Tectonic History of the South Central-American Orogen
Tectonic History of the South Central-American Orogen
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中美洲南部造山带的构造史
DOI：
10.1306/m2358.c9
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发表时间：
1963
影响因子：
3
通讯作者：
Joel J. Lloyd
中科院分区：
文献类型：
--
作者：
Joel J. Lloyd
连接原始大西洋和太平洋的中美洲海峡在上侏罗纪时期受到外力的作用，使海床折叠成一系列从东南到西北的平行山脊。向西和最脆弱的山脊被从海峡底部生长出来的喷出物破坏，形成了一系列火山岛--西部群岛。岛屿的侵蚀和东北部的沉积提供了现在暴露沿着哥斯达黎加和巴拿马西海岸的尼科亚复合体的沉积物。整个白垩纪的火山喷发和持续的侵蚀为浅河道区域提供了沉积物。这一时期的沉积物主要来自群岛，但也有一些物质来自北方的中美洲核物质。到白垩纪末，大部分裸露的岛屿已经沉没，西部群岛已经消失。伴随着拉腊米革命的地壳运动使一个内陆海脊--“瓜纳里瓦斯岛”恢复活力并进一步隆起。“巴拿马东部属于乔科边界，在整个白垩纪都出现了，在始新世早期开始建立，在始新世中期开始被淹没。早渐新世时，瓜纳里瓦斯岛和火山岛已经消失，这是一个相对平静的时代。渐新世中期的活动重新开始，导致塔拉曼卡海脊的增长以及哥斯达黎加南部和巴拿马东北部岛屿的出现。中新世早期的持续增长最终导致了西塔拉曼卡断层的发展，并在中新世中期结束时完全出现了山脊。断层隆起块体向东倾斜，产生的挤压力使高地的东部前缘断裂，并在哥斯达黎加南部和巴拿马东北部的大西洋前陆开始折叠。中新世地壳运动伴随着巴拿马海脊上火山的增长。一条以太平洋为边界的狭长陆地和通往加勒比海的巴拿马洼地的完全出现，导致了上新世时期南美洲与中美洲的第一次不间断的连接。到了第四纪，塔拉曼卡海脊已经稳定下来并得到调整，尼加拉瓜洼地被填满，只剩下尼加拉瓜湖、马那瓜湖和圣胡安河，造山带呈现出我们今天所知的形状。
The mid-American channel connecting the primeval Atlantic and Pacific oceans was subjected to forces in Upper Jurassic time that folded the sea bed into a series of parallel ridges striking SE to NW. The westward and most tenuous of the ridges was ruptured by extrusive material that grew from the channel floor and emerged to form a chain of volcanic islands--the western archipelago. Erosion of the islands and deposition to the northeast provided the sediments of the Nicoya complex now exposed along the west coast of Costa Rica and Panama. Volcanic eruption and continuing erosion throughout the Cretaceous supplied sediment to the shallowing channel area. Deposition during this period was mainly from the archipelago, although some material was derived from the northern Nuclear Central American mass. By the end of Cretaceous most of the denuded islands had foundered and the western archipelago had disappeared. Diastrophism accompanying the Laramide revolution rejuvenated and further upfolded one of the interior ridges--the "Guanarivas island." Eastern Panama, belonging to the Choco borderland, which had been emergent throughout the Cretaceous, began to founder in lower Eocene and was submerged by the beginning of the middle Eocene. Guanarivas island and the volcanic islands had disappeared by lower Oligocene time, which was an epoch of comparative quiescence. Renewed activity in the middle Oligocene resulted in the growth of the Talamanca ridge and the appearance of islands in southern Costa Rica and northeastern Panama. Continued growth through early Miocene culminated in development of the West Talamanca fault and total emergence of the ridge by the end of the middle Miocene. The faulted upthrust block was tilted eastward, creating compressive forces that fractured the eastern front of the high area and initiated folding on the Atlantic foreland of southern Costa Rica and northeastern Panama. The Miocene diastrophism was accompanied by the growth of volcanoes on the ridge in Panama. Total emergence of a narrow strip of land bordered by the Pacific Ocean and the Nicaraguan depression opening to the Caribbean, resulted in the first uninterrupted connection of South America with Nuclear Central America in Pliocene time. By Quaternary time the Talamanca ridge had become stabilized and adjusted, the Nicaraguan depression was filled, leaving only Lakes Nicaragua and Managua and the San Juan River to mark its former course, and the orogen had assumed the shape we know today.