scholarly journals Sedimentary Environments and Coal Accumulation of the Middle Xishanyao Formation, Jurassic, in the Western Dananhu Coalfield, Turpan-Hami Basin

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhiming Yan ◽  
Jinlong Wang ◽  
Xuetian Wang
Keyword(s):  
Sedimentary Environment ◽  
Transitional Zone ◽  
Mining Area ◽  
Alluvial Fan ◽  
Controlling Factor ◽  
Tectonic Subsidence ◽  
Sedimentary Environments ◽  
Delta Plain ◽  
Geological Conditions ◽  
Coal Accumulation

The Dananhu coalfield, at the southern margin of Turpan-Hami Basin, Xinjiang, has good coal-forming geological conditions. Due to the low research level on the depositional environment and coal accumulation, the comprehensive coal mining is restricted. Based on drilling and sectioning outcrop data, the depositional characteristics, lithofacies, paleogeography, and coal accumulation of the coal-bearing formations in western Dananhu coalfield are analyzed. The middle member of the Xishanyao Formation is the major coal-bearing strata of the Dananhu coalfield, composed of conglomerate, sandstone, siltstone, mudstone, and combustible organic rock, which can be further subdivided into 14 lithofacies according to substance composition, sediment texture, and structure. During the early Middle Jurassic coal-accumulating period, alluvial fan, fluvial plain, fluvial delta, and shallow lacustrine deposits were developed from northeast to southwest in the western Dananhu mining area. Coal accumulation was most developed in the center regions of the study area extending from northeast to southwest, which were primarily concentrated in margin fans, floodplains, interdeltaic bays, and lakeshore environments, especially the transitional zone between the fluvial plain and the delta plain in the west of No. 1 mining area. This coal accumulation was mainly controlled by synsedimentary tectonic subsidence and clastic sediments supply or sedimentary environment, where tectonic subsidence was the primary controlling factor and the source supply was the secondary controlling factor for coal accumulation, which provided theoretical support for the coal prediction and geological exploration in western Dananhu coalfield.

The Relationship Analysis of Surrounding Rock Stability and Continental Sedimentary Environment

2011 ◽  
Vol 217-218 ◽  
pp. 1580-1583
Author(s):  
Cui Liang ◽  
Chao Zhang ◽  
Nian Jie Ma ◽  
Ming Ming Wen ◽  
Chong Li
Keyword(s):  
Rock Strength ◽  
Sedimentary Environment ◽  
Flood Plain ◽  
Surrounding Rock ◽  
Sedimentary Environments ◽  
Delta Plain ◽  
Relationship Analysis ◽  
Rock Stability ◽  
The Relationship ◽  
Internal Relationship

The continental coal-bearing strata are mainly formed in the flood plain, delta plain and lake shore subfacies. Through the study on the sedimentary cause of differences of rock strength and sedimentary location, the paper analyzes the internal relationship between sedimentary environment and surrounding rock stability based on different coal-forming models. To take an example of Shendong Coal Mine Area, the differences of surrounding rock stability in various sedimentary environments are quantitative analyzed. The paper’s research promotes the combination between surrounding rock stability and sedimentology.

scholarly journals Adsorption and pH Values Determine the Distribution of Cadmium in Terrestrial and Marine Soils in the Nansha Area, Pearl River Delta

2022 ◽  
Vol 19 (2) ◽  
pp. 793
Author(s):  
Fangting Wang ◽  
Ke Bao ◽  
Changsheng Huang ◽  
Xinwen Zhao ◽  
Wenjing Han ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Pearl River Delta ◽  
Sedimentary Environment ◽  
Transitional Zone ◽  
River Delta ◽  
Pearl River ◽  
Coastal Zones ◽  
Undisturbed Soil ◽  
Sedimentary Environments ◽  
Cadmium Adsorption

Cadmium is a toxic element with a half-life of several decades, which can accumulate in the human body by entering the food chain and seriously harm health. The cadmium adsorption and desorption processes in the soil directly affect the migration, transformation, bioavailability, and ecotoxicity of this element in soil-plant systems. Coastal zones are located in the transitional zone between land and sea, and large amounts of terrigenous material input have important environmental effects on this ecosystem. The pH, hydrodynamic conditions, soil organic matter (SOM), and other factors defining the sea-land interaction within the sedimentary environment are significantly different from those defining land facies. In order to study the key factors affecting cadmium adsorption in soils at the sea-land interface in the Nansha area of the Pearl River Delta, a test was conducted on a column of undisturbed soil. The results showed that the adsorption constant KF and the Cd2+ adsorption capacity of marine soils were higher than those of terrestrial soils. However, the saturation adsorption of cadmium in terrestrial sediments was higher than in marine sediments. Soil pH was an important factor affecting cadmium adsorption capacity in both terrestrial and ma-rine sediments. Neutral and alkaline topsoil conditions inhibited the vertical migration of cadmium, while the acidic environment favored it. The higher the clay and SOM were, the stronger the Cd2+ adsorption capacity of the soil was. These findings suggest that the distribution of cadmium in marine and continental sedimentary soils is not only related to adsorption, but also to the physical and chemical processes occurring in different sedimentary environments.

Primary Geology Factors Controlling Coalbed Methane (CBM) Enrichment in Jixi Basin

2013 ◽  
Vol 316-317 ◽  
pp. 911-916
Author(s):  
Xiao Qian Guo ◽  
Da Meng Liu ◽  
Yan Bin Yao ◽  
Yi Dong Cai ◽  
Jun Qian Li
Keyword(s):  
Coalbed Methane ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Gas Content ◽  
Hydrodynamic Condition ◽  
Reverse Fault ◽  
Sedimentary Environments ◽  
Delta Plain ◽  
The North ◽  
Coal Accumulation

Jixi basin is one of the important coal basins in China. To explore the gas accumulation characteristics and its geological controls, it’s important for further exploration and development of coalbed methane (CBM). The gas content of Jixi Basin is high viable from 4.78 to 11.94 m3/t, indicating high gas content in the north and west but low gas content in the south and east. The further analysis results show that the delta plain and lake are favorable sedimentary environments for coal accumulation. The Chengzihe and Muleng formation are formed in these environments. Moreover, massive magmatic intrusion heat activities and subsequent continuous subside of strata increase coal rank of the coals. In the area of Pingma reverse fault and the area with thick Muleng formation, mud seals are favorable for CBM preservation. In these areas, CBM is sealed and accumulated by hydrodynamic condition. Finally, a comprehensive evaluation model for CBM was found. Based on the evaluation model, the most favorable zone for CBM exploration is forecasted to be J idong depression.

Postglacial Diatom Stratigraphy in Relation to the Recession of Glacial Lake Agassiz

1975 ◽  
Vol 5 (4) ◽  
pp. 529-540 ◽  
Author(s):  
J.C. Ritchie ◽  
L.K. Koivo
Keyword(s):  
Sandy Beach ◽  
Sedimentary Environment ◽  
Glacial Lake ◽  
Lake Agassiz ◽  
Organic Detritus ◽  
Sedimentary Environments ◽  
Grand Rapids ◽  
Glacial Lake Agassiz ◽  
Diatom Stratigraphy ◽  
Beach Sands

The sediment and diatom stratigraphy of a small pond on The Pas moraine, near Grand Rapids, Manitoba, reveals a change in sedimentary environment related directly to the last stages of Glacial Lake Agassiz. Beach sands were replaced by clay 7300 14C y. a., then by organic silt and, at 4000 14C y. a. by coarse organic detritus; the corresponding diatom assemblages were (I) a predominantly planktonic spectrum in beach sands, (II) a rich assemblage of nonplanktonic forms, and (III) a distinctly nonplanktonic acidophilous spectrum. These results confirm Elson's (1967) reconstruction of the extent and chronology of the final (Pipun) stage of Glacial Lake Agassiz. The sedimentary environments change from a sandy beach of a large lake at 7300 BP to a small, shallow eutrophic pond with clay and silt deposition from 7000 to 4000 BP. From 4000 BP to the present, organic detritus was deposited in a shallow pond that tended toward dystrophy.

Analysis of Metallogenic Conditions of Geothermal Resources in Heiyu Lake of Daqing

2012 ◽  
Vol 550-553 ◽  
pp. 2472-2477
Author(s):  
Yu Chun Bai ◽  
Yong Li Li ◽  
Fu Li Qi ◽  
Feng Long Zhang
Keyword(s):  
Transitional Zone ◽  
Geological Structure ◽  
Major Elements ◽  
Geothermal Field ◽  
Geophysical Data ◽  
Geothermal Resources ◽  
Lake Zone ◽  
Geological Conditions ◽  
Geothermal Drilling ◽  
Geological Background

Heiyu Lake zone of Daqing is located in the southwest hollow borderland of Heiyu Lake and on the arching transitional zone of Daqing placanticline. Based on the geological background of Heiyu Lake, this paper analyzes the landform, the regional geological structure, the formation lithology and the irruptive rock and other metallogenic conditions in detail. The indispensable geological conditions for forming geothermal field in layers were summed up. Combining with the development characteristics and geophysical data of formation, the bore hole site of geothermal well and target stratum were ascertained. The four major elements of forming geothermal resources in this region were confirmed by carrying out geothermal drilling.

Equilibrium Temperature Calculation of the Sulfur Isotope in Dongzhongla Pb-Zn Deposit in Tibet

2015 ◽  
Vol 1092-1093 ◽  
pp. 1394-1397
Author(s):  
Guang Chun Fei ◽  
Yi Fan Yu ◽  
Ke Qiang Hua
Keyword(s):  
Sulfur Isotope ◽  
Equilibrium Temperature ◽  
Mining Area ◽  
Isotopic Equilibrium ◽  
The North ◽  
Geological Conditions ◽  
Typical Type ◽  
Lead Zinc ◽  
Block Based ◽  
Exploration Area

The Dongzhongla Pb-Zn deposit, a newly-discovered medium-sized deposit, is located in the north margin of the eastern Gangdese, central Lhasa block. Based on the analysis of the ore-forming geological conditions in this deposit, sulfur isotope of this deposit were analyzed, and S isotopic equilibrium temperature of mineral pairs (sphalerite and galena) were calculated. This study has shown that the sulfur isotopic equilibrium temperature of sphalerite and galena in Dongzhongla Pb-Zn deposit ranged from 185℃ to 296℃. It indicated that the equilibrium temperature decreased gradually from the skarn stage to sulfide stage. The equilibrium temperature can be used as the reference of metallogenic temperature for Dongzhongla Pb-Zn deposit. DongzhongLa deposit is the typical type of skarn Lead-zinc deposit. East of the Dongzhongla mining area is the priority exploration area.

scholarly journals Analysis of lithofacies cyclicity in the Miocene Coal Complex of the Bełchatów lignite deposit, south-central Poland

Geologos ◽  
2015 ◽  
Vol 21 (4) ◽  
pp. 285-302 ◽  
Author(s):  
Wojciech Mastej ◽  
Tomasz Bartuś ◽  
Jerzy Rydlewski
Keyword(s):  
Statistical Tests ◽  
Surface Flow ◽  
Alluvial Fan ◽  
Statistical Testing ◽  
New Approach ◽  
Sedimentary Environments ◽  
Carbonate Sedimentation ◽  
South Central ◽  
Sedimentation Model ◽  
Almost All

Abstract Markov chain analysis was applied to studies of cyclic sedimentation in the Coal Complex of the Bełchatów mining field (part of the Bełchatów lignite deposit). The majority of ambiguous results of statistical testing that were caused by weak, statistically undetectable advantage of either cyclicity over environmental barriers or vice versa, could be explained if only the above-mentioned advantages appeared in the neighbourhood. Therefore, in order to enhance the credibility of statistical tests, a new approach is proposed here in that matrices of observed transition numbers from different boreholes should be added to increase statistical reliability if they originated in a homogeneous area. A second new approach, which consists of revealing statistically undetectable cyclicity of lithofacies alternations, is proposed as well. All data were derived from the mining data base in which differentiation between lithology and sedimentary environments was rather weak. For this reason, the methodological proposals are much more important than details of the sedimentation model in the present paper. Nevertheless, they did reveal some interesting phenomena which may prove important in the reconstruction of peat/lignite environmental conditions. First of all, the presence of cyclicity in the sedimentation model, i.e., cyclic alternation of channel and overbank deposits, represents a fluvial environment. It was also confirmed that the lacustrine subenvironment was cut off from a supply of clastic material by various types of mire barriers. Additionally, our analysis revealed new facts: (i) these barriers also existed between lakes in which either carbonate or clay sedimentation predominated; (ii) there was no barrier between rivers and lakes in which clay sedimentation predominated; (iii) barriers were less efficient in alluvial fan areas but were perfectly tight in regions of phytogenic or carbonate sedimentation; (iv) groundwater, rather than surface flow, was the main source of CaCO3 in lakes in which carbonate sedimentation predominated; (v) a lack of cyclic alternation between abandoned channels and pools with clayey sedimentation; (vi) strong evidence for autocyclic alternation of phytogenic subenvironments and lakes in which carbonate sedimentation predominated was found in almost all areas studied.

scholarly journals Geochemical Features of Redox-Sensitive Trace Metals in Sediments under Oxygen-Depleted Marine Environments

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1021
Author(s):  
Moei Yano ◽  
Kazutaka Yasukawa ◽  
Kentaro Nakamura ◽  
Minoru Ikehara ◽  
Yasuhiro Kato
Keyword(s):  
Sedimentary Environment ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Major And Trace Elements ◽  
Matter Content ◽  
Open Ocean ◽  
Chemical Compositions ◽  
Marine Environments ◽  
High Productivity ◽  
Sedimentary Environments

Organic- and sulfide-rich sediments have formed in oxygen-depleted environments throughout Earth’s history. The fact that they are generally enriched in redox-sensitive elements reflects the sedimentary environment at the time of deposition. Although the modern ocean is well oxidized, oxygen depletion occurs in certain areas such as restricted basins and high-productivity zones. We measured bulk chemical compositions (major and trace elements, total organic carbon, and total sulfur) of organic- and sulfide-rich sediments collected from eight areas having oxygen-depleted water to discuss relationships between geochemical features and sedimentary environments. Major elemental compositions generally show mixtures of terrigenous detritus and biogenic carbonate. Some redox-sensitive elements might be controlled by organic matter content, whereas others could be contained in sulfide minerals in sediments. In particular, Mo and U show a characteristic trend; areas with higher Mo and U—at least partially owing to a depositional process called the “particulate shuttle”—generally correspond to regions influenced by the open ocean. In contrast, areas with lower Mo and U are more restricted marine environments. This suggests that the degree of Mo and U enrichment reflects the geography in terms of proximity to the open ocean, or the degree of the supply of these elements from the open ocean.

scholarly journals Water Preservation and Conservation above Coal Mines Using an Innovative Approach: A Case Study

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2818
Author(s):  
Yujun Xu ◽  
Liqiang Ma ◽  
Yihe Yu
Keyword(s):  
Coal Mining ◽  
Water Conservation ◽  
Large Scale ◽  
Influencing Factor ◽  
Mining Area ◽  
Mining Operations ◽  
Narrow Strip ◽  
Geological Conditions ◽  
The Impact

To better protect the ecological environment during large scale underground coal mining operations in the northwest of China, the authors have proposed a water-conservation coal mining (WCCM) method. This case study demonstrated the successful application of WCCM in the Yu-Shen mining area. Firstly, by using the analytic hierarchy process (AHP), the influencing factors of WCCM were identified and the identification model with a multilevel structure was developed, to determine the weight of each influencing factor. Based on this, the five maps: overburden thickness contour, stratigraphic structure map, water-rich zoning map of aquifers, aquiclude thickness contour and coal seam thickness contour, were analyzed and determined. This formed the basis for studying WCCM in the mining area. Using the geological conditions of the Yu-Shen mining area, the features of caved zone, water conductive fractured zone (WCFZ) and protective zone were studied. The equations for calculating the height of the “three zones” were proposed. Considering the hydrogeological condition of Yu-Shen mining area, the criteria were put forward to evaluate the impact of coal mining on groundwater, which were then used to determine the distribution of different impact levels. Using strata control theory, the mechanism and applicability of WCCM methods, including height-restricted mining, (partial) backfill mining and narrow strip mining, together with the applicable zone of these methods, were analyzed and identified. Under the guidance of “two zoning” (zoning based on coal mining’s impact level on groundwater and zoning based on applicability of WCCM methods), the WCCM practice was carried out in Yu-Shen mining area. The research findings will provide theoretical and practical instruction for the WCCM in the northwest mining area of China, which is important to reduce the impact of mining on surface and groundwater.

Sedimentary environment prediction of grain-size data based on machine learning approach

2020 ◽  
Vol 8 (3) ◽  
pp. SL71-SL78
Author(s):  
Qiao Su ◽  
Yanhui Zhu ◽  
Fang Hu ◽  
Xingyong Xu
Keyword(s):  
Machine Learning ◽  
Grain Size ◽  
Prediction Model ◽  
Sedimentary Environment ◽  
Machine Learning Algorithms ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Data Set ◽  
Sedimentary Environments ◽  
Size Data

Grain size is one of the most important records for sedimentary environment, and researchers have made remarkable progress in the interpretation of sedimentary environments by grain size analysis in the past few decades. However, these advances often depend on the personal experience of the scholars and combination with other methods used together. Here, we constructed a prediction model using the K-nearest neighbors algorithm, one of the machine learning methods, which can predict the sedimentary environments of one core through a known core. Compared to the results of other studies based on the comprehensive data set of grain size and four other indicators, this model achieved a high precision value only using the grain size data. We have also compared our prediction model with other mainstream machine learning algorithms, and the experimental results of six evaluation metrics shed light on that this prediction model can achieve the higher precision. The main errors of the model reflect the length of the conversation area of sedimentary environment, which is controlled by the sedimentary dynamics. This model can provide a quick comparison method of the cores in a similar environment; thus, it may point out the preliminary guidance for further study.

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