Dyke Swarms of Peninsular India

Contents: Preface. Introduction. 1. Flow and crystallisation in dykes: a review of field and laboratory data in the light of recent advances in mathematical modelling/I.M. Platten, University of Greenwich, Britain. 2. Significance of paleomagnetic investigations of dyke intrusions/M.E. Evans, University of Alberta, Canada. 3. Tectonic implications of clouded feldspar in proterozoic mafic dyke swarms/Henry C. Halls and Baoxing Zhang, University of Toronto, Canada. 4. Proterozoic mafic dykes in southern peninsular India : a review/N.G.K. Murthy, Madras, India. 5. Magnetic properties and chemistry of precambrian dykes from peninsular India/V. Damodara Reddy, C.V.R.K. Prasad and N. Subba Reddy, Sri Venkateswara University; and K. Anjanappa, Indira Gandhi National Open University, India. 6. Geochronology and geochemistry of precambrian mafic dykes from Kolar gold field, Karnataka/Amitabha Sarkar and A.K. Mallik, Geological Survey of India, India. 7. Oxygen isotopes and mantle sources of the mafic dykes in South Indian high-grade terrain/T. Radhakrishna and J. Mathew, Centre for Earth Science Studies, India. 8. Mineral chemistry and petrogenesis of an unusual differentiated mafic dyke from Bangalore district, Karnataka/T.C. Devaraju and A.G. Ugarkar, Karnatak University, India; and T.A.A. Halkoaho, University of Oulu, Finland. 9. Dyke rocks in the precambrian crust of the Aravalli mountain, Rajasthan/A.B. Roy, P. Kataria, Rajani Upadhyaya and B.L. Sharma, Mohanlal Sukhadia University, India. 10. Mafic dykes in the Bastar precambrian : study of the Bhanupratappur-Keskal mafic dyke swarm/H.M. Ramachandra, V.P. Mishra and S.S. Deshmukh, Geological Survey of India, India. 11. Neo-proterozoic dyke swarms of southern Karnataka: Part I: Field characters, petrography and mineralogy/T.C. Devaraju, S.D. Khanadali, A.G. Ugarkar and M.S.R. Jamakhandi, Karnatak University, India; and K. Laajoki and H. Makkonen, University of Oulu, Finland. 12. Neo-proterozoic dyke swarms of southern Karnataka: Part II : Geochemistry, oxygen isotope composition, Rb-Sr age and petrogenesis/T.C. Devaraju, S.D. Khanandali and A.G. Ugarkar, Karnatak University, India; L. Laajoki, University of Oulu, Finland and D. Zozulya, Geological Institute, Russia. 13. 40Ar-39 Ar ages and geochemical characteristics of dolerite dykes around the proterozoic Cuddapah basin, South India/J. Mallikarjuna Rao and M.N. Rao, National Geophysical Research Institute, India; S. Bhattacharji, The City University of New York, USA and O.D. Hermes, University of Rhode Island, USA. 14. Time of early sedimentation and volcanism in the proterozoic Cuddapah basin, South India: evidence from the Rb-Sr age of Pulivendla mafic sill/Y.J. Bhaskar Rao, G.V.C. Pantulu and K. Gopalan, National Geophysical Research Institute; and V. Damodara Reddy, S.V. University, India. 15. Mineralogy and geochemistry of basic dykes and associated plugs of the Revas-Murud Sector, Konkan coastal belt, Maharashtra/K.B. Powar, Association of Indian Universities and S.V. Vadetwar, Nowrosjee Wadia College, India. 16. Basic intrusives in the Deccan trap along the west coast flexure zone/S.F. Sethna and Mortaza Mousavi, St. Xavier's College, India. 17. Geochemistry and tectonic significance of acid and basic dykes associated with Jalor magmatism, West Rajasthan/N. Kochhar, S. Dhar and Rajni Sharma, Panjab University, India. 18. Alkaline and tholeiitic dyke swarm associated with Amba Dongar and Phenai Mata Complexes, Chhota Udaipur alkaline sub-province, Western India/L.G. Gwalani, Nagpur University, India; Soledad Fernandez, Universidad Complutense de Madrid, Spain; R.V. Karanth, M.S. University of Baroda, India; A. Demeny, Hungarian Academy of Sciences, Hungary; W-J. Chang, The University of Western Australia, Western Australia and R.K. Avasia, St. Xavier's College, India. 19. Lineaments and dyke swarms of lower Narmada valley and Southern Saurashtra, Western India/R.V. Karanth and D.A. Sant, M.S. University of Baroda, India. 20. Multi-generation mafic dyke-swarm related to Deccan magmatism, south of Bombay: implications on the evolution of the western Indian continental margin/A.G. Dessai and A.A.A.A. Viegas, Goa University, India.

From the preface: "The Geological Society of India is happy to place in the hands of readers a memoir exclusively devoted to the Mafic Dyke Swarms of peninsular India as a companion volume to the memoirs on granite-greenstone belts and granulites of peninsular India issued earlier.

"Dyke rocks have a special significance as they mark reccurrring episodes of crustal extension during which enormous quantities of mafic material from the mantle were transferred to the crust. These dyke rocks range in age from the archaean to recent and their detailed study is expected to throw much light on the crustal evolution of peninsular India.

"For reasons not quite clear, a detailed study of the dyke rocks of India, their petrography and geochemical characters had not been seriously attempted. Being rocks which are least metamorphosed, they offer best material for carrying out palaeomagnetic studies and fixing the pole positions of the Indian shield through geological time. In recent years, black coloured dyke rocks have come into prominence because of their ornamental quality. An evalution of the many advances in our knowledge about these rocks was therefore long overdue."