Origin of hydrogen-nitrogen gas seeps,Oman |
| |
| Institution: | 1. Laboratory for Earthquake Chemistry, Faculty of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan;2. Department of Chemistry, Faculty of Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152, Japan;1. Lamont-Doherty Earth Observatory, Columbia University, NY, USA;2. School of Engineering and Applied Science, University of Pennsylvania, PA, USA;3. Department of Earth Sciences, University of Oxford, UK;4. School of Earth Sciences, The Ohio State University, OH, USA;5. College of Engineering, University of Notre Dame, IN, USA;1. Department of Earth, Environmental, and Planetary Sciences, Brown University, 324 Brook St, Box 1846, Providence, RI 02912, USA;2. Department of Geography, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, R3B 2E9, Canada;3. Department of Geological Sciences, Indiana University, 1001 East 10th Street, Bloomington, IN 47405-1405, USA;4. Department of Physics, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, R3B 2E9, Canada;5. Mount Holyoke College, Department of Astronomy, 50 College St., South Hadley, MA 01075, USA;1. Université Grenoble Alpes, CNRS, ISTerre, F-38058 Grenoble Cedex 9, France;2. Univ. Lille, Institut Mines-Télécom, Univ. Artois, Junia, ULR 4515 – LGCgE, Laboratoire de Génie Civil et géo-Environnement, F-59000 Lille, France;3. Géosciences Environnement Toulouse (GET), CNRS/IRD/UPS/CNES, Toulouse University, 14 Avenue Edouard Belin, 31400 Toulouse, France;1. Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma 2, Roma, Italy;2. Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca, Romania;3. Federal Geological Survey Sarajevo, Ustanička 11, 71210 Ilidža, Bosnia and Herzegovina;4. Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Italy;5. Dr. F. Bećirbegovića 19, 71000 Sarajevo, Bosnia and Herzegovina;1. E2S-UPPA, LFCR Rue de L''université, 64012, Pau, France;2. Institute of Earth Sciences, University of Iceland, Sturlugata 7, 101, Reykjavík, Iceland |
| |
| Abstract: | Six gas samples were collected from five thermal springs in the Semail Nappe ophiolite and the calcareous (calcite and dolomite) Hajar Formation, northern Oman. The3He/4He,4He/20Ne,40Ar/36Ar and38Ar/36Ar ratios, chemical compositions (H2, N2, CO2, CH4, O2, Ar and He), and stable isotope compositions (δDH2, δDH2O, δ13CCO2, δ13CCH4, and δ15NN2) are reported. Samples from the ophiolite region are significantly anoxic with major constituents of H2, CH4 and N2, while those from calcite and dolomite regions are ordinary gas seeps, consisting of N2, CO2 and/or O2. The former H2-rich gas is characterized by relatively high3He/4He ratio (0.4–0.8 Ratm) with low He content (<5 ppm), atmospheric40Ar/36Ar ratio, low N2/Ar ratio (<55) and high δ15NN2 value (∼1 ‰). On the other hand, the latter N2-rich gas shows relatively low3He/4He ratio (0.1–0.4 Ratm) with high He concentration (>300 ppm), slight radiogenic40Ar/36Ar ratio, high N2/Ar ratio (77–97) and low δ15NN2 value (<0‰). Observed δDH2 value of −536‰ in H2-rich gas is distinguished from the literature value of −699‰ in the ophiolite region, giving discrepant isotope formation temperatures. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
