Grain Size and Magnetic Susceptibility an implication of lithological composition as well as climatic variability of High Altitude lake sediments of Satopanth Tal, Uttarakhand, In

Abstract

Various attributes of particle distribution and magnetic analysis such as frequency distributions,
textural parameters and frequency dependent magnetic susceptibility respectively have been adopted
for many decades and investigated for potential information about transport behavior, size-sorting
and depositional processes in different environments. Grain size and Magnetic susceptibility
measurements are performed on sediment samples collected from Satopanth Tal, India. Polymodal
distribution of sediments indicates dominance of more than one process involved in the deposition of
sediments under lacustrine environments. The mean size of the surface and core sediments indicating
the dominance of coarse to fine silt and medium sand and medium Silt respectively. The dominance
of silt sediments can also be attributed to the low disturbance and low energetic condition. The
increase in grain size i.e. Medium to Fine Sand size at certain depth may indicate a time of increased
precipitation, likely provided more sediment available for transport into the lake. The standard
deviation value of both surface and core sediments are of moderate to poorly sorted type. The
variation of sign in Skewness is due to vary in energy conditions. The Very leptokurtic to mesokurtic
and Very leptokurtic to platykurtic values in southern core are due to poorly to very poorly sorted
sediments. The magnetic susceptibility reached maximum which reflect the highest proportion of
magnetic elements at the depth of 41cm in southern core and at 4cm in western core respectively. In
surface sediments eastern and western part of the lake is characterized by high magnetic susceptibly,
this is due to the presence of paramagnetic minerals. The lowest magnetic susceptibility values were
recorded in sediments taken from some part results the dominance of diamagnetic minerals.
Magnetic susceptibility scale infers all the sediments fall under the class I of K indicating the
magnetic properties can be successfully carried out on the fine-grained fractions of sediments which
contain most of the magnetic particles.