Petrogenesis of the Mesoproterozoic Lamproites from the Krishna Valley, Eastern Dharwar Craton, Southern India

Rao, N. V. Chalapathi; Kamde, G.; Kale, H. S.; Dongre, Ashish

doi:10.1016/j.precamres.2009.11.006

Cited by 48 publications

(27 citation statements)

References 92 publications

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“…Thus, a previously depleted as well as subsequently enriched mantle source is inferred in its genesis (see also Chalapathi Rao et al, 2004). A two stage model involving the source which has experienced initial depletion event and subse- ; for orangeites from Coe (2004) and for lamproite from Chalapathi Rao et al (2010). quent enrichment by an upwelling mantle plume in generation of Group I kimberlites from Kimberley, South Africa is also suggested by Le .…”

Section: Discussionmentioning

confidence: 96%

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Petrogenesis of macrocrystic and aphanitic intrusions in Mesoproterozoic diamondiferous pipe 2 kimberlite, Wajrakarur kimberlite field, eastern Dharwar craton, southern India

2014

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Mesoproterozoic Pipe 2 kimberlite intruding granitic gneisses in the Wajrakarur kimberlite field (WKF) of Eastern Dharwar craton, southern India, is one of the first discovered pipes from this field. The two different intrusions belonging to coherent facies are observed in this kimberlite which are texturally distinct i.e., macrocrystic (with abundant macrocrysts) as well as aphanitic (devoid of or very fewer macrocrysts). Petrographic observations give evidence of presence of veined metasomatic mantle in the source region. Distinct geochemical variation is observed between macrocrystic (Mg# 75.4-76.6, SiO 2 : 34.3-35.4 wt%, MgO: 18.7-20.4 wt%) and aphanitic samples (Mg# 74.7-75.5, SiO 2 : 30.4-31.8 wt%, MgO: 21 wt%), furthermore aphanitic samples are relatively more enriched in trace and rare earth elements. Geochemical studies point out that aphanitic and macrocrystic varieties of Pipe 2 kimberlite to be products of the same mantle source but have experienced different evolutionary histories. The inferred primary magma of Pipe 2 kimberlite (for both aphanitic and macrocrystic) is suggested to have a composition of ~33 wt% SiO 2 , Mg# ~ 75.6 and ~460 ppm Ni. Pipe 2 primary magma can be derived by using forward melting model assuming ~1% partial melting of a source enriched in light REE by a factor of ~11 x chondrite and almost chondritic heavy REE with 2% residual garnet. Differences between aphanitic and macrocrystic varieties in their chondrite normalized REE abundance patterns can be explained by about 5% crystal fractionation of primary magma and not by variations in the degree of partial melting. The primitive mantle normalized trace element patterns exhibit significant negative K, Sr, P, Ti and Hf anomalies that are interpreted to be characteristic of the primary magma. Combined petrology and whole rock geochemistry including compatible and incompatible element abundances and their ratios confirm that Pipe 2 kimberlite intrusions are archetypal Group I kimberlites similar to other kimberlites of EDC and not lamproites.

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Section: Discussionmentioning

confidence: 96%

“…Groundmass of macrocrystic variety is devoid of or very poor in spinels as compare to aphanitic samples. Gener- Rao et al (2010). Field of kimberlite is taken from Dawson and Smith (1977) and aillikite is from Tappe et al (2006).…”

Section: Spinelmentioning

confidence: 99%

Petrogenesis of macrocrystic and aphanitic intrusions in Mesoproterozoic diamondiferous pipe 2 kimberlite, Wajrakarur kimberlite field, eastern Dharwar craton, southern India

2014

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“…6c). The Fe 2 O 3 (T) contents of the Garledinne lamproites (6.5-7.47 wt%; Table 6) are lower than those from the Ramadugu (5.93-11.01 wt%; Chalapathi Rao et al 2014a), Krishna (10.06-27.82 wt%;Paul et al 2007;Chalapathi Rao et al 2010) and Cuddapah lamproites (7.08-10.42 wt%; Chalapathi Rao et al 2004) and reflect the absence of ilmenite and paucity of other iron oxides. Both CaO contents and Loss on Ignition (LOI) of the Garledinne lamproites are >10 wt% (Table 6) and reflect the carbonate and other volatile components.…”

Section: Whole-rock Geochemistrymentioning

confidence: 94%

Petrogenesis of Mesoproterozoic lamproite dykes from the Garledinne (Banganapalle) cluster, south-western Cuddapah Basin, southern India

et al. 2015

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We report mineral chemistry and whole-rock major and trace-element geochemistry for a recent find of Mesoproterozoic (~1.4 Ga) lamproites from the Garledinne (Banganapalle) cluster, south-western part of the PaleoMesoproterozoic Cuddapah Basin, southern India. The Garledinne lamproites occur as WNW-ESE-trending dykes that have undergone varying degree of pervasive silicification and carbonate alteration. Nevertheless, their overall texture and relict mineralogy remain intact and provide important insights into the nature of their magmas. The lamproite dykes have porphyritic to weakly porphyritic textures comprising pseudomorphed olivine macrocrysts and microphenocrysts, titanian phlogopite microphenocrysts, spinel having a compositional range from chromite to rarely magnesiochromite, Srrich apatite and niobian rutile. The Garledinne and other Cuddapah Basin lamproites (Chelima and Zangamarajupalle) collectively lack sanidine, clinopyroxene, potassic richterite, and titanite and are thus mineralogically distinct from the nearby Mesoproterozoic lamproites (Krishna and Ramadugu) in the Eastern Dharwar Craton, southern India. The strong correlation between various major and trace elements coupled with high abundances of incompatible and compatible trace elements imply that alteration and crustal contamination have had a limited effect on the whole-rock geochemistry (apart from K 2 O and CaO) of the Garledinne lamproites and that olivine fractionation played an important role in their evolution. The Garledinne lamproites represent small-degree partial melts derived from a refractory (previously melt extracted) peridotitic mantle source that was subsequently metasomatised (enriched) by carbonate-rich fluids/melts within the garnet stability field. The involvement of multiple reservoirs (sub-continental lithospheric mantle and asthenosphere) has been inferred in their genesis. The emplacement of the Garledinne lamproites is linked to extensional events, across the various Indian cratons, related to the break-up of the Proterozoic supercontinent of Columbia.

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“…6c). In terms of compositional range of phlogopite, the Kalmidadar 3.000 2.996 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 2.999 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 lamproite is closer to the West Kimberly lamproites of Australia (Jaques et al 1986;Mitchell and Bergman 1991) than to the Krishna lamproites in the Dharwar Craton of southern India (Reddy et al 2003;Chalapathi Rao et al 2010). …”

Section: Mineral Composition Of Lamproites and Lamproitoidsunclassified

“…This indicates that the negative K anomaly is a primary feature of the Nuapada lamproites, although the absolute magnitudes have been affected by different degrees of (c) Fig. 6 Compositional variation of mica in Nuapada lamproites and lamproitoids compared with that in Krishna lamproites, southern India (Reddy et al 2003;Chalapathi Rao et al 2010) and West Kimberly lamproites (Jaques et al 1986;Mitchell and Bergman 1991). a Cr 2 O 3 versus Cr/(Cr +Al) versus 100 Mg/(Mg ?…”

Section: Geochemical Characteristics Of the Mantle Source Of Lamproitesmentioning

confidence: 99%

Petrology of Lamproites from the Nuapada Lamproite Field, Bastar Craton, India

Sahu

Gupta²,

Patel³

et al. 2013

Proceedings of 10th International Kimberlite Conference

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This work presents the first mineralogical, geochemical and 40 Ar/ 39 Ar geochronological data on hypabyssal facies lamproites near Kalmidadar and Darlimunda in the Nuapada Lamproite Field of the Bastar Craton. The Kalmidadar lamproite is a diamondiferous intrusion with surface dimension of *320 m 9 160 m, whereas the Darlimunda lamproite is a dyke swarm comprising clusters of several narrow (\5 m wide) and elongated bodies. Indicator mineral suite around the Kalmidadar lamproite is marked by abundance of Cr-spinel, rarity of garnet and absence of Cr-diopside and picroilmenite. Mineralogically, the Kalmidadar lamproite comprises phenocrysts of olivine (pseudomorphed by calcite and talc) and microphenocrysts of phlogopite set in a groundmass of chlorite and calcite. The phlogopite is Ti rich (5.4-7.4 wt % TiO 2 ), and the relationship between its Ti content and octahedral site deficiency indicates two substitution mechanisms, viz. Ti + ' $ 2 Mg and Ti ? 2Al $ Mg ? 2Si. The Darlimunda lamproites have undergone pervasive hydrothermal and/or deuteric alteration, which has resulted in complete chloritisation of phlogopite and extensive silicification of the rocks. Tiny grains of rutile and apatite are commonly scattered in the groundmass of both Kalmidadar and Darlimunda lamproites. The Nuapada lamproites have high contents of compatible elements such as V, Cr and Ni and of incompatible elements such as Ba, Zr, Nb and Hf. They also show high abundance of REE and enrichment in LREE relative to HREE. The incompatible element distribution patterns of the lamproites are marked by Nb, Sr, P, Hf and Zr anomalies relative to REE. The observed petrological and geochemical characteristics of the Nuapada lamproites are consistent with the derivation of the magma from a metasomatised subcontinental lithospheric mantle source. Whole-rock 40 Ar/ 39 Ar isotopic data yields an age of 1055 ± 10 Ma for the Nuapada lamproites.

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Petrogenesis of the Mesoproterozoic Lamproites from the Krishna Valley, Eastern Dharwar Craton, Southern India

Cited by 48 publications

References 92 publications

Petrogenesis of macrocrystic and aphanitic intrusions in Mesoproterozoic diamondiferous pipe 2 kimberlite, Wajrakarur kimberlite field, eastern Dharwar craton, southern India

Petrogenesis of macrocrystic and aphanitic intrusions in Mesoproterozoic diamondiferous pipe 2 kimberlite, Wajrakarur kimberlite field, eastern Dharwar craton, southern India

Petrogenesis of Mesoproterozoic lamproite dykes from the Garledinne (Banganapalle) cluster, south-western Cuddapah Basin, southern India

Petrology of Lamproites from the Nuapada Lamproite Field, Bastar Craton, India

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