A c. 1900 Ma Tethyan-type ophiolite in the Penokean Orogen, Pembine, Wisconsin (USA): Insights from the volcanic stratigraphy
A c. 1900 Ma Tethyan-type ophiolite in the Penokean Orogen, Pembine, Wisconsin (USA): Insights from the volcanic stratigraphy
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DOI：
10.1016/j.precamres.2023.107223
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发表时间：
2023
影响因子：
3.8
通讯作者：
Roy, Supratik
中科院分区：
文献类型：
--
作者：
Guice, George L.;Viete, Daniel R.;Holder, Robert M.;Roy, Supratik
造山带蛇绿岩是中生代板块构造的标志，包含对基本构造-岩浆过程提供约束的火成岩岩性。梭美国威斯康星州的Pembine蛇绿岩与Penokean造山带有关，是古元古代蛇绿岩的一个罕见实例。Penokean造山带与中生代（<541 Ma）造山带具有广泛的特征，但Pembine蛇绿岩的起源仍不清楚，基性火山岩被解释为代表洋内弧或大陆弧后背景。为了验证这些假设，我们提出了一套34 Pembine岩石的岩相学，岩石地球化学和矿物化学的结果，以及两个样品的U-Pb锆石年代学。根据微量元素的研究岩石中建立为不动，我们表明，镁铁质火山作用进展（上地层剖面）从大洋中脊状玻安岩。化学演化与喜马拉雅-阿尔卑斯造山带< 250 Ma蛇绿岩中观察到的化学演化一致，后者记录了特提斯洋俯冲初期的弧前扩张。我们将彭宾蛇绿岩解释为俯冲启动期间形成的弧前岩石圈，并在佩诺克造山运动期间仰冲至上级克拉通边缘。形成（和保存）这个古元古代蛇绿岩的过程可能与古元古代地球上的过程没有什么不同。
Orogenic ophiolites are a hallmark of Phanerozoic plate tectonics, containing igneous lithologies that provide constraints on fundamental tectono-magmatic processes. The c. 1900Ma Pembine Ophiolite (Wisconsin, USA) is associated with the Penokean Orogen and represents a rare example of a proposed Paleoproterozoic ophiolite. The Penokean Orogen shares broad characteristics with Phanerozoic (<541 Ma) orogens, but the origin of the Pembine Ophiolite remains unclear, with the mafic volcanic rocks interpreted as representing either an intra-oceanic arc or continental back arc setting. To test these hypotheses, we present the results of petrography, bulk-rock geochemistry and mineral chemistry for a suite of 34 Pembine rocks, as well as U-Pb zircon geochronology for two samples. Based on trace elements established as immobile in the studied rocks, we demonstrate that mafic volcanism progressed (up-stratigraphic-section) from mid-ocean ridge-like to boninitic. The chemical evolution is identical to that observed in < 250 Ma ophiolites in the Himalayan–Alpine Orogen, which record forearc spreading during the nascent stages of subduction in the Tethys Ocean. We interpret the Pembine Ophiolite as forearc lithosphere formed during subduction initiation and obducted to the margin of the Superior Craton during the Penokean Orogeny. The processes responsible for forming (and preserving) this example of a Paleoproterozoic ophiolite may not have been dissimilar to those operating on the Phanerozoic Earth.
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影响因子：
2.6
作者：
M. Reagan;J. Pearce;K. Petronotis;R. Almeev;Aaron Avery;C. Carvallo;T. Chapman;G. Christeson
通讯作者：
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影响因子：
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作者：
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B. Jicha
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影响因子：
1.4
作者：
P. Sims;W. R. Schmus;K. Schulz;Z. Peterman
通讯作者：
Z. Peterman
DOI：
--
发表时间：
1976
期刊：
影响因子：
--
作者：
W. R. Schmus
通讯作者：
W. R. Schmus
共同铅、Sm-Nd 和 U-Pb 对威斯康星州佩诺克造山运动（古元古代）岩石成因、地壳结构和构造环境的限制
DOI：
--
发表时间：
1997
期刊：
影响因子：
--
作者：
N. V. Wyck;C. Johnson
通讯作者：
C. Johnson