首页|Tectono-stratigraphic evolution of the Jurassic-Cretaceous Laguna Merin Basin (Uruguay): New insights from magnetotelluric transects
Tectono-stratigraphic evolution of the Jurassic-Cretaceous Laguna Merin Basin (Uruguay): New insights from magnetotelluric transects
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NSTL
Elsevier
To understand the subsurface stratigraphy and structure of the Laguna Merin Basin (LMB), data from 42 magnetotelluric stations were interpreted by performing 1-D and 2-D inversions along three profiles perpendicular to the main basin borders. The Aigue-India Muerta-Chuy Lineament (AICL) constitutes the southern boundary of the LMB and is characterised by a subvertical sinistral transtensional fault with a general orientation of N85 degrees E. The basin's northern boundary, represented by the Cebollati-Merin Lineament (CML), is characterised by a set of echelon dextral transpressional faults with a general orientation of N50 degrees. Both faulting sets are associated with maximal horizontal stress oriented NE-SW. The infill of the LMB comprises thick Jurassic-Cretaceous igneous rocks (average of similar to 1500 m) overlying a crystalline Precambrian basement and overlain by <= 500 m-thick Cretaceous-Cenozoic sedimentary sequences. Likewise, a very deep (> 3500 m) conductive body was identified in the basement between the CML and AICL, coincident with the highest values of gravimetric Bouguer anomalies recorded in Uruguay. Shallow Cretaceous-Cenozoic sedimentary sequences show resistivities between 1 and 25 5-2.m, an average thickness of 250 m, and a maximum thickness of 500 m. The deeper Jurassic/Cretaceous igneous rocks show average resistivities between 40 and 252 Omega.m, and a maximum thickness of nearly 2000 m with intercalations of conductive layers (< 25 Omega.m) of unknown nature in the lower half of the basin infill. A tentative 3-D model is proposed to represent the early stage of magmatic emplacement during the opening of the South Atlantic Ocean.
NSTL
Elsevier
