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The aim of the present work is to define the geo-microbial signatures along with trace metals, and to investigate whether the geo-microbial anomalies have correlation with trace metal anomalies in Ahmedabad block of Cambay basin. The surface geochemical techniques are based on seepage of light hydrocarbon gases from the oil and gas pools to the shallow surface and can bring up near-surface oxidation reduction zones that favor the development of a diverse array of chemical and mineralogical changes. The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations and hydrocarbon oxidizing bacteria and its interrelationship. For the purpose a total of 90 soil samples are collected in grid pattern of 2 x 2 km interval. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above some of the major oil and gas fields of this petroliferous region. The concentrations of V (0 to149 ppm), Cr (2 to 192 ppm), Cu (4 to 171 ppm), Se (98 to 440 ppm), Zn (56 to 1215 ppm) are obtained. It is observed that the concentrations of trace elements are tremendously increased when they are compared with their normal concentrations in soils. In this study the hydrocarbon oxidizing bacterial counts ranged between 1.0 x 103 and 1.59 x 106 cfu/g of soil sample respectively. The attempt has made for the first time, which revealed good correlation as both these anomalies are found as apical in relation. Integrated studies between trace elements and hydrocarbon oxidizing bacterial anomalies showed positive correlation with existing oil and gas wells in the study area.  相似文献   
3.
ABSTRACT

Reductionist thinking will no longer suffice to address contemporary, complex challenges that defy sectoral, national, or disciplinary boundaries. Furthermore, lessons learned from the past cannot be confidently used to predict outcomes or guide future actions. The authors propose that the confluence of a number of technology and social disruptors presents a pivotal moment in history to enable real time, accelerated, and integrated action that can adequately support a ‘future earth’ through transformational solutions. Building on more than a decade of dialogues hosted by the International Society for Digital Earth (ISDE), and evolving a briefing note presented to delegates of Pivotal 2015, the paper presents an emergent context for collectively addressing spatial information, sustainable development, and good governance through three guiding principles for enabling prosperous living in the twenty-first century. These are: (1) open data, (2) real-world context, and (3) informed visualization for decision support. The paper synthesizes an interdisciplinary dialogue to create a credible and positive future vision of collaborative and transparent action for the betterment of humanity and planet. It is intended that these Pivotal Principles can be used as an elegant framework for action toward the Digital Earth vision, across local, regional, and international communities and organizations.  相似文献   
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ABSTRACT

The concept of seismic vulnerability is a yard-stick of damage estimation from a probable earthquake considering physical cum social dimension and enables a basis for decision-makers to develop preparedness and mitigation strategies. We aim at vulnerability assessment of the typical urban system of capital city Shillong situated on hilly terrain. High-resolution satellite imagery of Shillong facilitates analysis of building footprints, communication network, and open ground. Different building typologies are identified taking into account the building’s structural configuration assessed through a rapid visual survey of more than 15% of total residential households. Slope map demarcates the landslide-prone area through discrete elevation modelling. A methodology incorporating several parameters e.g. building typology, slope angle, shear wave velocity characteristics, geomorphology, and the number of occupants in correlation with a physical measurement of vulnerability is presented and is applied to estimate the dimension of vulnerability. Additionally, MASW survey indicates lithology up to 30?m deep along with the existence of stiff soil and rocks at different depths whereas resonant frequency is identified to be in the range of 6–8?Hz through H/V ratio. Integrating all, it is observed that more than 60% of Shillong city falls under moderate to higher vulnerability and the rest is less vulnerable.  相似文献   
5.
The study area is confined to a part of upper Assam basin, north of river Brahmaputra (north bank). Seven exploratory wells have been drilled in this part of the basin in order to probe the hydrocarbon prospects of the area. The exploratory efforts did not indicate significant hydrocarbon prospects in the north bank. Since the presence of source rock is an important component of the petroleum system, a detailed systematic study of source rock potential was carried out by analysing known source rock intervals in these seven wells. In the present study, Rock-Eval pyrolysis combined with specific geochemical analyses like GC and TLCFID has been used to characterise the source rocks, their distribution and thermal maturity of the organic matter. The source rocks in the area show mainly Type III, land-plant derived organic matter along with some Type II organic matter. They are predominantly gas prone in nature, although mixed and oil-prone source rocks are occasionally present. Although source rock intervals have been identified in the Langpar, Sylhet limestone and Kopili formations, the Barail Group and the Tipam sandstone Formation, the bulk of the source rock occurs within the Kopili Formation. Geochemical analyses of the cores indicate oil signatures at certain depths, although no commercial oil was discovered. The hydrocarbon generation potential of these source rocks are constrained by low maturity at the presently drilled depths.  相似文献   
6.
The gravity and magnetic data along three profiles across the northern part of the K-G basin have been collected and the data is interpreted for basement depths. The first profile is taken from Gadarada to Yanam covering a distance of 60 km and the second starts from Zangareddiguddem to Samathkur covering a distance of 110 km and the third is from Kotturu to Biyyapuppa covering a distance of 100 km. The gravity lows and highs have clearly indicated various sub-basins and ridges. The density logs from ONGC, Chennai, show that the density contrast decreases with depth in the sedimentary basin, and hence, the gravity profiles are interpreted using variable density contrast with depth. From the Bouguer gravity anomaly, the residual anomaly is constructed by graphical method correlating with well data, sub-surface geology and seismic information. The residual anomaly profiles are interpreted using polygon model. The maximum depths to the khondalitic basement are obtained as 5.61km, 6.46 km and 7.45 km for the first, second and third profiles respectively. The regional anomaly is interpreted as Moho rise towards coast. The aeromagnetic anomaly profiles are also interpreted for charnockite basement below the khondalitic group of rocks using prismatic models.  相似文献   
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8.
In this study, we are reporting bacterial diversity in crude oil-contaminated soil of Assam, India. Integration of physiological community profiling, culture-dependent and culture-independent (metagenome) approaches, was employed to obtain a complete picture of the total bacterial diversity. Samples collected from 10 sites contaminated with crude oil ranging from 0.22 to 89.36% were analysed, and altogether 160 culturable bacteria were isolated (117 Gram-positive and 43 Gram-negative bacteria). Molecular identification showed the predominance of genera Lysinibacillus, Alcaligenes, Bacillus, Clostridium, Enterobacter and Pseudomonas. Conversely, denaturing gradient gel electrophoresis (DGGE) profiles of 16S rDNA phylotypes showed the predominance of Sphingomonas, Ralstonia, Sphingobium, Massilia, Acinetobacter and Pseudomonas. Both culture-dependent and culture-independent approaches resulted in 11 genera of which Bacillus and Pseudomonas were the key inhabitants creating most favourable bacterial milieu in the presence of crude oil contaminants. Metabolic fingerprints data depicted in PCA plot demonstrated that sites CTF-D-1 and Core-10 were most diverged. It was further confirmed that variations of bacterial species dominance in different sites were due to origin of hydrocarbon contamination. We here claim that the present findings is a first-hand report on combined physiological community profiling, culture-based and culture-independent approaches in assessing total bacterial diversity in crude oil-contaminated soil of Assam.  相似文献   
9.
FT-IR and XRD analysis of coal from Makum coalfield of Assam   总被引：1，自引：0，他引：1  
High sulphur coal sample from Ledo colliery of Makum coalfield, Assam, India was studied using FT-IR and XRD methods. FT-IR study shows the presence of aliphatic -CH, -CH2 and -CH3 groups, aliphatic C-O-C stretching associated with -OH and -NH stretching vibrations and HCC rocking (single and condensed rings). XRD pattern of the coal shows that it is amorphous in nature. Function of Radial Distribution Analysis (FRDA) indicates that coal is lignite in type and there is no evidence of graphite-like structure. The first maximum in the G(r) plot of FRDA at r = 0.14 nm relates to the aliphatic C-C bond (Type C-CH=CH-C), the second maximum at r = 0.25 nm relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. The coal was found to be lignite in nature.  相似文献   
10.
Eco-restoration of mine overburden (OB) or abandoned mine sites is a major environmental concern. In the present investigation, an integrated approach was used to rejuvenate a high-sulphur mine OB dumping site in the Tirap Collieries, Assam, India, which is situated in the Indo-Burma mega-biodiversity hotspot. A mine OB is devoid of true soil character with poor macro and micronutrient content and contains elevated concentrations of trace and heavy metals. Planting of herbs, shrubs, cover crops and tree species at close proximity leads to primary and secondary sere state succession within a period of 3 to 5 years. A variety of plant species were screened for potential use in restoration: herbs, including Sccharum spontaneum, Cymbopogon winterianus Jowitt (citronella), and Cymbopogon flexuosus (lemon grass) cover plants, including Mimosa strigillosa, M. striata, and M. pigra; shrubs, including Sesbania rostrata (dhaincha) and Cassia streata (cassia); and tree species, including Gmelina arborea (gomari) and Dalbergia sissoo (sissoo). Amendment with unmined soil and bio-organic matter was required for primary establishment of some plant species. Management of these plant species at the site will ensure long term sustainable eco-restoration of the coal mine-degraded land.  相似文献   
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