Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-07-04T21:49:21.718Z Has data issue: false hasContentIssue false

Mineralogy of the P2-West ‘Kimberlite’, Wajrakarur kimberlite field, Andhra Pradesh, India: kimberlite or lamproite?

Published online by Cambridge University Press:  05 July 2018

Gurmeet Kaur
Affiliation:
Department of Geology, Panjab University, Chandigarh, UT-160014, India
R. H. Mitchell*
Affiliation:
Department of Geology, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1
*

Abstract

A detailed mineralogical examination of representative material from the P2-West 'kimberlite' located in the Wajrakarur Kimberlite Field (India) demonstrates that significant differences exist between these rocks and archetypal hypabyssal kimberlite. The intrusion consists of an olivine-phyric facies which has been transected by, and includes clasts of, a consanguineous phlogopite-rich pegmatitic facies. The olivine-rich parts of P2-West are relatively fresh and consist of euhedral-to-subhedral microphenocrystal olivine set in a groundmass of fine-grained anhedral monticellite, amoeboid apatite, and subhedral-to-euhedral perovskite within a partially chloritized-to-fresh phlogopite-rich mesostasis. The rock lacks the abundant olivine macrocrysts characteristic of kimberlite. Monticellite crystals are commonly partially or completely replaced by pectolite and hydrogarnet. Similar material occurs as irregular aggregates randomly scattered throughout the groundmass. The groundmass, in contrast to that of hypabyssal kimberlites, is relatively poor in spinels. Atoll spinels are absent, with the majority of spinels occurring principally as mantles upon microphenocrystal olivine. Disaggregated cumulate-like assemblages of intergrown anhedral perovskite and spinel are common. Spinel compositions are unlike those of kimberlites and their evolutionary trend is similar to that of lamproite and lamprophyre spinels. The pegmatitic facies of the intrusion are highly and pervasively altered, and characterized by the presence of large clasts, veins, and irregular aggregates consisting of large (1–5 mm) crystals of pinkish-bronze Al-poor phlogopite intergrown with and/or including: apatite; pectolite-hydrogarnet pseudomorphs after an unidentified euhedral phase; chlorite laths; barytolamprophyllite; perovskite; tausonite; diverse Sr-Ba-carbonates; and baryte. The presence of barytolamprophyllite and tausonite are typical of potassic undersaturated alkaline rocks and have never been reported from kimberlite; however, neither feldspar nor feldspathoids are present in P2-West. Micas in fresh and altered rocks are Al2O3- and BaO-poor, and exhibit compositional evolutionary trends towards tetraferriphlogopite rather than kinoshitalite. On the basis of these mineralogical data it is suggested that P2-West represents an unusual lamproite-like intrusion which has undergone extensive hydrothermal deuteric alteration and should not be considered a bona fide kimberlite.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anil Kumar, Gopalan, K., Rao K.R.P. and Nayak, S.S. (2001) Rb-Sr ages of kimberlites and lamproites from Eastern Dharwar Craton, south India. Journal of the Geological Society of India, 58, 135142.Google Scholar
Anil Kumar, Heaman, I.M. and Manikyamba, C. (2007) Mesoproterozoic kimberlites in south India: A possible link to ~1.1 Ga global magmatism. Precambrian Research, 154, 192204.Google Scholar
Anil Kumar, Padma Kumari, V.M., Dayal, A.M., Murthy, D.S.N. and Gopalan, K. (1993) Rb-Sr ages for Proterozoic kimberlites of India: evidence for contemporaneous emplacement. Precambrian Research, 62, 227237.CrossRefGoogle Scholar
Buie, B.F. (1941) Igneous rocks of the Highwood Mountains, Montana. Part 3, Dikes and related intrusives. Geological Society of America Bulletin, 52, 17531808.CrossRefGoogle Scholar
Chadwick, B., Vasudev, V.N. and Hegde, G.V. (2000) The Dharwar Craton, southern India, interpreted as the result of Late Archaean oblique convergence. Precambrian Research, 99, 91111.CrossRefGoogle Scholar
Chakhmouradian, A.R. and Mitchell, R.H. (1999) Primary, agpaitic, and deuteric stages in the evolution of accessory Sr,, REE,, Ba and Nb mineralization in nepheline syenite pegmatites at Pegmatite Peak, Bearpaw Mountains, Montana. Mineralogy and Petrology, 67, 85110.CrossRefGoogle Scholar
Chakhmouradian, A.R. and Mitchell, R.H. (2002) The mineralogy of Ba- and Zr-rich alkaline pegmatites from Gordon Butte, Crazy mountains (Montana, USA): comparisons between potassic and sodic agpaitic pegmatites. Contributions to Mineralogy and Petrology, 143, 93114.CrossRefGoogle Scholar
Chalapathi Rao, N.V., Miller, J.A., Pyle, D.M. and Madhavan, V. (1996) New Proterozoic K-Ar ages for some kimberlites and lamproites from the Cuddapah Basin and Dharwar Craton, south India: evidence for non-contemporaneous emplacement. Precambrian Research, 79, 363369.CrossRefGoogle Scholar
Chalapathi Rao, N.V., Miller, J. A., Gibson, S.A., Pyle, D.M. and Madhavan, V. (1999) Precise 40Ar/39Ar dating of Kotakonda Kimberlite and Chelima lamproite, India: Implication to the timing of mafic dyke swarm activity in the Eastern Dharwar Craton. Journal of the Geological Society of India, 53, 425432.Google Scholar
Chalapathi Rao, N.V., Gibson, S.A., Pyle, D.M. and Dickin, A.P. (2004) Petrogenesis of Proterozoic lamproites and kimberlites from the Cuddapah Basin and Dharwar Craton, Southern India. Journal of Petrology, 45, 907948.CrossRefGoogle Scholar
Chalapathi Rao, N.V., Creaser, R.A., Lehmann, B. and Panwar, B.K. (2013) Re-Os isotope study of Indian kimberlites and lamproites: Implications for mantle source and cratonic evolution. Chemical Geology, 353, 3647.CrossRefGoogle Scholar
Drury, S.A., Harris, N.B.W., Holtz, R.W., Reeves- Smith, G.J. and Wightman, R.T. (1984) Precambrian tectonics and crustal evolution in south India. Journal of Geology, 92, 320.CrossRefGoogle Scholar
Fareeduddin (2008) Training course notes on “An introduction to the petrology of diamond bearing rocks and modern methods in exploration for, and evaluation of, primary diamond deposits” conducted by The Geological Society of India, Bangalore between14th and 22 January 2008. 42 pp.Google Scholar
Fareeduddin and Mitchell, R.H. (2012) Diamonds and their source rocks in India. Geological Society of India, Bangalore, 434 pp.Google Scholar
Foley, S. (1992) Vein-plus-wall-rock melting mechanisms in the lithosphere and the origin of potassic alkaline magmas. Lithos, 28, 187204.CrossRefGoogle Scholar
Kaur, Gurmeet, Korakoppa, M., Fareeduddin and Pruseth, K.L. (2013) Petrology of P-5 and P-13 “kimberlites” from Lattavaram kimberlite cluster, Wajrakarur Kimberlite Field, Andhra Pradesh, India: Reclassification as lamproites. Proceedings of the 10th International Kimberlite Conference, 1, 183194.CrossRefGoogle Scholar
Gupta, S. Rai, S.S., Prakasam, K.S. and Srinagesh, D. (2003) The nature of the crust in southern India: implications for crustal evolution. Geophysical Research Letters, 30, 1419.CrossRefGoogle Scholar
Jaques, A.L., Lewis, J.D. and Smith, C.B. (1986) The kimberlites and lamproites of Western Australia. Geological Survey of Western Australia Bulletin, 132, 268 pp.Google Scholar
Liferovich, R.P. and Mitchell, R.H. (2005) Composition and paragenesis of Na-, Nb-, and Zr-bearing titanite from Khibina, Russia, and crystal structure data for synthetic analogues. The Canadian Mineralogist, 43, 795812.CrossRefGoogle Scholar
Lynn, M. (2005) The discovery of kimberlites in the Gulburga and Raichur districts of Karnataka. Pp. 4849. (abstract) in: Proceedings of the Group Discussion on Kimberlites and Related Rocks of India. Geological Society of India, Bangalore, India.Google Scholar
Mitchell, R.H. (1986) Kimberlites: Mineralogy, Geochemistry and Petrology. Plenum Press, New York and London, 442 pp.CrossRefGoogle Scholar
Mitchell, R.H. (1995) Kimberlites, Orangeites, and Related Rocks. Plenum Press. New York, 410 pp.CrossRefGoogle Scholar
Mitchell, R.H. (2002) Perovskites: Modern and Ancient. Almaz Press Inc., Thunder Bay, Ontario, Canada, 319 pp.Google Scholar
Mitchell, R.H. (2006) Potassic magmas derived from metasomatized lithospheric mantle: Nomenclature and relevance to exploration for diamond-bearing rocks. Journal of the Geological Society of India, 67, 317327.Google Scholar
Mitchell, R.H. (2010) Mineralogy of the P2-west “kimberlite”, Wajrakarur, A.P. India. 6th International Dyke Conference, February 4–7. 2010, Varanasi, India, p. 91 (abstract).Google Scholar
Mitchell, R.H. and Bergman, S.C. (1991) Petrology of Lamproites. Plenum Press, New York, 408 pp.CrossRefGoogle Scholar
Mitchell, R.H. and Vladykin, N.V. (1993) Rare earth element-bearing tausonite and potassium barium titanates from the Little Murun potassic alkaline complex, Yakutia, Russia. Mineralogical Magazine, 57, 651664.CrossRefGoogle Scholar
Miyajima, H., Miyawaki, R. and Ito, K. (2002) Matsubaraite, Sr4Ti5(Si2O7)2O8, a new mineral, the Sr-Ti analogue of perrierite in jadeitite from the Itoigawa-Ohmi district, Niigata Prefecture, Japan. European Journal of Mineralogy, 14, 11191128.CrossRefGoogle Scholar
Mukherjee, A., Sravan Kumar, C. and Reddy, K.K. (2007) Two new kimberlites in Bommaganapalli area, Anantapur district, Andhra Pradesh, based on systematic stream sediment sampling and ground magnetic survey. Journal of the Geological Society of India, 69, 625640.Google Scholar
Nayak, S.S. and Kudari, S.A.D. (1999) Discovery of diamond-bearing kimberlite in Kalyandurg area, Anantpur district, Andhra Pradesh. Current Science, 76, 10771079.Google Scholar
Neelkantam, S. (2001) Exploration for diamonds in southern India. Geological Survey of India Special Publication No. 58, 521555.Google Scholar
Osborne, I., Sherlock, S., Anand, M. and Argles, T. (2011) New Ar-Ar ages of southern Indian kimberlites and a lamproite and their geochemical evolution. Precambrian Research, 189, 91103.CrossRefGoogle Scholar
Paton, C., Hergst, J.M., Phillips, D., Woodhead, J.D. and Shee, S.R. (2007) New insights into the genesis of Indian Kimberlites from the Dharwar Craton via in situ Sr isotope analysis of groundmass perovskite. Geology, 35, 10111014.CrossRefGoogle Scholar
Paton, C., Hergst, J.M., Phillips, D., Woodhead, J.D. and Shee, S.R. (2009) Identifying the asthenospheric component of kimberlitic magmas from the Dharwar Craton, India. Lithos, 112, 296310.CrossRefGoogle Scholar
Paul, D.K., Nayak, S.S. and Pant, N.C. (2006) Indian kimberlites and related rocks: Petrology and geochemistry. Journal of the Geological Society of India, 67, 328355.Google Scholar
Ramakrishnan, M. and Vaidyanadhan, R. (2008) Geology of India. Geological Society of India, Volume 1, 994 pp.Google Scholar
Rao, S.R. and Phadtre, P.N. (1966) Kimberlite pipe rocks of Wajrakarur area, Ananatpur district, Andhra Pradesh. Journal of the Geological Society of India, 7, 118123.Google Scholar
Ravi, S., Vaideswaran, T. and Rao, K.S.B. (2009) Field guide to Wajrakarur kimberlite field, Anantpur district, Andhra Pradesh. Geological Survey of India, 43 pp.Google Scholar
Ravi, S., Bhaskara Rao, K.S. and Rao, K.R.P. (1999) Search for kimberlites in the granite green stone terrain in the central segment of the Wajrakarur Kimberlite Field, Anantpur district, Andhra Pradesh. Records of the Geological Survey of India, 132, 4043.Google Scholar
Reddy, T.A.K. (1987) Kimberlite and lamproitic rocks of Wajrakarur area, Andhra Pradesh. Journal of the Geological Society of India, 61, 131146.Google Scholar
Scott Smith, B.H. and Skinner, E.M.W. (1984a) Diamondiferous lamproites. Journal of Geology, 92, 433438.CrossRefGoogle Scholar
Scott Smith, B.H. and Skinner, E.M.W. (1984b) A new look at Prairie Creek, Arkansas. Pp. 255284. in: Proceedings of the 3rd International Kimberlite Conference (J. Kornprobst, editor). Elsevier Press, New York.Google Scholar
Scott Smith, B.H. (1989) Lamproites and kimberlites in India. Neues Jahrbuch für Mineralogie Abhandlungen, 161, 193225.Google Scholar
Sravan Kumar, C., Mukherjee, A. and Vishwakarma, R.K. (2004) Discovery of a new kimberlite pipe using multidisciplinary approach at Kalyandurg, Anantapur district, Andhra Pradesh. Journal of the Geological Society of India, 64, 813817.Google Scholar
Srinivas Choudary, V., Rau, T.K., BhaskarRao, K.S., Sridhar, M. and Sinha, K.K. (2007) Timmasamundram kimberlite cluster, Wajrakarur kimberlite Field, Anantapur district, Andhra Pradesh. Journal of the Geological Society of India, 69, 597609.Google Scholar
Swami Nath, J., Ramakrishnan, M. and Viswanatha, M.N. (1976) Dharwar stratigraphic model and Karnataka cratonic evolution. Records of the Geological Survey of India, 107, 149175.Google Scholar
Wendlandt, R.F. (1977) Barium phlogopite from Haystack Butte, Highwood Mountains, Montana. Carnegie Institute of Washington Year Book, 76, 534539.Google Scholar
Woolley, A.R., Bergman, S.C., Edgar, A.E., Le Bas, M.J., Mitchell, R.H., Rock, N.M.S. and Scott Smith, B.H. (1995) Classification of lamprophyres, lamproites, kimberlites and kalsilite-, melilite- and leucite-bearing rocks. (Recommendations of the IUGS Sub-Commission in the Systematics of Igneous Rocks). The Canadian Mineralogist, 34, 175186.Google Scholar