Oblique half-graben inversion of the Mesozoic Neuquén Rift in the Malargüe Fold and Thrust Belt, Mendoza, Argentina: New insights from analogue models
- 作者：Daniel L. Yagupsky ; Ernesto O. Cristallini ; Juliá ; n Fantí ; n ; Gonzalo Zamora Valcarce ; Germá ; n Bottesi ; Roberto Varadé
- 关键词：Analogue modeling ; Oblique inversion ; Malargü ; e fold ; Thrust belt
- 刊名：Journal of Structural Geology
- 出版年：2008
- 期刊代码：52_01918141
- 类别：ear
- 出版时间：July 2008
- 卷：30
- 期：7
- 页码：839-853
- 文件大小：4263 K
摘要
The Malargüe fold and thrust belt, located in the Andean mountains between 34°S and 36°30′S, formed in response to contraction during Cenozoic times. Its structural style and geometry was controlled by the Mesozoic rift system that formed the Neuquén basin in west-central Argentina. The rift architecture in the southern sector of this belt was previously interpreted in terms of the present N–S compressive structural trends, assuming the inversion of pre-existing normal faults with the same orientation. Here, we propose that the NW–SE-trending El Manzano–Liu Cullín lineament, located in the northern termination of the Sierra Azul, reflects the presence of a half-graben master fault in the subsurface. This hypothesis is supported by subsurface data, a balanced cross section, and it is tested using a series of scaled sandbox analogue models. We suggest that the lineament responds to a reactivated NW-trending half-graben fault, hidden by the mainly N–S-trending Andean structures. The proposed orientation is in agreement with the NE–SW extension developed in the Neuquén basin during the Triassic–Early Jurassic. The modeling of the inverted oblique half-graben reveals that the strikes of the main structures of inversion-related belts may often be independent of the orientation of the previously developed extensional system, providing a new perspective for their interpretation.