The Central India Tectonic Zone (CITZ) marks the trace of a major suture zone along which the south Indian and the north Indian continental blocks were assembled through subduction-accretion- collision tectonics in ...The Central India Tectonic Zone (CITZ) marks the trace of a major suture zone along which the south Indian and the north Indian continental blocks were assembled through subduction-accretion- collision tectonics in the Mesoproterozoic. The CITZ also witnessed the major, plume-related, late Cretaceous Deccan volcanic activity, covering substantial parts of the region with continental flood basalts and associated magmatic provinces. A number of major fault zones dissect the region, some of which are seismically active. Here we present results from gravity modeling along five regional profiles in the CITZ, and combine these results with magnetotelluric (MT) modeling results to explain the crustal architecture. The models show a resistive (more than 2000 Ω. m) and a normal density (2.70 g/cm3) upper crust suggesting dominant tonalite-trondhjemite-granodiorite (TTG) composition. There is a marked correlation between both high-density (2.95 g/cm3) and low-density (2.65 g/cm3) regions with high conductive zones (〈80 Ω. m) in the deep crust. We infer the presence of an interconnected grain boundary network of fluids or fluid-hosted structures, where the conductors are associated with gravity lows. Based on the conductive nature, we propose that the lower crustal rocks are fluid reservoirs, where the fluids occur as trapped phase within minerals, fluid-filled porosity, or as fluid-rich structural conduits. We envisage that substantial volume of fluids were transferred from mantle into the lower crust through the younger plume-related Deccan volcanism, as well as the reactivation, fracturing and expulsion of fluids transported to depth during the Mesoproterozoic subduction tectonics. Migration of the fluids into brittle fault zones such as the Narmada North Fault and the Narmada South Fault resulted in generating high pore pressures and weakening of the faults, as reflected in the seismicity. This inference is also supported by the presence of broad gravity lows near these faults, as well as the low velocity in the lower crust beneath regions of recent major earthquakes within the CITZ.展开更多
Mafic/ultramafic rocks derived from high siliceous(high-Si)high magnesium(high-Mg)mantle melts are an important feature observed during early Precambrian.They provide much important geological and petrological
The Upper Kaimur Group of the Vindhyan Supergroup in Central India,primarily consists of three rock types-DhandraulSandstone,Scarp Sandstone and Bijaigarh Shale.Mineralogically and geochemically,they are quartz arenit...The Upper Kaimur Group of the Vindhyan Supergroup in Central India,primarily consists of three rock types-DhandraulSandstone,Scarp Sandstone and Bijaigarh Shale.Mineralogically and geochemically,they are quartz arenite,sublitharenite to litharenite and litharenite to shale in composition,respectively.The A-CN-K ternary plot and CIA and ICV values suggest that the similar source rocks suffered severe chemical weathering,under a hot-humid climate in an acidic environment with higher PCO2,which facilitated high sediment influx in the absence of land plants.Various geochemical discriminants,elemental ratios like K2O/Na2O,Al2O3/TiO2,SiO2/MgO,La/Sc,Th/Sc,Th/Cr,GdN/YbN and pronounced negative Eu anomalies indicate the rocks to be of post-Archean Proterozoic granitic source,with a minor contribution of granodioritic input,in a passive margin setting.The sediments of the Upper Kaimur Group were probably deposited in the interglacial period in between the Paleoproterozoic and Neoproterozoic glacial epochs.展开更多
Petrographic, mineral chemical and whole-rock geochemical characteristics of two newly discovered lamproitic dykes(Dyke 1 and Dyke 2) from the Sidhi Gneissic Complex(SGC), Central India are presented here. Both these ...Petrographic, mineral chemical and whole-rock geochemical characteristics of two newly discovered lamproitic dykes(Dyke 1 and Dyke 2) from the Sidhi Gneissic Complex(SGC), Central India are presented here. Both these dykes have almost similar sequence of mineral-textural patterns indicative of:(1) an early cumulate forming event in a deeper magma chamber where megacrystic/large size phenocrysts of phlogopites have crystallized along with subordinate amount of olivine and clinopyroxene;(2) crystallization at shallow crustal levels promoted fine-grained phlogopite, K-feldspar, calcite and Fe-Ti oxides in the groundmass;(3) dyke emplacement related quench texture(plumose K-feldspar, acicular phlogopites) and finally(4) post emplacement autometasomatism by hydrothermal fluids which percolated as micro-veins and altered the mafic phases. Phlogopite phenocrysts often display resorption textures together with growth zoning indicating that during their crystallization equilibrium at the crystal-melt interface fluctuated multiple times probably due to incremental addition or chaotic dynamic self mixing of the lamproitic magma. Carbonate aggregates as late stage melt segregation are common in both these dykes, however their micro-xenolithic forms suggest that assimilation with a plutonic carbonatite body also played a key role in enhancing the carbonatitic nature of these dykes. Geochemically both dykes are ultrapotassic(K_2 O/Na_2 O: 3.0-9.4) with low CaO, Al_2 O_3 and Na_2 O content and high SiO_2(53.3-55.6 wt.%)and K_2 O/Al_2 O_3 ratio(0.51-0.89) characterizing them as high-silica lamproites. Inspite of these similarities, many other features indicate that both these dykes have evolved independently from two distinct magmas. In dyke 1, phlogopite composition has evolved towards the minette trend(Al-enrichment) from a differentiated parental magma having low MgO, Ni and Cr content; whereas in dyke 2, phlogopite composition shows an evolutionary affinity towards the lamproite trend(Al-depletion) and crystallized from a more primitive magma having high MgO, Ni and Cr content. Whole-rock trace-elements signatures like enriched LREE, LILE, negative Nb-Ta and positive Pb anomalies; high Rb/Sr, Th/La, Ba/Nb, and low Ba/Rb, Sm/La, Nb/U ratios in both dykes indicate that their pareintal magmas were sourced from a subduction modified garnet facies mantle containing phlogopite. From various evidences it is proposed that the petrogenesis of studied lamproitic dykes stand out to be an example for the lamproite magma which attained a carbonatitic character and undergone diverse chemical evolution in response to parental melt composition, storage at deep crustal level and autometasomatism.展开更多
The present paper enumerates an account of the lichen flora in Achanakmar-Amarkantak Biosphere Reserve located in Central India which comprises 78 species belonging to 25 genera under nine families. Of these, twenty t...The present paper enumerates an account of the lichen flora in Achanakmar-Amarkantak Biosphere Reserve located in Central India which comprises 78 species belonging to 25 genera under nine families. Of these, twenty two species have been reported for the first time from Central India. All the species are enumerated with their correct original citation, basionyms if any, their places of occurrence in the reserve area, distributional range and exsiccata have been provided.展开更多
In Nagpur, M.P.-Maharashtra Manganese Belt is exposed which is part of Sausar Belt. In Nagpur, four manganese mines viz Mansar, Kandri, Beldongri and Satak are selected for the ore microscopic study. These mining area...In Nagpur, M.P.-Maharashtra Manganese Belt is exposed which is part of Sausar Belt. In Nagpur, four manganese mines viz Mansar, Kandri, Beldongri and Satak are selected for the ore microscopic study. These mining areas are situated in that part of Central India which are highly deformed and metamorphosed and are characterised by high grade amphibolite facies to low grade greenschist facies. The Precambrian manganese ore deposits of Nagpur are formed by the metasediments of Sausar belt which is rich in manganese sediments. The manganese ores of the study area are co-folded with distinct rock types i.e. “gondites” and predominantly composed of a mixture of braunite, bixbyite, hausmannite, hollandite, jacobsite, vredenburgite, pyrolusite, cryptomelane and psilomelane. The dominant rocks are tirodi migmatitic gneiss, argillaceous and calcareous rock types. This paper discusses the mineralogy of the manganese ores of Kandri, Mansar, Satak and Beldongri. After the careful assessment of mineralogy, texture and paragenesis of the manganese ore of the study area, it has been concluded that the manganese ores of the study area are formed by the multiple processes i.e. metamorphism and supergene enrichment. These supergene enrichments are evidence of colloidal influx. Occurrence of free braunite, free hausmannite and free jacobsite indicates the high grade metamorphism. Pyrolusite, rhodonite, and psilomelane-cryptomelane are formed by supergene enrichment. The presence of lamellar twinning in braunite indicates about shear pressure. In this area the different manganese mineral assemblages and their textures suggest about the occurrence of different metamorphic activity and depositional environment. The texture and paragenesis of manganese ore of the study area are discussed here.展开更多
A new species of fossil Mus (Muridae, Rodentia) is described from the Pleistocene fluviatile deposits of the Narmada valley (Central India). The species, Mus narmadaensis sp. Nov., has a comparatively smaller lower mo...A new species of fossil Mus (Muridae, Rodentia) is described from the Pleistocene fluviatile deposits of the Narmada valley (Central India). The species, Mus narmadaensis sp. Nov., has a comparatively smaller lower molar which is characterized by a narrow molar with well connected cusps, small anterior expansion of lingual anteroconid, protoconid and metaconid, reduced posterior cingulum in addition to hypoconid and entoconid nearly at the same level. The large M3 has centrally placed bulbous hypoconid. Among the extant species, the present one is closest to M. shortridgei in having similarly placed protoconid and metaconid in M1 and a well developed hypoconid in M3.展开更多
Cellular damage or oxidative injury arising from free radicals or reactive oxygen species (ROS) now appears the fun-damental mechanism underlying a number of human neurodegenerative disorder, diabetes, inflammation, v...Cellular damage or oxidative injury arising from free radicals or reactive oxygen species (ROS) now appears the fun-damental mechanism underlying a number of human neurodegenerative disorder, diabetes, inflammation, viral infec-tions, autoimmune pathologies and digestive system disorders. Free radicals are generated through normal metabolism of drugs, environmental chemicals and other xenobiotics as well as endogenous chemicals, especially stress hormones (adrenalin and noradrenalin). Accumulated evidence suggests that ROS can be scavenged through chemoprevention utilizing natural antioxidant compounds present in foods and medicinal plants. In this review, research on the antioxi-dant potential of some medicinal plants of origin of Central India is considered.展开更多
Haemoglobinopathies are group of diseases characterized by abnormalities both quantitative and qualitative in the synthesis of haemoglobin. Haemoglobinopathies consist of sickle cell anaemia (SCA), thalassaemia (βT) ...Haemoglobinopathies are group of diseases characterized by abnormalities both quantitative and qualitative in the synthesis of haemoglobin. Haemoglobinopathies consist of sickle cell anaemia (SCA), thalassaemia (βT) and variant haemoglobins. In India, they are responsible for the largest number of genetic disorders and hence are of great public health hazardous. In India major concerned haemoglobinopathic disorders are sickle cell anaemia and β-thalassaemia. Of the several abnormal haemoglobin molecules, four which are widely prevalent in India include: HbS, HbβT, HbE and HbD. Examination of 6463 individuals showed high incidences for haemoglobin variants, HbS and HbβT in different ethnic groups, the frequency being varies from 0% - 20% and 0% - 9% respectively. The frequency of HbS in Brahmins is 4.17%, in Kalar 5.41%, in Rajput 2.04%, in Muslims 3.73% in Maratha 2.08% in Bania 9.09% while in Teli it is 3.65%. Among the Scheduled castes and Nomadic tribal groups HbS ranges from 1% - 12%;in backward caste categories it varies from 3% - 16%;while in Scheduled tribes it ranges from 0% - 20%. The high magnitude of sickle cell trait has been noticed in the Pardhan (20.31%) followed by the Marar (16.10%), the Dhiwar (11.90%), the Gond (11.89%), the Mahar (11.81%) and the Bania (9.90%). A considerable high frequency (9.27%) of β-thalassaemia has been observed among the Sindhi population. Sporadic occurrence of HbβT and HbD among other communities suggested the gradual spread of the genes into the region. The present findings in 11 communities with the thalassaemia syndrome suggest that the β-thalassaemia is accompanied by raised level of HbA2. Unusual greater mean RBC and WBC suggest the high concentration of hypochromic microcytosis in anaemia. The mean MCV and MCH in HbβT and HbD are much lower than the normal ranges compared to HbS. The mean MCHC is much lower in HbβT, HbDD and HbS than the normal range. The cumulative gene frequency of haemoglobinopathies in India is 4.2%. With a population of over 1 billion and a birth rate of 28 per 1000, there are over 42 million carriers and over 12,000 infants are born each year with a major and clinical significant haemoglobinopathy. Out of these, clinically significant sickle cell anaemia and β-thalassaemic disorders account for almost equal numbers.展开更多
The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary bas...The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary basins.This paper reports and discusses,for the first time,the occurrence of several cm-to dm-scale SSDS within sandstone successions of the Mesoproterozoic Kaimur Group(Vindhyan Supergroup),exposed at the Hanumandhara Hill of Chitrakoot-Satna border region,Madhya Pradesh State,India.The SSDS are confined to a deformed interval comprising seven individual sedimentary units of variable composition and texture,which are sandwiched between nearly horizontally undeformed sandstone beds.The SSDS consist of load structures(load casts,flame structures,pseudonodules and ball-and-pillow structures),contorted lamination,convolute lamination,boudins and pinch-and-swell structures,deformed cross-stratification,slump structures,clastic injections,fluid escape structures,and syn-sedimentary fractures/faults.The pre-sent study suggests that the formation of these SSDS is essentially related to a combination of processes(gravitational instability,liquefaction,fluidization,and fluid escape)predominantly induced by seismic shocks.In addition,the restricted occurrence of fractures/faults in these deformed layers emphasizes the passage of seismically-induced Rayleigh waves.Considering the observed types of SSDS,their lateral homo-geneity and geographic distribution along with the geodynamic framework of the Vindhyan Basin,the whole area can be tentatively attributed to having experienced moderate-to high-magnitude(M≥5)seismicity.The present study combined with earlier reports of seismically-induced SSDS,from other regionally disposed formations belonging to the Lower(e.g.,Kajrahat Limestone,Chopan Porcellanite,Koldaha Shale,Rohtas Limestone,and Glauconitic Sandstone of the Semri Group)and Upper(e.g.,Bhander Limestone of the Bhander Group)Vindhyan Supergroup,respectively,provides evidence for the constant regional-scale seismo-tectonic activity within the Paleo-Mesoproterozoic Vindhyan Basin.Importantly,this observation further suggests that the intracratonic basins can be active tectonically contrary to the earlier propositions.展开更多
In order to infer the climate and the floral changes during the early Cenozoic of central India, a critical analysis has been made of the generic composition of Deccan Intertrappean series of India, which is now known...In order to infer the climate and the floral changes during the early Cenozoic of central India, a critical analysis has been made of the generic composition of Deccan Intertrappean series of India, which is now known to a greater extent. Most of the information regarding Deccan Intertrappean flora is derived from the assemblages from Vidharbha-Chhindwara region and Mandla District in central India. The Vidharbha-Chhindwara region constituted by taxa representing all major groups of plant kingdom belonging to different habitats like(i) marine(3 genera of doubtful marine alga)(ii) estuarine(27 species of palms, Nypa and Viracorpon like Pandanaceous fruits, Sonneratia, Cocos like plants)(iii) fresh water(6 genera of fresh water algae, water ferns, Eichhornia, Nymphea like hydrophytic angiosperms)(iv) marshy(5 genera of bryophytes, water ferns, Selaginella and Equisetum like pteridophytes and many angiospermic plants showing aerenchymatous tissue and few parts infected by fungal spores) and(v) terrestrial(2 families of gymnosperms and 15 families of arborescent angiosperms). Mandla-Dindori District mainly comprise angiospermous flora. These constitute 15 species of palm woods and woods of 25 dicot families indicating terrestrial dry habitat. The fossil flora so far recovered from these beds indicate that the tropical evergreen to semi-evergreen type forests with some moist deciduous plants, similar to the present day forests of Western Ghats, and northeast India, were flourshing around Vidharbha, Chhindwara and Mandla area of Central India during Upper Cretaceous-Lower Tertiary period, in contrast to the present day dry deciduous to moist deciduous types of forest. This flora was well represented in India in the past but has become restricted to Burma and Andaman-Nicobar Islands due to change in the climatic conditions. The comparison of the temperature data from these fossiliferous localities and the comparable modern areas clearly indicates that the climate in Central India was much more uniform throughout the year.展开更多
The advent of modem forces and the changes in socio- economic patterns of forest dwellers have increased the pressures on the forests. In order to mitigate such pressures and also to protect the forests and wildlife t...The advent of modem forces and the changes in socio- economic patterns of forest dwellers have increased the pressures on the forests. In order to mitigate such pressures and also to protect the forests and wildlife the model of protected areas networks has shifted and en- hanced such pressures in the unprotected natural forests due to several reasons. Being a low profile category of protected status and continuous human settlements, the present study highlights the case of dry deciduous forests of Sarguja district of Chhattisgarh state of India. The major objec- tives of this study were to quantify the status of forests and wildlife and also to determine the extent of anthropogenic disturbances faced by the dry deciduous forests of central India. Transect and silent drive count methods were used for sampling wildlife and quadrat method was used for sampling vegetation. Besides, the local uses of various forest pro- duces were also studied in view of understanding the people dependency on forests. The forest vegetation, in the study area, was pre-dominated by Shorea robusta, which had Madhuca indica, Diospyrus melanoxylon and Buchnania lanzan as the major companion species. The forest had either the high girth class mature tree species or the saplings. The low vegeta- tion cover and density were due to the high anthropogenic pressures mainly in the form of heavy livestock grazing and collection of etlmo- botanically important species. The study though reveals that the area is not rich in wildlife and the forest is fragmented, the area still supports some important species, which include many rare and endangered plants and animals. The findings of this study have been discussed in view of the management and conservation of the forest and wildlife in the dry deciduous forests.展开更多
Bamboo shoots can be harvested at different ages but the data on the changes in nutritional composition with age are scanty. We standardized harvesting age of bamboo shoots in central India to obtain best quality prod...Bamboo shoots can be harvested at different ages but the data on the changes in nutritional composition with age are scanty. We standardized harvesting age of bamboo shoots in central India to obtain best quality produce with respect to nutritional composition. The shoots harvested on different days (2–20 days after emergence from ground) were analyzed for their nutritional (dietary fibres, carbohydrates, proteins, total phenols, ascorbic acid, sodium, potassium, phosphorus, calcium, magnesium and phenolic acids) and anti nutritional (cyanogen) constituents. A significant variation (at p ≤ 0.5) was observed in the nutritional composition of shoots of Dendrocalamus asper, D. strictus and Bambusa tulda harvested at different days. An overall decrease was observed in proteins and total phenols while dietary fibres and carbohydrates increased with ages. Significant variation (at p ≤ 0.5) was also observed in phenolic acids while minerals did not vary significantly. Results revealed that the optimum harvesting age for D. asper, D. strictus and B. tulda was on 10–14 days, 6–10 days and 10–16 days (after emergence from the ground) respectively. These results can be used to obtain quality bamboo shoots.展开更多
文摘The Central India Tectonic Zone (CITZ) marks the trace of a major suture zone along which the south Indian and the north Indian continental blocks were assembled through subduction-accretion- collision tectonics in the Mesoproterozoic. The CITZ also witnessed the major, plume-related, late Cretaceous Deccan volcanic activity, covering substantial parts of the region with continental flood basalts and associated magmatic provinces. A number of major fault zones dissect the region, some of which are seismically active. Here we present results from gravity modeling along five regional profiles in the CITZ, and combine these results with magnetotelluric (MT) modeling results to explain the crustal architecture. The models show a resistive (more than 2000 Ω. m) and a normal density (2.70 g/cm3) upper crust suggesting dominant tonalite-trondhjemite-granodiorite (TTG) composition. There is a marked correlation between both high-density (2.95 g/cm3) and low-density (2.65 g/cm3) regions with high conductive zones (〈80 Ω. m) in the deep crust. We infer the presence of an interconnected grain boundary network of fluids or fluid-hosted structures, where the conductors are associated with gravity lows. Based on the conductive nature, we propose that the lower crustal rocks are fluid reservoirs, where the fluids occur as trapped phase within minerals, fluid-filled porosity, or as fluid-rich structural conduits. We envisage that substantial volume of fluids were transferred from mantle into the lower crust through the younger plume-related Deccan volcanism, as well as the reactivation, fracturing and expulsion of fluids transported to depth during the Mesoproterozoic subduction tectonics. Migration of the fluids into brittle fault zones such as the Narmada North Fault and the Narmada South Fault resulted in generating high pore pressures and weakening of the faults, as reflected in the seismicity. This inference is also supported by the presence of broad gravity lows near these faults, as well as the low velocity in the lower crust beneath regions of recent major earthquakes within the CITZ.
文摘Mafic/ultramafic rocks derived from high siliceous(high-Si)high magnesium(high-Mg)mantle melts are an important feature observed during early Precambrian.They provide much important geological and petrological
基金The financial assistance from University Grants Commission,New Delhi under grant No. F. 31-196/2005 (SR) is thankfully acknowledged by one of the authors (MM)
文摘The Upper Kaimur Group of the Vindhyan Supergroup in Central India,primarily consists of three rock types-DhandraulSandstone,Scarp Sandstone and Bijaigarh Shale.Mineralogically and geochemically,they are quartz arenite,sublitharenite to litharenite and litharenite to shale in composition,respectively.The A-CN-K ternary plot and CIA and ICV values suggest that the similar source rocks suffered severe chemical weathering,under a hot-humid climate in an acidic environment with higher PCO2,which facilitated high sediment influx in the absence of land plants.Various geochemical discriminants,elemental ratios like K2O/Na2O,Al2O3/TiO2,SiO2/MgO,La/Sc,Th/Sc,Th/Cr,GdN/YbN and pronounced negative Eu anomalies indicate the rocks to be of post-Archean Proterozoic granitic source,with a minor contribution of granodioritic input,in a passive margin setting.The sediments of the Upper Kaimur Group were probably deposited in the interglacial period in between the Paleoproterozoic and Neoproterozoic glacial epochs.
基金the DST sponsored project vide SERB Grant No.SR/S4/ES-643/2012the CSIR-NGRI funded project(SHORE PSC0205 WP4.2)
文摘Petrographic, mineral chemical and whole-rock geochemical characteristics of two newly discovered lamproitic dykes(Dyke 1 and Dyke 2) from the Sidhi Gneissic Complex(SGC), Central India are presented here. Both these dykes have almost similar sequence of mineral-textural patterns indicative of:(1) an early cumulate forming event in a deeper magma chamber where megacrystic/large size phenocrysts of phlogopites have crystallized along with subordinate amount of olivine and clinopyroxene;(2) crystallization at shallow crustal levels promoted fine-grained phlogopite, K-feldspar, calcite and Fe-Ti oxides in the groundmass;(3) dyke emplacement related quench texture(plumose K-feldspar, acicular phlogopites) and finally(4) post emplacement autometasomatism by hydrothermal fluids which percolated as micro-veins and altered the mafic phases. Phlogopite phenocrysts often display resorption textures together with growth zoning indicating that during their crystallization equilibrium at the crystal-melt interface fluctuated multiple times probably due to incremental addition or chaotic dynamic self mixing of the lamproitic magma. Carbonate aggregates as late stage melt segregation are common in both these dykes, however their micro-xenolithic forms suggest that assimilation with a plutonic carbonatite body also played a key role in enhancing the carbonatitic nature of these dykes. Geochemically both dykes are ultrapotassic(K_2 O/Na_2 O: 3.0-9.4) with low CaO, Al_2 O_3 and Na_2 O content and high SiO_2(53.3-55.6 wt.%)and K_2 O/Al_2 O_3 ratio(0.51-0.89) characterizing them as high-silica lamproites. Inspite of these similarities, many other features indicate that both these dykes have evolved independently from two distinct magmas. In dyke 1, phlogopite composition has evolved towards the minette trend(Al-enrichment) from a differentiated parental magma having low MgO, Ni and Cr content; whereas in dyke 2, phlogopite composition shows an evolutionary affinity towards the lamproite trend(Al-depletion) and crystallized from a more primitive magma having high MgO, Ni and Cr content. Whole-rock trace-elements signatures like enriched LREE, LILE, negative Nb-Ta and positive Pb anomalies; high Rb/Sr, Th/La, Ba/Nb, and low Ba/Rb, Sm/La, Nb/U ratios in both dykes indicate that their pareintal magmas were sourced from a subduction modified garnet facies mantle containing phlogopite. From various evidences it is proposed that the petrogenesis of studied lamproitic dykes stand out to be an example for the lamproite magma which attained a carbonatitic character and undergone diverse chemical evolution in response to parental melt composition, storage at deep crustal level and autometasomatism.
文摘The present paper enumerates an account of the lichen flora in Achanakmar-Amarkantak Biosphere Reserve located in Central India which comprises 78 species belonging to 25 genera under nine families. Of these, twenty two species have been reported for the first time from Central India. All the species are enumerated with their correct original citation, basionyms if any, their places of occurrence in the reserve area, distributional range and exsiccata have been provided.
文摘In Nagpur, M.P.-Maharashtra Manganese Belt is exposed which is part of Sausar Belt. In Nagpur, four manganese mines viz Mansar, Kandri, Beldongri and Satak are selected for the ore microscopic study. These mining areas are situated in that part of Central India which are highly deformed and metamorphosed and are characterised by high grade amphibolite facies to low grade greenschist facies. The Precambrian manganese ore deposits of Nagpur are formed by the metasediments of Sausar belt which is rich in manganese sediments. The manganese ores of the study area are co-folded with distinct rock types i.e. “gondites” and predominantly composed of a mixture of braunite, bixbyite, hausmannite, hollandite, jacobsite, vredenburgite, pyrolusite, cryptomelane and psilomelane. The dominant rocks are tirodi migmatitic gneiss, argillaceous and calcareous rock types. This paper discusses the mineralogy of the manganese ores of Kandri, Mansar, Satak and Beldongri. After the careful assessment of mineralogy, texture and paragenesis of the manganese ore of the study area, it has been concluded that the manganese ores of the study area are formed by the multiple processes i.e. metamorphism and supergene enrichment. These supergene enrichments are evidence of colloidal influx. Occurrence of free braunite, free hausmannite and free jacobsite indicates the high grade metamorphism. Pyrolusite, rhodonite, and psilomelane-cryptomelane are formed by supergene enrichment. The presence of lamellar twinning in braunite indicates about shear pressure. In this area the different manganese mineral assemblages and their textures suggest about the occurrence of different metamorphic activity and depositional environment. The texture and paragenesis of manganese ore of the study area are discussed here.
文摘A new species of fossil Mus (Muridae, Rodentia) is described from the Pleistocene fluviatile deposits of the Narmada valley (Central India). The species, Mus narmadaensis sp. Nov., has a comparatively smaller lower molar which is characterized by a narrow molar with well connected cusps, small anterior expansion of lingual anteroconid, protoconid and metaconid, reduced posterior cingulum in addition to hypoconid and entoconid nearly at the same level. The large M3 has centrally placed bulbous hypoconid. Among the extant species, the present one is closest to M. shortridgei in having similarly placed protoconid and metaconid in M1 and a well developed hypoconid in M3.
文摘Cellular damage or oxidative injury arising from free radicals or reactive oxygen species (ROS) now appears the fun-damental mechanism underlying a number of human neurodegenerative disorder, diabetes, inflammation, viral infec-tions, autoimmune pathologies and digestive system disorders. Free radicals are generated through normal metabolism of drugs, environmental chemicals and other xenobiotics as well as endogenous chemicals, especially stress hormones (adrenalin and noradrenalin). Accumulated evidence suggests that ROS can be scavenged through chemoprevention utilizing natural antioxidant compounds present in foods and medicinal plants. In this review, research on the antioxi-dant potential of some medicinal plants of origin of Central India is considered.
文摘Haemoglobinopathies are group of diseases characterized by abnormalities both quantitative and qualitative in the synthesis of haemoglobin. Haemoglobinopathies consist of sickle cell anaemia (SCA), thalassaemia (βT) and variant haemoglobins. In India, they are responsible for the largest number of genetic disorders and hence are of great public health hazardous. In India major concerned haemoglobinopathic disorders are sickle cell anaemia and β-thalassaemia. Of the several abnormal haemoglobin molecules, four which are widely prevalent in India include: HbS, HbβT, HbE and HbD. Examination of 6463 individuals showed high incidences for haemoglobin variants, HbS and HbβT in different ethnic groups, the frequency being varies from 0% - 20% and 0% - 9% respectively. The frequency of HbS in Brahmins is 4.17%, in Kalar 5.41%, in Rajput 2.04%, in Muslims 3.73% in Maratha 2.08% in Bania 9.09% while in Teli it is 3.65%. Among the Scheduled castes and Nomadic tribal groups HbS ranges from 1% - 12%;in backward caste categories it varies from 3% - 16%;while in Scheduled tribes it ranges from 0% - 20%. The high magnitude of sickle cell trait has been noticed in the Pardhan (20.31%) followed by the Marar (16.10%), the Dhiwar (11.90%), the Gond (11.89%), the Mahar (11.81%) and the Bania (9.90%). A considerable high frequency (9.27%) of β-thalassaemia has been observed among the Sindhi population. Sporadic occurrence of HbβT and HbD among other communities suggested the gradual spread of the genes into the region. The present findings in 11 communities with the thalassaemia syndrome suggest that the β-thalassaemia is accompanied by raised level of HbA2. Unusual greater mean RBC and WBC suggest the high concentration of hypochromic microcytosis in anaemia. The mean MCV and MCH in HbβT and HbD are much lower than the normal ranges compared to HbS. The mean MCHC is much lower in HbβT, HbDD and HbS than the normal range. The cumulative gene frequency of haemoglobinopathies in India is 4.2%. With a population of over 1 billion and a birth rate of 28 per 1000, there are over 42 million carriers and over 12,000 infants are born each year with a major and clinical significant haemoglobinopathy. Out of these, clinically significant sickle cell anaemia and β-thalassaemic disorders account for almost equal numbers.
基金the Council of Scientific and Industrial Research, New Delhi, Government of India, for awarding him Shyama Prasad Mukherjee Fellowship [SPM-09/001(0328)/2020-EMRI]the Department of Science and Technology, Government of India, for the INSPIRE Fellowship [IF170168]
文摘The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary basins.This paper reports and discusses,for the first time,the occurrence of several cm-to dm-scale SSDS within sandstone successions of the Mesoproterozoic Kaimur Group(Vindhyan Supergroup),exposed at the Hanumandhara Hill of Chitrakoot-Satna border region,Madhya Pradesh State,India.The SSDS are confined to a deformed interval comprising seven individual sedimentary units of variable composition and texture,which are sandwiched between nearly horizontally undeformed sandstone beds.The SSDS consist of load structures(load casts,flame structures,pseudonodules and ball-and-pillow structures),contorted lamination,convolute lamination,boudins and pinch-and-swell structures,deformed cross-stratification,slump structures,clastic injections,fluid escape structures,and syn-sedimentary fractures/faults.The pre-sent study suggests that the formation of these SSDS is essentially related to a combination of processes(gravitational instability,liquefaction,fluidization,and fluid escape)predominantly induced by seismic shocks.In addition,the restricted occurrence of fractures/faults in these deformed layers emphasizes the passage of seismically-induced Rayleigh waves.Considering the observed types of SSDS,their lateral homo-geneity and geographic distribution along with the geodynamic framework of the Vindhyan Basin,the whole area can be tentatively attributed to having experienced moderate-to high-magnitude(M≥5)seismicity.The present study combined with earlier reports of seismically-induced SSDS,from other regionally disposed formations belonging to the Lower(e.g.,Kajrahat Limestone,Chopan Porcellanite,Koldaha Shale,Rohtas Limestone,and Glauconitic Sandstone of the Semri Group)and Upper(e.g.,Bhander Limestone of the Bhander Group)Vindhyan Supergroup,respectively,provides evidence for the constant regional-scale seismo-tectonic activity within the Paleo-Mesoproterozoic Vindhyan Basin.Importantly,this observation further suggests that the intracratonic basins can be active tectonically contrary to the earlier propositions.
基金supported by the University Grants Commission-New DelhiPrincipal J M Patel College Bhandara-India
文摘In order to infer the climate and the floral changes during the early Cenozoic of central India, a critical analysis has been made of the generic composition of Deccan Intertrappean series of India, which is now known to a greater extent. Most of the information regarding Deccan Intertrappean flora is derived from the assemblages from Vidharbha-Chhindwara region and Mandla District in central India. The Vidharbha-Chhindwara region constituted by taxa representing all major groups of plant kingdom belonging to different habitats like(i) marine(3 genera of doubtful marine alga)(ii) estuarine(27 species of palms, Nypa and Viracorpon like Pandanaceous fruits, Sonneratia, Cocos like plants)(iii) fresh water(6 genera of fresh water algae, water ferns, Eichhornia, Nymphea like hydrophytic angiosperms)(iv) marshy(5 genera of bryophytes, water ferns, Selaginella and Equisetum like pteridophytes and many angiospermic plants showing aerenchymatous tissue and few parts infected by fungal spores) and(v) terrestrial(2 families of gymnosperms and 15 families of arborescent angiosperms). Mandla-Dindori District mainly comprise angiospermous flora. These constitute 15 species of palm woods and woods of 25 dicot families indicating terrestrial dry habitat. The fossil flora so far recovered from these beds indicate that the tropical evergreen to semi-evergreen type forests with some moist deciduous plants, similar to the present day forests of Western Ghats, and northeast India, were flourshing around Vidharbha, Chhindwara and Mandla area of Central India during Upper Cretaceous-Lower Tertiary period, in contrast to the present day dry deciduous to moist deciduous types of forest. This flora was well represented in India in the past but has become restricted to Burma and Andaman-Nicobar Islands due to change in the climatic conditions. The comparison of the temperature data from these fossiliferous localities and the comparable modern areas clearly indicates that the climate in Central India was much more uniform throughout the year.
文摘The advent of modem forces and the changes in socio- economic patterns of forest dwellers have increased the pressures on the forests. In order to mitigate such pressures and also to protect the forests and wildlife the model of protected areas networks has shifted and en- hanced such pressures in the unprotected natural forests due to several reasons. Being a low profile category of protected status and continuous human settlements, the present study highlights the case of dry deciduous forests of Sarguja district of Chhattisgarh state of India. The major objec- tives of this study were to quantify the status of forests and wildlife and also to determine the extent of anthropogenic disturbances faced by the dry deciduous forests of central India. Transect and silent drive count methods were used for sampling wildlife and quadrat method was used for sampling vegetation. Besides, the local uses of various forest pro- duces were also studied in view of understanding the people dependency on forests. The forest vegetation, in the study area, was pre-dominated by Shorea robusta, which had Madhuca indica, Diospyrus melanoxylon and Buchnania lanzan as the major companion species. The forest had either the high girth class mature tree species or the saplings. The low vegeta- tion cover and density were due to the high anthropogenic pressures mainly in the form of heavy livestock grazing and collection of etlmo- botanically important species. The study though reveals that the area is not rich in wildlife and the forest is fragmented, the area still supports some important species, which include many rare and endangered plants and animals. The findings of this study have been discussed in view of the management and conservation of the forest and wildlife in the dry deciduous forests.
基金funded by National Bamboo Mission,Govt. of India
文摘Bamboo shoots can be harvested at different ages but the data on the changes in nutritional composition with age are scanty. We standardized harvesting age of bamboo shoots in central India to obtain best quality produce with respect to nutritional composition. The shoots harvested on different days (2–20 days after emergence from ground) were analyzed for their nutritional (dietary fibres, carbohydrates, proteins, total phenols, ascorbic acid, sodium, potassium, phosphorus, calcium, magnesium and phenolic acids) and anti nutritional (cyanogen) constituents. A significant variation (at p ≤ 0.5) was observed in the nutritional composition of shoots of Dendrocalamus asper, D. strictus and Bambusa tulda harvested at different days. An overall decrease was observed in proteins and total phenols while dietary fibres and carbohydrates increased with ages. Significant variation (at p ≤ 0.5) was also observed in phenolic acids while minerals did not vary significantly. Results revealed that the optimum harvesting age for D. asper, D. strictus and B. tulda was on 10–14 days, 6–10 days and 10–16 days (after emergence from the ground) respectively. These results can be used to obtain quality bamboo shoots.