用户名: 密码: 验证码:
Northern ancestry for the Goochland terr
详细信息   在线全文   PDF全文下载
  • journal_title:Geology
  • Contributor:Mervin J. Bartholomew ; Richard P. Tollo
  • Publisher:Geological Society of America
  • Date:2004-
  • Format:text/html
  • Language:en
  • Identifier:10.1130/G20520.1
  • journal_abbrev:Geology
  • issn:0091-7613
  • volume:32
  • issue:8
  • firstpage:669
摘要

The ancestral position of the Goochland terrane, an isolated block containing Mesoproterozoic crust in the Appalachian Piedmont of eastern Virginia, during Grenvillian orogenesis has direct bearing on the breakup of Rodinia. Ages, lithology, geochemistry, and Pb and Nd isotope compositions of the Montpelier Anorthosite and State Farm Gneiss of the Goochland terrane allow correlation with the Grenvillian Roseland Anorthosite and associated igneous suites of the Blue Ridge farther west in Virginia. In contrast, extensive metapelites, which underwent Devonian metamorphism and intrusion, and amphibolites of the Goochland terrane lack equivalents in the Blue Ridge. Dextral slip faults, which bound the Goochland terrane, as well as dextral faults farther north, suggest large-scale translation prior to late Paleozoic reaccretion. Ages of extension-related A-type granitoids within the Virginia Blue Ridge (735–680 Ma) suggest physical separation from compositionally similar granitoids in the Goochland terrane (630–588 Ma), Reading Prong (602 Ma), and Manhattan Prong (563 Ma). Pre-Iapetan restoration of the Goochland terrane northeastward of the Blue Ridge and outboard of the Reading Prong accounts for its affinities to the Blue Ridge (unique anorthosites), Manhattan Prong (abundant amphibolites), and Reading Prong (ca. 600 Ma magmatism). Thus similar to the translation of Madagascar out of Africa, the Goochland terrane was rifted from Laurentia, marooned in oceanic crust, and then dextrally translated southward ∼500 km prior to late Paleozoic reaccretion. Documentation of large-scale dextral translation of eastern Laurentia relative to its fragments and other cratons during the Neoproterozoic and Paleozoic may assist in locating far-traveled pieces of the Grenville orogen for reconstruction of Rodinia.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700