COSMOGENIC EXPOSURE AGES OF BASALT FLOWS - LUNAR CRATER VOLCANIC FIELD, NEVADA

Cl-36 and Be-10 cosmogenic exposure age data for the Black Rock basalt ic lava flow, Lunar Crater volcanic field, Nevada, imply an emplacemen t age of similar to 38 +/- 10 ka. Cl-36 data for the 600 ka flow north of the Lunar Crater maar are consistent with (1) an apparent erosion rate of similar to 3 m/m.y., (2) a model of desert pavement formation in which basalt clasts eroded from the flow remain on the surface of t he eolian derived sediments that mantle the flow, and (3) the early fo rmation of the eolian-derived sediment mantle.