Water-Rock-Microbial Interactions in the Hydrothermal Spring of Puertecitos, Baja California, Mexico

详细信息    查看全文

• 作者：Yorfrank Arellano-Ramirez^a ; Thomas G. Kretzschmar^a ; ^{tkretzsc@cicese.mx} ; Rufina Hernandez-Martinez^b
• 关键词：hydrothermal spring ; water/rock interacion ; microbes
• 刊名：Procedia Earth and Planetary Science
• 出版年：2017
• 出版时间：2017
• 年：2017
• 卷：17
• 期：Complete
• 页码：865-868
• 全文大小：415 K
• 卷排序：17

文摘

The interaction of microorganisms with minerals under high temperature hydrothermal systems is a little studied process. This study was conducted in the hydrothermal spring at Puertecitos, Baja California, Mexico, formed at an intertidal zone with fluctuating temperature due to the tides. The hydrothermal system is located in a vitreous dacitic tuff of Pliocene age; the spring has varying temperatures ranging from 73.5 °C in the fracture zone to 32 °C in areas close to the sea. At high temperatures, evidence of silicified microorganisms and a pH of 10.4 were observed; however, at lower temperatures, a pH of 7.3 was recorded, as well as abundant biofilms and debris of silicified diatoms. Scanning electron microscopy revealed that silicification of microorganisms allowed their morphological preservation. Precipitation / dissolution of minerals were strongly influenced by changes in temperature. The precipitation of gypsum and silica were found at temperatures of 55 °C in fractures with gas fumes; whereas at lower temperatures, mineral dissolution was apparent. The silicified biomorphic microstructures correspond to structures with sizes greater than 10 microns in length, bacillus from of up to 2 microns, diatomea and biofilms. At low temperatures a decrease of SiO2, Mg, Na, SO4 and Cl was observed, as well as the accumulation of biofilms.