Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Sarfaraz Ahmad ¹, Syed Iqbal Hasnain ¹

Affiliations
1 School of Environmental Sciences, Jawaharlal Nehru University, New Delhi- 110 067, IN

Abstract

A comparative study of the meltwater chemistry from the Gangotri, Satopanth-Bhagirathi, Dokriani, and Bagni glaciers has been done for the late ablation period in October from 1991 to 1994. This late ablation period is characterized by low atmospheric input and lean flow in the glacier streams due to less availability of solar energy for supraglacial melting. During this period subglacial melting has played a dominant role in determining the water chemistry of glacier meltwater. In all studies, the dominant controlling factor on meltwater chemistry has been rock weathering processes, The pH and electrical conductivity of the meltwater from these Himalayan glaciers ranged between 6.9-8.12 and 43-134.8 μS/cm, respectively. The concentration ranges of major cations and anions recorded in the meltwaters of Himalayan glaciers are Ca⁺² (166-800) μeql^-1, Mg⁺² (25.8-344.5) μeql^-1, Na⁺ (11.1 - 124.2) μeql^-1, K⁺ (80-677.6) μeql^-1, HCO₃^- (381-2349.85) μeql^-1, SO₄^2-(192-2234) μeql^-1, and Cl^- (0.72-53.25) μeql^-1. The order of anion concentration in the meltwater is HCO₃^- > SO₄^2- > Cl^-. However, the order of anion concentration in meltwater of Gangotri, Bagni is SO₄^2- > HCO₃^- > Cl^-. The order of cation concentration is Ca⁺² > Mg⁺² > K⁺ > Na⁺ in all studies, except in the Satopanth and Bhagirathi glacier, which showed cation concentration of Ca⁺² > Na⁺ > Mg⁺² > K⁺ type. The purpose of this comparative study is to explain the geological control on the hydrochemistry of the meltwater draining from four different glaciers in the Garhwal Himalaya and to establish the relationship between meltwater hydrochemistry and the basement rock type.

Keywords

Glacier Meltwater, Hydrochemistry, Geological Controls.

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Syed Iqbal Hasnain ¹

Affiliations
1 ICSI Working Group on Himalayan Glaciology, School of Environmental Sciences, Jawaharlal Nehru University, NewDelhi - 110067, IN

Abstract

No Abstract.

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Sarfaraz Ahmad ¹, Syed Iqbal Hasnain ²

Affiliations
1 Department of Geology, Aligarh Muslim University, Aligarh - 202 002, IN
2 School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067, IN

Abstract

Mineralogical composition of soil and sediments reveals a decreasing trend of chemical weathering intensily with elevations due to decreasing temperature and short period sf soil solution rcsidence at high altitude soil profiles. Lower values of CIA (lndex of Chemical Alteration) for the soil, suspended and bed sediment also indicates low intensity of chemical weathering and these mineralogical and chemically immature sediments play an important roled in fertility of the flood plains of Ganga - Indus - Brahmaputra system.

Keywords

Texture, Mineralogy, Himalaya, Alpine, Alpine-Subalpine, Sub-Alpine forest stream, Garhwal Himalaya.

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