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V. Madhavan , Shilpi Arora , Anita Murali , S. N. Yoganarasimhan

Abstract

Nymphoides indica (L.) Kuntze (Menyanthaceae) is an aquatic herb used as an admixture along with Nymphoides macrospermum and as a substitute of Ayurvedic drug Tagara (Valeriana jatamansi Jones) in the treatment of various diseases like epilepsy, anemia, jaundice, tuberculosis to name a few. The present study has been undertaken to evaluate the anti-convulsant effect of aqueous and alcohol extract of ischolar_mains and rhizomes of Nymphoides indica (L.) Kuntze using Maximum Electroshock Convulsion (MES) and Pentylenetetrazole (PTZ) induced convulsion methods in swiss albino mice. The oral administration of alcohol and aqueous extracts at the dose level of 300 and 600 mg/kg reduced duration of extensor phase (HLTE) and time taken for recovery in MES induced convulsion model. Similarly both extracts delayed onset of convulsions and reduced the time taken for recovery in PTZ induced convulsions. Alcohol extract was found to be more effective and effect of alcohol and aqueous extract on extensor phase (HLTE) (MES) and onset of convulsions (PTZ) was dose dependent. It is concluded that ischolar_mains and rhizomes of N. indica exhibit anticonvulsant activity, justifying its use as a substitute of Tagara (V. jatamansi) in treatment of epilepsy.

Keywords

Nymphoides Indica, Anti-convulsant Activity, Maximum Electro Shock (MES), Pentylenetetrazole (PTZ), Phenytoin and Diazepam

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N. V. Chalapathi Rao ¹, J. A. Miller ², S. A. Gibson ³, D. M. Pyle ³, V. Madhavan ⁴

Affiliations
1 Mineralogy Laboratory, Ore Dressing Division, Indian Bureau of Mines, Hingna Road, Nagpur- 440016, IN
2 Bullard Laboratories, Madingley Road, Cambridge- CB3 9BB, GB
3 Department of Earth Sciences, Downing Street, Cambridge- CB2 3EQ, GB
4 Department of Geology, Kakatiya University, Warangal- 506 009, IN

Abstract

⁴⁰Ar/ ³⁹Ar age spectra of groundmass phlogopite separates from the Kotakonda kimberlite (Eastern Dharwar craton) and the Chelima lamproite (Cuddapah basin) are dominated by major plateaus at 1401.4±4.6Ma and 1417.8±8.2 Ma respectively. These ages are consistent (within their error limits) with the conventional K-Ar dates on phlogopite separates from the same samples earlier reported by us. This study supports our contention that the emplacement of Kotakonda kimberlite and Chelima lamproite was contemporaneous and these pipes are older than the Anantapur kimberlites (-1090 Ma) of the Eastern Dharwar craton. The agreement of ages obtained by employing more than one technique is a testimony of confidence in our results and, therefore, firmly establishes an episode of Proterozoic mafic potassic magmatic activity in the Eastern Dharwar craton and adjacent Cuddapah basin at ca. 1400 Ma. The concordance of plateaus and correlation of isochron plots for both these bodies suggests that at least these parts of the Eastern Dharwar craton and Cuddapah basin have not been subjected to any subsequent tectono-thermal activity. Our results contrast with the recent suggestion that a ∼ 1000 Ma thermal event in and around the Cuddapah basin led to argon loss and was responsible for the variable K-Ar ages of dyke swarms in the Eastern Dharwar craton.

Keywords

⁴⁰Ar/ ³⁹Ar Ages, Kimberlite, Lamproite, Dyke Swarms, Dhanvar Craton, Andhra Pradesh.

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V. Madhavan ¹, C. Leelanandam ¹

Affiliations
1 Department of Geology, Osmania University, Hyderabad-503007, A.P., IN

Abstract

The rocks of the Elchuru alkaline pluton are broadly classified into (a) mafic-rich alkaline rocks and (b) leucocratic alkaline rocks. Field and petrographic observations suggest that these alkaline rocks constitute a differentiated series which conformably intruded the pre-existing gneisses. The occurrence of mafic-rich alkaline rocks points to a magmatic origin of the pluton and its abyssal Source.

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V. Madhavan ¹, C. Leelanandam ¹

Affiliations
1 Department of Geology, Osmania University, Hyderabad 500 007, IN

Abstract

The oblong alkaline pluton at Elchuru is constituted of shonkinite, malignite, nepheline syenite (foyaite and pulaskitic foyaite) and nepheline gneiss (including litchfieldite and mariupolite); the bulk of the pluton is, however, made up of nepheline syenite and nepheline gneiss. These alkaline rocks are emplaced conformably and permissively by a simple mechanism of dilation of the surrounding country rocks under tensional stress. During emplacement, the pluton deformed its own nearly solid periphery producing an outer ring of nepheline gneiss with subsolvus assemblage which surrounds the central core of nepheline syenite with hypersolvus assemblage.

The field, petrographic and geochemical studies, when viewed together, suggest that all the rocks of the pluron arc comagmatic and that nepheline syenites (and nepheline gneisses) are the differentiated products of a basic alkaline magma. The present study has shown that the alkaline magma remained strongly undersaturated throughout the differentia tion process.

The agpaitic coefficient of these rocks is very near to, but invariably less than unity. In tune with their miaskitic chemistry, these rocks show low Na₂O/K₂O and Fe₂O₃/FeO ratios and a generally lower content of MgO, TiO₂ and MnO. The contents of Sr and Ba are very high and with differentiation the ratios Ba/Sr and Sr/Ca fall whereas K/Ba ratio rises. The uniformly higher KJRb ratios of these rocks suggest a deep seated source for the magma.

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V. Madhavan ¹, J. Mallikarjuna Rao ²

Affiliations
1 Department of Geology, Osmania University, Hyderabad 500007, IN
2 National Geophysical Research Institute, Hyderabad 500007, IN

Abstract

The basic dyke combines the mineralogical assemblage of an olivine basalt and textural characteristics of a lamprophyre. This porphyritic rock contains few euhedral phenocrysts of olivine set in a fine-grained groundmass, constituted by plagioclase and clinopyroxene. The olivine crystals are invariably mantled by a thin reaction rim of Ca-poor pyroxene and in spite of this, the rock has developed nepheline in the norm. The composition of the basaltic liquid can be expected to lie very close to the Fo-Di-Ab plane (or the Ol-Cpx-Pl thermal divide) within the basalt tetrahedron. Petrogenetic considerations regarding (a) the crystallization of olivine basalt magma and (b) the role played by volatiles in modifying its composition (corresponding to that of olivine lamprophyre) elsewhere in the Prakasam district are briefly discussed.

Keywords

Petrology, Olivine Basalt, Lamprophyre, Uppalapadu Alkaline Pluton, Prakasam District, Andhra Pradesh.

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V. Madhavan ¹, J. Mallikharjuna Rao ², V. Balaram ², Ramesh Kumar ³

Affiliations
1 Department of Geology, Osmania University, Hyderabad-500 007, IN
2 National Geophysical Research Institute, Hyderabad-500 007, IN
3 Atomic Mineral Division, Civil Lines, Nagpur-440 001, IN

Abstract

Late stage intrusives, dominantly represented by lamprophyres, form a dyke swann in the Elchuru alkaline pluton of Andhra Pradesh; the other dykes of the swann which are non-lamprophyric include microshonkinite, nepheline syenite porphyry, basanite and olivine dolerite. The Elchuru lamprophyres and their plutonic equivalents, shonkinite and foidolite, consist of clinopyroxene, biotite. alkali feldspar and nepheline. Due to variation in the amount of nepheline, these lamprophyres, cover a wide range of rock types like minette, sannaite and tjosite. A plagioclase- bearing lamprophyre, camptonite, is also present though not abundantly.

The hallmark of the Elchuru lamprophyres is their transitional geochemical character-ranging between alkaline lamprophyres(AL) and calc-alkaline lamprophyres (CAL). From the present study it is surmised that these lamprophyres have crystallised from an LILE and LREE enriched, hydrous basic alkaline (mildly potassic) magma of a deep-seated (mantle?) origin. A petrogenetic scheme is presented covering the evolution of various rock units of the Elchuru alkaline pluton in general and the late stage intrusives (lamprophyres and other associated dykes) in particular.

Keywords

Lamprophyres, Dykeswarms, Elchuru, Andhra Pradesh.

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N. V. Chalapathi Rao ¹, V. Madhavan ²

Affiliations
1 Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Madingley Road, Cambridge-CB3 OEZ, GB
2 Department of Geology, Kakatiya University, Warangal - 506009, IN

Abstract

Electron probe studies on the phlogopites from the Zangamarajupalle kimberlitic rock (14°76'7" : 78°88'3" E) in the Proterozoic Cuddapah basin, Andhra Pradesh, reveal their titanium rich (6 wt%) nature - a character typical of lamproite micas. The compositions and their systematic variation in the phlogopite micas of the Zangamarajupalle-kimberlitic rock are compared and contrasted with those of other kimberlitic and lamproitic rocks including pipe-2 Wajrakarur, pipeS (Muligiripalle) and Maddur (Mahbubnagar) - all of which have an ambiguous identity. The utility of phlogopite compositions in discriminating between kimberlites and lamproites is emphasised and an attempt is made to classify the studied rock types accordingly and the implications are discussed.

Keywords

Petrochemistry, Phlogopite, Kimberlite, Zangamarajupalle, Andhra Pradesh.

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N. V. Chalapathi Rao ¹, V. Madhavan ²

Affiliations
1 Department of Earth Sciences, Bullard Laboratories, University of Cambridge, Cambridge-CB3 OEZ, GB
2 Department of Geology, Kakatiya University, Warangal-506 009 A. P., IN

Abstract

The olivine- lamproitic/kimberlitic rocks occuring in parts of the Mahbubnagar district of Andhra Pradesh are re-examined in the light of new petrological and geochemical data. The titanium poor <3 TiO₂, wt%) phlogopites, presence of primary calcite and composition of perovskites in these rocks are akin to those found in kimberlites. Calcium-rich iron silicate - kirschsteinite is being reported for the first time from Indian kimberlites in this work. The geochemical signatures of these rocks like potassic (K₂O <3 wt%) character, magnesian rich nature (>30 wt% MgO), high Mg numbers (73-82) and incompatible element enrichment levels further characterise them to be kimberlites. The abundances and the chondrite normalized distribution patterns of their REE are remarkably different from the olivine lamproites of Western Australia. It is put forward here that all these occurrences are true kimberlites and not olivine-lamproites resembling those of Western Australia, as suggested by some workers elsewhere. It is further argued that all the kimberlites of Mahbubnagar district are genetically related and are different in this aspect from atIeast one kimberlite from the Anantapur district - Chigicherla pipe-2, the latest pipe find in the Anantapur district, suggesting that the Mahbubnagar kimberlitic activity could be unrelated to the southern Anantapur.

Keywords

Kimberlite Lamproite, Mahbubnagar District, Andhra Pradesh.

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V. Madhavan ¹, M. Srinivas ², J. Mallikharjurna Rao ³, N. V. Chalapathi Rao ⁴

Affiliations
1 Department of Geology, Kakatiya University, Warangal-506 009, IN
2 Department of Geology, Osmania University, Hyderabad-500 007, IN
3 National Geophysical Research Institute, Hyderabad-500007, IN
4 Department of Earth Sciences, Bullard Laboratories, Madingley Rise; Cambridge, CB2 3EQ, IN

Abstract

The paper presents the mineral analyses and the major, trace and rare earth element geochemistry of the subalkaline syenites from Vikurthi and Kotappakonda in the Guntur district of Andhra Pradesh. A comprehensive model is proposed wherein these and other similar rocks from the Cuddapah intrusive province are envisaged as the differentiated products of an intermediate magma of trachybasaltic composition, which, in turn, has been derived by the differentiation of a parental gabbro magma.

Keywords

Geochemistry, Syenites, Igneous Petrology, Guntur District, Andhra Pradesh.

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N. V. Chalapati Rao ¹, V. Madhavan ²

Affiliations
1 Bullard Laboratories, Department of Earth Sciences, University of Cambridge CB3 OEZ, GB
2 Department of Geology, Kakatiya University, Warangal 506009, Andhra Pradesh, IN

Abstract

Detailed petological and geochemical studies pertaining to the lamproitic body recorded by the Geological Survey of India at Ramannapeta-Ustapalle, Krishna district, Andhra Pradesh, are presented. Unmistakable lamproite signatures like the presence of Ti-rich potassic richterite, abundance of Ti-rich, Al-poor phlogopite and Ca-rich, Al-poor clinopyroxene, absence of primary calcite, paucity of typical kimberlite indicator minerals and the ultra potassic nature are recognised. Major oxide as well as the trace elemental abundances of the body are observed to be similar to those of the Chelima lamproites occurring within the intra-cratonic Cuddapah basin. The available radiometric ages of all the known Indian lamproites and kimberlites are taken into consideration and a mid-Proterozoic lamproite event in the Indian sub-continent is postulated.

Keywords

Geochemistry, Lamproite, Krishna District, Andhra Pradesh.

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V. Madhavan ¹, A. G. Sugrive Reddy ²

Affiliations
1 Department of Geology, Osmania University, Hyderabad 500 007, IN
2 Central Ground Water Board, Southern Region, Hyderabad, IN

Abstract

The alkali syenites of Podili represent a mildly undersaturated nepheline nonnative microsyenites (NNMS) and quartz nonnative microsyenites (QNMS). All the microsyenites have developed nonnative acmite and are totally free from normative hypersthene. In contrast, the quartz syenites always carry normative hypersthene and are invariably devoid of normative acmite.

In the variation diagrams. the PodiIi syenites form distinct petrochemical trends indicating their consanguineous relationship. A dichotomous differentiation trend is discernible.

Keywords

Alkali Syenite, Alkaline Province, Andhra Pradesh, Geochemistry, Petrology.

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V. Madhavan ¹, J. Mallikharjuna Rao ², M. Srinivas ³, R. Natarajan ², Ausaf Sayeed ³

Affiliations
1 Geology Department, Kakatiya University, Warangal - 506 009, IN
2 National Geophysical Research Institute, Hyderabad - 500 007, IN
3 Geology Department, Osmania University, Hyderabad - 500 007, IN

Abstract

Rare bodies of syenites of alkaline or subalkaline character occur as intrusions in the rocks of the Cuddapah Supergroup within the Cuddapah basin. The alkali syenites (found at Racherla, Idamakallu and Giddalur) are mainly composed of riebeckite (arfvedsonite), ilmenite, orthoclase and the subalkaline syenites (located at Gundlapalle) comprise hedenbergite, and microcline-perthite. Accessory quartz is invariably present in both the syenites. These intrusive bodies display contrasting mineralogical and geochemical characteristics. The quartz- and hypersthenenormative subalkaline syenite has the attributes of a ferrosyenite and has been subjected to hydrothermal alteration which not only resulted in the formation of secondary minerals like nontronite, amphibole, biotite and magnetite- all at the expense of hedenbcrgite, but also partly converted the Fe⁺² into Fe ⁺³. These subalkaline syenites are characterized by an extreme paucity of Mg, has low to moderate contents of Ba, Sr, Rb, Zr and REE. The quartz, hypersthene and acmite- normative alkali syenites (lusitanite) on the other hand are abnormally enriched in Ti; Rb is low but Ba, Sr, Ce, Nb, Nd, Ta, Sm, La, Zr am also the ratios K/Rb, Ti/Zr, Ce/Y and HREE/LREE are conspicuously high.

The syenites of the Cuddapah basin, seem to have crystallized under contrasting conditions. While the alkali syenites crystallized under high PH₂O, the crystallization of subalkaline syenite took place under dry arid reducing conditions signifying a closed system. It is envisaged that the subalkaline ferrosyenite of Gundlapalle was formed by low-pressure crystal fractionation of a continental tholeiitic basaltic magma. The alkali syenites, on the other hand, are postulated to have crystallized from a mantle-derived, hydrous, alkaline magma enriched in Large Ion Lithophile Elements and Light Rare Earth Elements.

Keywords

Syenites, Igneous Petrology, Cuddapah Basin, Andhra Pradesh.

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V. Madhavan ¹

Affiliations
1 Department of Geology, Kakatiya University, Warangal-506 009, IN

Abstract

Archaean alkaline magmatism, constituting one of the rare global phenomena, was hitherto i ecorded only from the Australian and Noi th American (Canada and Greenland) continents With the recently reported occurrence of a late Archaean syenite pluton at Koppa] in the eastern Dharwar craton of India, the Asian continent has also entered into the record for hosting such a raie magmatic event Worldwide, alkaline magmatism was again sparsely manifested during Palaeoproterozoic time and the reported occurrence of Palaeoproterozoic syenite and carbonatite bodies from certain parts of India therefoie assumes considerable significance The Indian subcontinent was the target of alkaline-carbonatite magmatic activities during Mesoproterozoic, Neopioterozoic, Cretaceous and Eocene periods The compositional diversity of continental alkaline magmatism, as manifested in the Indian subcontinent during different geological times, has been documented here to provide a wider perspective foi investigating the Indian alkaline rocks in future.

Keywords

Alkaline magmatism,Temporal and Spatial Aspects, Documentation, Indian Subcontinent.

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V. Madhavan ¹

Affiliations
1 Department of Geology, Kakatiya Unviersity, Warangal - 560 009, IN

Abstract

No Abstract.

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V. Madhavan ¹, A. R. Nambiar ², S. Shivanna ², J. K. Srivastava ²

Affiliations
1 Department of Geology, Kakatiya University, Warangal- 506 009, IN
2 Geological Survey of India, Bangalore - 560 078, IN

Abstract

No Abstract.

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V. Madhavan ¹, J Mallikharjuna Rao ², M. Srinivas ³

Affiliations
1 Department of Geology, Kakatiya University, Warangal-506009, IN
2 National Geophysical Research Institute, Hyderabad-500007, IN
3 Department of Geology, P.G. College of Science, Saifabad, Osmania University, Hyderabad-500004, IN

Abstract

In the Dharwar craton, the recently recognized Cuddapah intrusive province hosts an array of mid-Proterozoic alkaline and non-alkaline intrusives; the latter are represented by two manifestly voluminous magma types: gabbro and granitoid, which are marked by a bimodal association. Here we present the tectono-magmatic framework of the Cuddapah intrusive province and in the light of it, the petrology, geochemistry and genesis of alkaline rocks are discussed to highlight the mid-Proterozoic intraplate alkaline magmatism in the eastern Dharwar craton.

Keywords

Igneous Petrology, Alkaline Magmatism, Mid-Proterozoic, Cuddapah Province, Eastern Dharwar Craton.

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V. Madhavan ¹, K. David ¹, J. Mallikharjuna Rao ², N. V. Chalapathi Rao ³, M. Srinivas ⁴

Affiliations
1 Department of Geology, Kakatiya University, Warangal, A.P. - 506 009, IN
2 National Geophysical Research Institute, Hyderabad- 500 007, IN
3 Department of Applied Geochemistry, Osmania University, Hyderabad- 500 007, IN
4 Department of Geology, Osmania University, Hyderabad- 500 007, IN

Abstract

The mid-Proterozoic lamprophyric rocks broadly represented by kimberlites, lamproites and lamprophyres (sensu stricto) are emplaced in and adjacent to the intracratonic Cuddapah basin in the eastern Dharwar craton of India which was recently recognized as the Cuddapah (intrusive) province (CIP). While the kimberlite pipes and lamprophyre dykes are located outside but close to the western and eastern margins of the Cuddapah basin respectively, the lamproites are hosted within the basin. Lamprophyres occur in seven locations of the Prakasam district of Andhra Pradesh. EIchuru, where more than one hundred lamprophyre dykes are found, represents a prominent centre of lamprophyre magmatism. Purimetla comes next to Elchuru with a tally of twenty lamprophyre dykes. At other places lamprophyres are numerically insignificant. The CIP lamprophyres encompass different varieties and they cut across an equally wide-ranging variety of host rocks; these lamprophyres come under 1) feldspathoidal or non- feldspathoidal and 2) plagioclase- or orthoclase-bearing categories. With a single exception, all the lamprophyres are micaceous and distinctly alkaline. The genesis of CIP lamprophyres as a manifestation of alkaline magmatism is discussed.

Keywords

Petrology, Geochemistry, Lamprophyres, Cuddapah Province, Andhra Pradesh.

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V. Gurumurthy ¹, R. Deveswaran ¹, S. Bharath ¹, B. V. Basavaraj ¹, V. Madhavan ¹

Affiliations
1 M.S. Ramaiah College of Pharmacy, M.S.R. Nagar, M.S.R.I.T Post, Bangalore-560054, IN

Abstract

The present investigation was aimed to estimate atenolol and amlodipine besylate simultaneously from bulk drug and tablets using hydrotropic solubilization technique employing 4M urea as hydrotropic solvent. Atenolol showed maximum absorbance at 224.5nm, whereas amlodipine besylate showed maximum absorbance at 237nm. The solubility of both atenolol and amlodipine besylate was increased to greater extent in 4M urea. Both the drugs showed linearity in the concentration range of 4-20μg/ml. The analysis of tablets indicated good correlation between the estimated and label claim. The values of LOD and LOQ were low, which confirmed the good sensitivity of the proposed method. The results of recovery studies showed that any small changes in drug concentration can be determined accurately by the proposed method. The method adopted is new, simple, accurate and cost-effective in the simultaneous estimation of atenolol and amlodipine besylate using hydrotropic solubilization phenomenon. This method can be successfully employed for routine analysis of atenolol and amlodipine besylate tablets.

Keywords

Simultaneous Estimation, Hydrotropy, Urea, Atenolol, Amlodipine Besylate.

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