上三叠统钦尔-多库姆古河流系统源头与终点之间的碎屑锆石联系

Detrital Zircon Link Between Headwaters and Terminus of the Upper Triassic Chinle-Dockum Paleoriver System.

作者信息

Riggs NR, Lehman TM, Gehrels GE, Dickinson WR

机构信息

N. R. Riggs, Department of Geology, Box 4099, Northern Arizona University, Flagstaff, AZ 86011, USA. T. M. Lehman, Department of Geosciences, Texas Tech University, Lubbock, TX 79409, USA. G. E. Gehrels and W. R. Dickinson, Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA.

出版信息

Science. 1996 Jul 5;273(5271):97-100. doi: 10.1126/science.273.5271.97.

DOI:10.1126/science.273.5271.97

PMID:8688060

Abstract

New detrital-zircon geochronologic data reveal that a through-going paleoriver connected Texas with Nevada in Late Triassic time. Sandstone from the Upper Triassic Santa Rosa Sandstone (Dockum Group) from northwestern Texas contains a detrital zircon suite nearly identical to that found in western Nevada in the Upper Triassic Osobb Formation (Auld Lang Syne Group, correlative with the Chinle Formation). The Santa Rosa Sandstone was derived in large part from the eroded Cambrian core of the Amarillo-Wichita uplift, as evidenced by abundant zircons with ages of 515 to 525 million years. Other zircon grains in the sandstone are Permian, Devonian, Proterozoic, and Archean in age and, with the exception of the Archean grain, are also matched by the population in the Nevada strata.

摘要

新的碎屑锆石地质年代学数据显示，在晚三叠世时期，一条连贯的古河流将得克萨斯州与内华达州连接起来。来自得克萨斯州西北部上三叠统圣罗莎砂岩（多克姆群）的砂岩含有一套碎屑锆石，与在内华达州西部上三叠统奥索布组（《友谊地久天长》群，与钦尔组对比）中发现的碎屑锆石几乎相同。圣罗莎砂岩大部分源自阿马里洛 - 威奇托隆起被侵蚀的寒武纪核心，这由大量年龄在5.15亿至5.25亿年的锆石所证明。砂岩中的其他锆石颗粒年龄为二叠纪、泥盆纪、元古代和太古代，除太古代颗粒外，也与内华达州地层中的锆石群体相匹配。