Professor Malpass presented his paper, Middle Preceramic Lithics from the Casma Valley: Bipolar Cores and Edge-Ground Cobbles," at the 35th annual Conference on Andean and Amazonian Archaeology and Ethnohistory, Harvard University, October 15-16, 2016.
Professor Malpass's paper discussed the Middle Preceramic Period (9400-4000 BCE) for the significant sociopolitical developments of the Late Preceramic Period (4000-2000 BCE). The Middle Preceramic Period appears to be a time of relatively undifferentiated hunting and gathering, with similar adaptations to similar environments along the coast. Tool complexes are generally very simple. However, closer examination suggests there are differences from valley to valley that reflect emerging cultural differences that likely resulted in more large-scale developments of the subsequent period. Professor Malpass used a case study of two unreported tool types to elaborate on this idea.
https://www.ithaca.edu/intercom/article.php/20161017160437360