Geology of an amber locality in the Hukawng Valley, Northern Myanmar

Coal fires burning out of control around the world : Thermodynamic recipe for environmental catastrophe

Abstract Extending along the east coast of peninsular India, the Eastern Ghats expose a deep section through a composite orogenic belt that once formed part of the Proterozoic mobile belt system within East Antarctica and East India. The critical evaluation of the existing geological and isotopic data strongly suggests that this orogenic belt includes not only the granulite facies Eastern Ghats Belt but also the Nellore-Khammam Schist Belt and lower grade units at the southern margin of the Singhbhum Craton. The present authors propose its subdivision into four crustal provinces with widely different geological evolutions. The Rengali and Jeypore Provinces formed at the margin of the Bhandara Craton in the Late-Archaean. In the Krishna Province, volcanosedimentary rocks equivalent to the Cuddapah Supergroup accumulated, probably on the Dharwar Craton in the Palaeoproterozoic, and the major tectonometamorphic event took place between 1.67 and 1.55 Ga, subsequent to a short-lived igneous activity. The Eastern Ghats Province, which shows considerable similarities with the Rayner Province of East Antarctica, was strongly affected by pervasive deformation, high-grade metamorphism and crustal-derived magmatism between 1.1 and 0.9 Ga, which extensively modified the crustal structure of present eastern peninsular India. Neoproterozoic and Early Phanerozoic tectonothermal activities were largely restricted to pre-existing shear zones, but the present configuration of the composite orogenic belt may have been achieved only during the Pan-African Orogeny.

Crustal architecture and evolution of the Eastern Ghats Belt and adjacent regions of India

An inverted metamorphic field gradient associated with a crustal-scale south-vergent thrust fault, the Main Central Thrust, has been recognized along the Himalaya for over 100 years. A major problem in Himalayan structural geology is that recent workers have mapped the Main Central Thrust within the Greater Himalayan Sequence high-grade metamorphic sequence along several different structural levels. Some workers map the Main Central Thrust as coinciding with a lithological contact, others as coincident with the kyanite isograd, up to 1–3 km structurally up-section into the Tertiary metamorphic sequence, without supporting structural data. Some workers recognize a Main Central Thrust zone of high ductile strain up to 2–3 km thick, bounded by an upper thrust, MCT-2 (= Vaikrita thrust), and a lower thrust, MCT-1 (= Munsiari thrust). Some workers define an ‘upper Lesser Himalaya’ thrust sheet that shows similar P – T conditions to the Greater Himalayan Sequence. Others define the Main Central Thrust either on isotopic (Nd, Sr) differences, differences in detrital zircon ages, or as being coincident with a zone of young (

Defining the Himalayan Main Central Thrust in Nepal

Tetanuran theropods represent the majority of Mesozoic predatory dinosaur diversity and the lineage leading to extant Aves. Thus their history is relevant to understanding the evolution of dinosaur diversity, Mesozoic terrestrial ecosystems, and modern birds. Previously, the fragmentary and poorly sampled fossil record of basal (non-coelurosaur) tetanurans led to uncertainties regarding their basic interrelationships. This in turn prevented determining the relationships of many incompletely known taxa that nonetheless document a global radiation spanning more than 120 million years. We undertook an exhaustive examination of all basal tetanurans and all existing character data, taking advantage of recent discoveries and adding new morphological, temporal and geographic data. Our cladistic analysis of 61 taxa achieved significantly improved phylogenetic resolution. These results position several ‘stem’ taxa basal to a succession of monophyletic clades (Megalosauroidea, Allosauroidea and Coelurosauria). Mega...

The phylogeny of Tetanurae (Dinosauria: Theropoda)

http://www.i-scholar.in/index.php/JGSI/article/download/70750/61283

B. P. Radhakrishna

Papers

Records of the Geological Survey of India