摘要
郯庐断裂带北段在进入东北地区后主要分为走向北东—北北东的三支断裂,由西向东依次为沈阳—长春—哈尔滨断裂、依兰—伊通断裂和敦化—密山断裂。由于不同时期的大地构造背景和地球动力学的不同,它们在中、新生代的构造体制转换主要表现有如下5个阶段:(1)早、中侏罗世直到早白垩世时以拉张为主,形成一系列断陷盆地或坳陷盆地,并伴有中-酸性岩浆侵入和喷发,形成了独特的火山-湖相沉积盆地;(2)早白垩世末,为北西—南东向的压缩构造应力场,使盆地内的中、上侏罗统地层发生走向近北东的逆冲推覆构造;(3)晚白垩世,为北东向左行剪切构造应力场,区内侏罗系和早白垩世早期的沉积物发生褶皱,与上覆地层呈明显的不整合;(4)古近纪时为北西—南东向拉张构造应力场,日本海从古近纪开始逐渐拉开,直到新近纪完成现在的格局;(5)新近纪时又转换为挤压构造应力场,以北西—南东向挤压为主,使古近系沉积物发生轻微的褶皱。
The northern part of Tanlu fault zone in NE China can be mainly subdivided into three faults of NE-NNE strike. They are Shenyang - Changchun - Harbin fault, Yilan - Yitong fault and Dunhua - Mishan fault from west to east. The faults have different tectonic background and dynamics in different periods. We find that these faults have five periods in tectonic regime transformation. 1 ） Extension mainly during Early-Middle Jurassic period, resuiting in a series of down-faulted basins or sunken basins, accompanied with intermediate-acidic magmatic intrusions and eruptions, forming special volcano-lake sedimentation basins; 2） Compression in NW-SE direction in Early Cretaceous period, resulting in NE trending thrusting nappe of Middle-Late Jurassic strata in basins ; 3 ） Leftlateral shear in Late Cretaceous period, leading to folding of Jurassic and Early Cretaceous sediments, which are unconformable with upper layers; 4 ） Extension in NW-SE direction in Eogene Period. Japan Sea pulled open in Eogene and completed as the patterns as nowadays in Neocene period; 5） Compression in NW-SE direction in Neocene Period, making Neocene sediments folding slightly.
出处
《高校地质学报》
CAS
CSCD
北大核心
2005年第4期577-584,共8页
Geological Journal of China Universities
关键词
郯庐断裂北段
构造体制转换
中新生代
盆地
拉张
挤压
剪切
northern part of the Tanlu fault zone
tectonic regime transformation
Mesozoic - Cenozoic
basin
extension
compression
shear
