3D reflection seismic imaging at the 2.5 km deep COSC-1 scientific borehole, central Scandinavian Caledonides
3D reflection seismic imaging at the 2.5 km deep COSC-1 scientific borehole, central Scandinavian Caledonides
复制标题
斯堪的纳维亚喀里多尼德中部 2 5 公里深的 COSC-1 科学钻孔的 3D 反射地震成像
DOI：
10.1016/j.tecto.2015.12.013
复制
发表时间：
2016
期刊：
影响因子：
2.9
通讯作者：
Rosberg
中科院分区：
文献类型：
--
作者：
Almqvist;Berthet;Juhlin;Krauß;Rosberg
2014年春季和夏季，成功钻探了2.5公里深的COSC-1科学钻孔（ICDP 5054-1-A），岩心回收几乎完成。通过目标下塞夫推覆体进行的井下和岩心测量提供了全面的数据集。在1700米以下观察到的应变逐渐增加，云母片岩和间歇性糜棱岩的频率和厚度增加，在这里解释为下塞夫推覆体的基底冲断带。该高应变带在整个钻井深度处没有完全穿透，因此厚度大于800 m，为了将井下测井、岩心分析和其他实验结果外推到围岩中，并将这些结果与区域构造背景和演化联系起来，在钻孔内和周围进行了三次钻后高分辨率地震实验。其中之一，第一个三维地震反射土地调查的目标推覆构造的斯堪的纳维亚加里东，在这里介绍。它提供了新的信息的三维几何结构都在钻井下塞夫推覆体和下伏岩石下降到至少9公里。所观察到的反射率相关性以及从核心分析和井下测井的结果，尽管在处理的挑战。从下塞夫推覆体的最上部反射有限的横向范围和不同的倾角，可能与镁铁质透镜体或长英质岩石内的变量字符石香肠。然而，发生在高应变带内的反射在1公里或更长的距离上是横向连续的，并向东南倾斜10-15°。从高应变单元和COSC-1钻孔下方的结构反射，可以通过大部分地震体跟踪到至少9公里，并有不同程度的倾角，主要是在造山带的东西向逆冲方向。
The 2.5 km deep scientific COSC-1 borehole (ICDP 5054-1-A) was successfully drilled with nearly complete core recovery during spring and summer of 2014. Downhole and on-core measurements through the targeted Lower Seve Nappe provide a comprehensive data set. An observed gradual increase in strain below 1700 m, with mica schists and intermittent mylonites increasing in frequency and thickness, is here interpreted as the basal thrust zone of the Lower Seve Nappe. This high strain zone was not fully penetrated at the total drilled depth and is thus greater than 800 m in thickness.To allow extrapolation of the results from downhole logging, core analysis and other experiments into the surrounding rock and to link these with the regional tectonic setting and evolution, three post-drilling high-resolution seismic experiments were conducted in and around the borehole. One of these, the first 3D seismic reflection land survey to target the nappe structures of the Scandinavian Caledonides, is presented here. It provides new information on the 3D geometry of structures both within the drilled Lower Seve Nappe and underlying rocks down to at least 9 km.The observed reflectivity correlates well with results from the core analysis and downhole logging, despite challenges in processing. Reflections from the uppermost part of the Lower Seve Nappe have limited lateral extent and varying dips, possibly related to mafic lenses or boudins of variable character within felsic rock. Reflections occurring within the high strain zone, however, are laterally continuous over distances of a kilometer or more and dip 10–15° towards the southeast. Reflections from structures beneath the high strain unit and the COSC-1 borehole can be followed through most of the seismic volume down to at least 9 km and have dips of varying degree, mainly in the east–west thrust direction of the orogen.
登录
查看更多内容
七推覆体变质作用年龄对比：瑞典喀里多尼德中部和北部的 U-Pb 结果
影响因子：
1
作者：
L. Gromet;H. Sjöström;S. Bergman;S. Claesson;R. Essex;P. Andreasson;L. Albrecht
通讯作者：
L. Albrecht
斯堪的纳维亚喀里多尼德省 Särv 推力片中的应变软化诱导延性流动
影响因子：
3.1
作者：
J. Gilotti;R. Kumpulainen
通讯作者：
R. Kumpulainen
斯堪德山脉的逆冲构造——斯堪的纳挤压期间的上地壳伸展
影响因子：
1
作者：
D. Gee
通讯作者：
D. Gee
斯堪的纳维亚喀里多尼德及相关地区的新视角
影响因子：
1
作者：
F. Corfu;D. Gasser;D. Chew
通讯作者：
D. Chew
通过整合瑞典中部喀里多尼德斯拟议 COSC-1 钻探地点附近的地震和位场数据进行 3D 解释
影响因子：
3.5
作者：
P. Hedin;A. Malehmir;D. Gee;C. Juhlin;D. Dyrelius
通讯作者：
D. Dyrelius