...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Late Paleozoic remagnetization of Precambrian crystalline rocks along the Precambrian/Carboniferous nonconformity, Rocky Mountains: a relationship among deformation, remagnetization, and fluid migration
【24h】

Late Paleozoic remagnetization of Precambrian crystalline rocks along the Precambrian/Carboniferous nonconformity, Rocky Mountains: a relationship among deformation, remagnetization, and fluid migration

机译：落基山前寒武纪/石炭纪不整合面前寒武纪晶体岩石的晚古生代复磁：变形，复磁和流体运移之间的关系

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Paleomagnetic and rock magnetic data and petrographic observations demonstrate that Archean to late middle Proterozoic rocks (three localities in metamorphic rocks, two in granitic plutons) in parts of the Rocky Mountains, along and below a regional nonconformity with Carboniferous strata, have acquired a secondary magnetization. This magnetization is exclusively of reverse polarity and, based on its unique direction, was presumably acquired during the Permo-Carboniferous Reverse Superchron. At most sites, the remanence is carried exclusively by hematite, although it also resides in magnetite at some localities. Based on comparison between paleomagnetic poles derived from locality mean secondary magnetizations (e.g. Decl. = 137.2°, Incl. = -18.2°α_(95) = 4.1°, k = 221.4, N=7 of seven samples, Archean gneiss, northern Laramie Range; Decl. = 148.7°, Incl.=-15.0°, α_(95)=4.6°, k=77.0, N=14 of 23 samples, Sherman Granite, southern Laramie Range; Decl. = 174.3°, Incl. = -18.9°, α_(95) = 6.6°, k = 48.6, N = 11 of 13 samples, metavolcanic rocks, Sandia Mountains) and late Paleozoic reference poles for North America, this secondary magnetization does not appear to have been acquired as a direct consequence of subareal erosion prior to deposition of younger sedimentary strata. At two localities, the age of the remanence is demonstrably younger than the oldest overlying strata. Locally, the nonconformity between basement rocks and late Paleozoic strata, as well as steep shear zones within the basement rocks, may have been efficient channelways for brines flushed out of basins created during Ancestral Rocky Mountains deformation. On a continental scale, migration of fluids and attending remagnetization is consistent with epeirogenic uplift of the Pangean supercontinent and a relative lowering of ground water levels. The fact that these basement rocks do not show evidence of subsequent remagnetization during latest Cretaceous to early Tertiary (Laramide) contraction in this area suggests that the characteristics of the late Paleozoic remagnetization phenomenon were unique in time.
机译：古磁性和岩石磁性数据以及岩石学观测表明，落基山脉部分地区的太古代至晚中元古代岩石（变质岩中的三个局部，花岗岩岩体中的两个局部），以及与石炭纪地层的区域不整合面以下。 。这种磁化作用完全是反极性的，并且基于其独特的方向，大概是在二叠纪-石炭纪逆超级时代中获得的。在大多数站点，剩磁仅由赤铁矿承载，尽管它也存在于某些地方的磁铁矿中。根据对来自局部平均二次磁化的古磁极之间的比较（例如，Dec13 = 137.2°，Incl。= -18.2°α_（95）= 4.1°，k = 221.4，N = 7），七个样本，太古片麻岩，北拉勒米范围;倾斜度= 148.7°，倾斜角= -15.0°，α_（95）= 4.6°，k = 77.0，N = 14 23个样品，谢拉曼花岗岩，拉勒米山脉南部;倾斜度= 174.3°，倾斜角= -18.9°，α_（95）= 6.6°，k = 48.6，N = 13个样品中的11个，桑迪亚山的中火山岩）和晚古生代参比极，这种二次磁化似乎没有被获得在沉积较年轻的沉积岩层之前，发生亚区域侵蚀的直接后果。在两个地方，剩余的年龄显然比最古老的上覆地层年轻。就局部而言，基底岩石与晚古生代地层之间的不整合以及基底岩石内的陡峭剪切带可能是从祖先洛矶山脉变形过程中冲出的盐水中冲出盐水的有效通道。在大陆范围内，流体的运移和再磁化与庞氏超大陆的致病性隆升和地下水位相对降低是一致的。这些基底岩石未显示该地区最近白垩纪至早第三纪（拉拉米德）收缩期间随后再磁化的证据，这表明晚古生代再磁化现象的特征在时间上是独特的。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号