Repeated crustal thickening and recycling during the Andean orogeny in north Chile (21°–26°S)
Repeated crustal thickening and recycling during the Andean orogeny in north Chile (21°–26°S)
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DOI：
10.1029/2001jb000328
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发表时间：
2002
影响因子：
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通讯作者：
Michael Haschke;W. Siebel;A. Günther;E. Scheuber
中科院分区：
文献类型：
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作者：
Michael Haschke;W. Siebel;A. Günther;E. Scheuber
(2)地壳下纵波速度为7.3 ~ 7.7 km s / 1，与下镀基性地壳相容；(3)近期岩石学实验结果表明，在12 kbar （40 km地壳厚度）的基性矿物中石榴石具有稳定性。与智利北部较老的安第斯岩浆期相似，新近下镀的玄武岩地壳可能解释了新近纪地壳增厚的剩余缺陷。安第斯山脉（200 Ma至今）岩浆岩的地球化学特征和Sr、Nd初始同位素特征相似，表明该地区的安第斯造山运动是由反复的弧迁移、构造和岩浆地壳增厚、火成岩再循环等过程共同演化而成的，这些过程受板块收敛速率和倾角的周期性变化以及相应的大陆地壳流变行为的变化控制。索引术语：1020地球化学：地壳组成；1030地球化学：地球化学循环（0330）；8159地球演化：流变学—地壳和岩石圈；9360地理区域相关信息：南美洲；关键词：安第斯造山运动，陆壳，再循环，埃达克岩，TTG，地壳增厚
posttectonic granitoids, (2) lower crustal P wave velocities of 7.3–7.7 km s � 1 compatible with underplated mafic crust, and (3) results from recent experimental petrologic work showing garnet stability in mafic mineralogies � 12 kbar (� 40 km crustal thickness). Analogous to older Andean magmatic episodes in north Chile, newly underplated basaltic crust may account for the remaining deficit in Neogene crustal thickening. Similar evolutionary patterns in geochemistry and initial Sr and Nd isotopic characteristics of Andean (200 Ma to present) magmatic rocks suggest that the Andean orogeny in this region evolved by a combination of processes of repeated arc migration, tectonic and magmatic crustal thickening, and igneous recycling which was controlled by periodically changing plate convergence rates and obliquity and corresponding changes in the rheologic behavior of the continental crust. INDEX TERMS: 1020 Geochemistry: Composition of the Crust, 1030 Geochemistry: Geochemical cycles (0330), 8159 Evolution of the Earth: Rheology– crust and lithosphere, 9360 Information Related to Geographic Region: South America; KEYWORDS: Andean Orogeny, Continental Crust, Recycling, Adakite, TTG, Crustal Thickening