Disentangling Late Quaternary climatic and seismo-tectonic controls on Lake Mucubají sedimentation (Mérida Andes, Venezuela)
Disentangling Late Quaternary climatic and seismo-tectonic controls on Lake Mucubají sedimentation (Mérida Andes, Venezuela)
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DOI：
10.1016/j.palaeo.2007.10.012
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发表时间：
2008-03
期刊：
影响因子：
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通讯作者：
E. Carrillo;C. Beck;F. Audemard;E. Moreno;R. Ollarves
中科院分区：
文献类型：
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作者：
E. Carrillo;C. Beck;F. Audemard;E. Moreno;R. Ollarves
穆库巴伊湖（Lake Mucubají）是委内瑞拉梅里达安第斯山脉的一个冰碛湖，由博科诺断层穿过。收集了4个长活塞岩心（长达8米）和24个短重力岩心（0.6至0.8米长），以研究湖泊的沉积充填。岩石地层学、磁化率、有机和无机含量以及14 C年龄允许岩心之间的横向相关性，并与前较大湖盆填充物的露出部分相关联。核心继承跨越了过去的16,000年。沉积物结构和成分的几次突变归因于深度和表面的改变。与软沉积物扰动一起，它们与Bocon断层的地震构造活动有关：冲击引起的现象（滑塌、假潮效应、液化）和同震陡坎。四次大地震表明平均最小复发间隔为1200年，这与从Boconó断层系统的邻近活动痕迹获得的海沟数据一致。尽管有地震构造的印记，但总体上可以追踪到末次盛冰期后的气候趋势，并将其与北半球的全球演变联系起来，特别是在过去的13，000年里。
Lake Mucubají is a moraine-dammed lake, crossed by the Boconó Fault, in the Mérida Andes, Venezuela. Four long piston-cores (up to 8 m long) and 24 short gravity cores (0.6 to 0.8 m long) were collected to study the sedimentary fill of the lake. Lithostratigraphy, magnetic susceptibility, organic and inorganic contents, and14C ages, permit lateral correlations between the cores, and with an emerged part of the former larger lacustrine basin fill. The cored succession spans the last 16,000 years. Several abrupt changes in sediment texture and composition are ascribed to depth and surface modifications. Together with soft-sediment disturbances, they are related to the seismo-tectonic activity of the Boconό Fault: shock-induced phenomena (slumps, seiche effects, liquefaction) and co-seismic scarps. Four major earthquakes indicate a mean minimum recurrence interval of 1200 years, which is consistent with trench data obtained from a neighbouring active trace of the Boconó Fault system. Despite the seismo-tectonic imprint, a general post-LGM climatic trend can be traced and correlated with northern-hemisphere global evolution, in particular for the last 13,000 years.