This book provides a detailed and thorough review of the 22 basins in India (frequently referred to as the ‘Purana Basins’ or simply ‘The Puranas’) that between them preserve a sedimentary and tectonic history from around 3.4Ga into the Eocambrian. The basin fill is in each case unmetamorphosed to only weakly metamorphosed, in contrast to the high grade metamorphic and igneous rocks of the underlying crystalline basement.
The first three papers are introductory: setting out the purpose of the book; reviewing basin classification schemes, particularly those based on plate tectonic setting and subsidence mechanism; and describing the structural history and geology of the four cratons that underlie the Puranas - the Aravalli-Bundelkhand, Singhbhum, Bastar and Dharwar Cratons.
The next 17 papers deal with the Purana Basins themselves, plus one chapter on some rather enigmatic metasediments south of all the other basins. Each of the papers follows the same pattern: geology of the basement; stratigraphy and geochronology of the basin fill; a detailed description of the sediment fill; discussion and conclusions. In each case, the basin-fill lithologies and structures are described in considerable detail at all scales from regional through outcrop to microscopic. Most of the basins are located on the margins of their host craton, and are related to divergent plate motion and associated lithospheric stretching and thinning. A small number are related to intra-craton transtension and to convergent plate motion.
The next two papers deal with the mineral resources. The first of the two stresses that though the Purana Basins are rich in building stone, limestone for cement, evaporites, phosphorite, barite and uranium, they are comparatively deficient in metallic minerals, apart from minor occurrences of pyrite, copper-lead-zinc and manganese ores. The second paper deals more with the cratons and their rich endowment of iron, manganese, chromium, copper-lead-zinc, molybdenum, gold and platinum ores.
The final paper summarises the Purana Basins, stressing that the concepts and mechanisms of both plate tectonics and sequence stratigraphy, initially studied and synthesised in Phanerozoic basins, are equally applicable to the Puranas. Any differences in the stratigraphic architecture can be ascribed to variations in accommodation vs. sediment supply, or to the evolving inter-relations between hydrosphere, atmosphere and biosphere.
The book is profusely illustrated, but whereas the originals were obviously coloured, nearly all of them have been reduced to B&W, so that one or more different rock groups in the same figure end up having the same shade of grey. This is my only reservation about what is otherwise a fine piece of work. There is a comprehensive index.
Reviewed by Pete Webb
PRECAMBRIAN BASINS OF INDIA: STRATIGRAPHIC AND TECTONIC CONTEXT, by R. MAZUMDER and P.G. ERIKSSON (Eds) Published by: The Geological Society 2015 ISBN: 978-1-86239-723-1 List price: £120; Geological Society £60; other qualifying societies £72 352 pp, hardback W: www.geolsoc.org.uk/m0043