Iron Speciation of Mud Breccia from the Dushanzi Mud Volcano in the Xinjiang Uygur Autonomous Region,NW China

作     者：XU Wang ZHENG Guodong MA Xiangxian Danielle FORTIN David R.HILTON LIANG Shouyun CHEN Zhi HU Guoyi 

作者机构：Key Laboratory of Petroleum ResourcesGansu Province/Key Laboratory of Petroleum Resources ResearchInstitute of Geology and GeophysicsChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of SciencesBeijing 100049China Department of Earth and Environmental SciencesUniversity of Ottawa25 Templeton St.OttawaOntarioK1N 6N5Canada Scripps Institution of OceanographyUniversity of California San DiegoLa JollaCA 92093-0244USA Key Laboratory of Mechanics on Disaster and Environment in Western China(Lanzhou University)Ministry of EducationLanzhou 730000China CEA Key Laboratory of Earthquake Prediction(Institute of Earthquake Forecasting)China Earthquake AdministrationBeijing 100036China Research Institute of Petroleum Exploration and DevelopmentPetroChinaBeijing 100083China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2018年第92卷第6期

页      面：2201-2213页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 

基　　金：partially supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05007001-004) the National Natural Science Foundation of China(41273112 41402129 41020124002 41402298) CAS"Light of West China"Program and Chinese Academy of Sciences Visiting Professorship for Senior International Scientists(2015VEA032) 

主　　题：mud volcano mud breccias iron species organic-inorganic interactions greenhouse gas 

摘      要：Organic-inorganic interactions occurring in petroleum-related mud volcanoes can help predict the chemical processes that are responsible for methane emissions to the atmosphere. Seven samples of mud breccia directly ejected from one crater were collected in the Dushanzi mud volcano, along with one argillite sample of the original reddish host rocks distal from the crater, for comparison purposes. The mineral and chemical compositions as well as iron species of all samples were determined using XRD, XRF and M?ssbauer spectroscopy, respectively. The results indicate that a series of marked reactions occurred in the mud volcano systems, more specifically in the mud breccia when compared to the original rocks. Changes mainly included:(1) some conversion of clay minerals from smectite into chlorite and illite, and the precipitation of secondary carbonate minerals such as calcite and siderite;(2) silicon depletion and significant elemental enrichment of iron, manganese, magnesium, calcium and phosphorus; and(3) transformation of iron from ferric species in hematite and smectite into ferrous species in siderite, chlorite and illite. These geochemical reactions likely induced the color changes of the original reddish Neogene argillite to the gray or black mud breccia, as a result of reduction of elements and/or alteration of minerals associated with the oxidation of hydrocarbons. Our results also suggest that greenhouse gases emitted from the mud volcanoes are lowered through a series of methane oxidation reactions and carbon fixation(i.e., through carbonate precipitation).