Black shale weathering profile Metagenome. terrestrial metagenome

Black shales weathering has an important impact on water quality, ecosystem sustain ability, agriculture, global climate change, the long-term global O2 and CO2 cycle, the biogeochemical cycles of various trace elements, and human health by redistributing elements and toxicants bound in them into the environment. Microorganism-related bioweathering was supposed to be an important approach to erosion, decay and decomposition of these black shales. Therefore, a comprehensive investigation on the microbial community within a black shale weathering profile is essential to characterize the roles that microbes played in the black shale weathering process under the near-surface weathering environments. A black shale weathering profile was developed on a natural exposure of Shuijingtuo Formation nearby the Town of Chengkou County, China. Black shale samples, including A1, A2, A3, A4, A5, A6, A7, A8 and A10, were collected orderly along this continuous depositional unit from bottom fresh parent shale towards the surface regolith of the weathering profile. The weathering extent was generally increasing from A1 to A10 through field observation. One relative fresh sample, S1, collected as a reference sample from another weathering filed at Chengkou area.

黑色页岩风化通过将赋存于其中的元素与有毒物质重新释放至环境中，对水质、生态系统可持续性、农业生产、全球气候变化、全球长期氧（O₂）与碳（CO₂）循环、各类微量元素的生物地球化学循环以及人类健康均具有重要影响。与微生物相关的生物风化，被认为是这类黑色页岩侵蚀、崩解与分解的重要途径。因此，针对黑色页岩风化剖面内微生物群落开展全面调查，对于阐明近地表风化环境下微生物在黑色页岩风化过程中所发挥的作用至关重要。本次研究在中国城口镇附近的天然露头处，建立了一套水井沱组（Shuijingtuo Formation）黑色页岩风化剖面。沿该连续沉积单元，从底部新鲜母岩页岩直至风化剖面的地表风化层，依次采集了包括A1、A2、A3、A4、A5、A6、A7、A8及A10在内的黑色页岩样品。经野外观测，从A1至A10的风化程度整体呈递增趋势。另在城口区域的另一处风化剖面采集了1件相对新鲜的样品S1作为参照样品。