Geological characterization and provenance of As-enriched aquifers in the Indus basin Pakistan: Tracing arsenic source from zircon trace element geochemistry and UPb isotope data.

Autor: Hussain I; Environmental Hydro-geochemistry Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320, Pakistan; Department of Environmental Health Sciences & Management, Health Services Academy, Islamabad 44000, Pakistan., Rehman HU; Graduate School of Sciences and Engineering, Kagoshima University, Japan., Itai T; Department of Earth and Planetary Environmental Science (UG), Graduate School of Science, The University of Tokyo, Japan., Khattak JA; Environmental Hydro-geochemistry Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320, Pakistan., Lee HY; Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan., Chung SL; Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan; Department of Geosciences, National Taiwan University, Taipei, Taiwan., Hussain A; State Key Laboratory of Geological Processes and Mineral Resources, Collaborative Innovation Center for Exploration of Strategic Mineral Resources, School of Earth Resources, China University of Geosciences, Wuhan 430074, China., Farooqi A; Environmental Hydro-geochemistry Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320, Pakistan. Electronic address: afarooqi@qau.edu.pk.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Dec 09; Vol. 958, pp. 177922. Date of Electronic Publication: 2024 Dec 09.
DOI: 10.1016/j.scitotenv.2024.177922
Abstrakt: Geochemical surveys conducted on groundwater within the Punjab floodplains revealed high contamination of Arsenic (As). Although the spatial distribution of As and the mechanism of its release have been largely studied and understood however uncertainties still remain regarding its source and derivation. In this research, sediment samples from four boreholes were collected to study As contamination and main sediment phases that host As. To find the source of As-contaminated sediments, zircon trace element geochemistry and UPb isotope analyses were conducted on aquifer sediment samples collected from the Indus basin floodplain. Two lithofacies associations were identified in vertical lithological sequences: (1) a fine-grained over-bank layer and (2) a sandy channel-fill layer. Mineralogy of aquifer sediments is predominantly composed of quartz (30-57 %), plagioclase (4-25 %), mica (3-10 %), and trace amounts of pyrite and hematite. Geochemical analyses indicate biotite, chlorite, amphibole, garnet, and magnetite as the principal host of As. UPb isotope analysis, performed on zircon grains extracted from selected borehole samples from Ravi River floodplain, yield ages in the range from 1784 to 51 Ma, exhibiting several dominant peaks at 929 Ma and 307 Ma. The age data indicate sedimentary provenance from mixed magmatic lithologies that are exposed in the Himalayan mountain range in north Pakistan. Similarly, UPb ages of zircons from Chenab River floodplain showed a range from 1902 to 12 Ma with dominant peaks at 2000 Ma and 800 Ma, also indicating a similar sediment source. Trace element data of oscillatory zoned zircon grains suggest their formation mostly from igneous rocks and discriminate their source from crustal origin, mainly from magmatic rocks. The association of As-bearing sediment of the aquifer to a particular and known magmatic unit within the Himalayan region is complex because the sediments could have been derived from a vast area and may contain a mixed parental source.
Competing Interests: Declaration of competing interest Authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024. Published by Elsevier B.V.)
Databáze: MEDLINE
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