The Tectonic Studies Group (TSG) will organise a field trip to Death Valley in April 2017. The trip will be of particular interest for those who wish to learn more about tectono-volcanic processes, tectono-sedimentary processes, and the Basin and Range/ San Andreas system.

The trip is being organised and delivered by Phil Benson & Derek Rust of the University of Portsmouth. more

Pieces of history, mapping faults, and maps – today is Friday and here are your links!

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Quaternary shortening at the Andean orogenic front (31°-33°s), Argentina: Current issues and challenges

 Carlos Costa¹, Emilio Ahumada¹, Benjamin Brooks², Andrew Meigs³, Lewis Owen⁴, Thomas Rockwell⁵, Lindsay Schoenbohm⁶, Carlos Gardini¹, Héctor Cisneros¹, Fabricio Vázquez^{1, 7}

1. Universidad Nacional de San Luis, Argentina. costa@unsl.edu.ar
2. U.S. Geological Survey, USA
3. Oregon State University, USA
4. University of Cincinnati, USA
5. San Diego State University, USA
6. University of Toronto, Canada
7. CONICET

Outstanding exposures, new data, and novel hypotheses developed during the last decade have turned the frontal deformation zone of the Andes between 31°S and 33°S (Fig. 1) into one of the most promising areas worldwide for improving the understanding on mountain building processes and seismic hazards related to thrust tectonics.

Because the Andes are relatively narrow in these latitudes, the geodetic signal in the backarc is dominated by the subduction zone locking process at the Chile trench. Nonetheless the geodetic analysis provides some useful constraints on the location and rates of modern backarc shortening, though not necessarily on the vergence. It is currently understood that backarc shortening occurs at rates of ~4-5mm/yr over a zone that is ~30km wide (across-strike) (Brooks et al., 2003; Kendrick et al., 2006). In the north (31°- 32°10° S) this would imply that the west-vergent, Eastern Precordilleran structures are the most likely to be active, while south of 32°10° S the east-vergent structures in the Southern Precordillera belt are likely to be most active (Fig. 1).

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I came across this great initiative after Richard Styron sent the announcement via the Geotectonics mailing list. He’s currently maintaining these projects. The idea is to compile all available data on active structures in the Himalaya using the GitHub infrastructure (basically a collaborative platform for programming) . Everyone can join and help compiling active faults in this region. The data is then available to everyone for free in different data formats. The same thing is currently happening for the Andes region, too! more