Fabric and Origin of Lateral Moraines, Bethartoli Glacier, Garhwal Himalaya, India

Abstract

AbstractUnusually strong till fabrics in lateral moraines of Bethartoli Glacier provide information on the genesis and growth of the moraines. On the west side of the valley, down-stream of the present glacier snout, several lateral moraine crests are juxtaposed. Because the crests generally become higher towards the valley axis, they must represent re-advances of the glacier rather than recessional stages. On the east side of the valley only a single lateral ridge is found; presumably the ridge is composed of debris from several glacial advances. On the eroded proximal flank of this ridge a strong fabric is visible; the plane defined bya- andb-axes of stones is parallel to the distal flank of the moraine ridge, indicating that the moraine grew mainly by accretion of debris on to its distal flank. On the eroded proximal flank of the innermost west-side ridge the equivalent fabric is weaker, suggesting that distal flank accretion was less significant and proximal flank accretion more significant than on the east side.