new aspects of the late to post glacial deglaciation around the nilgri himal and the southern...

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 !!!