Bokaro Coalfield Research Articles

GIS-Based Evaluation of Water Quality Index of Groundwater Resources in West Bokaro coalfield, India

Water Quality Index (WQI), a technique of rating water quality, is an effective tool to assess quality and ensure sustainable safe use of water for drinking. The present work is aimed to assess the groundwater quality of West Bokaro coalfield region for knowing the suitability of drinking purpose by calculating the WQI and using Geographical Information System (GIS) techniques. Thirty three groundwater samples were collected from dug wells during post-monsoon, 2012 for comprehensive physico-chemical analysis. Ten parameters were considered for calculating the WQI such as: pH, fluoride (F ), chloride (Cl ), nitrate (NO 3 ), sulphate(SO 4 2), bicarbonate (HCO 3 ) calcium(Ca 2+ ), magnesium (Mg 2+ ), total hardness (TH) and total dissolved solid (TDS). The spatial distribution maps of the above mentioned parameters were prepared by using GIS, software. The computed WQI value ranges from 21 to 131 with an overall average of WQI value 73. More than half of the locations fall in Excellent to Good category indicating the groundwater in the study area is suitable for drinking purposes.

Isotopic and trace element geochemistry of alkalic–mafic–ultramafic–carbonatitic complexes and flood basalts in NE India: Origin in a heterogeneous Kerguelen plume

The Archean East Indian cratonic margin was affected by the Kerguelen plume (KP) ∼117Ma, causing flood-basalt eruptions of the Rajmahal–Bengal–Sylhet Traps (RBST). The RBST cover ∼one million km2 in and around the Bengal Basin as alkalic–ultrabasic intrusives in the west and Sikkim in the north, and Sylhet basalts and alkalic–carbonatitic–ultramafic complexes in the Shillong plateau – Mikir hills farther east of the Rajmahal–Bengal Traps. We provide new Nd–Sr–Pb-isotopic and trace element data on 21 unreported discrete lava flows of the Rajmahal Traps, 56 alkalic–carbonatitic–mafic–ultramafic rocks from four alkalic complexes, and three dikes from the Gondwana Bokaro coalfields, all belonging to the RBST. The data allow geochemical correlation of the RBST with some contemporaneous Kerguelen Plateau basalts and KP-related volcanics in the southern Indian Ocean. Specifically, the new data show similarity with previous data of Rajmahal group I–II basalts, Sylhet Traps, Bunbury basalts, and lavas from the southern Kerguelen Plateau, indicating a relatively primitive KP source, estimated as: εNd(I)=+2, 87Sr/86Sr(I)=0.7046, with a nearly flat time-integrated rare earth element (REE) pattern. We model the origin of the uncontaminated RBST basalts by ∼18% batch melting with a 2× chondritic KP source in the spinel-peridotite stability depths of 60–70km in the mantle. The new geochemical data similar to the Rajmahal group II basalts indicate a light REE enriched average source at εNd(I)=−5, 87Sr/86Sr(I)=0.7069. Our geochemical modeling indicates these lavas assimilated granulites of the Eastern Ghats, reducing the thickness of the continental Indian lithosphere. Lack of an asthenospheric MORB component in the RBST province is indicated by various trace element ratios as well as the Nd-Sr isotopic ratios.Three alkalic complexes, Sung, Samchampi, and Barpung in NE India, and one in Sikkim to the north are of two groups: carbonatites, pyroxenites, lamproites, nephelinites, sovites, melteigite in the first group and syenites and ijolites in the second. The Nd–Sr–Pb-isotopic and trace element geochemistry of the first group of carbonatitic–ultrabasic rocks are consistent with similar data of the RBST lavas of the present and previous studies, and are modeled as derived from a relatively primitive carbonated garnet peridotite source in the KP. In contrast, the syenites and ijolites of the second group show a wide range of Nd–Sr–Pb isotopic compositions, modeled by low-degree melts of an ancient recycled carbonated eclogite also in the KP. The KP thus reflects heterogeneities in the lower mantle-derived plume with carbonated components yielding ultrabasic melts at greater depths with low-degree melting, followed by rise of the plume at shallower depths causing tholeiitic flood basalt volcanism. Collectively, these data imply a zone of influence of the plate-motion-reconstructed KP head for ∼1000km around the Bengal Basin, as represented by the widely scattered and diverse rock types of the RBST.

Optimization of Solvent Extraction Process Parameters of Indian Coal

Medium coking coals from West Bokaro coalfield, India, were extracted with N-methyl-2-pyrrolidone (NMP) and ethylenediamine (EDA) under reflux condition at atmospheric pressure. The objective of the study was to maximize the clean coal yield maintaining the specified clean coal ash content. Experimentations using three level full factorial designs were carried out to elucidate the importance of variables such as extraction time, coal to solvent ratio, and filtration mesh size upon solvent extraction of coal. To determine the significance of the effects, Pareto chart, residual analysis, and surface plots were used. It was found that the maximum extraction yield was obtained for 1 h extraction time and 1:12 coal to solvent ratio. Finer mesh (0.025 mm) size in filtration was found favorable in producing low ash clean coal (CC). Under optimum conditions it was possible to produce clean coal with 6% ash and 55% yield for coals having about 29% ash.

Palynological dating of a subsurface coal bearing horizon in East Bokaro Coalfield, Damodar Basin, Jharkhand, India

Palynological dating of a subsurface coal bearing horizon in East Bokaro Coalfield, Damodar Basin, Jharkhand, India

359 Palyno-petrographical facet and depositional account of Gondwana sediments from East Bokaro coalfield, Jharkhand, India

359 Palyno-petrographical facet and depositional account of Gondwana sediments from East Bokaro coalfield, Jharkhand, India

Evaluation of coal bed methane potential of coal seams of Sawang Colliery, Jharkhand, India

The coal seams of Sawang Colliery, East Bokaro Coalfields are bituminous to sub-bituminous in nature and categorized as high gaseous seams (degree II to degree III level). These seams have the potential for coal bed methane (CBM) and their maturity increases with increasing depth, as a result of enhanced pressure-temperature conditions in the underground. The vitrinite maceral group composition of the investigated coal seams ranges from 62.50–83.15%, whereas the inertinite content varies from 14.93–36.81%. The liptinite content varies from 0.66% to 3.09%. The maximum micro-pores are confined within the vitrinite group of macerals. The coal seams exhibit vitrinite reflectance values (Ro% calculated) from 0.94% (sample CG-97) to 1.21% (sample CG-119). Proximate analyses of the investigated coal samples reveal that the moisture content (M%) ranges from 1.28% to 2.98%, whereas, volatile matter (VM%) content is placed in the range of 27.01% to 33.86%. The ash content (A%) ranges from 10.92% to 30.01%. Fixed carbon (FC%) content varies from 41.53% to 55.93%. Fuel ratio variation shows a restricted range from 1.53 to 1.97. All the coal samples were found to be strongly caking and forming coke buttons. The present study is based on the adsorption isotherm experiments carried out under controlled P-T conditions for determination of actual gas adsorption capacity of the coal seams. This analysis shows that the maximum methane gas adsorbed in the coal sample CG-81 is 17 m3/t (Std. daf), at maximum pressure of 5.92 MPa and experimental temperature of 30°C. The calculated Langmuir regression parameters PL and VL range from 2.49 to 3.75 MPa and 22.94 to 26.88 m3/t (Std. daf), respectively.

Indialite in xenolithic rocks from Somma-Vesuvius volcano (Southern Italy): Crystal chemistry and petrogenetic features

The rare mineral indialite, a hexagonal high-temperature form of cordierite, has been discovered for the first time in Italy at Somma-Vesuvius volcano in unusual pyrometamorphic ejecta. The indialite- bearing xenoliths are composed of several pale yellow fragments consisting of very fine-grained indialite with traces of cristobalite. On the surface of the fragments, colorless indialite and pale-blue, prismatic osumilite crystals form whitish crusts, with subordinate phlogopite and trace amounts of corundum. Gypsum and Fe-oxides are ubiquitous. Chemical composition of the Italian indialite is characterized by high X Mg (~0.95) and significant K 2 O (~1.4 wt%). Single-crystal X-ray diffraction measurements give cell dimensions very similar to those of the indialite from the Bokaro coalfield. The diffraction pattern shows no significant deviation from the symmetry conditions of the space group P 6/ mcc , which is the space group generally accepted for high-cordierite. The presence of guest K (and lesser Ca) in the sixfold channel does not produce appreciable distortions in the framework of T2 tetrahedra, probably because of the weak interactions between guest and the ring O2 atoms. Indialite-bearing rocks originated through a pyrometamorphic process at shallow depth and at maximum temperature close to ~1200 °C. Rapid crystallization and subsequent quenching favored a higher symmetry, thus “freezing” the space group P 6/ mcc .

On the species of genus Glossopteris from barakar formation of Karanpura and Bokaro coalfields, India

The assemblage of fossil plants of Barakar Formation from North Karanpura. South Karanpura and West Bokaro Coal fields contain thirty-two species of the genus Glossopteris. Among these three species are new, twenty-one species are recorded for the first time from the Barakar Formation of South Karanpura, nine species from North Karanpura and eight species from West Bokaro group of coalfields. The range of variation within species have been observed by taking more than one specimens as complex, from different collieries of these three coal fields. The comparison. diagnosis and range of distribution of species in context of other coalfields have also been given.
 In the present study. the speciation of genus Glossopteris is based on morphography and cuticular features. Here, morphographical characters have been critically analysed in order to find a reasonable basis for precise specific delimitations. Morphographical circumscriptions are further verified by characters of the cuticle wherever available but only as associated or supportive characters.

Role of Storm in Ramgarh and West Bokaro Coalfields and Its Implication in Adjacent Peninsular Gondwana Coalfields, India

The Permian Gondwana sediments in the Damodar-Koel Valley, Rajmahal and Deoghar basins were deposited on a northwest palaeoslope in broad valleys within uplands (e.g. Aravalli-Vindhyan, Chattisgarh, Chotanagpur and Santhal Parganas upland). The main winds during Permian Period were mostly the westerly winds coming from the northwest low pressure belt in the Tethys, which found no barrier between the Vindhyan and Santhal Parganas uplands and then changing its direction, moving towards east. Frequent storm activity also took place from the northwest Tethyan low pressure belt and followed the same path of wind. Possibly there was a barrier in the form of a dense rain forest or elevated land at the place of East Bokaro coalfield and its adjoining southern part, which acted as a deterrent and minimized the effect of storm towards further east of the Damodar Valley. Intense tropical hurricanes for the generation of storm generated bedforms, cannot be ruled out, which probably, in some cases, causes marine inundation/flooding deep into the landmass and also mass (?) uprooting of trees.

Early Permian Palaeoenvironment in Damodar Valley Coalfields, India: an Overview

In the Damodar Valley Basin, coalfields containing coal bearing Barakar Formation are Raniganj, Jharia, Bokaro, Ramgarh, and Karanpura. The Barakar Formation is composed of conglomerate, sandstone, siltstone, shale, fireclay, and coal. The lower part of Barakar Formation represents a braided channel deposit, and also in few places glacio-fluvial deposit which changes to meandering channel system with the formation of some ox-bow lake, and cut-off channel in the middle part. In a few places deltaic/brackish water condition possibly existed along with this meandering channel system. In the upper part of Barakar Formation, marine signatures are more prominant. Marine signatures/influences have been reported from Barakar Formation of Ramgarh, South Karanpura, and West Bokaro coalfields on the basis of trace fossil assemblage, sedimentation character, and trace element content. Although, definite marine signatures have not been observed from Jharia, and Raniganj coalfields, high concentration of boron, vanadium, and chromium, and presence of skolithos, and thalassinoides burrows possibly suggest a brackish water condition. The upper part clearly suggest that the sediments were deposited in a geographic setting very close to the sea or at the edge of the sea possibly in a peritidal setting where storm activity played a vital role during sedimentation which in turn suggests the presence of a broad shallow sea (epeiric/epicontinental sea) that develop during times of high sea level. The sea water possibly entered from the northeastern side as vast seaways or as embayment through the Damodar Valley which acted as a channel.

Megaspores from the Panchet Formation of East Bokaro Coalfield, India

Megaspores from the Panchet Formation of East Bokaro Coalfield, India

97/02532 A preliminary study on the nature of coal in Siari area of East Bokaro Coalfield

97/02532 A preliminary study on the nature of coal in Siari area of East Bokaro Coalfield

Potassic cordierites: characteristic minerals for high-temperature, very low-pressure environments

The mineral chemistry of cordierites from three different sanidinite facies localities-1) volcanic xenoliths from the Eifel, Germany; 1) buchites of the Blaue Kuppe, Germany; 3) paralavas from the Bokaro coalfield, India-is characterized by unusually high potassium contents up to 1.71 wt%, equivalent to 0.22 K atoms per formula unit (p.f.u.) based on 18 oxygens. Significantly, these cordierites are either hexagonal highcordierites (indialites) with Δ=0 or exhibit intermediate Δ-values 0<Δ<0.20 relative to well Al,Si-ordered orthorhombic low-cordierite. Based on microprobe analyses, the predominant substitutional mechanism for alkali incorporation is Alk[Channel]+Al[4] for □+Si[4], thus leading to Al/Si-ratios deviating considerably from the value 4:5 in ideal cordierite M2[Al4Si5O18]. The most highly substituted cordierite from Blaue Kuppe is about (K0.22Na0.07)[Ch](Mg1.33Fe 0.66 2+ )[6][Al4.16Si4.79O18]. Bokaro cordierites are further characterized by obvious (Al+Si)-deficiencies against the ideal value of 9.0 p.f.u., a tendency of which is apparent in most Blaue Kuppe analyses as well. As the tetrahedral deficiencies are often equivalent to excess cations in the octahedra, we assume that ferric iron fills up the remaining tetrahedral sites, again linked with the introduction of potassium according to K+Fe3+ for □+Si. In comparison with the available experimental data, these natural potassic cordierites are considered stable high-temperature phases regarding their compositions, but not their structural states. Although the substitution KAl for Si in Mg-cordierite is known to lower the maximum Δ-value to be attained, the hexagonal nature of the cordierites must be due to very rapid crystallization and subsequent quenching. The higher Δ-values of the Blaue Kuppe cordierites might be caused by their topotactic origin from preexisting biotite. The complicated twin and domain patterns of the hexagonal Eifel and Bokaro cordierites as observed in thin section could perhaps be attributed to structural modulations as postulated recently for hexagonal cordierite shortly after its growth.

Trace elements and their variation along seam profiles of certain coal seams of Middle and Upper Barakar formations (Lower Permian) in East Bokaro coalfield, district Hazaribagh, Bihar, India

Trace-element data are presented for the first time for any coal seam in India, across a full working section, based on systematically collected channel samples of coal, together with their maceral composition. The trace-element variation curves along the seam profile are presented together with group maceral compositions of Kargali Bottom, Kargali Top, Kargali, Kathara, Uchitdih, Jarangdih Bottom, Jarangdih, and Jarangdih Top seams, East Bokaro coalfield. The Kathara and Uchitdih seams have also been sampled at two other localities and lateral variation in data in their trace-element and maceral compositions is also evaluated. The East Bokaro coals have: Ba and Sr > 1000 ppm; Mn < 450 ppm; Zr < 400 ppm; Ni and V < 250 ppm; Cr < 185 ppm; La < 165 ppm; Cu, Nb, and B < 125 ppm; Pb, Co and Y < 75 ppm; Ga, Sn, Mo, In and Yb < 15 ppm; Ag 2 ppm; and Ge 7 ppm. Petrographically, the coals are dominant in vitrinite (33–97%), rare in exinite (<15%), and semifusinite (0.8–49%) is the dominant inertinite maceral, with variable mineral and shaly matter (11–30%), graphic representation of trace elements versus vitrinite, inertinite, and coal ash indicates the affinity of (a) vitrinite with Cu, Ni, Co, V, Ga and B; (b) inertinite with Nb and B; and (c) coal ash (mineral matter) with Pb, Cu, Ni, La, Mn and Y; Ba, Cr, Sr, Zr, Cu and Ni are of organic as well as inorganic origins. The trend of the variation patterns and average compositions of the different seams are shown to be distinct and different. The variation along the same profile is inferred to be different for different seams of the coalfield. Trace-element data for certain coals of seams from different coalfields in the Gondwana basins of India are presented. There is a wide difference for each of these basins with respect to certain elements. This is suggestive of the proportions of Cu, Ni, V, Y, Ba, Sr, Cr, B, Zr and Ag, characterizing the different Gondwana Basins.

The nature of Grooved Pavement and Palynology from overlying Talchir and Karharbari sediments in west Bokaro Coalfield, Bihar, India

A sequence of Talchir Formation overlying the polished pavement of metamorphic rocks has been palynostratigraphically studied from the Dudhi River section of West Bokaro Coalfield. The groove-like markings on the pavement, trending S 60ºE in direction, have been observed. The tillite, rafted boulders and the thick laminated shales suggest glacial as well as f1uvio-glacial conditions during Talchir sedimentation. The thin carbonaceous beds, associated with the sandstone at the top of this formation, have been found to contain a Callumispora, Microbaculispora and Parasaccites rich mioflora. Palynologically this resembles the Lower Karharbari miospore assemblages known from other areas. The Talchir mioflora is less diverse while the subsequent one shows significant complexity in quality as well as quantity.

Studies in the Talchir flora of India - 10. Early and Late Talchir microfloras from the west Bokaro coalfield, Bihar

Two miofloral assemblages - one from the base and the other from the top of the Talchir Formation - are described from a single sequence in the Dudhi River, West Bokaro Coalfield. The impoverished nature of the early Talchir assemblage is reflected by very limited number and variety of taxa (8 genera &amp; 14 species) - chiefly Parasaccites, Plicatipollenites and Potonieisporites and some apiculate triletes. Disaccates - especially Striatiti - are strikingly absent. Leiosphaeridia and spicule-like microfossils are significantly associated.&#x0D; The late Talchir mioflora, on the contrary demonstrates distinct improvement both in diversity and quantity of miospores (14 genera &amp; 29 species). Besides the stronghold of Parasaccites, Plicatipollenites and Potonieisporites, several genera make new appearance, viz., Jayantisporites, Tuberisaccites, Caheniasaccites, Limitisporites and especially all the striate disaccates like Crescentipollenites, Faunipollenites and Striatoparvisaccites gen. nov. A number of species are apparently represented only in the late Talchir. Leiosphaeridia are rare and spicule- like bodies are absent.&#x0D; In the light of the present study, and from an assessment of the better known Talchir miofloras, it is suggested that not one but two miofloral assemblages of early and late Talchir age respectively - are evident in the Talchir Formation.

Miospore assemblage in some coals of Barakar stage (Lower Gondwana) of India

Sporae dispersae have been referred to 53 miospore genera with 131 species out of which 59 species are new. For each species a large number of specimens have been studied and the probable range of variation in the qualitative as well as quantitative characters within a species has been determined. For specific delimitation the association of morphographic characters has been given primary importance. New species have been diagnosed, described and compared in detail.&#x0D; The qualitative and quantitative compositions of the assemblages from Korba Coalfield and W. Bokaro Coalfield have been compared. It has been concluded that the mioflora of Korba Coalfield is divisible into an older and a younger assemblage. The younger assemblage shows some closeness with the mioflora of W. Bokaro Coalfield.

Megaspores from the West Bokaro Coalfield (Lower Gondwanas) of Bihar

Megaspores from the West Bokaro Coalfield (Lower Gondwanas) of Bihar