北京猿人洞堆积旋回与黄土和深海气候旋回对比

北京猿人洞13个堆积层可划分为7个堆积旋回。每个旋回早期的堆积层(砂、粉砂、粘土和钙扳层),含有暖温带气候特征的哺乳动物和孢粉组合;晚期的堆积层(洞穴角砾与巨砾层),含有温带较干冷气候特征的哺乳动物和孢粉组合。堆积层年代测定数据表明北京猿人洞7个堆积旋回形成于更新世中期,年代为128-730ka,与中国黄土层L2-S7,相当,可与深海氧同位素阶段6-19和气候旋回C-I对比。北京猿人在此洞断续生活了约35万年,即从距今约60万年的第5堆积旋回(δ18O第14阶段)至距今约25万年的第2堆积旋回(δ18O第8阶段)。

DEPOSITIONAL CYCLES OF PEKING MAN CAVE AND THEIR COMPARISON WITH THE LOESS DEPOSITIONAL CYCLES AND THE CLIMATIC CYCLES OF DEEP SEA CORES

The cave deposits of thirteen layers in Peking Man Cave can be divided into seven depositional cycles. The lowermost deposits of early stage in every cycle consist of sand, silt, clay layers and travertine which were formed by underground flow in the cave and contain the mammals and sporo-pollen assemblages of warm temperate climate. The uppermost deposits of late stage in a cycle consist of breccia and huge breccia layers which were formed by disintegration of cave wall and roof co-llaps, these breccia layers contain the mammals and sporo-pollen assemblages of colder and drier climate of temperate zone. The isotopic dating of cave deposits shows that the seven depositional cycles in Peking Man Cave were formed in Middle Pleistocene, 128-730 ka B. P., that is the lower and mildle parts of the 13th layer, the upper part of the 13th layer and the lower part of the 12th layer, the upper part of the 12th layer and the 11th layer, the 10th-8th layers, the 7th-6th layers, the 5th-3rd layers and the 2nd-1st layers which consist of the 7th, 6th, 5th, 4th, 3rd, 2nd and 1st cycles; their ages are 730-690 ka, 690-620 ka, 620-500ka, 500-400 ka, 400-350 ka, 350-250ka and 250-128ka, respectively. They can be correlated with the S₇-L₇, S₆-L₆, S_5de-S_5bc, S_5a-L₅, S₄-L₄, S₃-L₃ and S₂-L₂ of loess in China and also can be corresponded to δ¹⁸O stages 19-18, 17-16, 15-14,13-12,11-10,9-8 and 7-6 and also with the climatic cycles I,H,G,F,E,D and C of deep sea cores, respectively. Peking Man has lived in the Peking Man Cave intermittently for about 350 ka, from the 5th depositional cycle about 600 ka δ¹⁸O stage 14) to the 2nd depositional cycle about 250 ka (δ¹⁸O stage 8).