Landscapes into Rock - geoscience meeting

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

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

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.

© RomaniaRocks

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.

© RomaniaRocks

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.

Update on the Black Sea earthquakes

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

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

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.

© RomaniaRocks

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.

© RomaniaRocks

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.

© RomaniaRocks

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.

© RomaniaRocks

Trip to the Mesozoic

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.