COLLABORATIVE RESEARCH: Age, Origin and Emplacement History of the Precordillera Ophiolite, Western Argentina: Constraints on the Tectonic Significance of the Laurentia...

[9614826] Roeske最近的研究显著改变了Laurentia和Gondwana晚元古代-早古生代古地理重建的传统观点。目前基本上有两种模式：由于劳伦西亚和冈瓦纳之间的实际碰撞，北美东部和南美西部靠近，或者只有北美的裂谷部分与南美碰撞，大陆块之间留下了大片海洋。这项研究将通过研究沿前科迪勒拉西侧的超基性和基性岩石带来检验这些选择，该岩石带代表了假定的劳伦西亚-前科迪勒拉海洋。特别是，年龄定年将处理这些岩石的结晶和变质年龄，它们在每种情况下都是不同的。研究结果有望通过提供有关Precordillera地体西部海洋盆地的信息，澄清南美西南部古生代构造模型，并为碰撞模型与裂陷和漂移地体模型之间的检验提供依据。

9614826 Roeske Recent studies have significantly changed traditional views of the late Proterozoic- early paleozoic paleogeographic reconstructions for Laurentia and Gondwana. Essentially two models are current: eastern North America and western South America were in proximity due to actual collision between Laurentia and Gondwana, or only a rifted portion of North American collided with South America, with a large ocean remaining between the continental masses. This research will test these options by study of a belt of ultramafic and mafic rocks along the west side of the Precordillera which represents the postulated Laurentia- Precordillera ocean. In particular, age dating will address both crystallization and metamorphic ages of these rocks, which differ in each scenario. Results are expected to clarify models for Paleozoic tectonics in southwestern South American by providing information about the ocean basin to the west of the Precordillera terrane and provide the basis for a test between the collisional model and the rifted and drifted terrane model.