Early Paleozoic orogeny in southern South America
Early Paleozoic orogeny in southern South America
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南美洲南部早古生代造山运动
DOI：
10.1016/0301-9268(82)90052-3
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发表时间：
1982
影响因子：
3.8
通讯作者：
H. Miller
中科院分区：
文献类型：
--
作者：
F. Aceñolaza;H. Miller
在阿根廷西北部，晚前寒武纪至下寒武纪的弱变质碎屑和钙质沉积岩（蓬科维斯卡纳组和相关单元）包含丰富的具有年代地层和古环境价值的动物群。在潘皮纳斯山脉西部和中部，变沉积岩和变火山岩被认为是同一大地构造单元的一部分。这个“潘普亚造山旋回”包括最新前寒武纪至下寒武世的地槽沉积，以及中至上寒武统的岩浆作用、变质作用和变形，由“法马田造山旋回”的上寒武统至泥盆纪岩石下方的角度不整合记录。在潘普亚旋回的一些变质岩中，前奥陶纪褶皱也与后来的构造叠印区分开来。因此，潘普亚旋回的概念不同于仅由辐射年龄定义的南美洲晚前寒武纪造山旋回的其他概念。潘潘造山运动可以与横贯南极山脉的罗斯造山运动、澳大利亚的蒂南造山运动和纳米比亚达马拉造山带的一些变形阶段进行比较。
In northwest Argentina, weakly metamorphic clastic and calcareous sedimentary rocks of latest Precambrian to Lower Cambrian age (Puncoviscana Formation and related units) contain an abundant ichnofauna of both chronostratigraphic and paleoenvironmental value. In the western and central Sierras Pampeanas, metasedimentary and metavolcanic rocks are considered to form part of the same geotectonic unit. This “Pampean orogenic cycle” includes geosynclinal sedimentation of latest Precambrian to Lower Cambrian age, as well as magmatism, metamorphism and deformation of Middle to Upper Cambrian age, documented by an angular unconformity below the Upper Cambrian to Devonian rocks of the “Famatinian orogenic cycle”. In some of the metamorphic rocks of the Pampean Cycle a pre-Ordovician folding is also distinguished from a later tectonic overprinting. Hence, the concept of a Pampean cycle differs from other concepts of late Precambrian orogenic cycles of South America which are only defined by radiometric ages. The Pampean orogenesis may be compared with the Ross orogenesis of the Transantarctic Mts., the Tyennan orogenesis of Australia and some of the deformation phases of the Damara orogen in Namibia.