In 1982 a fossil hominid calvaria was found in a middle Pleistocene deposit in the central Narmada valley of Madhya Pradesh, India, and was assigned to the new taxon Homo erectus narmadensis. Subsequently, morphometric studies of the specimen were conducted by two separate research teams from France and the United States, both in collaboration with Indian colleagues. Results of the most recent study, which includes morphometric and comparative investigations, lead to the conclusion that "Narmada Man" is appropriately identified as Homo sapiens. While the calvaria shares some anatomical features with Asian Homo erectus specimens, it exhibits a broader suite of morphological and mensural characteristics suggesting affinities with early Homo sapiens fossils from Asia, Europe, and Africa as well as demonstrating that the Narmada calvaria possesses some unique anatomical features, perhaps because the specimen reflects the incoherent classificatory condition of the genus Homo.
Site U1359 is located on the eastern levée of the Jussieau submarine channel on the Wilkes Land margin, East Antarctica. The upper approximately 60 m of the sediment core records more than 2.5 Ma of the depositional history. Present work focuses on inferring provenance from the heavy mineral fraction from the Pleistocene sediments. Clay and non-clay fractions were characterized using X-ray diffraction and micro-beam techniques. Metamorphic minerals including orthopyroxene, high-Ca garnet and high-Ti biotite indicate a source in a high-grade metamorphic terrain. Mixing from a low-to medium-grade metamorphic component is also indicated. Several basaltic rock fragments, showing mineralogical affinities to the Ferrar volcanic province in the Ross Sea sector, are present. The metamorphic component is correlatable with the Proterozoic East Antarctic cratonic shield component. Ordovician-Silurian ages for the euhedral xenotime and monazite, coupled with the Ferrar equivalent basalts, indicate an additional sediment source from the Ross Orogen along with that from the craton.
ice growth, nearby cratonic east antarctica shield provided biotite-rich sediments to the depositional site. On the other hand, the presence of smectite, only in the clay size fraction, suggests the effective role of sorting probably due to the deposition from distal source in ice retreat condition. During times of ice retreat, smectite-rich sediment derived from Ross Orogen is transported to the core site through surface or bottom water currents. Poor crystallinity of illite due to degradation further corroborates the ice retreat condition. The ice sheet proximal sediments of U1359 show that in the eastern part of Wilkes land, the 'warming' was initiated during late Miocene.
Sediment trap samples collected from the Western Arabian Sea yielded a rich assemblage of intact and non-living (opaque white) pteropod tests from a water depth of 919 m during January to September 1993. Nine species of pteropods were recorded, all (except one) displaying distinct seasonality in abundance, suggesting their response to changing hydrographical conditions influenced by the summer/winter monsoon cycle. Pteropod fluxes increased during the April--May peak of the summer monsoon, and reached maximum levels in the late phase of the southwest summer monsoon, probably due to the shallowing of the mixed layer depth. This shallowing of MLD coupled with enhanced nutrient availability provides ideal conditions for pteropod growth which is also reflected in corresponding fluctuations in the flux of the foraminifer Globigerina bulloides.Pteropod/planktic foraminifer ratios displayed marked seasonal variations, the values increasing during the warmer months of April and May when planktic foraminiferal fluxes declined. The variation in fluxes of calcium carbonate, organic carbon and biogenic opal show positive correlations with fluxes of pteropods and planktic foraminifera. Calcium carbonate followed by biogenic opal was the main contributor to the total particulate flux especially during the SW monsoon. In the study area pteropod flux variations follow the other flux patterns indicating that they too could be used as a potential tool for palaeoclimatic reconstruction of the immediate past.
Well-preserved and diverse microfossils are described for the first time from the Kushalgarh Formation of Ajabgarh Group around Baraud Village in Alwar District, Rajasthan. The assemblage comprises 10 genera and 17 species belonging to filamentous and coccoid blue-green algae, of which two genera and 10 species are new. The new forms are Myxococcoides compactus sp. nov., Palaeolyngbya distinctica sp. nov., P. elongata sp. nov., P. baraudensis sp. nov., Palaeoscytonema indica sp. nov., P. intermingle sp. nov., P. misrae sp. nov., Ghoshia bifurcata gen. et sp. nov., Primorivularia robusta sp. nov. and Vesicophycus problematieus gen. et sp. nov. Morphological features and the size range of taxa suggest procaryotic nature of the assemblage. Coccoid forms are aggregated in colonies and dominated by filamentous forms. Baraud assemblage contains hormogonia, heterocysts, and false branching and the most significant is the record of true branching showing Stigonematalean affinity. The composition of the microflora suggests that the rocks of the Delhi Supergroup are equivalent to Vindhyans. This is also supported by the radiometric dates.
A gravity core collected from the upper slope of southwest of Quilon at a water depth of 776 m (Lat: 8 • 12 263 N, Long: 76 • 28 281 E) was analysed for texture (carbonate free), calcium carbonate and organic carbon. Variation in silicic fraction seems to be controlled by silt, i.e., enrichment from 15 ka BP to 10 ka BP and then constant in Holocene. Below 15 ka BP, the silicic fraction gets depleted compared to the Holocene section with a minimum around 21 ka BP. Clay content remains nearly constant except in the Holocene where it shows an enrichment. Carbonate content of less than 63 micron when computed by subtracting coarse fraction content from the total carbonate suggests that the total carbonates are mainly concentrated in the finer fraction. All these carbonate phases show an inverse relationship with silicic fraction except in Holocene. Below 15 ka BP, CaCO 3 dominates in sediments comprising more than 65%, such an increase is also seen in the coarse fraction. Coarse fraction from these sections contains abundant nodular type aggregates encrusting small forams. This period is marked by a high sedimentation rate comparable to Holocene. These parameters suggest that the productivity and precipitation have increased in the Holocene due to the intensification of the southwest monsoon. During the last glacial maximum and early deglacial period the high sedimentation rate indicates redeposition of the carbonates from the existing carbonate lithofacies situated between Quilon and Cape Comorin probably due to the slope instability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.