Lutetium-Hafnium Ages and the P-T History of High-Pressure Rocks in the Appalachians
Lutetium-Hafnium Ages and the P-T History of High-Pressure Rocks in the Appalachians
批准号:
0087448
负责人:
Eric Essene
金额:
$18.83万
依托单位国家:
美国
项目类别:
Standard Grant
财政年份:
2001
资助国家:
美国
项目状态:
已结题
起止时间:
2001-02-01 至 2005-01-31
中文摘要
我们的研究是针对开发技术,将解决的地质历史套件的岩石,曾经深埋在俯冲洋壳或在随后的大陆碰撞。 这些岩石都是在北美东部阿巴拉契亚山脉的一次古老的造山运动中被埋在40-60公里深的地方。 这一地区经历了复杂的构造历史,有三个造山事件与中生代海洋物质或外来碎屑的增生有关:450 Ma,在ca. 400 Ma,而阿勒格尼期开始于320 Ma。 一些构造切片包含的物质也是古北美的一部分,并在大约1.1 Ga前的格伦维尔时间经历了更古老的高级变质作用。 在任何这种反复变形、埋藏和断层的岩石圈中,通常很难确定任何特定事件的发生时间,需要强大的地质年代学和温压技术来确定矿物的生长,而不是在随后的造山运动中冷却或重置。 我们的工作将Lu-Hf同位素测年技术应用于这些元素(石榴石、单斜辉石、金红石和锆石)具有高阻断温度的矿物,这些元素可以从高压岩石(榴辉岩和石榴石麻粒岩)中分离出来,在某些情况下,这些岩石经历了随后的低级事件(角闪岩相变质作用)。 这项工作将与新的温压技术相结合,旨在尽量减少在大多数榴辉岩中发现的高方差组合中遇到的问题。 这些方法将结合绘图,结构分析和U-Pb地质年代学正在做的我们的合作者,以更好地建立在阿巴拉契亚山脉冲断层片的早期构造历史的时间。
英文摘要
Essene/MukasaEAR-0087448Our research is directed toward developing techniques that will address the geological history of suites of rocks that were once deeply buried during subduction of ocean crust or during subsequent continental collision. The rocks under consideration all were buried to depths of 40-60 km during an ancient mountain-building event, the Taconic Orogeny, in the Appalachian Mountains of eastern North America. This area has undergone a complex tectonic history, with three mountain-building events linked to accretion of oceanic materials or exotic terranes in the Phanerozoic: the Taconic at ca. 450 Ma, the Acadian at ca. 400 Ma, and the Alleghenian beginning at 320 Ma. Some tectonic slices contain materials that were also part of ancient North America and underwent a much older high-grade metamorphism in Grenville time about 1.1 Ga ago. In any such repeatedly deformed, buried and faulted terrane, it is often difficult to identify with certainty the timing of any given event, and robust geochronogical and thermobarometric techniques are needed to identify the growth of minerals rather than their cooling or resetting during some subsequent orogeny. Our work will apply the Lu-Hf isotopic dating technique on minerals with high blocking temperatures for these elements (garnet, clinopyroxene, rutile and zircon) that can be separated from high-pressure rocks (eclogites and garnet granulites) which, in some cases, have undergone subsequent lower grade events (amphibolite facies metamorphism). This effort will be combined with new thermobarometric techniques designed to minimize the problems encountered in high-variance assemblages found in most eclogites. These approaches will be combined with mapping, structural analysis and U-Pb geochronology being done by our collaborators to better establish the timing of the early tectonic history of thrust slices in the Appalachians.
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会议论文
Thermodynamic Measurements and Phase Equilibria of High-Pressure Silicates
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批准号:0537068
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项目类别:Continuing Grant
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资助金额:$26.92万
-
财政年份:2006
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负责人:Eric Essene
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依托单位:
Sulfidation and Oxidation States of Calc-Alkaline Granitoids
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批准号:0230098
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项目类别:Standard Grant
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资助金额:$14.17万
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财政年份:2002
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负责人:Eric Essene
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依托单位:
Acquisition of a New Electron Microprobe at the University of Michigan
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批准号:9911352
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项目类别:Standard Grant
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资助金额:$54.06万
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财政年份:2000
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负责人:Eric Essene
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依托单位:
Collaborative Research: Calibration and Application of Trace Element Thermobarometry in Metamorphic Rocks
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批准号:9706349
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项目类别:Standard Grant
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资助金额:$12.34万
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财政年份:1997
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负责人:Eric Essene
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依托单位:
Alpine Eclogites and Blueschists - Markers of Subduction or Continental Collision?
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批准号:9526596
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项目类别:Standard Grant
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资助金额:$7.97万
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财政年份:1996
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负责人:Eric Essene
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依托单位:
Structural, Petrological and Geochronological Studies of the Granulite to Eclogite Transformation in the Deep Continental Crust, Bergen Arcs, Norway
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批准号:9205649
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项目类别:Standard Grant
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资助金额:$7.25万
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财政年份:1992
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负责人:Eric Essene
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依托单位:
Petrogenetic and Chronological Studies in the Central Metasedimentary Belt of the Grenville Orogen
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批准号:9117772
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项目类别:Continuing Grant
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资助金额:$14.99万
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财政年份:1992
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负责人:Eric Essene
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依托单位:
Thermochronological Studies of High-Grade Metamorphism: The Grenville Terrane
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批准号:9004302
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项目类别:Continuing Grant
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资助金额:$10.34万
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财政年份:1990
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负责人:Eric Essene
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依托单位:
Evolution of the Grenville Terrane in Ontario
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批准号:8805083
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项目类别:Continuing Grant
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资助金额:$14.31万
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财政年份:1988
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负责人:Eric Essene
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依托单位:
Origin and History of High-Grade Metamorphic Terranes
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批准号:8408169
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项目类别:Continuing Grant
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资助金额:$25.66万
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财政年份:1984
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负责人:Eric Essene
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依托单位:
Electron Microprobe Analyzer
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批准号:8212764
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项目类别:Standard Grant
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资助金额:$20.0万
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财政年份:1983
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负责人:Eric Essene
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依托单位:
Doctoral Dissertation Research in Earth Sciences
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批准号:7923664
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项目类别:Standard Grant
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资助金额:$0.92万
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财政年份:1980
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负责人:Eric Essene
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依托单位:
Thermodynamics and Phase Equilibria of Certain Transition- Element Minerals
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批准号:8009538
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项目类别:Standard Grant
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资助金额:$9.82万
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财政年份:1980
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负责人:Eric Essene
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依托单位:
The Role of Fluids in Metamorphism
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批准号:7823568
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项目类别:Standard Grant
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资助金额:$8.93万
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财政年份:1979
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负责人:Eric Essene
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依托单位:
Evaluation of Fluid Compositions Attained By Rocks Metamorphosed at High Temperatures
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批准号:7522388
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项目类别:Standard Grant
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资助金额:$4.7万
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财政年份:1976
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负责人:Eric Essene
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依托单位:
海外基金