Archive for June 13th, 2010

An igneous rock for Dr. Pollock

June 13th, 2010

Micah Risacher and Andrew Retzler exploring a stock of nordmarkite in the Gevanim Valley, Makhtesh Ramon, southern Israel. It is somewhat rudely intruded into the Gevanim and Saharonim Formations we're studying. How do we know it's nordmarkite? We're just that good.

A dip into Triassic seas

June 13th, 2010

MITZPE RAMON, ISRAEL — We wish there was still some water in those seas because it was 41°C (106°F) this afternoon, but alas the only water we saw was that which was warmly sloshing in our plastic bottles.  Today we looked at the Middle Triassic in the southern limb of Makhtesh Ramon as part of a project for Sarah Greene, a graduate student at the University of Southern California.  She is working on fossil shellbeds as indicators of the tempo and mode of the Triassic recovery from the Permian extinctions.  We are providing information from the Gevanim and Saharonim Formations.  The shellbeds were easy to find, describe and measure.

The Gevanim Valley showing the Gevanim Formation in the foreground and the Saharonim as the yellowish unit in the upper right. Not a lot of shade here, you might notice.

Cross-section view of one of the Middle Triassic shellbeds in the Saharonim Formation.