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| 陕西蓝田公王岭黄土古土壤序列的磁组构特征及其古环境意义 | |
| 引用本文： | 谢久兵,朱照宇,周厚云,付淑清,饶志国.陕西蓝田公王岭黄土古土壤序列的磁组构特征及其古环境意义[J].地球化学,2007,36(2):185-192. |
| 作者姓名： | 谢久兵 朱照宇 周厚云 付淑清 饶志国 |
| 作者单位： | 1. 中国科学院,广州地球化学研究所,边缘海地质重点实验室,广东,广州,510640;中国科学院,研究生院,北京,100049 2. 中国科学院,广州地球化学研究所,边缘海地质重点实验室,广东,广州,510640;中国科学院,地球环境研究所,黄土与第四纪地质国家重点实验室,陕西,西安,710054 3. 中国科学院,广州地球化学研究所,边缘海地质重点实验室,广东,广州,510640 |
| 基金项目： | 中国科学院知识创新工程项目，国家重点基础研究发展计划(973计划)，国家自然科学基金 |
| 摘 要： | 对黄土高原南部边缘公王岭黄土剖面的磁组构的研究发现,该剖面与前人的研究结果有一些相似之处,但更具有其特殊性.几乎所有样品的磁面理值F都大于磁线理值L,各向异性度P与磁面理值F相关性较高,磁化率椭球体表现为压扁状.水成黄土的P、L和F值均大于典型黄土古土壤,而混合黄土或古土壤则介于这两者之间.且典型黄土的P、L和F值也比典型古土壤高.另一方面,水成黄土的最大磁化率主轴方向为SW方向,与现代灞河水系的方向一致,其次要的方向为NNW方向.典型黄土的方向表现为SWW方向,而典型古土壤则为NNW方向,这是由于秦岭山脉的阻隔作用造成的.混合黄土或古土壤受到季风和坡面流水的共同作用,其最大磁化率主轴方向表现为EW方向.不同类型沉积物代表了不同的古环境古气候条件,这一切都可能受控于秦岭山脉阶段性抬升等构造运动的影响.本研究结果也将为进一步了解蓝田直立人的生存环境提供新的方法. |
| 关 键 词： | 磁组构 黄土 古土壤 古环境 公王岭 陕西省 |
| 文章编号： | 0379-1726(2007)02-0185-08 |
| 修稿时间： | 2006年3月21日 |
Magnetic fabric of Gongwangling loess-paleosols from Lantian County, Shaanxi Province and its Paleoenvironmental implications |
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| XIE Jiu-bing,ZHU Zhao-yu,ZHOU Hou-yun,FU Shu-qing,RAO Zhi-guo.Magnetic fabric of Gongwangling loess-paleosols from Lantian County, Shaanxi Province and its Paleoenvironmental implications[J].Geochimica,2007,36(2):185-192. | |
| Authors: | XIE Jiu-bing ZHU Zhao-yu ZHOU Hou-yun FU Shu-qing RAO Zhi-guo |
| Abstract: | The anisotropy of magnetic susceptibility (AMS) for a loess-paleosols section at Gongwangling, southern Loess Plateau, China are studied. The results show that there is a resemblance between the previous studies and this profile results, but this profile has its special characteristics. The magnetic foliation (F) of almost all of the samples is higher than the magnetic lineation (L) and the degree of AMS (P) is correlative with F more effectively, and the shape parameter of the AMS ellipsoid is oblate. Moreover, the AMS parameters of P, L and F of redeposited loess are higher than those of typical loess-paleosols, while mixed loess-paleosols are between them. Furthermore, typical loess is higher than typical paleosols in P, L and F. As we know, this profile is located in the southern Chinese Loess Plateau and the northern slope of the Qinling Mountains, and the AMS has its particular characteristics due to its unique tectonic- geographical location. The Kmax directions of redeposited loess are mostly along a NE-SW, which is corresponding to the trend of the Bahe River, and there is also a subordinate NW-SE orientation that may show an adjustment of the Bahe River. We think it could be affected by the uplift of the Qinling Mountains at that time. Because of the combination of windblown and water-lain, the Kmax directions of mixed loess-paleosols are clustered east. However, because the Qinling Mountains can partially obstruct the transport direction and change the wind from a NW-SE to SWW-NEE, which is parallel to the trend of the Qinling Mountains and the Bahe River, the Kmax directions are biased towards SWW in the loess which developed due to the winter monsoon during cold/dry periods. In contrast, the paleoprecipitation of this study area was more abundant than that of the central and western CLP, so the Kmax directions are biased to NNW that are perpendicular to the trend of the Qinling Mountains in the paleosols which developed due to the summer monsoon during warm/humid periods. We think these kinds of deposits may represent the variations of paleoenvironmental conditions, which may be controlled by the uplift of the Qinling Mountains. Our AMS results would also be of great help for detailed reconstruction of regional paleoenvironment of the Lantian Homo erectus. |
| Keywords: | magnetic fabric loess paleosol paleoenvironment Gongwangling Shaanxi Province |
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