Early pleistocene habitat in member 1 Olorgesailie based on paleosol stable isotopes.
Early pleistocene habitat in member 1 Olorgesailie based on paleosol stable isotopes.
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基于古土壤稳定同位素的 1 Olorgesailie 成员的早更新世栖息地。
DOI：
10.1006/jhev.1999.0343
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发表时间：
1999
影响因子：
3.2
通讯作者：
A. Behrensmeyer
中科院分区：
文献类型：
--
作者：
N. Sikes;R. Potts;A. Behrensmeyer
稳定的碳和氧同位素值从土壤碳酸盐被用来确定植被的考古遗址和当地的气候条件下，在约0.99马的古土壤是暴露在侧面的Olorgesailie盆地，肯尼亚南部裂谷。作为这一大型项目的一部分，对盆地三个相邻部分近4 km露头处沿着的一段上段古土壤样品进行了分析。现代东非土壤和植物群落类似物被用来解释同位素比值。古土壤碳酸盐的碳同位素组成表明，在土壤形成时期，该地区支持了约75-100%的C（4）植物的局部生物量。在对每个海沟的数据进行平均后，开放的C（4）草原由碳值的一半表示，在古地貌中，树木繁茂的草原比现在的地区更丰富。这种植被重建得到了哺乳动物区系组合的支持，其中食草动物的比例很高。虽然主要挖掘区以外的相对较小的样本量排除了对上段1次盆地内植被多样性的可靠表征，但研究区东部和西部的地区可能比之间广泛采样的区域有更多的木本C（3）植物。氧同位素表明，当时的低地盆地比今天的半干旱气候稍冷、稍湿，年降雨量也更大。考古遗迹在整个古地貌中几乎是连续分布的，但出现的密度不同。有强有力的证据表明，C（4）草原作为主要的植被背景在大多数的研究领域，没有栖息地偏好阿舍利工具制造商在Olorgesailie显示在我们的碳同位素值和石头/骨密度之间的初步比较。
Stable carbon and oxygen isotope values from soil carbonates were used to determine the vegetation context of archaeological sites and local climatic conditions represented in a approximately 0.99 Ma paleosol that is exposed laterally in the Olorgesailie basin, southern Kenya rift valley. As part of this landscape-scale project, samples of an upper Member 1 paleosol were analyzed along nearly 4 km of outcrop in three adjacent parts of the basin. Modern East African soil and plant community analogs are used to interpret the isotope ratios. The carbon isotopic composition of the paleosol carbonates indicates that the area supported a local biomass of about 75-100% C(4)plants during the period of soil formation. After averaging the data for each trench, an open C(4)grassland is represented by half of the carbon values, with wooded grassland more abundant across the paleolandscape than it is in the area now. This vegetational reconstruction is supported by the mammalian faunal assemblage, which has a high percentage of grazers. Although the relatively small sample size outside the main excavation area precludes firm characterization of vegetational diversity across the basin in upper Member 1 times, eastern and western localities in the study area may have had more woody C(3)plants than the widely sampled zone in between. Oxygen isotopes indicate that the lowland basin was slightly cooler and moister than today's semi-arid climate, with greater annual rainfall. Archaeological traces have a virtually continuous distribution across the paleolandscape, but vary in density of occurrence. With the strong evidence for C(4)grassland as the primary vegetation context across most of the study area, no habitat preference by the Acheulean toolmakers at Olorgesailie is shown in our initial comparison between carbon isotope values and stone/bone densities.