1篇
您的检索式：作者名="B.K.Panwar"
|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Petrogenesis of the crater-facies Tokapal kimberlite pipe,Indrvati Basin,Central India显示文摘New geochemical data of the crater-facies Tokapal kimberlite system sandwiched between the lower and upper stratigraphic horizons of the Mesoproterozoic Indr avati Basin are presented.The kimberlite has been subjected to extensive and pervasive low-temperature alteration.Spinel is the only primary phase identifiable,while olivine macrocrysts and juvenile lapilli are largely pseudomorphed(talc-serpentinecarbonate alteration).However,with the exception of the alkalies,major element oxides display systematic fractionation trends; likewise,HFSE patterns are well correlated and allow petrogenetic interpretation.Various crustal contamination indices such as(SiO2+Al2O3+Na2O)/(MgO+ K2O) and Si/Mg are close to those of uncontaminated kimberlites.Similar La/Yb(79-109) of the Tokapal samples with those from the kimberlites of Wajrakarur(73-145) and Narayanpet(72-156),Eastern Dharwar craton,southern India implies a similarity in their genesis.In the discriminant plots involving HFSE the Tokapal samples display strong affinities to Group II kimberlites from southern Africa and central India as well as to ‘transitional kimberlites' from the Eastern Dharwar craton,southern India,and those from the Prieska and Kuruman provinces of southern Africa.There is a striking similarity in the depleted-mantle(TDM) Nd model ages of the Tokapal kimberlite system,Bastar craton,the kimberlites from NKF and WKF,Eastern Dharwar craton,and the Majhgawan diatreme,Bundelkhand craton,with the emplacement age of some of the lamproites from within and around the Palaeo-Mesoproterozoic Cuddapah basin,southern India.These similar ages imply a major tectonomagmatic event,possibly related to the breakup of the supercontinent of Columbia,at 1.3-1.5 Ga across the three cratons.The ‘transitional'geochemical features displayed by many of the Mesoproterozoic potassic-ultrapotassic rocks,across these Indian cratons are inferred to be memories of the metasomatising fluids/melts imprinted on their source regions during this widespread event. | N.V.Chalapathi Rao B.Lehmann B.K.Panwar Alok Kumar D.Mainkar | 2014 | Geoscience Frontiers2014，5，6： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员