With National Science Foundation support Dr. Anthony Marks and his colleagues will conduct test archaeological excavations in the mouths of collapsed caves at Almonda, Portugal. These form several of many entrances to an extensive case system which has been mapped and explored. On the basis of archaeological materials recovered from surface contexts within the caves themselves it is likely that the entrances to these systems contained buried cultural deposits of Middle Paleolithic age. Prehistoric peoples most often lived in the well lighted and ventilated entrances of caves rather than their interiors. Exploration has revealed the surface position of several entrances. In a brief field season Dr. Marks and colleagues will excavate from an exterior cliff face to remove large blocks of limestone roof-fall as well as sediment which has washed into the openings to expose in situ deposit. Test excavations will then be conducted to determine whether they contain Middle Paleolithic industries. This exploratory work will, if successful, provide the basis for a larger, longer term research project. Archaeological evidence indicates that approximately 40,000 years ago Neanderthal peoples who inhabited Western Europe were replaced by anatomically modern humans. However the process by which they occurred is unclear. Relatively late in the Neanderthal period changes in material culture foreshadow adaptations which characterized the succeeding modern humans. Archaeologists do not know whether these represent borrowings or an independent development. The question is difficult to resolve because it is likely that ca. 40,000 years ago the two groups were in potential contact across much of Europe. Portugal is important because modern humans enter this region relatively late and thus Neanderthal peoples survived for at least 10,000 years longer here than elsewhere. Because of this isolation Portugal provides an excellent arena to examine the issue of Neanderthal adaptation, and what this may reflect about underlying behavioral abilities. This research is important for several reasons. It will, if successful, provide data of interest to many archaeologists and shed new light on the prehistoric human record. It will also set the stage for a more extensive research project.