Abstract:
Thiruchendur coast of southern Tamilnadu, India
has been studied for grain-size spectrum and textural parameters
namely mean, sorting, skewness and kurtosis. The grainsize
spectrum shows a marked variation in the berm, high tide
line (HTL) and low tide line (LTL) stretches. Variation in
energy condition is controlled by geomorphology of the sedimentary
beach. Textural pattern shows complicated profile as
a result of the fluctuation in the physicochemical conditions
due to the sediments and the marine interactions. Abundance
of the medium sand to fine sand shows the prevalence of
comparatively moderate- to low-energy condition in the Thiruchendur
area. Linear discriminate function of the samples
indicates an aeolian, shallow marine deposition environment
and less influence of fluvial (7 %) process. CM diagram (C 0
one percentile in microns M 0 medium in microns) of Thiruchendur
coast sediments suggests that deposition takes place
by (1) rolling, (2) bottom suspension, (3) graded suspension.
This is also supported by the wave energy in different
stretches in beach line and also tractive current figure implies
the sediments disturbed by the tractive and turbidity currents.
The heavy minerals are concentrated in the berm (average,
11.8 %) and high tide line (average, 11.2 %) because of highenergy
condition and aeolian action. Quartz microtextures
show the mechanical action due to high-energy condition in
Manapad and Kuduthalai areas, the chemical action because
of to low-energy condition along the Thiruchendur, Kallamozhi
areas.
