| Autor: |
Saurabh Kumar Rastogi, Rameshwar Bali, Pradeep Srivastava, K. K. Agarwal, S. Nawaz Ali, Kalyan Krishna |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Journal of Asian Earth Sciences. 66:224-233 |
| ISSN: |
1367-9120 |
| DOI: |
10.1016/j.jseaes.2013.01.011 |
| Popis: |
Palaeoglacial reconstruction based on geomorphological mapping in the Pindari glacier valley, Alaknanda basin (Central Himalaya), has revealed five glacial stages with decreasing magnitude. The oldest and most extensive stage-I glaciation deposited sediments at ∼2200 masl (Khati village). The stage-II glaciation was around 7 km long and luminescence dated to 25 ± 2 ka, and has deposits at 3200 masl (Phurkia village). Stage-III glaciation is represented by degraded linear moraine ridges and is dated to 6 ± 1 ka and its remnants can be found around 3850 masl. A sharp crested crescentic moraine extending from around 3650 masl to 3900 masl is attributed to stage-IV glaciation and is dated to 3 ± 1 ka. Following this, there appears to have been a gradual recession in Pindari glacier as indicated by four sharp crested unconsolidated moraines (stage-V) on the valley floor which abuts the stage-IV moraine. We suggest that the stage-I glaciation occurred during the cool and wet Marine Isotopic Stage 3/4 (MIS-3/4), stage-II glaciations began with the onset of MIS-2, whereas the stage-III and IV glaciations occurred during the mid-to late Holocene (MIS-1). We speculate that the first sharp crested unconsolidated moraines around 3600 masl correspond to the later phase of the Little Ice Age (LIA). Historical data suggests that the remaining three ridges represent Pindari glacier snout positions at 1906, 1958 and 1965. We argue that the late Quaternary glaciations in the Pindar valley were modulated by changing insolation and summer monsoon intensity including the LIA, whereas the 20th century recessional trends can be attributed to post-LIA warming. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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