________________
16
Central Himalayan Geological Observations
Augusto Gansser Summarized by Mayur Desai and Ajit Shah
The following document presents excerpts from publication by A. Gansser, titled "Geology of Himalayas", published by Inter-science Publications, 1964. The selected excerpts related to geology of Mt. Kailash region are presented in here.
Regional Setting
The regional settings of the Himalayas have some striking particularities, such as their outstanding height, the thrusts, rock composition and their isolated position. The Himalayas have no direct continuation either towards the west or to the east. The singular syntaxial bends on both extremes preclude a straight forward continuation of the Himalayan elements.
In the west, the Sulaiman Range is not a direct continuation of the Lower Himalayas, but is a fold system of younger sediments (Mesozoic and younger) which develops out of the Hazara Ranges in the west. Westwards, the Sulaiman belt is sharply limited by an ophiolitic tectonic line from the Flysch-type Baluchistan and Afghan sediments. This suture line may be a continuation, or most likely a branch, of the Indus suture line. The other branch seems to form the southern border of the Hindu-Kush Range, the western equivalent of the Karakorum. It is much more difficult to follow the eastern continuation of the Himalayas due to lack of geological information. The little we know indicates that here too there is no direct continuation of the range. The southeastern Assam foothills (Naga Hills) differ from the corresponding Himalayan foothills. The crystalline rocks of the Mishmi Hills seem to belong to the Higher Himalayas, though some indications of inverted metamorphism do exist. The backbone of the western Burmese ranges, the peculiar Arakan Yoma, has no affinities with the Lower or Higher Himalayas. The Flysch type sediments, mostly of Cretaceous age, expose some ultra basic rocks aligned along the eastern border which is faulted and partly thrusted. Acertain similarity with the Indus Flysch belt seems evident, but no direct connection with this important north Himalayan element is known. We have noted that the latter disappears east of the Manasarovar Lake in the northern Kumaon Himalayas. The Arakan Yoma Ranges certainly is on eastern equivalent of the Sulaiman Range. Within the mountain ranges of Asia, the Himalayas display thrusting of such a magnitude that a crustal shortening of about 400 km is suggested. This is not the figure assumed by some authors for the crustal shortening in the Alps. This amount,
Copyright Acknowledgement - Inter Science Publishers.
Original Source Central Himalaya: Geological observations of the Swiss Expedition, 1936
Ref. Vol. XII Ch. 86 F Pg. 5534-5555
Central Himalayan Geological Observations
190
