PALEOMAGNETIC STUDIES FROM THE MOORE-HANCOCK FARMSTEAD, AUSTIN, TEXAS

Excavations in front of the 19th-century Moore-Hancock Farmstead (site 41TV1405, Austin, Texas) exposed an apron of sand and rock rubble. So me 30 randomly scattered, as well as clustered, limestone clasts among the rubble show by their coloration to have been heated to high tempe ratures. Oriented samples were taken from 12 of these clasts for paleo magnetic analyses in an attempt to establish their functional relation ship to the log house. The directions of the natural remanent magnetiz ation as well as the directions after thermal demagnetization show nea r-random distributions, implying that the clasts were already burned w hen introduced into the fill. Thus the events or activities responsibl e for the burning did not occur where the burned rocks were found. Pri ncipal component analyses of the paleomagnetic data suggest that seven samples were heated to 300-degrees-450-degrees-C, while five samples were heated above 550-degrees-C. This work demonstrates the usefulness of paleomagnetic analyses of burned rocks in determining details abou t temperatures to which they were heated as well as movement of stones during or since their last cooling.