The Quebrada de los Colorados Formation, at the north end of Calchaquí Valley in Salta Province, northwest Argentina, preserves evidence of syndepositional deformation since the middle Eocene
The Quebrada de los Colorados Formation, at the north end of Calchaquí Valley in Salta Province, northwest Argentina, preserves evidence of syndepositional deformation since the middle Eocene
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位于阿根廷西北部萨尔塔省 Calchaquí 山谷北端的 Quebrada de los Colorados 地层保留了始新世中期以来同沉积变形的证据
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发表时间：
2007
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通讯作者：
Sang
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作者：
Myung;Sang
271生态学，2007年3月；v . 35;否。3;p。271 - 274;doi: 10.1130 / G23189A.1;2图；数据存储库项目2007058。©2007美国地质学会。获取复制权限，请联系版权权限、GSA或editing@geosociety.org。阿根廷西北部萨尔塔省Calchaquí山谷北端的Quebrada de los Colorados组保存了中始新世（约40 Ma）以来同沉积变形的证据，包括(1)与下伏的萨尔塔群（古近系）的角度不整合，(2)内部不整合以及垂直相序列和物源的变化。它的化石记录[哺乳动物（非有蹄动物），中始新世]与Casa Grande组相关，Casa Grande组也不整合地覆盖在Salta群上；两个单元都记录了普纳高原东部边界始新世中期的变形，勾勒出与白垩纪裂谷盆地边界有关的一级力学非均质性。在普纳西缘，始新世变形与热（岩浆弧）和机械（盆地反转）非均质性一致。因此，始新世变形的分布是一种不规则的模式，这是先前存在的非均质性遗产的结果。
271 eology, March 2007; v. 35; no. 3; p. 271–274; doi: 10.1130/G23189A.1; 2 fi gures; Data Repository item 2007058. © 2007 Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or editing@geosociety.org. ABSTRACT The Quebrada de los Colorados Formation, at the north end of Calchaquí Valley in Salta Province, northwest Argentina, preserves evidence of syndepositional deformation since the middle Eocene (ca. 40 Ma) that includes (1) an angular unconformity with the underlying Salta Group (Paleogene), and (2) internal unconformities and changes in vertical facies succession and provenance. Its fossil record [mammalian (notoungulates), middle Eocene] is correlatable to the Casa Grande Formation, which also unconformably overlies the Salta Group; both units record middle Eocene deformation along the eastern border of the Puna Plateau and outline previous fi rst-order mechanical heterogeneities related to the Cretaceous rift basin border. Along the western margin of the Puna, Eocene deformation coincides with thermal (magmatic arc) and mechanical (basin inversion) heterogeneities. Thus, the distribution of Eocene deformation followed an irregular pattern as a consequence of the heritage of preexisting heterogeneities.