Akademik Veri Yönetim Sistemi
Topics in Igneous Petrology: a tribute to Prof. Mihir K. Bose, Ray,J.,Sen,G.,and Ghosh,B., Editör, Springer, Berlin, ss.383-417, 2011
The Kodaikanal–Palani Massif is an important component of India’s
Southern Granulite Terrain; understanding the tectonic history of its rocks lends
considerable insight into its role within South India. The massif is located south
of the Palghat Cauvery Shear Zone (PCSZ). Compilations of available geochronologic
and geochemical information from charnockites north and south of the PCSZ
show these rocks largely differ in age, with northern samples recording Archaean
crystallization events, whereas those to the south yielding Cambro-Ordovician and
Neoproterozoic ages. The Kodaikanal–Palani charnockitic rocks contain monazite
grains that fall within the Cambro-Ordovician timescale. The Oddanchatram
anorthosite, located along the northern boundary of the Kodaikanal–Palani Massif,
contains zircon grains that record mid-Neoproterozoic to Cambro-Ordovician
crystallization ages. This anorthosite differs in texture and composition depending
on location, that may be the result of its multi-stage metamorphic and/or intrusion
history. Charnockitic rocks north and south of the PCSZ also differ geochemically.
For example, north of the PCSZ, these rocks become more calcic with increasing
SiO2 contents, whereas those to the south become alkali-calcic.