new aspects of the late to post glacial deglaciation around the nilgri himal and the southern...
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New aspects of the late to post glacial deglaciation around the Nilgri Himal and the southern Thakkola (Nepal Himalaya). Presented by Markus Wagner at the "Perth II: Global Change and the World's Mountains" conference in Perth, Scotland in September 2010.TRANSCRIPT
New aspects on the late to post glacial
deglaciation around the Nilgiri Himal and
the southern Thakkola (Nepal Himalaya)
Markus Wagner
Northwest German Forest Research Station
Goettingen
Germany
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paleoclimate research in the Himalaya
• extent: glaciogeomorphology
• chronology: relative: e.g. glaciogeomorphology, pedology
• chronology: absolute: e.g. 14C, TL, OSL, TCN
• extent and chronology of pleistocene glaciation
• rating of the present climate and modelling of future climate trends
requires knowledge of climate and climate change in the past
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paleoclimate research in the Himalaya
• extent: glaciogeomorphology
• chronology: relative: e.g. glaciogeomorphology, pedology
• chronology: absolute: e.g. 14C, TL, OSL, TCN
• extent and chronology of pleistocene glaciation
• rating of the present climate and modelling of future climate trends
requires knowledge of climate and climate change in the past
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Last Glacial Maximum for High Asia after Kuhle (2004)
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Last Glacial Maximum for High Asia after Zhou et al. (2004)
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Kuhle (1982)
Fort (2000)
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TCN dating: 2.1 ± 1.7 and 0.6 ka BP (Zech et al. 2009)
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TCN dating: 18188 ± 3084 and 23007 ± 4397 a BP (Gayer et al. 2004)
28 ka ± 3 ka BP (Zech et al. 2009)
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soil profiles of the investigation areas
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pedological relative dating
1. formation of pedogenic iron and aluminium oxi-hydroxides
2. changing total element concentrations due to the element
specific mobilisation and leaching affinity
3. grain size distribution of fine earth
proof of the degree of soil development by:
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Exemplarily assortment of pedological weathering indices, Thini Khola
100
7,0
aCa
25,0
aK
9,0
aMg
35,0
aNa)P(WI
well chrystallised iron oxides: total iron ratio
clay mass
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Exemplarily assortment of pedological weathering indices, Dhampu Basin
Modfied Weathering Potential Index
(Na2O+K2O+CaO+MgO)/(Na2O+K2O+
CaO+MgO+Al2O3+Fe2O3+SiO2)*100
pedogenic iron oxides: total iron ratio
clay mass
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Exemplarily assortment of pedological weathering indices, Kali Gandaki south of
the Higher Himalaya
Clay Accumulation Index
well chrystallised iron oxides: total iron ratio
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Synoptical discussion of the results
• The own geomorphological investigations confirm the more extended last
high glacial glaciation found in the literature
• ELA depressions of at least 1300 m can be reonstructed; this is in
conformity with results from neighbouring regions
• lower and highly variable maximum ELA depressions, which are
explained by a weaker and shifting monsoon, can not be confirmed by
geomorphological investigations
• for pedological relative dating of moraines in the Himalaya similar
conditions of soil formation, and sufficient precipitation amounts are
required; in the central part of the Higher Himalaya around the Nilgiri-
Himal this is on the south-face of the Higher Himalaya extreme
topography and strong human influence prevent a for that necessary
continous soil development
Thank you very much for your attention !!!