QUATERNARY GLACIAL DEPOSITS IN NORTH AFRICA: FIELD AND REMOTE SENSING-BASED EVIDENCE FROM AL BAYDA PROVINCE IN NE LIBYA

Quaternary glacial deposits and landforms of the last glacial maximum are reported here for the first time in the vicinity of Al Bayda area in the northeastern part of Libya. These glacial deposits are relatively small in comparison to the world standards. This study uses detailed field observations and remote sensing datasets to map the distribution of the Quaternary glacial deposits and landforms around Al Bayda province and assesses the allogenic and autogenic processes that controlled the deposition of those deposits. Two major glacial facies were delineated in two locations. Glacial facies 1 (GF1) consists of massive, poorly sorted, subangular, and matrix supported gravel. This subangular facies occurs at the base of the sequence and indicates little clast abrasion during transport in the subglacial zone and perhaps formed as a consequence of glacier advance. Glacial facies 2 (GF2) contains poorly to moderately sorted, occasionally bedded diamictites. This facies is interpreted as glaciofluvial outwash deposits derived from subglacial, englacial, and supraglacial tills following the glacier retreat or meltout. In the two locations, there are evidence of at least three episodes of glacier advance and retreat resulting from glacier buildup and meltout. The glacier advance and retreat may have been caused by climatic changes, such as an increase or decrease in the amount of solar insolation during the Quaternary time. The glacial sequence provides insights on the dynamic behavior of the glaciers in the Mediterranean region and can be considered as significant archives of regional and global climate fluctuations.