December Geology and GSA Today ...( pression: Implications for fault growth...)

There aren't many places in the world where you can watch an ocean basin form, which is why East Africa has captured the attention of many geologists. Using new high-resolution satellite maps of topography, the authors studied a population of faults in the Afar depression of Ethiopia and Djibouti. These faults are especially interesting to study because different regions in this setting are at different stages in the transition from continent to ocean basin. The authors found that certain fault dimensions could be linked to the total amount of stretching, which is controlled by tectonic forces. The way these related variables change is an important constraint in modeling the physics of faulting and earthquakes.

Mass failure of the North Atlantic margin triggered by the Cretaceous-Paleogene bolide impact.
Richard D. Norris et al.

The impact of a 10-km-diameter bolide at the end of the Cretaceous (65 Ma) not only precipitated one of the five largest mass extinctions of all time, but also generated a Richter Scale 10-13 earthquake. We find evidence from deep sea drilling that much of the eastern seaboard of North America (from the Bahamas to Nova Scotia) catastrophically failed and generated vast flows of debris into the deep sea as a result of the quake. The resulting mass flows reached as much as 1200 km offshore and accumulated in thickness as much as 25 m. The mass flows cover an area up to 3.9 million square kilometers, making them easily the most widespread mass failure deposits on Earth.

Regional warming: Pliocene (3 Ma) paleoclimate of Europe and the Mediterranean.
A.M. Haywood et al.

This paper examines the past climatic character of the mid-Pliocene warm period over the European and Mediterranean regions. The robustness of climate simulations, derived from an advanced numerical climate model, is evaluated by reference
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Contact: Ann Cairns
acairns@geosociety.org
303-447-2020 ext 156
Geological Society of America
27-Nov-2000