1 - Cochin University of Science and Technology

are interbanded with quartzo-feldspathic layers. Other
occurrences are observed near Kerala-Tamil Nadu border in the
Walayar Reserve Forest. Occasional bands of intensely
fractured calc granulites are reported from south of the
limestone
Further,
deposit, closer to the migmatitic gneisses.
occurrence of calc granulites and
associated
limestones is known from the Gap proper near Gopalapuram.
Towards the eastern part of the study area, in the plains
near Madukkarai, calc granulites veined by pegmatites (Fig.7)
both across and along the foliation, are seen. A few of
these show minor scale displacement (- 30 cm) along NE - SW
trending fractures (Fig.8). A second set of prominet joints
in the E - W direction, with a dip of 20 0 N and a third set in
the N 58°E - S 58°W direction with a dip of 58° SE direction,
are also. observed here.
Crystal line limestones:- presence of
exploitable crystal line limestone deposits
commercially
in Kerala is
rather scarce. The largest among the known deposits is
located at Pandarettu (Mani, 1962 a & b; Rao et aI, 1974 ;
1975) falling within the study area, towards the northern
flank of the Pal ghat Gap. It occurs within calc granulites,
interbanded with garnet-sillimanite-graphite gneiss as an
isocl inal antiform, with limbs steeply dipping
towards south and plunging towards east (F i g. 9) • The
limestone band (Fig.l0) has a strike length of about 630 m
36