shown in the pictures above, which I took during the trip the other week.

There are no outcrops of the sandstone or the granite in the city, but the courthouse reminds the San Antonians and the tourists alike of the strong link between human creativity, the Earth and its rocks.

Geology field notes: tufa towers on Mono Lake, California

2010-08-11T19:54:00.000-07:00

We arrived at Mono Lake on a late afternoon, and timed it this way because the lighting is better for photography. Low angle light makes the beautiful blue-green color of the lake and the tufa towers even more spectacular.

The Mono Lake is an enclosed saline lake formed in a low area of the Mono Basin, which is located in the Basin and Range Province of the United States. The greatest attraction are the tufa towers, spectacular features in the form spires and rounded knobs rising several feet above lake level.

Tufa is a form of calcium carbonate, and is similar to the stalactites and stalagmites that we enjoy so much in caves. At Mono Lake the towers start forming on the bottom of the lake, where fresh water springs rich in calcium mix with the water from the lake, which contains sodium and potassium carbonate in solution. The fresh water is lighter than the saline water of the lake and, as a result, it rises up. As the fresh water rises, the calcium in solution combines with the sodium and potassium dissolved in the lake water and precipitates tufa.

The tufa in the towers is porous, and as more fresh water enters the lake through the springs, it flows through the intricate structure of the pores and when escapes and reaches the lake water, it precipitates more tufa, creating the impressive knobs and spires we see today.

Landscapes into Rock - geoscience meeting

2010-08-10T21:18:00.000-07:00

This fall I will attend and present at the William Smith 2010 meeting "Landscapes into Rock", hosted by the Geological Society in London, 21-23 of September. Landscape into Rock is an inspiring title, with an even more inspiring set of sessions and keynote speakers. Below is a synopsis of the meeting; you can also go to the website here, find out more, and register if you are planning to attend.

The Erosional Engine - co-chaired by Alex Whittaker (Imperial College London) and Andy Carter (Birkbeck College, University of London); Keynote speakers: Kelin Whipple (Arizona State University) and Niels Hovius (Cambridge University)

The Dynamics of Sediment Routing Systems - co-chaired by Alex Densmore (Durham University) and Ruth Robinson (St. Andrew’s University):; Keynote speakers: James Syvitski (University of Colorado-Boulder) and Chris Paola (University of Minnesota)

Landscapes into Rock: the Making of Stratigraphy - co-chaired by Sébastien Castelltort (ETH-Zürich) and Emma Finch (Manchester University); Keynote speakers: Mike Leeder (University of East Anglia) William Smith Lecture 2010 and Rudy Slingerland (Pennsylvania State University)

Integrative Studies of Sediment Routing and the Petroleum System - co-chaired by Ian Lunt (Statoil) and Mike Blum (ExxonMobil); Keynote speakers: Ole J. Martinsen (Statoil) and Peter Burgess (Shell)

I am planning to microblog (via twitter and Tumblr) in real time, and blog at the end of each day (in semi-real time at Romania Rocks), but I do not promise. Internet connection can be quite a luxury while abroad (especially in Europe) and I hate paying an arm and a leg for the real-time thing. In any case, I will certainly take good notes and blog heavily real-time or after the event.

Comparative geology

2010-08-10T18:52:00.000-07:00

I am starting a new series of posts on “comparative geology”, in which I will compare and contrast geological features, settings, processes, events mostly for … the fun of it. Comparison is used as an investigative tool in other sciences; comparative anatomy is one example. The closest to my background is the case of sedimentary geologists using the term “analogs” when they compare rocks formed in similar depositional settings. Often analogs are used to compare rocks in the subsurface, where information is sparse and often one-dimensional (or three-dimensional but low resolution), with outcrops where rocks may be often seen in three-dimensions, touched, smelled, even tasted (ok, you have to be a geologist to enjoy that aspect). Another example of comparative geology is from the Earth and Planetary Sciences, where geomorphic or geologic features or processes on Earth are compared to those observed on other planets, with the goal of understanding processes on distant places in the Universe. The “distributary fans on Mars” are one example of this comparative geology concept.

The idea came to me this past week, while on vacation in the Sierra Nevada, a paradise for geologists. Many places I've seen during this trip reminded me one way or another of geologic features or settings in Romania; hence the opportunity for comparative geology on Romania Rocks.

There are many advantages for using comparison as an investigative tool in geosciences: when you compare and contrast features or processes, you understand them better; and then, there is the opportunity to come up with that wacky idea that would turn into a big breakthrough because you looked at things in a different way, or from a different perspective.

Geology field notes: granite exfoliation

2010-08-09T22:03:00.000-07:00

The "Geology field notes" is intended to be be a series of short posts on observations, measurements or geologic features I was intrigued by, awed or excited enough to take a picture of while in the field.

I returned recently from a trip to the Sierra Nevada and I was lucky to be able to spend some time in the Yosemite area. What a paradise for geologists and outdoor enthusiasts alike!

Exfoliation features, or exfoliation joints, are commonly seen in Yosemite. There is still debate about their genesis, but is it believed that they occur when concentric shells or plates of a rock break from its surface. Exfoliation is common in intrusive igneous rocks such as granite, formed under great pressure and temperatures. When granitic rocks are exposed to the surface, the pressure is released and the granite expands slightly, resulting in exfoliation.

There are many examples of exfoliation feature in Yosemite; I will show here only a couple, the Royal Arches and the North Dome, both visible from the Glacier Point.

The Royal Arches (labeled RA in the figure above) formed during the Pleistocene glaciation, when glaciers peeled away the outer exfoliation shells along the side of an exfoliation dome, the North Dome (labeled ND in the picture above). The smooth and broad arches were possible to form primarily because of the strong and homogenous fabric of the rock. The more geologically inclined folks would be excited to know that the rock that made the arches possible is a coarse-grained granodiorite of Cretaceous age (87 my old), with well-formed plates of biotite and long rods of black hornblende, an especially good rock to provide the geologist with exfoliation features. Also in the picture above (and below) is the Washington Column (WaC), separated from the Royal Arches by a steep gully, which is a major joint in the granodiorite.

The outer arch of the Royal Arches spans a distance of ~550m (1800 feet), is about 60m (200 feet) thick and 300m (1000 feet) high.

Glaciers, Scandinavian-style mansions, recessional moraines, tea-houses and roche moutonee

2010-08-08T20:57:00.000-07:00

This eclectic title expresses my fascination with how Earth history and human culture intertwine. In 1929, Lora J. Knight commissioned a Swedish architect to build a Scandinavian-style summer home on her property on Emerald Bay, Lake Tahoe area.

Emerald Bay and Scandinavia have one thing in common: glaciers and their influence on the modern-day landscape.

The Emerald Bay is located on a depression scooped up by Pleistocene glaciers. Scandinavian fjords are sculpted by glaciers too; Ms. Knight was wooed by the beauty of both and immediately made the connection, which resulted in the building of Vikingsholm, her summer retreat on the shores of Lake Tahoe.

I visited the Lake Tahoe area last week, and its beauty impressed me as much as it did Ms. Knight many years ago. The picture above shows the Emerald Bay (foreground) entering Lake Tahoe (background) through a gap in a recessional moraine.

The moraine (detailed picture to the left) was formed as the glacier melted and deposited the glacial debris along the shoreline of Lake Tahoe. I had a great time walking the moraine deposits, because.... I am a geoscientist, but also because the August weather was great and the views were magnificent.
The Emerald Bay has another interesting feature of glacial origin, the Fannette Island, a roche moutonnée.

The picture to the left shows the quaint island, and the closeup picture below shows the gently inclined upstream slope to the right, and its steep and rough downstream side ( to the left).
Ms. Knight built a tea-house on top of the island (visible in the picture if you look carefully), but I am not sure if she ever thought, as she was sipping her tea, that the rock formation was carved from a piece of basement rock as it was overridden by the Emerald Bay glacier. But who knows, maybe she was as fascinated by geology and glaciers as I am.

Update on the Black Sea earthquakes

2010-07-25T14:10:00.000-07:00

Since my post this morning about the three earthquakes in the Ukraine side of the Black Sea, one more happened today at 16:10:56 (UTC).

Here is the map with all four events:

I also found a tectonic map with the major fault zones at the end Jurassic (after Robinson et al, 1997), that may shed some light regarding the seismicity in the Black Sea. It appears that the lone event is related to a fault zone bounding the Shatsky Ridge in the eastern Black Sea, and the three clustered ones SW of Sevastopol are near the Jurassic tectonic boundary of the Tavrik-Kure basin.

Low magnitude earthquakes are not uncommon in the Black Sea. Below is a list of all the 2010 seismic events with a magnitude greater than 2 on the Richter scale (from the National Institute of Earth Physics, Romania):

Black Sea Earthquakes

2010-07-25T09:22:00.000-07:00

On Saturday, three earthquakes in the Black Sea succeeded over an interval of five minutes.

The first was located west of Sevastopol and occurred at 18:51 (UTC).

The second took place SE of Sevastopol at 18:55:24 (UTC).

The third earthquake was located very close to the first, about 64km W of Sevastopol, and occurred at 18:55:52 (UTC). The four maps above are courtesy of the National Institute for Earth Physics in Romania.

I do not know much about the earthquakes in the Black Sea, since the big events in Romania are related to the Vrancea region (see my previous post here on the geology and wine - seismic terroir). I will try to find out more about the focal mechanism and other information, but if any of you know more, please leave comments.

From information I found on EarthquakeDB, in 103 A.D an earthquake in Ukraine (map below) associated with a Tsunami had the epicenter located very close to the ones that occurred yesterday. Fortunately, no Tsunami on Saturday!

Trip to the past

2010-07-24T13:48:00.000-07:00

I recently returned from a trip to Romania, in Zarnesti-Bran-Piatra Craiului area; this was a trip to the past in a couple of ways: my past, and the geologic past.
Twenty-some years ago I was an aspiring geologist, and while I was waiting to find out if I made it into the Geological Sciences School at the University of Bucharest, I went with a group of friends on the week-long trip to the Piatra Craiului Mountains. We had a great time and I have great memories, so this year I decided to retrace some of my steps of many years ago.

We accessed the trails from our home-base in Zarnesti, you can see the town in the distance in this picture. I took it from the hiking trail leading to Curmatura cabin, the placed my friends and I used as our base camp on our vacation from the past. The picture is looking towards ESE, and in it you can also see the Barsa Mare River and, in the distance, the Southern Carpathians.
Piatra Craiului is a spectacular mountain range, its crest is about 25 km long (Google map in my previous post), and it owes its beauty to geology.

And here comes the trip to the geologic past. The mountains consist primarily of Jurassic and Cretaceous limestone, with the entire section about 1050 m thick. The lower 500m consist of a carbonate breccia and conglomerate sourced from Late Jurassic reefs located to the south, in the area of today's Bucegi Mountains. The rest of the section consists of reef carbonates and these are the rocks that give the area its beauty. The picture above shows the western versant of the Piatra Craiului and is taken from the Plaiul Foii Chalet , the place where we will stay for sure on our next trip here.

The mountains are a dream for spelunking, rock climbing, hiking, or just hanging out. Dambovicioara Gorge (shown in the picture to the left), a 2 km spectacular narrow, v-shaped canyon with steep sides, is another attraction.
We returned home from the trip to the past driving through the Rucar-Bran corridor. It was a rainy day, with heavy fog at times, which made the picture taking not an easy task, but the image below gives a good idea of the natural beauty of the area.
Piatra Craiului became a National Park in 1938; a nice post about the park, with info and pictures, came out recently in the True Romania blog here.

Trip to the Mesozoic

2010-06-06T14:31:00.000-07:00

This summer we are going to Romania to visit family and friends and are planning a trip to the Piatra Craiului Mountains. We will spend at least a couple of days hiking the Mesozoic reef buildups in the area, and will enjoy some of the most amazing scenery in the Southern Carpathians. Our first excursion will most likely be on the Northern side of the mountains, from the town of Zarnesti (link in Romanian) to Turnu and Padina Popii Peaks via Padina Hotarului. A fun hike with about 1200m of elevation gain.

The invisible oil spill

2010-05-23T07:46:00.000-07:00

I am a geoscientist and the Earth is not only my home, but also my passion and my profession. The oil spill in the Gulf of Mexico saddens and troubles me deeply. Much has been talked, published and blogged about it, so I will not discuss it here. Instead, I would like to talk about the "invisible oil spill", which is happening every day, ever since oil was discovered. This is the oil that you and I consume daily, and in every way it is the fundamental reason we have an oil spill in the Gulf today. Bare with me through this simple calculation.

I drive to work about 20 days every month (some days I bike to work), which makes about 240 days/year. My car gets about 25mi/gal. If, on average, one barrel of crude yields 19.5 gallons of gasoline, and if my math is correct, in 16.25 days my car consumes one barrel of crude just by driving to work, and every year I use 14.8 bbl of oil, just to drive to work. Another way to look at this - I "spill" about 15 gallons every year just by driving my car to work - an invisible spill, but one that is real.

The US oil consumption is estimated at about 19 million barrels/day, so WE collectively "spill" millions of barrels every day. This is a complex issue; petroleum (and coal) fuel the world's economy, and through that, contributed to the progress of the human civilization as we know it. We humans, collectively, have the responsibility to find a sustainable path that will take the civilization forward and be sensitive to the planet in the same time. The blame game is never very effective. One cannot point fingers and roll up the sleeves in the same time.

Volcanoes -- modern and ancient

2010-04-18T18:31:00.000-07:00

The recent eruption of the Eyjafjallajökull Volcano in Iceland made a lot of press lately and captured the interest of scientists and non-technical folks alike. In this post I want to compare and contrast the modern volcanism in Iceland with the Neogene-Quaternary volcanic setting in Romania and, in doing so, to briefly review two different tectonic settings in which volcanic activity may take place.

Iceland is located at a divergent plate boundary over the Mid-Atlantic Ridge, along which the North American Plate and Eurasian Plate are being pushed apart by newly formed crust (diagram below from USGS Credit: U.S. Geological Survey Department of the Interior/USGS)

A deep-seated mantle plume is also present in the area and interacts with the North American Plate. This plume (or hotspot) and the active spreading axes are producing the volcanism of present day Iceland. The map below (from R.G. Trønnes, Nordic volcanological Institute, University of Iceland) shows both the active and old spreading axes as well as the position of the mantle plume between present day and 40 million years ago.

The ash cloud from the icelandic volcanic eruption was observed in the Northern part of Romania on April 16 and 17, but Romania had ash produced from its own volcanoes as recently as 10,000 years ago. In contrast to Iceland, the Romanian volcanoes were active at a convergent plate margin. The resulting volcanic arc deposits are Neogene to Quaternary in age and are located in the Northern part of the Eastern Carpathian mountains. The map below (from A. Szakracs,I. Seghedi, 1995) shows the volcanic cones and the associated deposits in Calimani-Gurghiu-Hargita mountains.

The Eastern Carpathians volcanic arc is 160km long, the longest in the entire Carpathian mountain belt. It formed as a result of the convergence between two plate fragments, the Transylvanian micro-plate and the Eurasian plate. The volcanic activity spanned from ~15 Ma to 0.01 Ma ago. The area is interesting not only from the geological point of view, but also for its natural beauty, but about this in another post.

Free books and ... geology of course

2010-04-14T17:37:00.000-07:00

I was driving back home from the office today listening to NPR, and Andrei Codrescu's commentary "Getting From Here to There" inspired me in many ways. His story also pointed me to an iPhone app "FreeBooks", which I immediately searched for and downloaded when I arrived home. The app is advertised as "23,469 classics for less than a cup of coffee" and I can tell that it will become one of my favorite apps. It will take me a while to read all of this good stuff, but for sure among the first will be the "geology-flavored" books. Here are some of them, now accessible anytime from my trusty iPhone (if I would only have more than 24h in a day):

The Student's Elements of Geology - by Charles Lyell (1870)
Geological Observations on South America - by Charles Darwin (1846)
Geological Observations of Volcanic Islands - by Charles Darwin (1844)
Geological Contemporaneity and Persistent Types of life - by Thomas H. Huxley (1862)
The Economic Aspects of Geology - by C.K. Leith (1921)
Discourses: Biological and Geological Essays - by Thomas Henry Huxley (1894)
Town Geology - by Charles Kingsley (1871)
The Boy Scouts of the Geological Survey - by Robert Shaler

So, drink one less cup of coffee, relax with a good ole book and be happy!

Geoscience metaphors (or geo-puns) #2 - "Rock solid"

2010-04-08T22:03:00.000-07:00

Oh! parent, parent! send no son to California except he be rock-solid adamant to all vice. Be her mountains pure gold, let them stand; send no kith or kin of thine to dig them, nor thyself turn towards them, unless armed like an old knight, cap-a-pie, for a desperate conflict, not with revolver and bowie knife, -lead and steel are of small worth, - but with manly principle, a moral coat of mail, light and easy, but impervious.

This is the oldest reference I could find of rock-solid being used as a geoscience metaphor. It is an excerpt from the letter "Straws from the Gold Coast" written on June 26, 1849 in San Francisco and published in the "Daily Southern Cross". The article also offers an interesting account of what San Francisco was like not even one year after the official start of the Gold Rush:

A timeline from Google News Archive for this geo-pun looks like this:

just follow the link above and chose your favorite rock-solid reference.

In a more recent reference of this metaphor, Joshua Greenman describes his iPad experience with the words "Zippy web browsing, rock-solid feel: New Apple iPad is perfect down to the last micrometer".

One of most famous Romanian rock-solid geo-puns is "tare ca piatra, iute ca sageata", translated as "rock solid and fast as the arrow"; it is part of an ancient Romanian New Year's custom, when kids go around with a stick adorned with flowers and wish the loved ones all the best in the new year. One can find more info on this custom, which is known as "Sorcova", here.

Geology and wine #4 - Wine and Earthquakes

2010-03-28T16:22:00.000-07:00

Some of the oldest wine growing regions in Romania are in Vrancea, an area also known for the highest seismicity in Romania. The red ellipse on the image below shows where Vrancea is located: within a structurally complex area named in Romanian "zona de curbura" literally translated as the "bend zone", because the Carpathian arch bends as it transitions from the Eastern Carpathians to the Southern Carpathians.

I'll start with the earthquakes, so that my post will have a happy ending, on the topic of wine.
Vrancea is a subduction zone and the widely accepted model for the seismicity is shown in the E-W cross section below (sourced from the Romanian earthquake forum, Cutremur.net):

It is postulated that a slab from the plunging plate detached about 10 million years ago and its motion, as it sinks and is consumed in the mantle, generates quakes. The depth range for the hypocenters varies between 15 and 220 km. Areas to the NE or SW of Vrancea are the most affected during an earthquake, which is why Bucharest is the number two European capital with the highest seismicity (after Lisbon). I went through a 7.4 earthquake in Bucharest in 1977, and it was not fun (I wasn't even a geologist yet at the time, to at least find "pleasure" in the scientific aspect of the event). More on Vrancea quakes here and here.

As for the wine, the best known wine regions in Vrancea are Panciu, Odobesti and Cotesti. The best wines from native grapes here are the Feteasca Regala, Tamaiosa Romaneasca and Feteasca Neagra. The last is my favorite, with its bouquet of blackberries and dried plums, and a hint of bitterness as it gets more mature.

Depositional facies models - the need to move on?

2010-03-27T13:18:00.000-07:00

I am reading John S. Bridge's River and Floodplains, which I highly recommend for anyone interested in fluvial processes and the resulting deposits. His comments on depositional facies models deeply resonate with me:

Most facies-association models in the literature are inadequate for anything more than a very general qualitative environmental interpretation because: (i) the deposits are normally represented in only one or two vertical sections, normal and parallel to the flow direction; (ii) the information shown in these two-dimensional sections lacks critical detail of the spatial variation of strata thickness and orientation, grain size, internal structures, paleocurrents, and biological features; (iii) the nature of preservation of the strata is not indicated, because the models are not dynamic; and (iv) the models are purely qualitative and many do not even contain scales. The reasons for this state of affairs are: (i) incomplete knowledge of depositional environments (ii) incomplete knowledge of the evolution of depositional environments and their deposits over time periods in excess of a few hundred years; and (iii) uncertainties in translating essentially two-dimensional (parallel to land surface) information representing a single snapshot in time into a fully three-dimensional dynamic model.

I really agree with Bridge's comments and strongly believe that the principal focus on descriptive and qualitative, amplified by the proliferation of conceptual models in sedimentary geology was and is detrimental to the advancement of the science. Which reminds me of a Twitter exchange I had with @clasticdetritus a while ago. It started from my venting over how overwhelmingly descriptive and qualitative sedimentary geology is, and how beneficial would be to have a much stronger link between designing (quantitative) experiments to test concepts. The Twitter thread is shown below, in "proper stratigraphic order", with the newest comment at the top.

This was a fun exchange, unfortunately for me it was so late in the day, and the 140 character limitation was not helping.
There is a solution to this problem, and I will cite again from Bridge, because he expressed it so well:

The solution to these problems require much more serious, comprehensive studies of modern processes and deposits, supplemented by scale-model experimentation and quantitative theoretical modeling

What are your thoughts on this?

Ada Lovelace Day 2010: Stefania Maracineanu

2010-03-24T00:01:00.000-07:00

Today is "Ada Lovelace Day", the international day of blogging to celebrate the achievements of women in technology and science. My post recognizes the Romanian physicist, Stefania Maracineanu, a woman whose research impacted the field of radioactivity. She .... almost received the Nobel Prize in chemistry for discovering the artificial radioactivity. She is inspiring because she represents the struggles that women scientists had to face in the early 1900s in order to have an impact and be recognized in their field of research.

Stefania was born in Bucharest, on 18 June 1882. Very little is known about her early life, except that she had an unhappy childhood about which she did not want to talk. She obtained an advanced degree in physical and chemical sciences at age 28, after which she begun teaching at the Royal Boarding School in Bucharest, a public school for girls from the social elite. In 1922 Maracineanu received support from the Romanian Science Minister to pursue graduate research in France with Marie Curie.

Studying in Paris at Curie's Institute must have been a dream come true, and Maracineanu started her first project focusing on determining the precise half-life of Polonium. One of the first observations she made was that Polonium's half-life depends on the metal onto which the Polonium layer has been deposited. Her explanation of the phenomenon was that the alpha-rays of the Polonium must have transformed some of the atoms of the metal into radioactive isotopes. At the time, this was a very important observation and it is unclear why Maracineanu did not pursue the topic in more detail. Further experiments and documentation would have turned this observation into the first documented example of artificial radioactivity.

After receiving her doctorate degree in 1924, and as a result of the research conducted at the Curie's Institute, Stefania stayed for six more years in Paris to study the effect of the solar radiation on the radioactivity of substances. In 1930 she returned to Romania and studied the link between radioactivity and rainfall, and later the relationship between earthquakes and rainfall.

In 1935, the Nobel Prize in chemistry was awarded to Frederik Joliot and Irene Joliot-Curie for the discovery of artificial radioactivity. Stefania Maracineanu expressed her dismay at the fact that Irene Joliot-Curie used much of her observations and work dealing with artificial radioactivity without giving proper credit. Maracineanu publicly claimed that she first discovered artificial radioactivity during her research years in Paris.

Stefania Maracineanu is often considered an "ignored Romanian scientist". Was this because of the challenges that women faced in the scientific community in the early 1900s ? Because she did not have a proper network of scientists with which to discuss ideas, and as a result lost focus and pursued research topics on the fringe of science? Was she marginalized in favor of bigger names and interests? Were her scientific methods and observations not careful or focused enough? We may never find an answer to these questions, or the answer may be a combination of all of the above, and then some...

Other references:

Stefania Maracieneanu: ignored Romanian Scientist

Bulletin of the National Research Council, v.10, 1925-1926, The National Academy of Sciences, Washington DC

Martisor - the Spring is here!

2010-03-01T00:01:00.000-08:00

On the 1st of March Romanians celebrate the arrival of spring. Many other countries have some sort of spring celebration, but as far as I know, "Martisor" (Romanian pronunciation: [mərt͡siˈʃor]) is a Romanian custom. A "martisor" is a little object attached to a red-and-white string and is worn pinned to the blouse, or sweater, or whatever you are wearing. It may look something like this (I received it from my brother last year):

Nowdays it is worn by women and children during the first couple of weeks in March. It is a symbol of the nature coming back to life after a long winter and it is supposed to brings good luck. In some parts of Romania, during the first weeks of March the young women used to wear necklaces made of round pebbles collected from a river bed, which they pained red and white.
I don't have the red-white pebbles, but I made my own geology-related "martisor". It may be too heavy to pin on to my blouse, but it matches the "Romania Rocks" theme. Happy Spring everyone!

Getic Basin, Romania

2010-02-19T20:31:00.000-08:00

The Getic basin, also known as the Southern Carpathians foredeep, is a geologic province located in south-central Romania, between the crystalline belt of the Southern Carpathians and the Moesian Platform.

Pictures from Salatruc, Topolog River valley, Curtea de Arges, Corbi village, give a feel for how this part of Romania looks like.

The basin formed during Late Cretaceous time (more than 70 million years ago) by flexure of the lithosphere in response to thrusting and crustal thickening in the adjacent mountain belt. During Early Tertiary time (or about 60 million years ago), the Getic basin was an elongated and asymmetrical foredeep, with an axis oriented parallel to the Southern Carpathians orogenic belt, a steeply dipping flank on the orogen side, and a gently dipping flank overlying the platform.
Thrusting in the Southern Carpathians resulted from the interaction between two plate fragments, the Rhodopian and Moesian fragments.

This interaction had important consequences for the development of the Getic basin and was characterized by continental collision and subduction during the Late Cretaceous, and compression with a component of dextral wrenching during the Paleogene.
The Paleogene-Lower Miocene basin fill consists of siliciclastic, continental to shallow marine rocks in the northern part of the basin, grading basinward (southward) into deep marine deposits. The sediment source area was the Southern Carpathians orogenic belt.

What geology taught me about time

2010-02-14T13:40:00.000-08:00

For a geologist the concept of time has a dual character: the time on the human scale, measured in years, months, hours, seconds, and the time on the geologic scale, measured in millions of years. The beauty of this for me is that I do not completely partition the two scales; instead, because I deal with the time at the geologic scale as part of my profession, I am able to place the human scale in a different perspective.

The planet is about 4.6 billions year old, give or take; the first Homo Sapiens appeared only two (yes, that is 2!) millions year ago. The recorded human history started only about 10,000 years ago.

If the age of our planet is scaled to the human scale, that would make the Earth ... let's say 80 years old (by using the average life span for people in the developed countries). That means that the recorded human history started only about 2.5 hours ago, Homo Sapiens is almost 13 days old, and the dinosaurs became extinct only about a year ago (409 days). (You can build your own geologic time scale metaphors here).

Placing events in a broader perspective is what geology taught me most. Especially in a time when instant gratification is the norm, I know that focusing on the long term with a constant effort is what has the most impact.

Geoscience metaphors (or geo-puns) #1 - "Won by a landslide"

2010-02-02T18:52:00.000-08:00

A few days ago I posted a question on twitter about favorite geo-puns (or geo-metaphors):

Replies followed very fast:

Other good posts on geoscience metaphors were published by "All my Faults are Stress Related", by "The Theatrical Tanystrospheus" and also at Yahoo Answers.

Rather than posting a "new and improved" list of geo-puns, I decided to do something different and search for the origin and first uses of various expressions. My opening post is on landslide as a geoscience metaphor. First some definitions.

The term landslide, as far as I can tell, was first defined by Charles Lyell in "Principles of Geology" in 1830. Lyell used the term "landslip" and not "landslide" and defined it as

A portion of land that has slid down in consequence of disturbance by an earthquake or from being undermined by water washing away the lower beds that supported it.

Principal components of a landslide are shown in this figure from the North Carolina Geological Survey .
The Wikipedia definition can be found here. Here and here are examples of landslides from Romania, taken from the post on "Hazards and mud volcanoes in Romania"

The most common use of landslide as a metaphor is in politics; "won by a landslide" refers to capturing an overwhelming majority of votes by one party or candidate in an election. First record I could find with this meaning is from a New York Times article from August 8, 1884 describing the Chicago's Mayor Carter Harrison outlook on his chances for an upcoming election:

If it shall become reasonably clear in October that the Democratic Party will carry New York, New Jersey and Connecticut - and by October we shall know about where we stand - I shall look for the election of the Democratic Electoral ticket in Illinois by 10,000 majority - a perfect landslide in fact

Jacques Chirac's victory in the French presidential election of 2002 by 82% is perhaps the best modern example of a landslide election. In Romania's historic election of 1990, Ion Iliescu, a former communist party official, won by a landslide and became the first post-communits president.
Politics also inspired two boardgames named "Landslide", about the US presidential elections. And of course there is also the music: Fleetwood Mac's 1975 "Landslide" song remade in 1994 by the Smashing Pumpkins and later in 2002 by Dixie Chicks.

Geology and wine #3

2010-01-30T11:33:00.000-08:00

In a previous post, I mentioned that for a country its size, Romania has an amazingly varied geology. A geologic map, courtesy of the Romanian Geological Institute website shows this complexity.

And for the third installment of the geology and wine, here it is, side by side, a geological map and a map of the wine regions of Romania, (the later from the Romanian wine website).

I will talk in more detail, in a future post, about the geology of Romania and what the bright colors on the map mean, but for now, it is worth observing the relationship between the two maps. The Carpathian mountains certainly stand out on the geologic map and they influence the wine regions in many ways. I already talked about how geology (and the resulting topography) influences present-day climate, and more specifically how the Foehn-type wind influence the wine making in the Cotnari region. Geology also has a lot to do with the other elements of terroir, such as soil type and topography. So when you have the next sip of your favorite wine, try to imagine the tumultuous geologic history that permeates every drop and gives in its "earthy minerality" (yes, that is a common sensory descriptor used in wine tasting).

Mystery trace fossils

2010-01-12T19:42:00.000-08:00

During my field research years ago in the Paleogene of the Southern Carpathians (Romania), I found these interesting trace fossils. They are cylindrical, perpendicular to bedding, and always occur in pairs, suggesting they are U-shaped. The hosting formation is Eocene in age, consists of silty mudstone deposited in a distal shelf environment and is bounded at the top by a sequence boundary, which occurs immediately above this burrowed interval.

My interpretation at the time was that the intensely burrowed interval suggests slow rates of sedimentation, which allowed organisms sufficient time for bioturbation. Abrupt changes in habitat conditions (e.g. increased sediment content in the water column caused by landward subaerial exposure and erosion) destroyed the animal population. The abandoned burrows were subsequently filled with sediment (e.g. fine sand and silt) during a time when sediment bypass occurred.

I was never able to clearly identify these trace fossils. The closest I came to it was "Lanicoidichna", but I do not think this is correct. A colleague suggested that this may be related to the jackknife clam Tagelus (see pictures here and here).

If you recognize these and can name the type of borrow, please let me know; it would be nice to be able to finally find an answer.

Rural and small town Texas

2010-01-03T14:46:00.000-08:00

Yesterday we spent the day on our six-acre property west of Houston, near Brenham. It was a beautiful January day, sunny and crisp, the type of weather I wish Texas would have more of.

We purchased the property a couple of years ago, to be our way to escape the life of the big city. It is about half-way between Houston and the hill country, at the point where the topography is just escaping the flatness of Houston and starts to roll a little. At the time we bought it, the property was badly overgrazed (previous owner kept miniature horses) and we vowed to bring its beauty back as soon as possible. After two years, we made good to that promise. Yesterday we planted a few more bushes and trees, a New Year tradition which we try to keep.

The geology of the area is fairly "uneventful"; our property sits on the Miocene Fleming Formation, which consists primarily of clay, with rare stringers of sandstone. The predominance of clay makes the soil fairly awful for planting. These rocks allegedly contain Cretaceous invertebrate fossils, but we did not find any yet, nor did we make a concerted effort in that direction.
The Bluebonnets are gorgeous here in early spring, I promise to share a post with nice images at peak season this year.

Below are a few other images from the area.

A New Year family tradition

2010-01-01T15:25:00.000-08:00

We do not have too many traditions in my family. We are pretty unconventional and non-traditional (I will spare you the boring details). We do have one New Year tradition, however, we always watch the New Year's Concert from Vienna. I started watching the concert in the 80's; as a teenager living in Romania, the event gave me a sense of connection to the free world. The "Blue Danube Waltz", one of the signature pieces of music performed every year at the concert, offered me the certainty that the world is connected, even when stupid political barriers are imposed on people. After all, the Danube flows through Vienna and makes its way all the way to Romania, ending its course in the Black Sea.

I brought the tradition with me to the US, my adopted country. Now, when I am part of the free world, the concert offers me a different sense of connection: the connection to the free-spirited world of my youth and young adulthood, full of idealism, where everything and anything was possible.

This year again, I enjoyed a glass of Champagne listening to the music of the Strauss family and feeling connected the the past, present and the future.

A happy and prosperous New Year to everyone.

Geoscience articles on my current reading list

2009-11-21T13:31:00.000-08:00

Quantification of the degree of confinement of a turbidite-filled basin: A statistical approach based on bed thickness distribution - Felletti et al -- method attempting to predict the degree of confinement of a deep-water system by using bed-thickness distribution; study area is in the Tertiary Piedmont Basin of Italy.

Facies controls on the distribution of diagenesis and compaction in fluvial-deltaic deposits - Hammer et al -- facies controls on diagenesis and compaction trends in the Triassic-Jurassic Are Formation of mid-Norway.

Lacustrine turbidite channels and fans in the Mesozoic Songliao Basin, China - Feng Zhi-qiang et al. -- documentation of delta-fed lacustrine turbidites, including dimensional data.

Fascinated by uncertainty

2009-11-07T10:10:00.000-08:00

I have always been fascinated by uncertainty. Maybe because is part of my background, or maybe, as Dennis Lindley says (quote below), because uncertainty is everywhere.

You are uncertain, to varying degrees, about everything in the future; much of the past is hidden from you; and there is a lot of the present about which you do not have full information. Uncertainty is everywhere and you cannot escape from it.

I also suspect that uncertainty is to some degree responsible for my passion for the Earth Sciences, where lack of certainty is the norm. When you are not sure of the outcome, there is always the thrill of possibility, the excitement of anticipation, the prospect for the unconquered horizon.

Pinnacle Park, Western Australia

2009-10-13T18:29:00.000-07:00

Last year I had my first trip in the Land Down Under. I was in Perth for most of the time, but my first escape to the bushland was to visit the Nambung National Park and to see the pinnacles.

The trip in itself was awesome: my friend and I took off from Perth, driving "on the wrong side of the road", checking religiously the gas level in the tank to make sure we are not stuck on the road, no gas, in the middle of nowhere. The car windshield cracked midway there... you get the picture, it was a blast. The trip was fantastic, the geology great. The pictures show these pinnacles, which are believed to be syngenetic karstic geomorphological features formed by karstification and lithification of aeolian calcarenite. The origin of these features is controversial, which explains why I was confused reading the info in the park, but here is a recent paper discussing the subject. The pillars are produced by

simultaneous karstifcation and lithifcation of aeolian calcarenite

Eolian calcarenites are sands consisting of fragments of carbonate-skeleton organisms such as foraminifera, mollusks, red algae, echinoderms. These skeleton fragments were transported by wind and deposited as dunes or other eolian land forms. Shortly after deposition, these sands were affected by karstification (dissolution) and lithification (the process of turning a sediment into a rock), resulting in the formation of the pillars.

Geology and wine Sunday #2

2009-10-11T09:56:00.000-07:00

Judging by its location, the Cotnari region in Romania should be a tough place for wine makers. The vineyards are located between 47o17' and 47o35' northern latitude, in the middle of the continent, away from the beneficial influence of the Atlantic or the Mediteranean Sea. In spite of that, from Cotnari come some of the finest wines in Romania, thought to be "some of the best in the world" by A. Julien, the Frenchmen who mentioned this area in Topographie des vignobles connus of 1832.

There are two factors that cause this area to be great for wine-grape growers: the Foehn-type winds, and the string of depressions that offer protection from the cold air from the North. By the way, "depression" in geology is a landform at a lower elevation compared to the surrounding areas -- nothing to get depressed about. Both the Foehn-type winds and the depressions are influenced by geology, hence the point of the post: geology and wine are very much linked.

The Foehn winds, or Chinook winds as they are known in North America, are dry and warm winds that blow downslope of a mountain range.

The Cotnari area is in the rain shadow of the Eastern Carpathians, hence the warmer climate, somewhat unusual for this northern latitude. The Eastern Carpathians started forming in Cretaceous time, by collision between tectonic plates. The Eastern Carpathians thrust-and-fold belt slowly uplifted since the Cretaceous to become the beautiful mountains of today. Prior to the Cretaceous time, no mountains, no Foehn winds, no warm climate, no wine. The dinosaurs could not have grown wine around the Cotnari area, maybe that's one of the reason they went extinct... The small depressions that offer protection and good micro-climate for grape-vine growing are also a result of geology: they are controlled by subsidence along the miriad of faults associated with the mountain belt.

The result for Cotnari and its wine? Nice annual average temperatures of 9deg C, early springs and nice late autums lasting through October.

The Cotnari wines come from native varieties of grape: Grasa de Cotnari, Feteasca Alba, Francusa, Busuioaca de Moldova. My favorites are Francusa, for its subtle, flowery taste, and of course Grasa de Cotnari, the perfect companion for your dessert.

Sources and further info:

Cotnari website

Romania, the land of wine by V. Cotea and F. Andreescu

Nice photography from the Carpathians in Romania are found here

Cotnari vineyard blogpost on TrueRomania

Vineyard -- Cotnari region(source www.cotnari.ro)

Cool Science #1

2009-10-10T14:34:00.000-07:00

(image source http://www.wired.com/wiredscience/2009/10/fractal-genome/)
A team of researchers in the Harvard MIT Division of Health Sciences and Technology found a way to resolve the 3D structure of the human genome. They used a method dubbed Hi-C, which involves: 1) bonding together gene-sequences situated close together in the 3D-structure but not in the linear sequence, 2) breaking the genome into million pieces, 3) marking the ends of the bonded genome fragments, 4) glue the ends of each fragment together, to form a circle of DNA and 5) sequencing of the marked pieces to visualize which pieces of DNA were physically close together.

I know I am off topic, but this is not only amazing in itself, but a similar method may be applied/addapted to visualize and understand many other complex systems. And geology certainly has plenty of such systems.

More on this may be found here and here.

Romanian-born German wins 2009 Nobel Prize

2009-10-08T19:24:00.000-07:00

Herta Müller, the Romanian-born German novelist and essayist won the 2009 Nobel Prize for literature. She grew up in communist Romania and lived part of her adult life there. I relate to that experience, I left Romania when I was 25-years old. My circumstances were different, and my adopted country was different, but I recognize many of my experiences in her writings. Ms. Muller's modesty and down-to-earth attitude when interviewed after she learned of the award stuck with me:

"I am the person that I am, I am now nothing better and I’m nothing worse. It’s O.K., it’s nice, but it won’t change anything for me. My inner thing is writing. That I can hold on to."

This is a great! The typical news from Romania these days are not great, usually "no news is good news". This is truly extraordinary, and makes me very happy and proud.

Geology and wine Sunday - #1

2009-10-04T11:34:00.000-07:00

I am passionate about geology and I like a good glass of wine. Some Sunday musing about the two seems like a good idea, especially that the elements of wine terroir (climate, soil type and topography) are all linked in one way or another to geology.
To celebrate my first blog post on geology and wine I went to Phoenicia and bought some Romanian wine. The wines I can find in in the US stores are not the best, to get good Romanian wines I have to go to my favorite places in Romania; but at least Phoenicia caries my favorite types, which I show in the picture below, together with my Romanian placemat.

Feteasca Regala from the Jidvei winery in Transylvania (first bottle from the right) is what I would start a meal with. This is a dry wine, lively, with a fruity flavor. Its balance fits very well not only the nature of the Transyslvanian people, but also the gentle topography and, why not, the less tumultuous geologic evolution of the area. While continental collision was taking place in the Eastern Carpathians about 15 million years ago, and volcanoes were erupting to the east 5 million years ago, the only geologic excitement in Transylvania was the slow and steady movement of salt.

Transylvania is tucked inside of the Carpathians like a hidden treasure, and the Jidvei winery is its crown jewel (landscape pictures used here are from the winery website). Jidvei area, because of its location, does not have the Carpathians protecting it against the cold air coming from the North. The vineyards are located on the South facing gentle slopes of the Transylvanian hills, which offer more protection and good sun exposure. Temperatures average about 9 deg C during the year, and the sunny days are plentiful throughout the grape growing season.
Next time you want something different, try a glass of Feteasca Regala from Jidvei and think about what gave its taste: the people, the climate, the geography and, why not, the geologic history. Noroc!

Choosing good analogs

2009-09-15T20:41:00.000-07:00

The use of analogs is common practice in scientific research. A good analog can be instrumental in understanding concepts, systems or situations that are difficult or imposible to study or analyze directly. More importantly, a good analog enables to make predictions away from data or observations. A poorly chosen analog, however, leads to false interpretations or conclusions and bad predictions.
As a geologist, I study present-day Earth processes and use them to understand what happend in the past. It would be great if I can travel back in time, 50 million years ago for example, and witness first hand what was happening then, but it is impossible, hence the need to "approximate" by using analogs.

This is a picture of a Paleocene conglomerate in the Southern Carpathians of Romania. The outcrops in this area are not great, but through careful analysis of lateral and vertical relationships, sedimentary structures and internal character, I concluded that these rocks were deposited by alluvial fans. I can only guess what the landscape was 58 million years ago when these rocks were formed, but I can use analogs to make a prediction.

I envision the alluvial fans in the Romanian landscape of 58 million years ago being similar to the ones that exist today in the Death Valley, California, shown in this landsat picture. This is a good analog but not a perfect one. I can use it to predict the lateral extent and the overlapping nature of the fans, the size and internal architecture but there are major differences too, like tectonic setting and climate, and these have important implications.

An article published recently in the Scientific American shows the impact that an inapropriate analog has to a subsequent model; it also shows how important it is to test a model or hypothesis once it is proposed.
More than fifty years ago Nobel laureates Alan Hodgkin and Andrew Huxley came up with a model to calculate the power behind electrochemical currents in neurons. To come up with this model the two scientists used as an analog the brain of a squid and concluded that the energy split in the brain between action potential propagation and synaptic transmission is about 50-50. It took more than fifty years for new research to show that the split in the human brain is more like 15-85; the problem with the original prediction was primarily the analog used. A squid's brain has little in common with the human brain (good to know!); by using it as an analog, instead of a mammalian brain, which is what was used for the recent research, one makes the wrong prediction.

From Romanian conglomerates to alluvial fans in Death Valley, squids and the human brain -- I love where geology takes my imagination.

Churches and turbidites

2009-09-09T21:26:00.000-07:00

Deep-water channel complex successions make great hosts for stone-carved churches -- something I found out during one summer of field work in the Southern Carpathians of Romania.

This little church in the village of Corbi (another photo can be viewed here) is carved in sandstone deposited about 29 million years ago by submarine gravity flows, which means that 29 million years ago this locality was under about 500m of water -- neat!

The villagers still use it for religious ceremonies during important Christian holidays and to celebrate important events in the life of the community, like weddings and funerals. The interior is nice and clean and the simplicity reminds me of my grandmother's house in the NE Romania.

Dracula and geology

2009-09-07T20:54:00.000-07:00

Poienari Fortress (in Romanian -Cetatea Poienari) is located on the upper reaches of the Arges Valley, in the Southern Carpathians of Romania. It was built between 1456-1462 by Vlad Tepes, or Vlad the Impaler (photo below), the Prince who ruled the southern part of Romania, the Pricipality of Valachia. Yeah, the one that inspired the story of Dracula, but I am talking about the real person here, so let's stick to the facts and history.

Legend has it that part of the construction was done by some of Vlad's landlords who conspired against him. The Impaler brought them at the construction site and pointing his sword he told them to build it or else....

I discovered the fortress during field work one summer, while working on my graduate degree in geology. It is located very close to the boundary between the Paleogene strata of the Carpathian Foredeep and the crystalline basement of the Southern Carpathians. This geologic boundary results in a very rough topography, which of course was the main reason why Vlad chose this location.

During the mid 1400s, Valachia was on the border between the Christian Europe and the Otoman Empire, and Vlad had ... a big problem with the Turks, as in .... he did not want them in his country. His court was in Targoviste, a locality in the hills of south-central Romania, but this place was too exposed and hard to defend.

Vlad needed remote places to take refuge when the Otomans attacked. The roughed peaks of the Southern Carpathins thrust and fold belt offered good protection, and a place to regroup and then attack back to defend his land.

Today, the Poienari fortress can be reached by climbing ~1480 steps, which were built between 1969-1972 by the local Government, in an effort to make the place accessible to the public.

(source http://www.rounite.com/2009/07/11/carpathians/)

Romania ROCKS!

2009-09-06T16:32:00.000-07:00

If you are a geologist, Romania rocks! Considering its size (about 238,000 km2, or similar in size to the state of Oregon), Romania has an amazingly diverse geography and geology. The picture below, courtesy of Google Earth, shows some of that diversity. The South Carpathians fold-and-thrust belt is in the center and separates the Transylvanian Basin to the North (left) from the Southern Carpathians Foredeep to the South (right). Far in the distance, to the East (or top of the image) is the Danube Delta and the Black Sea continental shelf.

Romania is an ideal playground and a "natural sandbox" for the passionate geologist who can experiment with, and test most geological concepts. It is also one of the best examples of how geology and history intertwine. After all, its complex geology gave the country the beauty and the resources that made it the target of empires and superpowers, and the playground of fancy political footwork.