Paleoclimatic field studies in and along the Qinling Shan (Central China)

Abstract

Recent investigations in and along the mountains south of the Loess Plateau (Central China) give no evidence of Pleistocene glaciations below 2800 m asl. Reliable Late-Pleistocene glacial landforms and till only occur in the Qinling Shan (3767 m). The paleosnowline in altitudes of 3250–3300 m was more than 1000 m lower than at present. A Late-Pleistocene periglacial region has been descended to about 2300 m asl, resulting an increase of the sediment yield of the rivers and intensified sediment aggradation in the valleys in and along the Qinling Shan. The Late-Pleistocene descend of the coniferous forest was comparable to the snowline depression. A spruce-fir forest dominated along the northern flank of the mountain range during the time 30-20 ka BP. Towards the end of the Pleistocene glacial periods respectively at the beginning of the following interglacial phase, dissection of alluvial deposits and terracing began in the mountain valleys and in the northern foreland. The replacement of forest vegetation by a more steppe-like vegetation as well as the loess accumulation along the northern Qinling Shan indicates increasing aridity as the climate warmed at the end of the last glacial period and during the Early Holocene. The widespread occurrence of Mid-Holocene paleosols within the loess proves a more moist and warm interval, which is followed by a drier and cooler Late Holocene period.