Fine sand and clay mineralogy of selected horizons of forest soils representing various landforms of Maldeota, Satengal and Dhanaulti areas of Raipur and Jaunpur ranges of Mussoorie forest division of Garhwal Himalaya were investigated. Light minerals constituted more than 80 percent of total fine sand fractions and consisted of quartz, feldspar and mica in order of their abundance. Heavy minerals occurred in minute amounts and constitute 20 percent of the minerals and were dominated by opaque minerals followed by biotite, chlorite, chloritized mica, zircon, garnet, hornblende, tourmaline, rutile etc. Quartz is the dominant mineral in Maldeota and Satengal sites followed by Dhanaulti while feldspar and mica are abundant in Dhanaulti followed by Maldeota and Satengal. Among the heavy minerals opaque minerals, biotite and calcite are present in appreciable quantity in all the three sites viz. Maldeoata, Satengal and Dhanaulti. The other heavy minerals are present in small quantities at all the three sites. The clay fractions from the soils of Maldeota are characterized by illite as the dominant clay mineral associated with kaolinite, chlorite, vermiculite and quartz. The clays from Satengal contained mixture of illite as dominant mineral followed by mica, mixed layer minerals, vermiculite, chlorite and quartz. The soil clays from Dhanaulti indicates the presence of illite, muscovite, kaolinite, mixed layer minerals, chlorite and small traces of vermiculite, calcite and quartz. Differences in mineralogical make up were mostly associated with nature and composition of parent material and degree of weathering. The study, therefore, suggests that soils of the study area contained low to moderate amount of weatherable minerals indicating their podzolic nature.
The Tibetan Plateau is considered to be one of the best natural laboratories for seismological research. This study sought to determine the spatial variations of b-values in the western part of the Tibetan Plateau, along with its surrounding areas, and the relation with the region’s fault blocks. The study region lies within 27–36.5° N, 78–89° E, and its fracture structure consists of strike-slip faults, as well as normal and thrust faults. A catalog record from 2009–2019 provided 4431 well-centered earthquakes that varied in magnitude from 0.1 to 8.2 M. The record was obtained from China’s seismological network, which is capable of recording low magnitudes to analyze b-values in the study area. The key findings of this study are as follows: (1) the range of earthquake depth in the region was 0–256 km, with the depth histogram showing a high frequency occurrence of shallow earthquakes in the area; (2) a time histogram showed that the major earthquakes occurred between 2014–2015, including the notable 2015 Gorkha earthquake (M = 8.2); (3) the b-value computed in the study area was 0.5 to 1.6, but in most of the study area, the b-value ranged from 0.6 to 0.9, which was a low to intermediate value, due to the presence of strike-slip faults in the central part of the study area and underthrusting in the region (south of the study area); and (4) a high b-value was found in the northwestern and eastern regions of the area, which proved that the area is prone to small earthquakes in the near future. The study also showed that the central and southern areas of the study region had low to intermediate b-values, meaning that it is prone to destructive and massive earthquakes with high magnitudes, such as the Gorkha earthquake (southern part of the study area). Low b-values revealed the degree of variation in rock properties, including large stress and strain, a fractured medium, a high deformation rate, and large faults. Small b-values were observed when the stress level was high in the investigated region, which might be used to predict a massive high-magnitude earthquake in the near future.
The Hangu Formation (Paleocene) consists of sandstone, siltstone, carbonaceous shale, coal and laterite. It is well exposed in the Trans Indus Surghar range and the southern Hazara basin. The sandstone is yellowish brown, fine to coarse grained and medium to thick bedded. The sandstone of the Hangu Formation is classified as quartz arenite on the Q-F-L diagram. It is mostly grain supported and are cemented by silica cement. The study of different stratigraphic sections reveal that Hangu Formation can be sub-divided into a number of lithofacies on the basis of sedimentary structures and lithological variations. These include lateritic lithofacies, coal and carbonaceous shale, cross-bedded sandstone, bioclastic limestone and bioturbated sandstone. All these lithofacies are well-developed in the Baroch Nala section of the Surghar range except the lateritic lithofacies which contains a thin bed of ferruginous clay. In the studied sections of the Hazara basin, the lateritic lithofacies is the only well-developed lithofacies present in the area. The coal occurs at two stratigraphic levels in the Baroch Nala section. The lower coal seam is thick and its chemical study indicates higher calorific value and carbon content than the upper coal seam and with low moisture/ash content. On the basis of the calorific value, the coal of the Hangu Formation is characterized as high volatile bituminous. The degree of laterization is strong in the Langrial and Khanpur sections and moderate in Baroch Nala section.
The coal bearing Patala Formation (ranges from 5 9O m thick) is composed of dark gray, fossil iferous shale interbedded with white quartzose sandstone, siltstone, marl, and limestone. Coal and carbonaceous shale deposits generally occur as a single bed «1 m thick) that is commonly split by dark gray shale or thin «0.25 m thick) bands of quart zose sandstone. These laterally discontinuous coal and carbonaceous shale beds overlie and are laterally associated with northeasterly trending, elongate, quartzose sandstone bodies (ranges from 1 2O m thick, fig. 2) and are interpreted to have been deposited in back barrier and near marine environments (Alam and others, 1987; Warwick and Shakoor, 1988a,b). METHODS Seventeen of the samples described in this report were collected as core during a drilling program conducted by the Geological Survey of Pakistan in the Eastern Salt Range. Eleven of these samples were shale and carbonaceous shale (sediments that comprise the majority of the coal-bearing Patala Formation) that were collected from drill hole DSM-17 (fig. 2; Appendix-I). Forty three samples were collected as whole bed or bench channel samples from active working faces of 35 underground coal mines in all parts of the Salt Range coal field (Appendix I). Coal and carbonaceous shale channel samples were collected following ASTM (1986) procedures. Roof and floor rock, and partings greater than 1 cm thick were not included in the coal and carbonaceous shale channel and core samples. The proximate and ultimate analytical data reported here was done in the laboratories of Geochemical Testing Incorporated in Somerset, Pennsylvania, and Dickinson Laboratories Incorporated of El Paso, Texas using ASTM <1986) methods. Randomly selected coal and carbonaceous shale samples were analyzed for major , minor , and trace element contents by USGS laboratories in Reston, Virginia using methods described in Golightly and Simon (1989). Correlation coefficients were calculated among trace element, proximate, ultimate, location, and coal bed thickness data. Few samples have a complete set of analytical data; therefore, the number of samples used in each correlation will vary. Sample locations (Areas 1, 2, and 3 on fig. 2) were assigned to the western, central, and eastern parts of the Salt Range coal field. RESULTS
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