Using the geologic setting of talc deposits as an indicator of amphibole asbestos content |
| |
Authors: | Email author" target="_blank">Bradley?S?Van GosenEmail author Heather?A?Lowers Stephen?J?Sutley Carol?A?Gent |
| |
Institution: | (1) U.S. Geological Survey, Denver Federal Center, M.S. 905, Box 25046, Denver, CO 80225, USA |
| |
Abstract: | This study examined commercial talc deposits in the U.S. and their amphibole-asbestos content. The study found that the talc-forming environment directly influenced the amphibole and amphibole-asbestos content of the talc deposit. Large talc districts in the U.S. have mined hydrothermal talcs that replaced dolostone. Hydrothermal talcs, created by siliceous fluids heated by magmas at depth, consistently lack amphiboles as accessory minerals. In contrast, mineable talc deposits that formed by contact or regional metamorphism consistently contain amphiboles, locally as asbestiform varieties. Examples of contact metamorphic deposits occur in Death Valley, California; these talc-tremolite deposits contain accessory amphibole-asbestos. Talc bodies formed by regional metamorphism always contain amphiboles, which display a variety of compositions and habits, including asbestiform. Some industrial mineral deposits are under scrutiny as potential sources of accessory asbestos minerals. Recognizing consistent relations between the talc-forming environment and amphibole-asbestos content may be used in prioritizing remediation or monitoring of abandoned and active talc mines. |
| |
Keywords: | Talc Amphibole-asbestos Geologic setting Hydrothermal Metamorphic USA |
本文献已被 SpringerLink 等数据库收录! |
|