| 赣东北前寒武纪变质地层钕模式年龄初步研究 |
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| 引用本文： | 马长信,项新葵.赣东北前寒武纪变质地层钕模式年龄初步研究[J].地质科学,1993,0(2):145. |
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| 作者姓名： | 马长信 项新葵 |
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| 作者单位： | 江西省地质矿产局916大队 九江332009
(马长信)，江西省地质矿产局916大队 九江332009(项新葵) |
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| 摘 要： | 报道本区前寒武纪变质地层中一批钕模式年龄结果(TDM=1437.23—2741.40Ma,平均为1865.27Ma)。在再沉积过程中,由于当时地壳活动强烈,常有来自上地幔的火山物质混入,从而降低了TDM值。由此认为,含火山物质较少的沉积岩之钕模式年龄(TDM=1924.52—2741.40Ma,平均TDM=2272.81Ma,∑Nd=-10.15,(143)Nd/144Nd=0.5121125),才能相对代表陆源区大陆地壳的实际形成年龄。推测本区及外围还有一个尚未出露的晚太古代陆壳,这个陆壳正是元古宙的陆源区。
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| 关 键 词： | 赣东北 亏损地幔 陆壳形成时间 钕模式年龄 寒武纪地层 |
| 修稿时间： | 1992-01-01; |
PRELIMINARY STUDY OF THE Nd ISOTOPIC MODEL AGES OF THE PRECAMBRIAN METAMORPHIC STRATUM IN NORTHEASTERN JIANGXI PROVINCE |
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| Ma Changxin Xiang Xinkui.PRELIMINARY STUDY OF THE Nd ISOTOPIC MODEL AGES OF THE PRECAMBRIAN METAMORPHIC STRATUM IN NORTHEASTERN JIANGXI PROVINCE[J].Chinese Journal of Geology,1993,0(2):145. |
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| Authors: | Ma Changxin Xiang Xinkui |
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| Institution: | No.916 Geological Party of Jiangxi Bureau of Geological and Mineral Resources, Jiujiang City 332009 |
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| Abstract: | The Nd model ages of the Precambrian metamorphic stratum in the northeastern Jiangxi have been studied in this parper. The values of TDM range from 1437.23 to 2741.40 Ma with an average of 1 865.27 Ma. In the course of redeposition, the value of TDM was decreased because Volcanic materials from upper mantle was mixed into sediments. Therefore the authors believe that only the value of TDM of the sedimentary rock with little volcanic materials can represent the real age of formation of the continental crust in terrigenous region. The values of TDM from 19244.52 to 2741.40 Ma are given by six samples with volcanic materials. The everage value of TDM is 2272.81 Ma.ΣNd=-10.15.143Nd/144Nd =0.5121125. It is inferred that there is a late Archaeozoic continental crust in the northeastern Jiangxi and its neighbour which has not exposed yet, and this continental crust could be the Proterozoic terrigenous source region. |
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| Keywords: | Nd model age Depletedmantle Formation age of crust |
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