Exposure History of Shergottites Dar AI Gani 476/489/670/735 and Sayh AI Uhaymir 005

Introduction: Four basaltic shergottites, Dar al Gani (DaG) 476, 489, 670, and 735 were found in the Libyan Sahara Experimental Procedures and Results: The total recovered mass of DaG 476/489/670/735 was 6,368 g and the total recovered mass of SaU 005/008/051 was 10,359 g. 1°Be, 2aAI, 36Cl, and ~lCa measurements. We received exterior and interior chips from DaG 476, 489, and 670 in order to investigate SCR effects. "The distances between exterior and interior chips are about 30, 20, and 10-15 mm respectively. Only interior chips were obtained for DaG 735 and SaU 005. Weathering products were observed on the surface of the specimens, especially DaG 476, 489, and 670. The surfaces of DaG 735 and SaU 005 were cleaner than those of DaG 476, 489, and 670. To eliminate weathering products, each sample was etched twice with,0.2 N HNO3 solution in an ultrasonic bath for 5-15 minutes