Beach Monazites from Alleppey: A Window to the Trivandrum Block, Southern India

Abstract

Detrital monazites can be used to reconstruct the tectonothermal history of their provenance. Dating of beach monazites from Alleppey by EPMA U-Th-Pbtotal technique using the centroid method demonstrates that the ages recorded by even a small number of 28 analyses from a single thin section grain mount can potentially reveal a considerable portion of the tectonothermal history of the Trivamdrum block. Three monazite populations were identified that yielded ages 605 ± 9, 575 ± 23 and 548 ± 11 Ma, which have their more or less exact counterparts reported from the Trivandrum Block. One monazite grain yielded random Paleoproterozoic ages ranging from 1756 Ma to 1345 Ma representing similar ages which earlier have been interpreted as due to differential Pb-loss from >2000 Ma monazites during the late Neoproterozoic-Cambrian metamorphism.

Monazite chemistry and its distribution along the coast of Neendakara–Kayamkulam belt, Kerala, India

“…Shrivastava et al (2018) use HPGe semiconductor detector for studying the uranium content in Indian monazite samples [12]. Dating of beach monazites collected from Alleppey in Kerala clearly reveals the age of tectono-thermal history of Trivandrum block [13].…”