Neotectonic Control on the Geomorphic Evolution of the Gangotri Glacier Valley, Garhwal Himalaya

The paper records evidences of neotectonic activities in the Gangotri glacier valley that are found to be responsible for the present-day geomorphic set-up of the area since the last phase of major glaciation. Geomorphological features indicate the presence of a large glacier in the valley in the geological past. Prominent planar structures present in the rocks were later on modified into sets of normal faults in the present-day Himalayan tectonic set-up giving rise to graben structures. The block nearest the snout is traversed by the NW-SE trending Gaumukh fault. A number of terraces mark the entrenchment of Bhagirathi River in this part. The contrasting drainage morphometric parameters of two sides of the valley and asymmetric recessional patterns of the tributary glaciers further document movement along the fault. The distribution and orientation of debris fans also seem to be controlled by neotectonic activity. The neotectonic activity that followed the process of deglaciation has brought the glacially carved, wide U- shaped valley in contact with the present-day fluvially incised narrow and relatively deep valley. The wider segments have become sites of active deposition of glacially eroded debris. The low gradient and excessive filling has resulted in the river attaining a braided nature in these segments.     

Nitrate reductase activity: A solution to nitrate problems tested in free and Immobilized algal cells in presence of heavy metals

Every organism has different potential to accumulate NO₃ ^?from the environment. Nitrate reduction processes are perhaps most significant in maintaining water quality by alteration of nitrate to nitrite. A comparative study between the nitrate reductase NR activity of green and blue green algae in presence of heavy metals is being conducted to present a situation where nitrate reductase process may be affected in presence of heavy metals. Metals interacted negatively with the nitrate reductase activity of a blue green alga, Anacystis nidulans and green algae, Chlorella vulgaris in both free and immobilized state. The activity was more repressed in C. vulgaris in presence of Ni compared to Zn and Cd. However, Cd was more toxic to NR activity in A. nidulans (free state). Metal dependent variation between free and immobilized cells were found to be significant (P< 0.01) however, the concentration dependent pattern in the activity between free and immobilized state was non significant in both the test organisms. C.vulgaris is more efficient in conversion of nitrate to nitrite compared to A.nidulans in presence of heavy metals.     

Holocene tectono-geomorphic evolution of Haryana plains,Western Ganga plain,India

Haryana plain is the drainage divide between the Ganga plain in the east and the Indus plain in the west. Being a part of the Himalayan foreland, its geomorphology, sedimentation processes, and tectonism are broadly controlled by the Himalayan tectonics. Soil and geomorphological mapping in Haryana plain bring out geomorphic features such as paleochannels, various active drainage patterns, and landforms such as old fluvial plains, floodplains, piedmonts, pediments, terminal fans, and eolian plains. Based on the degree of soil development, and Optical stimulated luminescence (OSL) ages, the soil-geomorphic units were grouped into six members (QIMS-I to VI) (Quaternary Indus Morphostratigraphic Sequence) of a morphostratigraphic sequence: QIMS-VI 9.86–5.38 Ka, QIMS-V 5.38–4.45 Ka, QIMS-IV 4.45–3.60 Ka, QIMS-III 3.60–2.91 Ka, QIMS-II <?2.91–1.52 Ka, and QIMS-I <?1.52 Ka. OSL chronology of different geomorphic features suggests six episodes of tectono-geomorphic evolution in the region since 10 Ka. Neotectonic features such as nine faults, two lineaments, and five fault-bounded tectonic blocks have been identified. Independent tilting and sagging of the blocks in response to neotectonics have resulted in modification of landforms, depositional processes, and hydro-geomorphology of the region. Major rivers like the Yamuna, the Ghaggar, and the Sutlej show different episodes of shifting of their courses. Lineament controlled few extinct channels have been recorded between 20 and 25 m depth below the surface in the ground-penetrating radar (GPR) profiles. These buried channels are aligned along the paleo-course of the Lost Saraswati River interpreted from the existing literature and hence are considered as the course of the lost river. Seven terminal fans have been formed on the downthrown blocks of the associated faults. The Markanda Terminal Fan, the first of such features described, is indeed a splay terminal fan and was formed by a splay distributary system of the Markanda River. Association of three terminal fans of different ages with the Karnal fault indicates the segment-wise development of the fault from west to east. Also, comparison with other such studies in the Ganga plain to further east suggests that the terminal fans formed by streams with distributary drainage pattern occur only in semiarid regions as in the present area and thus are indicators of semiarid climate/paleoclimate. Though the whole region is tectonically active, the region between the Rohtak fault and Hisar fault is most active at present signified by the concentration of earthquake epicenters.     

Remote sensing for landscape parameters and scale effect

Journal of the Indian Society of Remote Sensing - Development activities must be compatible for possibilities and limitation of natural environment and resources. Predevelopmental analysis must...     

Potential of fungus <Emphasis Type="Italic">Trichoderma harzianum</Emphasis> for toxicity reduction in municipal solid waste leachate

The purpose of this research was to test the ability of selected fungus Trichoderma harzianum for municipal solid waste leachate treatment. The research carried out by inoculating the enzyme produced by T. harzianum with different ratio (10% up to 80% v/v) of solid waste leachate. The findings clearly indicated that the enzymatic addition was effectively acted (86.09% of chemical oxygen demand removed), and the rate of chemical degradation amended treatment enhanced as compared to control. Also, the enzymatic addition excellently reduced the inhibition of germination (35.8 ± 0.7) of seed (Zea mays L.) and improved the environmental quality of treated leachate. Therefore, these results can be use to articulate the preliminary feedstock for pilot to field-scale application.     

Hydrogeochemistry of the Koyna River basin,India

Hydrogeochemistry of the Koyna River basin, famous for the Koyna earthquake (magnitude 7) of 1967, has been studied. Basalt is the primary aquifer; laterites, alluvium, and talus deposits form aquifers of secondary importance. Groundwater generally occurs under water table conditions in shallow aquifers. Deeper aquifers are associated only with basalts. One hundred and 87 water samples were collected from various sources, such as dugwells, borewells, springs, and surface water, including 40 samples for analysis of iron. Only major constituents were analyzed. Analyses show that the concentrations of Ca²⁺ exceed that of Mg²⁺ in almost all water samples; the concentrations of Na⁺ are generally next to Ca²⁺ and are always higher than that of K⁺; and CO₃ ^2– and SO₄ ^2– are very low and are often negligible. Groundwater in borewells tapping deeper aquifers has higher mineralization compared to that in dugwells representing shallow aquifers. Majority of the water samples are dominated by alkaline earths (Ca²⁺, Mg²⁺) and weak acids (HCO₃ ⁻, CO₃ ^2–). Groundwater from shallow aquifers is generally calcium-bicarbonate type (53%) and calcium-magnesium-bicarbonate type (27%). In case of deeper aquifer, it is mostly calcium-magnesium-bicarbonate type (29%), sodium-bicarbonate type (24%), calcium-bicarbonate type (19%), calcium-magnesium-sodium-bicarbonate type (19%) and sodium-calcium-bicarbonate type (9%). Groundwater water is generally fit for drinking and irrigation purposes, except in the lower reaches of the Koyna River basin, which is affected by near water logging conditions.     

Age and geochemistry of the Newania dolomite carbonatites, India: implications for the source of primary carbonatite magma

The Newania carbonatite complex of India is one of the few dolomite-dominated carbonatites of the world. Intruding into Archean basement gneisses, the rocks of the complex have undergone limited diversification and are not associated with any alkaline silicate rock. Although the magmatic nature of the complex was generally accepted, its age of emplacement had remained equivocal because of the disturbed nature of radioisotope systems. Many questions about the nature of its mantle source and mode of origin had remained unanswered because of lack of geochemical and isotopic data. Here, we present results of our effort to date the complex using ¹⁴⁷Sm–¹⁴³Nd, ²⁰⁷Pb–²⁰⁶Pb and ⁴⁰Ar–³⁹Ar dating techniques. We also present mineral chemistry, major and trace element geochemistry and Sr–Nd isotopic ratio data for these carbonatites. Our age data reveal that the complex was emplaced at ~1,473 Ma and parts of it were affected by a thermal event at ~904 Ma. The older ²⁰⁷Pb–²⁰⁶Pb ages reported here (~2.4 Ga) and by one earlier study (~2.3 Ga; Schleicher et al. Chem Geol 140:261–273, 1997) are deemed to be a result of heterogeneous incorporation of crustal Pb during the post-emplacement thermal event. The thermal event had little effect on many magmatic signatures of these rocks, such as its dolomite–magnesite–ankerite–Cr-rich magnetite–magnesio-arfvedsonite–pyrochlore assemblage, mantle like δ¹³C and δ¹⁸O and typical carbonatitic trace element patterns. Newania carbonatites show fractional crystallization trend from high-Mg to high-Fe through high-Ca compositions. The least fractionated dolomite carbonatites of the complex possess very high Mg# (≥80) and have similar major element oxide contents as that of primary carbonatite melts experimentally produced from peridotitic sources. In addition, lower rare earth element (and higher Sr) contents than a typical calcio-carbonatite and mantle like Nb/Ta ratios indicate that the primary magma for the complex was a magnesio-carbonatite melt and that it was derived from a carbonate bearing mantle. The Sr–Nd isotopic data suggest that the primary magma originated from a metasomatized lithospheric mantle. Trace element modelling confirms such an inference and suggests that the source was a phlogopite bearing mantle, located within the garnet stability zone.     

Hydrogeologic framework of the Deccan terrain of the Koyna River basin, India

The Koyna River basin in India drew the attention of geoscientists after an earthquake (magnitude 7) in 1967. Since then, detailed geological, tectonic, and seismic investigations of this river basin have been carried out by several workers. However, very little study has been done on its hydrogeological framework. The present work aims at filling this gap. Basalts, laterites, alluvium, soils, and talus deposits form shallow unconfined aquifers, with transmissivity of 27–135 m²/d and a regional specific yield of 0.012. In shallow basaltic aquifers, the lower part of the highly weathered and highly jointed horizon above, and the poorly weathered and highly jointed horizon below, form the most potential zone for groundwater occurrence. Well yields in the deeper basaltic aquifers are directly related to the occurrence of lineaments, whereas at a shallower level they are related to geomorphic features. Spring discharges are highly dependent on their source aquifers and areas of recharge. They have a mean winter discharge of 46 m³/d and a summer discharge of 28 m³/d. Chemically, groundwaters are dominated by alkaline earths (Ca²⁺, Mg²⁺) and weak acids (HCO₃ ^–, CO₃ ^–); they are calcium-bicarbonate type (53%) and calcium-magnesium-bicarbonate type (27%) at shallower levels; and calcium-magnesium-bicarbonate type (29%), sodium-bicarbonate type (24%), calcium-bicarbonate type (19%), and calcium-magnesium-sodium-bicarbonate type (19%) in deeper aquifers. The Koyna River basin is characterized by both scarcity and abundance of groundwater. In the water-scarce areas in the dissected plateaus, artificial recharge of aquifers through construction of several recharge structures at suitable locations is highly recommended. In the water-abundant areas in the central valley, on the other hand, expanded consumptive use of water resources is encouraged. Electronic Publication     

Implication of drainage basin parameters of Chhoti Gandak River,Ganga Plain,India

The drainage basin parameters of the groundwater-fed Chhoti Gandak River originating in the terai area of the Ganga Plain were analyzed using topographical sheets, satellite data, and field documentation with emphasis to its implication for flood mitigation and recharging of groundwater. The analyses indicate dominance of first order streams, gentle slope gradient, low surface run-off, low sediment production, high infiltration rate, and low value of basin relief. The low water storage capacity, spreading of water and concentration of peak discharge in the distal part of the river basin explain that whenever precipitation is high in the catchment area there is flood in the distal part of the basin. The bifurcation ratio value (4.34) of this basin describes that the drainage is carved naturally by slope and local relief and not influenced by geological structures like lineaments and faults.     

Natural hazards in the Ghaghara River area, Ganga Plain, India

The Ganga Plain is one of the most densely populated regions of the world due to its fertile soil and availability of water. The rivers of this plain are the lifeline for millions of people of this vast alluvial plain. All rivers of this plain are characterized by narrow channel confined within wide valley. Continuously increasing pressure of population on this plain has led to the intensification of settlement even into the valley of the river. This unplanned expansion has enhanced the damage due to flooding during high-discharge period and lateral erosion during low-discharge period. Flooding and lateral erosion are identified as fluvial hazards in the Ghaghara River area. Extensive studies have been carried out on flooding, but not much attention has been paid to the phenomenon of lateral erosion. However, it has been observed that lateral erosion is an independent fluvial hazard that operates during low-discharge period. Low degree of compaction due to the presence of sandy and silty facies in the river valley deposits, mass movement, palaeocurrent pattern, and fractures initiates and enhances the lateral erosion. The present paper deals with the fluvial hazards in the Ghaghara River area.