PAYEL DEY
Articles written in Journal of Earth System Science
Volume 125 Issue 8 December 2016 pp 1681-1696
Santanu Acharjee Jyotisankar Ray Payel Dey Debapriya Bhattacharyya Mousumi Banerjee Basab Chattopadhyay Shyamal Sengupta A K Bhatt D Chowdhury A K Dwivedi Sanjoy Mahato Arka Ranjan Jana P B Maithani P V Ramesh Babu
The area of investigation at and around Mashak Pahar, Bankura district, West Bengal, India comprises a number of rock types namely: granite gneiss, migmatized quartz tourmaline gneiss, quartz pebbleconglomerate, ferruginous quartzite, quartz tourmaline veins (as veins) and graphite schists. Interestingly, the study area lies in the region extending South Purulia Shear Zone (∼Tamar–Porapahar Shear Zone) which marks the boundary between two contrasting tectonic blocks of eastern India, namely, the Chhotanagpur Gneissic Terrane (CGC) to the north and Singhbhum Group of rocks to the south. The rocks of the study area are poly-phasedly deformed by three phases of folding, namely, F1, F2 and F3. All the tourmalines are classified to be of ‘Alkali Group’. Chemistry of tourmalines from migmatized quartz tourmaline gneiss and those from quartz tourmaline veins are in conformity with their relation to (earthquake induced) shear system evolution in this terrain. In general, the compositional evolutionof tourmaline during prograde metamorphism (∼400°–730°C) has been supported by both petrographic and chemical evidences. Assessment of mineral–chemical data of constituent tourmaline grains clearly suggests compositional variations across zonal boundaries within tourmaline that was controlled by changing metamorphic milieu in this terrane. Field and petrographic evidences clearly indicate activation of earlier and later shears in this region accompanied by infiltration of boron and formation of zoned tourmaline crystals.
Volume 131 All articles Published: 23 July 2022 Article ID 0163 Research article
PAYEL DEY JYOTISANKAR RAY JANISAR M SHEIKH SURESH C PATEL CHRISTIAN KOEBERL AVIPSHA CHAKRABORTY
Multivariate statistical analysis involving hierarchical clusters was carried out for basaltic samples
(and associated units) from Khandwa (21°49'N, 76°21'E). ‘Highly significant’ or ‘significant’ linear correlation
coefficient values (
$\bf{Highlights}$
$\bullet$ Multivariate statistical analysis from a portion of eastern Deccan volcanic province deciphers distinctive nature of crystallization.
$\bullet$ Cluster patterns indicate distinct ‘bulk level of crystallization’ and ‘ultimate crystallization’ for the lavas.
$\bullet$ Rapid quenching of dyke rocks only allows them to crystallize up to the bulk level.
$\bullet$ Ambient temperature controls bulk level of crystallization for the lavas.
Volume 131 All articles Published: 28 September 2022 Article ID 0210 Research article
PAYEL DEY JYOTISANKAR RAY JANISAR M SHEIKH SURESH C PATEL CHRISTIAN KOEBERL SIMRAN DUTTA
Continental flood basalts of the world are represented either by picrobasalt/picrite layers (with abundant growth of olivine) or by (almost) olivine-depleted tholeiite basalts. We have taken a case study from the olivine-depleted basaltic rocks from Khandwa (21°49'N: 76°21'E) Eastern Deccan Volcanic Province. Our research shows that recent cooling experiments (available in the literature) involving a dry basalt and construction of some selected binary major element variation diagrams (entailing lever rules) can explain (and quantify) the insignificant level (${\sim}$2–4%) of olivine crystallization (${\sim}$olivine decadence) in tholeiite basalts. Such decadent olivine retains a skeletal crystallographically-oriented geometry. We contemplate that our simplistic model of olivine decadence can be extended to other flood basalt provinces of the world as well.
$\bf{Highlights}$
$\bullet$ First-time cogent model of olivine decadence in Deccan basalts
$\bullet$ Integration of newly obtained experimental data and binary variation diagrams
$\bullet$ Petrographic support validates the model
$\bullet$ Model can be extended to other continental Flood basalts
Volume 132, 2023
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