Geology of Ladakh,Lahaul and spiti regions of Himalaya with special reference to the stratigraphic position of flysch deposits

An attempt has been made to produce the geological map of Ladakh, Lahaul and Spiti regions of Himalaya on the basis of the field work done by the authors and the observations made by earlier workers. The stratigraphy of this region has been discussed in the light of new fossil finds from different stratigraphical horizons. Stratigraphical columns have been prepared and the formations of this region have been correlated with those exposed in other parts of the Himalaya. The age of the flysch deposits (Indus Flysch of Ladakh and Chikkim Shales of Spiti) has been defined on the basis of the microfauna.

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Zusammenfassung Aus Feldarbeiten und bereits vorliegenden Fakten resultierte eine neue geologische Karte des Gebietes von Ladakh, Lahaul und Spiti im Himalaya. Die Stratigraphie wird mit Hilfe neuer Fossilfunde geändert und mit anderen Teilgebieten des Himalayas verglichen. Das Alter der Flyschserien (Indus-Flysch von Ladakh und Chikkim-Shales von Spiti) wurde mit Hilfe von Mikrofaunen bestimmt.

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Résumé Les levés de terrain des auteurs, combinés avec des travaux antérieurs, ont permis de dresser une nouvelle carte géologique du Ladakh, Lahaul et Spiti dans l'Himalaya. La stratigraphie a été modifiée grâce à de nouvelles découvertes de fossiles et comparée avec celle d'autres régions de l'Himalaya. L'âge de la série du flysch (Flysch de l'indus de Ladakh et schistes de Chikkim de Spiti) a été déterminé à l'aide de microfaunes.

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Vertical structure of orographic precipitating clouds observed over south Asia during summer monsoon season

Orography profoundly influences seasonal rainfall amount in several places in south Asia by affecting rain intensity and duration. One of the fundamental questions concerning orographic rainfall is nature of the associated precipitating clouds in the absence of synoptic forcing. It is believed that these clouds are not very deep, however, there is not much information in the literature on their vertical structure. The present study explores the vertical structure of precipitating clouds associated with orographic features in south Asia using data collected with the precipitation radar on board the Tropical Rainfall Measuring Mission satellite. Two types of precipitating clouds have been defined based on cloud echo top height, namely, shallow echo-top cloud and medium echo-top cloud. In both, radar reflectivity factor is at least 30 dBZ at 1.5 km altitude, and tops of shallow and medium echo-top clouds lie below 4.5 km and between 4.5 and 8 km, respectively. The Western Ghats contains the highest fraction of the shallow echo-top clouds followed by the adjacent eastern Arabian Sea, while the Khasi Hills in Meghalaya and Cardamom Mountains in Cambodia contain the least fraction of them. Average vertical profiles of shallow echo-top clouds are similar in different mountainous areas while regional differences are observed in the medium echo-top clouds. Below 3 km, precipitation liquid water content in medium echo-top clouds is the highest over the Western Ghats and the eastern Arabian Sea. The average precipitation liquid water content increases by \(0.16\,\hbox { gm m}^{-3}\) for shallow echo-top clouds between 3 and 1.5 km altitude, while the corresponding increase for medium echo-top clouds is in 0.05–0.08 \(\hbox { gm m}^{-3}\) range.     

A new find of lamproite dyke near Chintalapalle area,NW margin of the Cuddapah basin,eastern Dharwar craton,southern India

A singular outcrop of a lamproite dyke is located ~1.5 km south-west of Chintalapalle village at the NW margin of the Cuddapah basin, eastern Dharwar craton, southern India.. The dyke trends E-W and is emplaced within the granitic rocks belonging to the peninsular gneissic complex. The lamproite dyke has a porphyritic to weakly porphyritic texture comprising microphenocrysts of sanidine, and potassic richterite set in a groundmass rich in carbonate, and chlorite with rutile and titanate as accessory phases. This new occurrence of lamproite is located mid-way between the well-known Narayanpet kimberlite field towards the west and the Ramadugu and Vattikod lamproite fields in east. The Chintalapalle lamproite dyke, together with those from Vattikod, Ramadugu, Krishna and Cuddapah basin lamproite fields, constitute a wide spectrum of ultrapotassic magmatism emplaced in and around the Palaeo-Mesoproterozoic Cuddapah basin in southern India.     

An elegant coupled model

This paper deals with a new family of coupled wave equations which are basically nonlinear in nature. An analyt-ical study enables us to show that these equations exhibit solitary wave profiles. Finally some remarks are drawn from the standpoint of atmospheric problem.     

http://www.sciencedirect.com/science/article/pii/S1674987111001277

A numerical model is developed for investigating the evolution of fracture permeability in a coupled fracture-matrix system in the presence of fracture-skin with simultaneous colloidal and bacterial tr...     

Temporal transition analysis of coal mine fire of Jharia coalfield,India, using Landsat satellite imageries

Coal is dominant energy source of world at large and India in particular for several decades and expected to being continued for foreseeable future. However, fire in this fossils fuel is still a global catastrophe for the major coal-producing countries. There are several direct and cascading distress of coal mine fire has been encountered by environment, economy, safety and society. Without knowledge of actual status and extent of coal mine fire, any scope for its better managements may be futile. In India, the coal mine fire of well-known Jharia coalfield (JCF) has been continued since last ten decades and still spreading towards newer areas. The aim of this paper is to highlight the chronological net lateral spatial changes in coal mine fire areas of JCF using Landsat satellite thermal imageries. The mapping of coal mine fire area of JCF during 1988–2013 has been carried out with consecutive 5-year intervals. The lateral changes in surface and subsurface fire areas along with propagation towards new area have been studied. The study also included to evaluate changes of status and extent fire during this time span and effect of its management efforts. On the basis of aforementioned analysis, the study concludes a slow reducing trend in coal mine fire area during last 25 years.     

Stable isotopes of carbon and nitrogen in suspended matter and sediments from the Godavari estuary

Spatial distribution of the carbon and nitrogen content and their isotopic enrichment in suspended matter and sediments were measured in the Godavari estuary to identify the sources and transformation mechanism of organic matter. Significant variability in isotopic distribution was found over the entire length of the Godavari estuary, suggesting multiple sources of organic matter. The mean isotopic ratios (δ¹³C_sed −25.1 ± 0.9, δ¹³C_sus −24.9 ± 1, δ¹⁵N_sed 8.0 ± 2 and δ¹⁵N_sus 6.5 ± 0.9‰) and elemental concentrations (C_sed 0.45 ± 0.2%, C_sus 0.9 ± 0.7%, N_sed 0.07 ± 0.05% and N_sus 0.16 ± 0.1%) support a predominantly terrigenous source. Significant enrichment in the isotopic ratios of δ¹³C from the upper to lower estuary in both suspended (−27.5 and −24.3‰, respectively) and sedimentary (−26.2 and −24.9‰, respectively) phases indicates a decrease in the influence of terrigeneous material toward the mouth of the estuary. A significant positive relationship exists between the δ¹³C of suspended and sediment, which indicates that these two organic carbon pools are likely coupled in the form of a significant exchange between the two phases. A positive relationship exists between chlorophyll a and suspended organic matter, which may mean that a significant source of organic carbon is the in situ produced phytoplankton. But, applying a simple mixing model to our isotopes, data yielded about 46% as the contribution of the terrestrial source to suspended matter, which may support the excessive heterotrophic activity in the Godavari estuary reported earlier.