Arid
DOI10.1016/j.epsl.2005.12.039
Paleomagnetism of Early Cambrian Itabaiana mafic dikes (NE Brazil) and the final assembly of Gondwana
Trindade, RIF; D’Agrella, MS; Epof, I; Neves, BBB
通讯作者Trindade, RIF
来源期刊EARTH AND PLANETARY SCIENCE LETTERS
ISSN0012-821X
EISSN1385-013X
出版年2006
卷号244期号:1-2页码:361-377
英文摘要

Paleomagnetic analysis on 15 early Cambrian mafic dikes from Itabaiana (Paraiba State) yielded a southern (northwestern) direction with steep upward (downward) inclination (D-m = 167.5 degrees, I-m =-63.7 degrees, alpha 95=7.3 degrees). AF and Thermal demagnetization, thermomagnetic curves, and hysteresis results suggest that this component is dominantly carried by fine-grained SD magnetite. The high stability of this component and positive baked contact tests on three dikes indicate it represents a primary thermoremanent magnetization. Ar-Ar analysis on whole-rock samples from two sites provides a strong constraint on the age of the Itabaiana paleomagnetic pole (134.6 degrees E, 34.9 degrees S; A(95) = 7.3, K=28) defined by plateau ages of 525 +/- 5 and 526 +/- 4 Ma. This pole completely satisfies six out of the seven quality criteria proposed by Van der Voo [R. Van der Voo, The reliability of paleomagnetic data, Tectonophysics 184 (1990) 1-9] and permits a tight constraint on the Early Cambrian sector of the Gondwana apparent polar wander path. Paleogeographic reconstructions consistent with the available paleomagnetic and geological record show that Gondwana was sutured along three major orogenies, the Mozambique (Brasilano/Pan-African) Orogeny (800-650 Ma), the Kuunga Orogeny (570-530 Ma) and the Pampean-Araguaia Orogeny (540-520 Ma). We suggest that after rifting away from Laurentia at the end of the Neoproterozoic, opening the Iapetus ocean, the Amazonian craton and minor adjoining blocks, such as Rio Apa and Pampia, collided with the proto-Gondwana by Cambrian times at ca. 530-520 Ma. Unless for small adjustments, Gondwana was completely formed by 525 Ma whose paleogeography is defined by the Itabaiana pole. (c) 2006 Elsevier B.V. All rights reserved.


英文关键词Gondwana Cambrian Neoproterozoic paleomagnetism paleogeography
类型Article
语种英语
国家Brazil
收录类别SCI-E
WOS记录号WOS:000236991300025
WOS关键词SKINNER COVE VOLCANICS ; NTONYA RING STRUCTURE ; SAO-FRANCISCO CRATON ; BELT SE-BRAZIL ; WESTERN NEWFOUNDLAND ; BRASILIA BELT ; PRECORDILLERA TERRANE ; BORBOREMA PROVINCE ; SOUTHERN BRAZIL ; EASTERN DESERT
WOS类目Geochemistry & Geophysics
WOS研究方向Geochemistry & Geophysics
资源类型期刊论文
条目标识符http://119.78.100.177/qdio/handle/2XILL650/151189
作者单位(1)Univ Sao Paulo, Dept Geofis, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo, Brazil;(2)Univ Sao Paulo, Inst Geociencias, Dept Mineral & Geotecn, BR-05508090 Sao Paulo, Brazil
推荐引用方式
GB/T 7714
Trindade, RIF,D’Agrella, MS,Epof, I,et al. Paleomagnetism of Early Cambrian Itabaiana mafic dikes (NE Brazil) and the final assembly of Gondwana[J],2006,244(1-2):361-377.
APA Trindade, RIF,D’Agrella, MS,Epof, I,&Neves, BBB.(2006).Paleomagnetism of Early Cambrian Itabaiana mafic dikes (NE Brazil) and the final assembly of Gondwana.EARTH AND PLANETARY SCIENCE LETTERS,244(1-2),361-377.
MLA Trindade, RIF,et al."Paleomagnetism of Early Cambrian Itabaiana mafic dikes (NE Brazil) and the final assembly of Gondwana".EARTH AND PLANETARY SCIENCE LETTERS 244.1-2(2006):361-377.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Trindade, RIF]的文章
[D’Agrella, MS]的文章
[Epof, I]的文章
百度学术
百度学术中相似的文章
[Trindade, RIF]的文章
[D’Agrella, MS]的文章
[Epof, I]的文章
必应学术
必应学术中相似的文章
[Trindade, RIF]的文章
[D’Agrella, MS]的文章
[Epof, I]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。