从明矾石的40Ar/39Ar测年看卡尔斯巴德洞穴及相关洞穴的年代与起源

Age and origin of carlsbad cavern and related caves from 40Ar/39Ar of alunite.

作者信息

Polyak VJ, McIntosh WC, Guven N, Provencio P

机构信息

V. J. Polyak and N. Guven, Department of Geosciences, Texas Tech University, Lubbock, TX 79409-1053, USA. W. C. McIntosh, New Mexico Geochronology Research Laboratory, New Mexico Institute of Mining and Technology, Socorro, NM 87801-4796, USA. P.

出版信息

Science. 1998 Mar 20;279(5358):1919-22. doi: 10.1126/science.279.5358.1919.

DOI:10.1126/science.279.5358.1919

PMID:9506939

Abstract

40Ar/39Ar dating of fine-grained alunite that formed during cave genesis provides ages of formation for the Big Room level of Carlsbad Cavern [4.0 to 3.9 million years ago (Ma)], the upper level of Lechuguilla Cave (6.0 to 5.7 Ma), and three other hypogene caves (11.3 to 6.0 Ma) in the Guadalupe Mountains of New Mexico. Alunite ages increase and are strongly correlative with cave elevations, which indicates an 1100-meter decline in the water table, apparently related to tectonic uplift and tilting, from 11.3 Ma to the present. 40Ar/39Ar dating studies of the hypogene caves have the potential to help resolve late Cenozoic climatic, speleologic, and tectonic questions.

摘要

对洞穴形成过程中形成的细粒明矾石进行的40Ar/39Ar测年，得出了新墨西哥州瓜达卢佩山脉卡尔斯巴德洞穴大房间层（400万至390万年前）、莱丘吉利亚洞穴上层（600万至570万年前）以及其他三个深成洞穴（1130万至600万年前）的形成年龄。明矾石年龄增加且与洞穴海拔高度密切相关，这表明从1130万年前至今，地下水位下降了1100米，这显然与构造隆升和倾斜有关。对深成洞穴的40Ar/39Ar测年研究有潜力帮助解决晚新生代的气候、洞穴学和构造问题。