Allochthonous terranes in the Andes of Ecuador and northwestern Peru
Allochthonous terranes in the Andes of Ecuador and northwestern Peru
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厄瓜多尔安第斯山脉和秘鲁西北部的异地地体
DOI：
10.1139/e87-028
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发表时间：
1987
影响因子：
1.4
通讯作者：
T. Feininger
中科院分区：
文献类型：
--
作者：
T. Feininger
在厄瓜多尔和秘鲁西北部，安第斯山脉和邻近国家，特别是在太平洋一侧，至少由五个独特的地质构造组成。这些地体彼此之间以及从克拉通南美洲到东部的地体之间存在不同的基底、盖层岩、侵入岩和布格重力异常场。皮农地体占据了厄瓜多尔沿海的大部分地区，具有玄武岩基底，其特征是已知最大的陆地布格正异常西半球。塔胡因河流域占据了秘鲁西北部的大部分地区和厄瓜多尔的西南角。该地区有一个特别复杂的基底，是布格异常普遍为正的地方。小比龙岩具有一个不寻常的基底，部分由堇青石片麻岩和斜长角闪岩组成，给出了一致的晚白垩世K-Ar矿物年龄。楔形的Chauchae部分位于西安第斯斜坡上，位于北部的海洋Pinone和大陆Bir之间。
In Ecuador and northwestern Peru the Andes and adjacent country, particularly on the Pacific side, are composed of at least five distinctive geologic terranes. The terranes are distinguished from one another and from cratonic South America to the east by dissimilar basements, cover rocks, intrusive rocks, and Bouguer gravity anomaly fields.The Pinon terrane, occupying most of coastal Ecuador, has a basaltic basement characterized by the largest known on-land positive Bouguer anomalies in the western hemisphere. The Tahuin terrane occupies most of northwestern Peru and the southwestern corner of Ecuador. The terrane has an especially complex basement and is the site of generally positive Bouguer anomalies. The small Biron terrane has an unusual basement composed in part of cordierite gneiss and amphibolite that give consistent Late Cretaceous K – Ar mineral ages. The wedge-shaped Chaucha terrane lies in part on the western Andean slope, between the oceanic Pinon terrane on the north and the continental Bir...