Palynofacies as a tool for high-resolution palaeoenvironmental and palaeoclimatic reconstruction of Gondwanan post-glacial coal deposits: No. 2 Coal Seam, Witbank Coalfield (South Africa)

2016 ◽  
Vol 97 (2) ◽  
pp. 259-271 ◽  
Author(s):  
Alexander Wheeler ◽  
Annette E. Götz
Keyword(s):  
South Africa ◽  
High Resolution ◽  
Coal Seam ◽  
Coal Deposits ◽  
Palaeoclimatic Reconstruction

scholarly journals Identifying Correlation of Coal Seams in the Tien Hai Area, Northern Vietnam by Using Multivariate Statistic Methods

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
The Hung KHUONG ◽  
Phuong NGUYEN ◽  
Thi Cuc NGUYEN ◽  
Nhu Sang PHAM ◽  
Danh Tuyen NGUYEN
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Coal Seam ◽  
Rare Earth Elements ◽  
Major And Trace Elements ◽  
Coal Seams ◽  
Multivariate Statistic ◽  
Northern Vietnam ◽  
Coal Deposits ◽  
Indicator Elements

In northern Vietnam, the Tien Hai area is considered a high potential area of coal deposits. Twohundred fifty-six geochemical coal samples of 13 cores in the Tien Hai area investigate coal seams andcoal deposits to identify the correlation of coal seams. According to the statistical method and clusteranalysis of geochemical samples, the results indicate that the Mg, V, As, Ca, Zn, Cr, Co, K, Na, Sr, Fe,Ge, Re, U, Mo, Th, and Ga elements are good indicator elements of the major and trace elements in coal.Most of them comply with the normal or lognormal distribution rules. Besides, the Yb, Sc, Ho, Er, Tm,Lu, Y, Tb, Pr, Dy, and Sm elements are also good indicator elements for rare earth elements in the region.Therefore, the selected elements are used to identify the correlation of the coal seams in the Tien Hai area.Based on the similarity degree between studied objects, the results of grouping boreholes in coal seamsshow that the correlation of coal seam TV2-11 is suitable and acceptable, the coal seams TV3-6a, TV3-6b, and TV3-6c can be grouped into the coal seam TV3-6. These results present that the models can helpstudy geochemical coal samples and identify the correlation of the coal seams in the Tien Hai area.Additionally, the statistical analysis shows a remarkable degree to determine the correlation of the coalseams. Geochemical coal data can help to evaluate the indicator elements of the major, trace elements,and rare earth elements in coal seams and coal rashing of adjoining and pillar rocks in the Tien Hai area,northern Vietnam.

The Significance of Erosion Channels on Gold Metallogeny in the Witwatersrand Basin (South Africa): Evidence from the Carbon Leader Reef in the Carletonville Gold Field

2020 ◽  
Author(s):  
G. T. Nwaila ◽  
J. E. Bourdeau ◽  
Z. Jinnah ◽  
H. E. Frimmel ◽  
G. M. Bybee ◽  
...  
Keyword(s):  
South Africa ◽  
High Resolution ◽  
Mass Balance ◽  
Closed System ◽  
Seismic Data ◽  
Crucial Role ◽  
Sediment Load ◽  
Witwatersrand Basin ◽  
Petrographic Analyses ◽  
Group A

Abstract Within the eastern portion of the Carletonville gold field, the gold- and uranium-rich Carbon Leader reef of the Central Rand Group (Witwatersrand Supergroup) is truncated by an erosion channel. This channel is asymmetrical and lenticular in shape, measuring 150 to 180 m in width and up to 100 m in depth. High-resolution seismic data show that the erosion channel cuts from the Carbon Leader reef into all older units of the Central Rand Group down to the Roodepoort Formation of the underlying West Rand Group. A total of seven bore-holes were drilled into the channel, revealing that it is composed of quartzite at its base (9 m thick), overlain by deformed (lower) and laminated (upper) chloritoid-bearing shale (21 m thick) and quartzite (18 m thick). The Carbon Leader reef is highly enriched in gold (5–40 g/t Au), whereas the gold tenor of the erosion channel fill is in general much lower (<1 g/t Au), although locally grades of as much as 3.8 g/t Au are reached. Detailed seismic, sedimentological, and petrographic analyses revealed that the channel was filled with locally sourced sediments from the Main Formation. A closed-system mass balance further demonstrates that gold in the erosion channel could have been entirely sourced from the Carbon Leader reef. Sediment load played a crucial role in the distribution of gold in the channel, thus supporting a stratigraphically controlled modified placer model for the origin of gold in the Carbon Leader reef.

GIS Based Coal Seam Floor DEM Construction According to Floor Contours and Considering Faults Distribution

2014 ◽  
Vol 1046 ◽  
pp. 516-520
Author(s):  
He Yu Zhang ◽  
Fan Lei ◽  
Fei Huang
Keyword(s):  
Spatial Distribution ◽  
Coal Seam ◽  
Three Dimensional ◽  
Coal Production ◽  
Mine Design ◽  
Coal Seams ◽  
Inverse Distance Weighted ◽  
Coal Deposits ◽  
Distance Weighted ◽  
Inverse Distance

Coal seam floor contours are one of the most important 8 mine maps, and was usually used for coal mine decision-making. However, the graph, which was expressed as lines, has many disadvantages, including inadequate intuitive, poor visibility, and weak in expression of three-dimensional morphology formation. Thus, the readers have to spend more time to reveal the spatial distribution of coal deposits. According to the coal seam floors contours, and considering the constraints of faults in coal seams, the following steps were implemented to acquire coal seam floor DEM, which are: 1) contours discrete; and 2) interpolation using Inverse Distance Weighted method (IDW). The process was easy-manipulated, and the results could reflect the spatial distribution of coal seams in an objective, intuitively, and strong visibility manner. The method could facilitate and guide the analysis of mine design and coal production.

scholarly journals Improving AfriPop dataset with settlement extents extracted from RapidEye for the border region comprising South-Africa, Swaziland and Mozambique

2015 ◽  
Vol 10 (2) ◽  
Author(s):  
Julie Deleu ◽  
Jonas Franke ◽  
Michael Gebreslasie ◽  
Catherine Linard
Keyword(s):  
South Africa ◽  
High Resolution ◽  
Census Data ◽  
Population Distribution ◽  
Malaria Incidence ◽  
Border Region ◽  
Land Use Classification ◽  
Population Growth Rates ◽  
Kwazulu Natal ◽  
Satellite Sensors

For modelling the spatial distribution of malaria incidence, accurate and detailed information on population size and distribution are of significant importance. Different, global, spatial, standard datasets of population distribution have been developed and are widely used. However, most of them are not up-to-date and the low spatial resolution of the input census data has limitations for contemporary, national- scale analyses. The AfriPop project, launched in July 2009, was initiated with the aim of producing detailed, contemporary and easily updatable population distribution datasets for the whole of Africa. High-resolution satellite sensors can help to further improve this dataset through the generation of high-resolution settlement layers at greater spatial details. In the present study, the settlement extents included in the MALAREO land use classification were used to generate an enhanced and updated version of the AfriPop dataset for the study area covering southern Mozambique, eastern Swaziland and the malarious part of KwaZulu-Natal in South Africa. Results show that it is possible to easily produce a detailed and updated population distribution dataset applying the AfriPop modelling approach with the use of high-resolution settlement layers and population growth rates. The 2007 and 2011 population datasets are freely available as a product of the MALAREO project and can be downloaded from the project website.

scholarly journals Study on Borehole Arrangement Methods for Gas Extraction by Hydraulic Slotting in Long-Distance Through-Coal Seam Tunnel

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Cunfang Zhu ◽  
Shuang Cai
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Simulation Models ◽  
Gas Production ◽  
Gas Extraction ◽  
Long Distance ◽  
Pressure Relief ◽  
Coal Deposits ◽  
Geological Conditions ◽  
Rapid Pressure

How to quickly eliminate outburst in long-distance through-coal seam tunnels is one of the major challenges faced by the tunnel industry in mountainous areas. Compared with coal mine rock crosscut coal uncovering, the work surrounding the rock of through-coal seam tunnels has a high degree of breakage, large cross-section of coal uncovering, and tight time and space. In this paper, a method of networked slotting in long-distance through-coal seam tunnels for rapid pressure relief and outburst elimination is proposed. Based on this method, the corresponding mathematical governing equations and numerical simulation models have been established. The optimal borehole arrangement spacing and the slot arrangement spacing obtained by numerical optimization are 2.85 m and 3.1 m, respectively. Field gas production data of through-coal seam tunnels show that compared with the traditional dense-borehole gas extraction, the method of networked slotting in long-distance through-coal seam tunnels for rapid pressure relief and outburst elimination can shorten the extraction time by about 66%, the net quantity of peak extraction is increased by 3.55 times, and the total quantity of gas extraction when reaching the outburst prevention index is increased by 1.26 times, which verifies the feasibility of this method and the reliability of numerical simulation results. This study could be used as a valuable example for other coal deposits being mined under similar geological conditions.

A 3000-year high-resolution stalagmitebased record of palaeoclimate for northeastern South Africa

The Holocene ◽  
1999 ◽  
Vol 9 (3) ◽  
pp. 295-309 ◽  
Author(s):  
K. Holmgren ◽  
W. Karlén ◽  
S. E. Lauritzen ◽  
J. A. Lee-Thorp ◽  
T. C. Partridge ◽  
...  
Keyword(s):  
South Africa ◽  
High Resolution

scholarly journals Structural analysis of the Spike of the Omicron SARS-COV-2 variant by Cryo-EM and implications for immune evasion

2021 ◽  
Author(s):  
Dongchun Ni ◽  
Kelvin Lau ◽  
Priscilla Turelli ◽  
Charlene Raclot ◽  
Bertrand Beckert ◽  
...  
Keyword(s):  
South Africa ◽  
United Kingdom ◽  
Structural Analysis ◽  
High Resolution ◽  
Immune Evasion ◽  
Spike Protein ◽  
Spike Glycoprotein ◽  
The United Kingdom ◽  
New Variant ◽  
Structural Insights

The Omicron (B.1.1.529) SARS-COV-2 was reported on November 24, 2021 and declared a variant of concern a couple of days later. With its constellation of mutations acquired by this variant on its Spike glycoprotein and the speed at which this new variant has replaced the previously dominant variant Delta in South Africa and the United Kingdom, it is crucial to have atomic structural insights to reveal the mechanism of its rapid proliferation. Here we present a high-resolution cryo-EM structure of the Spike protein of the Omicron variant.

Sign in / Sign up

Export Citation Format

Share Document