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首页> 外文学位 >Tectono-magmatic evolution of peri-Laurentian and peri-Gondwanan arc-back arc complexes along the Red Indian Line, central Newfoundland Appalachians.
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Tectono-magmatic evolution of peri-Laurentian and peri-Gondwanan arc-back arc complexes along the Red Indian Line, central Newfoundland Appalachians.

机译：纽芬兰中部阿巴拉契亚山脉的红印线沿劳伦山脉和冈瓦纳山脉弧背弧复合体的构造岩浆演化。

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摘要

The Appalachian-Caledonian Orogen is a classic example of a Paleozoic accretionary orogen which turned into a collisional orogen. The Newfoundland Appalachians represent a critical element of the Appalachian-Caledonian Orogen to evaluate terrane linkages and tectonic models between the North American and European segments, especially those formed during the closure of lapetus. This thesis presents new geochemical, geochronological, Sm/Nd isotope, structural and P/T data and proposes informal tectonostratigraphic framework for the central Newfoundland Appalachians. The data presented in this thesis are used to test tectonic models for closure of the lapetus and thus have important implications for the interpretation of tectonic relationships in other parts of the northern Appalachians (e.g. New England) and the British Caledonides.; Central Newfoundland is underlain by the peri-Laurentian Annieopsquotch Accretionary Tract and peri-Gondwanan Victoria Lake Supergroup, separated by the Red Indian Line, the main lapetan suture zone. Subduction in the Annieopsquotch Accretionary Tract initiated at c. 480 Ma. Subsequently two distinct continental arc-backarc terranes (c. 473 Ma Buchans and 465-460 Ma Red Indian Lake arcs) were formed over an approximately 15 Ma period. A refined tectonic model is proposed for the Annieopsquotch Accretionary Tract involving both thrust and strike-slip displacements. The data require rapid accretion of arc-backarc complexes to the Laurentian margin less than 10 Ma after their formation. This accretion forms part of the Taconic Orogeny and is associated with development of D1 shear zones as early as c. 470 Ma.; The subduction in the Victoria Lake Supergroup initiated prior to 513 Ma. Subsequently two distinct arc complexes were formed (513-485 Ma Penobscot arc and 473-453 Victoria arc). The Penobscot arc has been previously interpreted as an intraoceanic arc, however Sm/Nd isotopes, zircon inheritance data and stratigraphic relationships indicate formation of the Penobscot arc on continental crust. This crust is similar to Ganderia, which is a postulated peri-Gondwanan microcontinent. The gap in arc magmatism between the Penobscot and Victoria arcs coincides with the obduction of ophiolites onto Ganderia (Penobscot Orogeny). The data presented herein support a new model for the tectonic evolution of the Penobscot arc above an east dipping subduction zone. In this model the Penobscot ophiolites are obducted as a result of backarc basin inversion, possibly due to accretion of a seamount (Summerford Group) or ridge subduction. Following the Penobscot Orogeny, arc volcanism recommenced as the Victoria arc which rifted from the Ganderia margin opening a wide Exploits-Tetagouche backarc in its wake. (Abstract shortened by UMI.)
机译：阿巴拉契亚-卡莱多期造山带是古生代增生造山带演变成碰撞造山带的经典例子。纽芬兰阿巴拉契亚山脉是阿巴拉契亚-卡莱多尼亚造山带中评估北美和欧洲地段之间的地层联系和构造模型的重要元素，尤其是在拉普拉特斯闭合期间形成的那些。本文提出了新的地球化学，地球年代，Sm / Nd同位素，结构和P / T数据，并为纽芬兰的阿巴拉契亚中部提出了非正式的构造地层学框架。本文所提供的数据被用于检验闭合层的构造模型，因此对解释北部阿巴拉契亚山脉（例如新英格兰）和英国喀里多尼德群岛的构造关系具有重要意义。纽芬兰省中部是劳伦时期的Annieopsquotch增生带和贡多瓦南周边的维多利亚湖超群的底层，被拉丹缝合线的主要地带印度红线分开。在c。开始的Annieopsquotch增生道中的俯冲。 480毫安随后在大约15 Ma的时间内形成了两个独特的大陆弧-后弧地层（约473 Ma Buchans和465-460 Ma Red Indian Lake弧）。为Annieoposquotch增生道提出了一种精巧的构造模型，该模型涉及推力和走滑位移。数据要求弧形-后弧形复合物在形成后不到10 Ma的时间内迅速增加到Laurentian边缘。这种积聚形成了塔康尼克造山带的一部分，并且早在c时就与D1剪切带的发育有关。 470玛；维多利亚湖超群的俯冲始于513 Ma之前。随后形成了两个不同的弧络合物（513-485 Ma Penobscot弧和473-453 Victoria弧）。 Penobscot弧以前曾被解释为洋内弧，但是Sm / Nd同位素，锆石继承数据和地层关系表明在大陆壳上形成了Penobscot弧。这种地壳类似于冈底亚（Ganderia），后者是一个假定的冈瓦纳河外围微大陆。 Penobscot和Victoria弧之间的弧岩浆作用间隙与在蛇麻岩上引诱蛇绿岩（Penobscot造山运动）相吻合。本文提供的数据支持东倾角俯冲带以上Penobscot弧构造演化的新模型。在该模型中，由于后弧盆地倒转而导致了Penobscot蛇绿岩的俯冲，这可能是由于海山（Summerford Group）的增加或or陷的俯冲。在Penobscot造山运动之后，弧形火山重新出现，维多利亚弧从甘德里亚边缘裂开，在其后方打开了一个宽阔的Exploits-Tetagouche后弧。 （摘要由UMI缩短。）

著录项

  • 作者

    Zagorevski, Alexandre.;

  • 作者单位

    University of Ottawa (Canada).;

  • 授予单位 University of Ottawa (Canada).;
  • 学科 Geology.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 318 p.
  • 总页数 318
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 地质学;
  • 关键词

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