Causes and implications of Mid- to Late Holocene relative sea-level change in the Gulf of Kachchh, western India
Causes and implications of Mid- to Late Holocene relative sea-level change in the Gulf of Kachchh, western India
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DOI：
10.1017/qua.2020.86
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发表时间：
2020-11
影响因子：
2.3
通讯作者：
Shubhra Sharma;Gaurav Chauhan;A. Shukla;Romi Nambiar;R. Bhushan;Bhawanisingh G. Desai;Shilpa Pandey;M. Dabhi;S. Bhandari;Suraj Bhosale;A. Lakhote;N. Juyal
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文献类型：
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作者：
Shubhra Sharma;Gaurav Chauhan;A. Shukla;Romi Nambiar;R. Bhushan;Bhawanisingh G. Desai;Shilpa Pandey;M. Dabhi;S. Bhandari;Suraj Bhosale;A. Lakhote;N. Juyal
摘要利用卡罗德河河口、卡奇奇湾和科里河末端的残留潮间沉积物来推断印度西部全新世中晚期的相对海平面变化。利用沉积学、地球化学、孢粉学、遗迹学、光学和放射性碳测年等方法，研究表明，在16.5 ± 1.6和9.9 ± 0.7 ka之间，河流活动占主导地位。在~7 ka（7.3 ± 0.4，6.8 ± 0.5ka）以后，海平面上升趋势一直持续到4.7 ± 0.2ka。经构造校正的中全新世RSL变化估计为1.45 ± 0.33 m之间~7和~5 ka。研究表明，中全新世RSL高是由于来自喜马拉雅冰冻圈的融水的贡献，其次是冰川均衡调整和地壳沉降的贡献。晚全新世构造校正的RSL变化在~1 ka（1.1 ± 0.1ka和1045 ± 175 cal yr BP）估计为0.53 ± 0.43 m。这是由于季风风驱动的潮汐入侵，可能会影响潮汐振幅积极。这项研究表明，中全新世RSL的变化并没有起到决定性的作用，在哈拉帕沿海定居点的放弃。
Abstract The relict intertidal deposits from the Kharod River Estuary, Gulf of Kachchh, and the distal end of Kori Creek are used to infer the Mid- to Late Holocene relative sea-level (RSL) change in western India. Employing sedimentology, geochemistry, palynology, ichnology, and optical and radiocarbon dating, the study suggests the dominance of fluvial activity between 16.5 ± 1.6 and 9.9 ± 0.7 ka. After ~7 ka (7.3 ± 0.4, 6.8 ± 0.5 ka), the sea level showed a positive tendency until 4.7 ± 0.2 ka. The tectonically corrected Mid-Holocene RSL change is estimated as 1.45 ± 0.33 m between ~7 and ~5 ka. The study suggests that the Mid-Holocene RSL high was due to the meltwater contribution from the Himalayan cryosphere, with subordinate contribution from glacio-isostatic adjustment and crustal subsidence. The Late Holocene tectonically corrected RSL change at ~1 ka (1.1 ± 0.1 ka and 1045 ± 175 cal yr BP) is estimated as 0.53 ± 0.43 m. This is ascribed to monsoon wind-driven tidal ingression that might have affected the tidal amplitude positively. The study suggests that the Mid-Holocene RSL change did not play a deterministic role in the abandonment of the Harappan coastal settlements.