Magnetostratigraphy of the Qiliting section (SE China) and its implication for geochronology of the red soil sequences in southern China
Magnetostratigraphy of the Qiliting section (SE China) and its implication for geochronology of the red soil sequences in southern China
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DOI：
10.1111/j.1365-246x.2008.03814.x
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发表时间：
2008-07-01
影响因子：
2.8
通讯作者：
Deng, Chenglong
中科院分区：
文献类型：
--
作者：
Liu, Caicai;Xu, Xinmin;Deng, Chenglong
中国南部和东南部的红壤序列提供了古气候和古环境的重要陆地档案，是旧石器时代定居点的重要来源，因此也是早期人类居住的重要来源。在这里，我们对中国东南部七里亭红土序列进行了详细的古地磁调查以及矿物磁学和岩相分析。沉积物既含有强磁性矿物（如磁赤铁矿和磁铁矿），也含有弱磁性矿物（如赤铁矿和可能的针铁矿）。磁赤铁矿和赤铁矿被确定为天然残余磁化强度的主要载体。只有赤铁矿在特征残余磁化强度中占主导地位。古地磁发现表明，七里亭沉积层序记录了早期的Brunhes Chron和晚期的Matuyama Chron，包括Jaramillo Subchron。我们的发现，结合之前发表的磁性地层学，确定中国南方的红土层序开始堆积不晚于哈拉米洛年龄（即类似于 1.0 Ma）。进一步表明，由于不同的气候条件，中国红壤序列记录磁极性地层的能力在不同地区之间存在差异。
The red soil sequences in southern and southeastern China provide important terrestrial archives of palaeoclimate and palaeoenvironment and are important sources of Palaeolithic settlements and, therefore, early human occupation. Here we present detailed palaeomagnetic investigation coupled with mineral magnetic and petrographic analyses of a red soil sequence at Qiliting, southeastern China. The sediments contain both strongly magnetic minerals (such as maghemite and magnetite) and weakly magnetic minerals (such as haematite and possibly goethite). Maghemite and haematite were identified as the main carriers of the natural remnant magnetisations. Only haematite dominates the characteristic remnant magnetisations. Palaeomagnetic findings suggest that the Qiliting sedimentary sequence recorded the early Brunhes Chron and the late Matuyama Chron, including the Jaramillo Subchron. Our finding, coupled with previously published magnetostratigraphy, establishes that the red soil sequences in southern China began to accumulate no later than the Jaramillo age (i.e. similar to 1.0 Ma). It is further suggested that the capabilities of recording magnetic polarity stratigraphy in Chinese red soil sequences are variable between areas because of different climate regimes.