bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diamond Mines Near Raichur
Authors: Sakuntala S. , Krishna Brahmam N. 
Published: November 2024

Abstract
Information relating to diamond mining in Raichur region (Karnataka State, India), as recorded by some foreign and Indian chroniclers in the fifteenth century, is brougbt to light and critically analysed. The places Alibenchi and Nelaha near Raichur are identified as the sites where ancients worked for diamonds. Supporting evidence is furnished by the presence of one diamond, known as 'Raichur Diamond', in the Museum of the Directorate of Department of Mines and Geology (Government of Andhra Pradesh), Hyderabad. The geological implications of this finding are discussed and a detailed geological study of the region for locating kimberlite pipes is suggested.
Changes in the Fluvial Regime of Western Maharashtra Upland Rivers During Late Quaternary
Authors: Rajaguru S. N. , Kale V. S. 
Published: November 2024

Abstract
Recent geomorphological, archaeological, palaeontological and carbon -14 dating of alluvial deposits and the observations on buried as well as exposed channel deposits of Upper Krishna, Bhima and the Upper Godavari rivers of Western Maharashtra have brought out five major phases of fluvial activity, since late middle Pleistocene. These rivers were dominantly aggrading during theTermial late Pleistocene (c 40.000-11,000 yrs. B.P.) and incision predominated during the major port of the Holocene. These changes in the fluvial activity can be explained in terms of climatic changes of the late Quaternary period.
The present study disproves the earlier view that the late Quaternary geomorphic history of the study area has been stable and uneventful.
Contact Metamorphic Granophyres of Partial Melting Origin Adjacent to Dolerite Dykes in Karnataka
Authors: Ramakrishnan M. , Bhattacharyya Samit 
Published: November 2024

Abstract
Granophyric rocks produced at the contact of post-Dharwar dolerite dykes in the host gneisses and granites of Peninsular Gneissic Complex stand out conspicuously at the weathered dyke margins in the vicinity of Hole Narsipur, Karnataka. The degree of development of granophyric texture is variable, and with its progressive increase, there is a shift in the host rock composition from granodiorite to alkali granite. Since there is no possibility of addition of potash from the dolerite to the granodiorite (the reverse is commonly the case) to cause this potash enrichment in host rocks, the origin of granophyres in the contact zones is attributed to partial melting rather than metasomatism or assimilation. This view is consistent with experimental evidence that partial melting of sodie gneisses (tonalites, trondjhemites and even granodiorites) results in the production of more potassic rocks like adamellites and alkali granites. The production of granophyres in the present case is, therefore, taken as a textural evidence for the partial melting of quartzofeldspathic gneisses. Similar phenomena are observed at the contact of Skaergaard intrusion of Greenland and Newer Dolerite of Singhbhum in eastern India.
Petrology and Geochemistry of the Oddanchatram Anorthosite and Associated Basic Granulites, Tamil Nadu, South India
Authors: Janardhan A. S. , Wiebe Robert A. 
Published: November 2024

Abstract
Preliminary studies of the Oddanchatram anorthosite body, the largest of the bodies lying along a 100 km linear; on the northern slopes of Patni hilI ranges, show that it has all the chemical and mineralogical characters of Proterozoic massif anorthosites. Plagioclase compositions reveal two types: a) primary plagioclase of An60 and b) secondary plagioclase with An94 occurring as breakdown product of garnet. Estimates based on primary pyroxenes indicate intrusive temperatures between 960°C-1000°C; pressures of 5.3 kb. based on garnet breakdown products suggest a steep geothermal gradient. The chemistry suggests that the parental magma was unusually feldspathic; primary hornblende indicates a higher H2O content of the magma.
Paragenesis of Uraninite and Associated Ore Minerals in the Precambrian Oligomictic Conglomerates from Walkunji, South Kanara District, Karnataka, India
Authors: Aurora S. N. 
Published: November 2024

Abstract
Mineragraphic study of the Early Proterozoic uraniferous oligomictic quartzpebble conglomerate of Walkunji reveals 'three types of uraninites, designated as U-I, U-II and U-III respectively. Textural and mineralogical characteristics indicate . that (i) U-I with plenty of filled-in fractures is subrounded to rounded in shape, detrital, allogenic and oldest in the sequence; (ii) U-II and U-III are authigenic with fine-grained U-II, occurring as fillings in gangue minerals, and appear to be hydrothermal; and (iii) colloform-textured U-III (pitchblende) is the youngest formed at low temperature due to remobilization of earlier phases. In addition, a little detrital, partially altered brannerite occurs with anatase.
Among the sulphides, melnicovite-pyrite and pyrite-marcasite are the most dominant followed by galena pyrrhotite and marcasite. The oxide sulphide mineral assemblage suggests that mineralization was primarily strata-bound in the initial stages followed by hydrothermal phase and ended with remobilization that resulted in the formation of U-lIl. The textural relationships among different ore minerals indicate the following paragenetic sequence: U-I, brannerite, pyrite, melnicovite-pyrite and gel. pyrite (oldest); U-II, arsenopyrite, pyrrhotite-marcasite, chalcopyrite, galena, sphalerite and molybdenite; and U-lIl, gel-pyrite and marcasite (youngest).
Geochemistry of Jahaj-Govindpura Volcanics, Bayana Sub-Basin, Northeastern Rajasthan
Authors: Singh S. P. 
Published: November 2024

Abstract
The Jahaj-Govindpura Volcanics - the youngest formation of the Rajalo Group in the Bayana sub-basin, comprises lava flows, agglomerates, volcanic breccias, tuffs, and quartzite interbeds. Volcanics have been fed by feeder dykes which clearly cut the underlying rocks. Plots of geochemical data from this volcanic suite reveal that compositionally they are transitional between aikali basalt and tholeiite. They resemble high-K2O continental tholeiites.
Rb-Sr Age of the Tusham Ring Complex, Bhiwani, India
Authors: Kochhar N. , Pande K. , Gopalan K. 
Published: November 2024

Abstract
Acid volcanics and associated granites from the Tusham Ring Complex in northwestern India yield a well defined Rb-Sr isochron corresponding to an age of 754±20 Ma (?=1.42 x 10-11 yr-1 ) and an initial Sr composition of 0.7131±0.0025. This is in good agreement with the age of the Malani suite of igneous rocks of western Rajasthan.
Organa-Geochemical Studies of Proterozoic Stromatolitic Phosphorite and the Intercolumnar Dolomite from the Aravalli Group, India
Authors: Banerjee D. M. , Klemm Ursula 
Published: November 2024

Abstract
Stromatolitic phosphorites and carbonates from the Proterozoic Aravalli sediments of Western India, have been subjected to organo-geochemical studies, involving a modified gc-ms technique. The stromatolitic phosphorites have an average value of 0.22% TOC which is significantly different from the average TOC value (0.64%) for all types of phosphorite from the Indian subcontinent. With only a few exceptions, the isoprenoids-pristane and phytane and the n-alkanes, account for about 30% of the total amount of volatiles (1-20 ppm). Normal alkanes occur in the range of n-c12 to n-c31 with maxima between n-c17 and n-c21 . No odd/even predominance has been observed. Besides pristane and phytane, other isoprenoids identified in these rocks are iSO C16 and iSO-C18. The low pristane to phytane ratio of 1.14 suggests a reducing micro-environment within the laminae of shallow-water cyanobacterial/algal stromatolites. The phosphate is assumed to be precipitated within the pore-waters under anoxic conditions through the activities of biological agents, which is supported by geological and geochemical data. The overall basinal environment, however, remained oxidizing, as is evident from the associated sedimentary structures.
Origin of White Sands from Prakasam District, Andhra Pradesh
Authors: Rao A. T. , Sankara Pitchaiah P. 
Published: November 2024

Abstract
White sands in Prakasam District, Andhra Pradesh, occur as a narrow zone extending 45 km in length and 3-4 km in width between Karlapalem and Chinnaganjam. The origin and provenance of white sands are worked out based on geology and textural analysis of the white sand belt. The textural parameters and the gradational changes in the white sands support interpretation of the depositional environment as belonging to a beach system. The sub-angular to sub-rounded shape of the grains and appreciable amount of feldspars in the white sands suggest that they have undergone transportation locally and originated from a nearby source. It is established that the Gondwana sandstones exposed around Pavalur and Budavada were the source rocks for the white sands and they were deposited as a near shore bar.
Geomorphic Processes in the Formation of (Red) Sands at Bhimilipatnam, Visakhapatnam District, Andhra Pradesh
Authors: Prudhvi Raju K. N. , Mahalakshmi K. B. , Prasada Raju P. V. S. P. , Krishna Bhagavan S. V. B. , David Emmanuel B. 
Published: November 2024

Abstract
The (red) sands at Bhimili with an areal spread of about 7 km2 and a height of 90 m above M.S.L. adjoining the beach (sea) has a dome like form. Within this, a typical badland topography has been formed. Three horizons of red, white to brownish and white to yellowish sand occur beneath white sand at the top, The red sands are fine-grained. White to brownish sands are coarse and show partially cemented parallel laminations. White to yellowish sands at the bottom, are coarse and pebbly, and stone lines within them occur inclined towards the sea, with small pebbles to boulders at different heights above M.S.L. and at different distances from the sea. A part of the bed of a major stream in the badland is a uniform wave-cut rocky platform, at a height of 7 m above M.S.L.
The height (7 m) of the rocky platform confirms that the sea level was possibly higher. It is inferred that the white to yellowish sand horizon may be a beach deposit, the white to brownish sands to be coalesced dune deposits and the red sand to be of aeolian nature. Statistical values substantiate mixed populations in the dune environment.
On the Tonalitic Suite of Khammam, A.P.- A Study of Mineral Correlation as Petrogenetic Clue
Authors: Maitra Monoj 
Published: November 2024

Abstract
Extensive occurrence of granitoid suite comprising tonalite-granodiorite and granite around Khammam, A.P. is reported. Correlation between mineralogical attributes (free from close table effect) having petrogenetic significance has been achieved through statistical procedure. It is indicated that members of the suites are interrelated by a broad fractionation history.
Chitradurga Metallogeny - A Case Study for Regional Metallogenic Analysis
Authors: Mishra R. N. 
Published: November 2024

Abstract
Chitradurga schist belt has traditionally been accepted as a long and narrow curvilinear Archaean geosynclinal pile, cratonised long ago. Important economic minerals are gold ore at Gadag, Bellara, Ajjanahalli and Honnemaradi; antimony at Chikkanayakanahalli; copper-lead-zinc and pyrite at Ingaldhal; iron and manganese ores at the western margin of the belt; limestone and dolomite around Dodguni, Chikkanayakanhalli and Javanahalli; barytes and fuchsite quartzite around Ghattihosahalli.
Salient features of the zonation of metals and minerals show a trend from the central to peripheral areas in the belt:
Cu, Pb, Zn, Pyrite ? Au, Ag, Sb, As ? Fe, MD, Carbonates ? Barite, Fuchsite Quartzite, Kyanite ? Feldspar, Quartz, Corundum.
The appropriate name for the container of this varied mineral spectrum across the time and space concept, could be 'metallogen'. The significant features of mineral zones in the Chitradurga metallogen; could prognostically lead to search for ore and the speculative size-up of the mineral in a futuristic perspective, thus forming a basis for a Resource Base. Regional metallogenic analysis thus opens up new vistas for future mineral appraisals. Chitradurga metallogen could thus form a subject for case study.
Accumulation of Oil in Coal-Bearing Strata North of Ahmedabad
Authors: Desikachar S. V. 
Published: November 2024

Abstract
The main oil sands of the Cambay Basin in the area north of Ahmedabad are in the Kalol Formation of upper Eocene age. The lower coal slit member of this formation can be identified all over the basin. In the fields north of Ahmedabad, this unit comprises mainly of coal and is identified as the reservoir unit. Hydrocarbon accumulations are found within high pressure lenses of poorly permeable silts within the coals. Study of the nature and environment of deposition of the reservoir rocks and a study of the development of the Kalol structure vis-a-vis the depositional and structural history of this part of the basin with the help of palaeostructural profiles and the production performance of the reservoir rocks provide some indication of the nature of distribution and accumulation of hydrocarbons in the area.
Bababudan - A Late Archaean Intracratonic Volcanosedimentary Basin, Karnataka, Southern India
Authors: Chadwick B. , Ramakrishnan M. , Viswanatha M. N. 
Published: November 2024

Abstract
The stratigraphy of the volcanosedimentary rocks of the late Archaean Dharwar Supergroup that make up the Bababudan basin is described in terms of six lithostratigraphic divisions, in ascending order, the Kalasapura, the Allampur, the Santaveri, the Mulaingiri, the Jagar and the Mundre Formations, the Jagar and the Mundre Formations being lateral equivalents. The three lower formations, each varying in thickness from a few metres to about 2000m, are dominated by metabasaItic rocks with local cross-bedded quartzites, including the basal quartz-pebble Kartikere Conglomerate which unconformably overlies the basement Peninsular Gneiss (c. 3100 Ma) in the south; the western, northern and eastern boundaries of the basin arc steep faults. The Mulaingiri Formation (200-1500m) is dominated by banded ferruginous cherts interbedded with phyllites, the Jagar Formation (? up to 2000m) comprises poorly exposed metabasaltic rocks and phyllites on the west of the basin, and the Mundre Formation, restricted to the northeast, contains the KaIdurga Conglomerate with a lower division dominated by clasts of Dharwar cover and an upper division dominated by clasts of Peninsular Gneiss basement: the conglomerate passes laterally into phyllites and crossbedded quartzites. The Mundre Formation is intruded by small bodies of pre- or syn-tectonic granite s.l.
The lithostratigraphic formations thicken from west to east indicating greater subsidence of the basin in the east, with the thickest accumulations marked by the Kaldurga Conglomerate (7 up to 5000 m) in the northeast. Sedimentary facies suggest that relatively shallow, intertidal or nearshore, marine environments persisted throughout most of the depositional and volcanic phases of basin development with banded ferruginous cherts and interbedded phyllites accumulating in areas (also relatively shallow ?) starved of terriginous detritus. The Kaldurga Conglomerate built out as a composite, shallow marine and alluvial cone into a rapidly subsiding part of the basin, detritus being provided by erosion of uplifted cover and basement to the north and northeast.
A Compilation of Sr and Nd Isotope Data on Mexico
Authors: Verma Surendra P. , Verma Mahendra P. 
Published: November 2024

Abstract
A compilation is given of the available Sr and Nd isotope data on Mexican volcanic-plutonic terranes which cover about one-third of Mexico's territory. The available data are arranged according to a subdivision of the Mexican territory in terms of geological provinces. Furthermore, site and province averages and standard deviations are calculated and their petrogenetic implications are pointed out.
Rb-Sr whole-Rock and Mineral Isochron Ages of the Tirodi Gneiss, Sausar Group, Rhandara District, Maharashtra
Authors: Sarkar S. N. , Trivedi J. R. , Gopalan K. 
Published: November 2024

Abstract
Six whole rock samples of the Tirodi gneiss belonging to the basal part of the Sausar Group rocks in the Dongri Buzurg area yield a good Rb-Sr isochron corresponding to an age of 1525±70 Ma and an initial Sr ratio of 0.7148±0.0033. Mineral isachrons for two of these rocks give concordant but younger ages at 860 Ma in good agreement with the previously reported K/Ar ages on minerals separated from the Sausar Group rocks. The 1525 Ma event is interpreted to mark the main phase of regional metamorphism of the Sausar Group of rocks including the granitization of the basal Tirodi unit. The deposition of the sediments of the Sausar Group and their basement must therefore be even older. The good agreement of the RblSr and K/Ar mineral ages at about 860 Ma indicates the latest thermal overprint on the Sausar - rocks, The regional metamorphism of the Tirodi gneiss at about 1500 Ma ago is also reflected in the Rb/Sr and K/Ar mineral ages of the Amgaon gneiss and Dongargarh granite to the east of the Tirodi gneiss.
Mineralogy of Saurashtra Miliolites
Authors: Baskaran M. , Somayajulu R. L. K. 
Published: November 2024

Abstract
The results of CaCO3, carbonate minerals and quartz measurements on 114 miliolites (some of which are dated) and of sedimentatogical and clay mineral studies on select (10-20) samples are reported and discussed.
The miliolite deposits are predominantIy calcite (CaCO3 range = 50.2 to 100 %, mean 86.8 %) with aragonite and quartz as minor components. None of the measured parameters show any trend/pattern between coast and inland which, coupled with field observations indicate that long distance (&lt; 100 Km) eolian transport was unlikely.
Despite the fact that miliolites rest on Deccan trap basalts and several local and Narbada and Tapti river sediments as well as the near coastal sediments of Saurashtra are enriched in clay mineral smectite, the miliolite clays show the dominance of illite which is principally generated by weathering of granites and brought by the Indus river. This observation implies that the processes responsible far bringing Indus clays to Saurashtra region when the miliolites were formed (60 Kyr - 200Kyr) are not operative in recent times.
Microstructural Studies and Distribution of Mineral Matter in the Macroscopic Ingredients of Coal, Jharia Coalfield, India : An Appraisal of SEM Study
Authors: Singh Mahendra P. , Singh R. M. , Chandra D. 
Published: November 2024

Abstract
Scanning Electron Micrography of the Jharia Coals has been attempted with a view to decipher the enigmatic microstructural features and diversities in distribution of mineral matter in the banded constituents and coal. A wide variation has been observed in the distribution of mineral matter in coal lithotypes. The mineral matter is most abundant in durain; abundant in c1arain and dull clarain, less abundant in bright clarain and vitrain; and rare in fusain. The order of abundance of the mineral matter may be put as; Durain &gt; Dull Clarain &gt; Clarain &gt; Bright Clarain &gt; Vitrain &gt; Fusain.
The microstructural relation of mineral. matter with coaly substances reveals that in durain and elarain, mineral matter is associated as massive impregnation, superficial infilling of micropores and filling of cavities. In vitrain, this occurs mainly iS superficial inlilling of pores, superficial mountings, and in and around cavities. In c1arain mineral matter is mainly confined to dull bands, while bright bands contain sporadic mineral matter. Fusain is almost devoid of inorganic contamination. At places, however, mineral matter is observed filling the cavities of cell fibres and cell lumina.
Sulphide are Mineralisation in Archaean Volcanogene-Sedimentary Ensemble of Ganacharpura, Kolar Greenstone Belt, Dharwar Craton, India
Authors: Vasudev V. N. , Mukherjee Ananda Deb 
Published: November 2024

Abstract
Stratiform pyrrhotitic sulphide ores occur at Ganacharpura which forms a part of mafic volcanic and volcano-sedimentary terrain of the Archaean Kolar greenstone belt. The ores are interbanded with graphite-quartz-sericite schist and are metamorphosed and deformed along with the associated rock types of the area. Dominant ore mineral is pyrrhotite while chalcopyrite, pyrite, sphalerite, galena, magnetite and mackinawite are present in subordinate amounts. The mineral chemistry of the co-existing sulphide phases indicate equilibration at 587°C and 4.98 Kbar total pressure. The fugacities of sulphur and oxygen, reflected in various sulphide assemblages varied considerably, but the fluid composition during metamorphism was essentially internally controlled instead of being externally imposed. The co-existing pyrrhotite, pyrite and magnetite indicate log fs2= -2.4 and log fo2= -17.8 during culmination of metamorphism. It is suggested that the ores are of volcano-sedimentary type and are later modified by mobilisation/remobilisation during diastrophism. The arc-forming metals and sulphur have probably been derived from volcanic exhalations.
Anorthosites and Associated Rocks of Nellore-Gudur, South India
Authors: Kanungo D. N. , Chetty T. R. K. , Mallikarjuna Rao J. 
Published: November 2024

Abstract
Structural, petrographic and geochemical characters of several anorthosite bodies exposed over a length of eight km in the eastern margin of India are presented. From the asymmetry of parasitic folds and cleavage/bedding relationship in the host rocks, it is concluded that these were emplaced into anticlinal cores of isoclinally folded Precambrian schistose formations.
Textural variation from centre to border, mafic enrichment towards the margins. alignment of linear structures combined with steeply dipping foliation of arcuate nature parallelling the boundaries. suggest that anorthositic bodies are plug-shaped and viscous magmatic fluid moved vertically upwards. The progressive variation in mineralogy. grain-size and some of the major oxides is attributed to flow differentiation.
Decisive Controls in the Formation of the East Coast Bauxite Deposits of India
Authors: Ramam P. K. 
Published: November 2024

Abstract
The formation of lateritic bauxite deposits is, by and large, governed by the cumulative effect of several controls. Salient amongst them are: (i) favourable source rock, (ii) effective porosity, (iii) high rainfall, (iv) good drainage, (v) tropical climate, (vi) low to moderate topographic relief, (vi i) prolonged stability, and (viii) presence of vegetation. Despite a general consensus on these causative factors to promote bauxitisation, the decisive controls, still remain to be discerned. A synthesis attempted from this angle in respect of the East Coast Bauxite (EeB) deposits of India has brought to focus the effective permeability of the source rock and a congenial geomorphic base, preferably unidirectional, of low to moderate slope angles (3° to 15°) as the decisive controls in their formation. These, in turn, are dependent on the structural history of the terrain.