Journal of Geographical Sciences ›› 2008, Vol. 18 ›› Issue (4): 425-442.doi: 10.1007/s11442-008-0425-6

• Climate and Environmental Change • Previous Articles     Next Articles

Chronology of the Holocene loess-paleosol section and its deposition and pedogenesis on the south of Chinese Loess Plateau

JIA Yaofeng1,2, HUANG Chunchang1, PANG Jiangli1, NIU Junjie1   

  1. 1. College of Tourism and Environment, Shaanxi Normal University, Xi’an 710062, China|
    2. North University for Nationalities, School of Management, Yinchuan 750021, China
  • Received:2008-02-20 Revised:2008-07-10 Online:2008-12-25 Published:2008-12-25
  • Supported by:

    National Natural Science Foundation of China, No.40571154; No.40471119

Abstract:

Optically stimulated luminescence (OSL) dating for polymineral fine-grained loess samples, collected in Laoguantai (LGT) section on the south of the Chinese Loess Plateau, was made by application of single-aliquot regenerative-dose (SAR) protocol. A ‘Double-SAR’ procedure in which aliquots are subjected to both infrared (IR) and blue stimulations was used, and two sets of equivalent dose (De) determinations were produced and assumed to relate predominantly to feldspathic and quartz fine grain populations respectively. The OSL ages estimated from IRSL signals are smaller than those estimated from [post-IR] OSL signals due to the anomalous fading of feldspar IR signals, based on fading experiment. The young ages of the samples near ground surface may be originated from the post-depositional disturbance by the intensifying humanity’s cultivation since 3.0 ka BP in the Guanzhong Basin, south of the Chinese Loess Plateau. Based on OSL dating, as well as field observations and stratigraphic correlation, we determine the chronology of the LGT loess-paleosol sequence. In combination with climate proxy records, it is indicated that aeolian loess deposition and pedogenesis underwent polyphase changes during the Holocene, likely to have been driven by shifts in the East Asian monsoon. This suggests that aeolian loess deposition is episodic and highly variable, with contributions from non-aeolian processes such as alluvial deposition found in the area.

Key words: Chinese Loess Plateau, loess, deposition and pedogenesis, East Asian monsoon, Holocene