当前位置: X-MOL 学术J. South Am. Earth Sci. › 论文详情
Shortening history of the Neoproterozoic oroclinal bending in Paraguay belt, Central Brazil, based on structural interpretation of field work and high resolution aerogeophysical data
Journal of South American Earth Sciences ( IF 1.704 ) Pub Date : 2020-11-20 , DOI: 10.1016/j.jsames.2020.103043
Marcelo Ferreira da Silva; Elton Luiz Dantas; Roberta Mary Vidotti

Different phases of the orogen's evolutionary history can be geometrically restored by identifying associated tectonic features in the thrust-and-fold belts in the foreland basin. The geometry and fold styles allow understanding the rate of crustal shortening of the Paraguay Belt Neoproterozoic oroclinal. We suggest that high resolution airborne geophysical data provides critical information to understand the tectonic history of Brasiliano fold belts. Geophysical studies integrated to structural analysis in field mapping may unveil the crustal architecture as well as the sequence of events of rocks exposed in two structural windows of the basement in the region of Planalto da Serra and Nova Xavantina, in the state of Mato Grosso, northern segment of the Paraguay Belt, Central Brazil.

The evolutive history of rocks exposed southwards of the Amazonian craton margin represents extensional tectonics followed by the development of a passive margin. It is estimated that the original width of the depositional space was ∼350 km during the formation of the hyperextended platform and, after the intense shortening during the Brasiliano orogenesis, the oroclinal was restricted to ∼130 km wide, in the post-deformation phase. Planalto da Serra region is characterized by asymmetrical, harmonic folds with thickened hinge zones. They show variable styles between tight and isoclinal and form pairs of EW and NE anticlines and synclines. In Nova Xavantina structural window, the magnetic lineaments mark important lithospheric discontinuities represented by the Campinápolis (CAL) and General Carneiro (GCL) lineaments, which seem to be the deep basement faults that controlled the extension and where the rift axial zone developed. The Transbrasiliano Lineament (TBL) is a major shear zone that controls the secondary lineaments propagation, forming a network of folds and drag faults, with lateral escapes and vertical movement. Between the two main lineaments occurred the deposition of sediments and volcanic successions related to Nova Xavantina Metavolcanosedimentary Sequence representing a marginal ocean basin. The transition from EW trending features of the Paraguay Belt to NE trend Araguaia Belt lies within Nova Xavantina region and is marked by the direct influence of TBL. TBL is evident in the magnetic images, forming a mosaic of different crustal blocks and corresponding to various curvilinear shear zones with unidirectional trend N30-45E. It is composed of mega-sigmoids interlaced with mainly dextral kinematics, within shallow and deep levels.

During the Neoproterozoic orogeny, a foreland basin system was formed in response to the flexural subsidence due to the tectonic inversion of the basin. Several depocenters were formed and served as accumulation sites for the deposition of sediments of the Alto Paraguay Group (Raizama, Sepotuba and Diamantino formations). Gravimetric data allowed individualization of the foreland basin system, which is characterized by four discrete depozones (back-bulge, forebulge, foredeep and wedge-top), between the Amazonian Craton and the inner structural zone.

更新日期:2020-11-21
全部期刊列表>>
施普林格,自然编辑
ERIS期刊投稿
欢迎阅读创刊号
自然职场,为您触达千万科研人才
spring&清华大学出版社
城市可持续发展前沿研究专辑
Springer 纳米技术权威期刊征稿
全球视野覆盖
施普林格·自然新
chemistry
物理学研究前沿热点精选期刊推荐
自然职位线上招聘会
欢迎报名注册2020量子在线大会
化学领域亟待解决的问题
材料学研究精选新
GIANT
ACS ES&T Engineering
ACS ES&T Water
屿渡论文,编辑服务
ACS Publications填问卷
阿拉丁试剂right
林亮
南方科技大学
朱守非
华东师范大学
胡少伟
有机所林亮
隐藏1h前已浏览文章
课题组网站
新版X-MOL期刊搜索和高级搜索功能介绍
ACS材料视界
上海纽约大学
浙江大学
廖矿标
天合科研
x-mol收录
试剂库存
down
wechat
bug