Zl. Ding et al., Climate instability during the penultimate glaciation: Evidence from two high-resolution loess records, China, J GEO R-SOL, 104(B9), 1999, pp. 20123-20132
The Xinzhuangyuan and Lijiayuan loess sections in the northwestern part of
the Chinese Loess Plateau were studied down to paleosol unit S2, which prob
ably formed during marine oxygen isotopic stage 7, similar to 200,000 years
B.P. The thickness of the loess-soil sequence above S2 is similar to 63 m
at Xinzhuangyuan and 43 m at Lijiayuan. A 2 cm sample spacing yields a mean
depositional resolution of 50-80 years for the last and penultimate glacia
l loess units (L1 and L2) and similar to 200 years for the last interglacia
l soil unit (S1), thus:enabling us to reconstruct high-resolution climatic
changes during the last two glacial-interglacial cycles. The grain size rec
ords of the two sections are regarded as a proxy for changes in the monsoon
-desert system over northern China. Results show that frequent, large-ampli
tude climatic oscillations on millennial timescales occurred during the pen
ultimate glaciation in a manner similar to that during the last glaciation,
suggesting that suborbital-scale climatic variations may be a common featu
re of the climate system during glacial periods of the Pleistocene. The las
t interglacial soil (S1) is composed of three individual soils and two thin
intervening loess horizons in both of the sections. Short-term variations
in grain size are not prominent within the soil complex, implying the absen
ce of strong millennial-scale climatic oscillations during the last intergl
aciation in northern China.