U-ages in soils and groundwater evidencing wet periods 400-600 kyr ago in southeast Brazil

被引：7

作者：

Bonotto, D. M. ^{[1
]}

Jimenez-Rueda, J. R. ^{[1
]}

机构：

[1] Univ Estadual Paulista, Dept Petrol & Metalogenia, BR-13506900 Rio Claro, SP, Brazil

来源：

APPLIED RADIATION AND ISOTOPES | 2007年 / 65卷 / 07期

基金：

巴西圣保罗研究基金会;

关键词：

uranium isotopes; groundwater; Guarani aquifer; soils; Parana sedimentary basin;

D O I：

10.1016/j.apradiso.2007.03.001

中图分类号：

O61 [无机化学];

学科分类号：

070301 [无机化学]; 081704 [应用化学];

摘要：

U-238 and its radiogenic daughter U-234 have been utilized for dating soil formation and groundwater residence time during the last 1.5 million years, in this case based on the U-clissolution/precipitation occurring during modifications of the oxidation-reduction conditions. In this paper, we report a 400-600 kyr proxy of wet periods from sediments occurring in a soil profile developed over rocks outcropping at the Parana sedimentary basin in Brazil, and from groundwater exploited of Guarani aquifer at the same basin. The approaches indicated successful use of the U-modeled ages for suggesting wet periods exceeding the past 116-210 kyr from previous studies. (C) 2007 Elsevier Ltd. All rights reserved.

引用

页码：776 / 783

页数：8

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