Dry cave deposits and their palaeoenvironmental significance during the last 115 ka, Sodmein Cave, Red Sea Mountains, Egypt

摘要

The Sodmein cliff foot cave is the present-day remnant of an ancient cavity, probably of karstic origin. Physical breakdown of the limestone bedrock, rather than solution, has governed its subsequent evolution. Long before 115 ka BP an estimated 8000 m(3) of debris came off the weathered roof and mixed with contemporaneous cliff rockfall. Over 4 m of sediments have since accumulated. Wet conditions outside the cave during isotopic stage 5e are documented by sedimentary properties of the J-complex and by its detailed botanical and faunal content. These wet conditions were of regional significance. Shortly after 115 ka BP further subsidence of the roof of the ancient cave led to the present-day cave form. The cave interior has remained dry up to the present, but the deposits indicate an increase of animal passage and plant growth around 25 ka BP and during the Holocene interglacial. The latter period was rather arid in absolute terns, receiving less precipitation under a less regular pluvial regime, compared with the interglacial during isotopic stage 5e. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 55]