Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China
The Pisha Sandstone is widely exposed in the northeastern margin of the Ordos basin. Since the Mesozoic the basin was subjected to uneven uplift several times, strong weathering and erosion have been occurring and a large amount of sediments derived from these erosional strata are input into the low...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-04-01
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| Series: | Heliyon |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S240584402405151X |
| _version_ | 1827261818808041472 |
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| author | Shuhua Fan Fucang Qin Zhihui Che |
| author_facet | Shuhua Fan Fucang Qin Zhihui Che |
| author_sort | Shuhua Fan |
| collection | DOAJ |
| description | The Pisha Sandstone is widely exposed in the northeastern margin of the Ordos basin. Since the Mesozoic the basin was subjected to uneven uplift several times, strong weathering and erosion have been occurring and a large amount of sediments derived from these erosional strata are input into the lower Yellow River, posing a fragile ecological environment along the river. However, the geochemical characteristics of the Pisha Sandstone have remained poorly understood. In this study, we focus on the Pisha Sandstone from Early–Middle Triassic Liujiagou, Heshanggou and Ermaying Formation, present a very first petrographic and geochemical data together with detailed field geological characteristics, aiming to place geochemical indicators on weathering, provenance and tectonic setting of the Pisha Sandstone. The results show that sandstones in Pisha Sandstone are classified as arkose, litharenite and wacke. The geochemical proxies including Chemical Index of Alteration (CIA = 67.2), Chemical Index of Weathering (CIW = 80.1), Plagioclase Index of Alteration (PIA = 75.6) and Index of Compositional Variability (ICV = 1.6) indicate Pisha Sandstone experienced first–cycle deposit and moderate to strong chemical weathering. Trace element and rare earth element concentrations together with their ratios (La/Sc, La/Co, Th/Sc, Th/Co, Cr/Th) reveal a felsic provenance, and source rock compositions are predominantly granodiorite and granite from the north margin of the Inner Mongolia Paleo–Uplift (IMPU), with a small amount of mafic or intermediate components. The geochemical signatures and tectonic discrimination diagrams display a collision setting for the Pisha Sandstone and further reveal the sediments had been deposited in a continental island arc setting. The results of this work may provide new theoretical basis for environmental protection in the Pisha Sandstone area. |
| first_indexed | 2024-04-24T07:05:05Z |
| format | Article |
| id | doaj.art-1c92269e81b74e1690670a903bbca204 |
| institution | Directory Open Access Journal |
| issn | 2405-8440 |
| language | English |
| last_indexed | 2025-03-22T03:04:25Z |
| publishDate | 2024-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj.art-1c92269e81b74e1690670a903bbca2042024-05-01T05:08:21ZengElsevierHeliyon2405-84402024-04-01108e29120Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, ChinaShuhua Fan0Fucang Qin1Zhihui Che2Key Laboratory of Aeolian Physics and Desertification Control Engineering from Inner Mongolia Autonomous Region, College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China; Inner Mongolia Hangjin Desert Ecological Position Research Station, Ordos, 017400, ChinaInner Mongolia Academy of Forestry Science, Hohhot, 010010, ChinaSchool of Architecture, Inner Mongolia University of Technology, Hohhot, 010051, China; Corresponding author.The Pisha Sandstone is widely exposed in the northeastern margin of the Ordos basin. Since the Mesozoic the basin was subjected to uneven uplift several times, strong weathering and erosion have been occurring and a large amount of sediments derived from these erosional strata are input into the lower Yellow River, posing a fragile ecological environment along the river. However, the geochemical characteristics of the Pisha Sandstone have remained poorly understood. In this study, we focus on the Pisha Sandstone from Early–Middle Triassic Liujiagou, Heshanggou and Ermaying Formation, present a very first petrographic and geochemical data together with detailed field geological characteristics, aiming to place geochemical indicators on weathering, provenance and tectonic setting of the Pisha Sandstone. The results show that sandstones in Pisha Sandstone are classified as arkose, litharenite and wacke. The geochemical proxies including Chemical Index of Alteration (CIA = 67.2), Chemical Index of Weathering (CIW = 80.1), Plagioclase Index of Alteration (PIA = 75.6) and Index of Compositional Variability (ICV = 1.6) indicate Pisha Sandstone experienced first–cycle deposit and moderate to strong chemical weathering. Trace element and rare earth element concentrations together with their ratios (La/Sc, La/Co, Th/Sc, Th/Co, Cr/Th) reveal a felsic provenance, and source rock compositions are predominantly granodiorite and granite from the north margin of the Inner Mongolia Paleo–Uplift (IMPU), with a small amount of mafic or intermediate components. The geochemical signatures and tectonic discrimination diagrams display a collision setting for the Pisha Sandstone and further reveal the sediments had been deposited in a continental island arc setting. The results of this work may provide new theoretical basis for environmental protection in the Pisha Sandstone area.http://www.sciencedirect.com/science/article/pii/S240584402405151XGeochemical indicatorsWeatheringProvenanceTectonic settingPisha sandstoneFragile ecological environment |
| spellingShingle | Shuhua Fan Fucang Qin Zhihui Che Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China Heliyon Geochemical indicators Weathering Provenance Tectonic setting Pisha sandstone Fragile ecological environment |
| title | Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China |
| title_full | Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China |
| title_fullStr | Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China |
| title_full_unstemmed | Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China |
| title_short | Geochemical indicators to constrain weathering, provenance and tectonic setting of the Pisha Sandstone (Early–Middle Triassic) in Northeast Ordos Basin, China |
| title_sort | geochemical indicators to constrain weathering provenance and tectonic setting of the pisha sandstone early middle triassic in northeast ordos basin china |
| topic | Geochemical indicators Weathering Provenance Tectonic setting Pisha sandstone Fragile ecological environment |
| url | http://www.sciencedirect.com/science/article/pii/S240584402405151X |
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