MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

Community news

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That sheet erosion is erosion occurring over widespread tabular sedimentary or effusive rock [16].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for coal (Keyword) returned 84 results for the whole karstbase:
Showing 76 to 84 of 84
Hydrogeochemistry and possible sulfate sources in karst groundwater in Chongqing, China, 2012, Pu J. , Yuan D. , Zhang Ch. , Zhao H.

Groundwater from karst subterranean streams is among the world’s most important sources of drinking water supplies, and the hydrochemical characteristics of karst water are affected by both natural environment and people. Therefore, the study of karst groundwater hydrochemistry and its solutes’ sources is very important to ensure the normal function of life support systems. This paper focused on the major ion chemistry and sulfate isotope of karst groundwater in Chongqing for tracing the sulfate sources and related hydrochemical processes. Hydrochemical types of karst groundwater in Chongqing were mainly of the Ca-HCO3 type or Ca(Mg)-HCO3 type. However, some hydrochemical types were the K ? Na ? Ca-SO4 type (G25 site) or Ca-HCO3 ? SO4 type (G26 and G14 sites), indicating that the hydrochemistry of these sites may be strongly influenced by anthropogenic activities or unique geological characteristics. The d34S-SO4 2- of collected karst groundwater sample fell into a range of -6.8 to 21.5 %, with a mean value of 5.6 %. In dolomite aquifer, the d34S-SO4 2- value ranges from -4.3 to 11.0 %, and in limestone aquifer, it ranged from -6.8 to 21.5 %. The groundwater samples from different land use types showed distinctive d34S-SO4 2- value. The d34S-SO4 2- value of groundwater samples had range of -6.8 to 16.7 % (mean 4.0 %, n = 11) in cultivated land areas, 1.5–21.5 %(mean 7.2 %, n = 20) in forested land areas, and -4.3 to 0.8 % (mean -1.7 %, n = 2) in coalmine areas. The d34S-SO4 2- values of groundwater samples collected from factory area and town area were 2.2 and 9.9 %, respectively. According to the d34S information of potential sulfate sources, this paper discussed the possible sulfate sources of collected karst groundwater samples in Chongqing. The variations of both d34S and 1/SO4 2- values of the groundwater samples indicated that the atmospheric acid deposition (AAD), dissolution of gypsum (GD), oxidation of sulfide mineral (OS) or anthropogenic inputs (SF: sewage or fertilizer) contributed to sulfate in karst groundwater. The influence of oxidation of sulfide mineral, atmospheric acid deposit and anthropogenic inputs to groundwater in Chongqing karst areas was much widespread. For protecting, sustaining, and utilizing the groundwater resources, the sewage possibly originating from urban, mine or industrial area must be controlled and treated, and the use of fertilizer should be limited


Micro-Charcoal Abundances in Stream Sediments from Buckeye Creek Cave, West Virginia, USA, 2012, Springer G. S. , Mihindukulasooriya L. N. , White D. M. , Rowe H. D.

 

We compare micro-charcoal abundances in laminated cave-stream sediments to the presences of Native Americans and later settlers in the same watershed. Samples were obtained from a core taken from a 2.5 m high point bar located 1 km inside of Buckeye Creek Cave, West Virginia. Thirty-three subsamples were treated with hydrogen peroxide to bleach or whiten non-charcoal organic matter. In the absence of opaque mineral grains, this technique creates a large visual contrast between dark charcoal grains and other substances. The subsamples were photographed using a microscope-mounted camera, and pixels darker than 99/255 (grayscale) were used to calculate charcoal concentrations. The record spans the last 6,000 years, and four of the five highest charcoal concentrations are from the last 2,000 years. The highest concentration is from AD 1093, and the second-highest concentration is from the nineteenth century. Post-Colonial settlers began making extensive use of the watershed sometime in the eighteenth century and may, therefore, be responsible for the second-highest charcoal concentration. However, archaeologists independently concluded that Native Americans made peak use of the watershed between AD 1000 and 1200, which coincides with the highest charcoal concentration in the record. Native Americans are known to have extensively used fire, so there is good circumstantial evidence tying high concentrations in the last 2,000 years to human activities. Our method is suitable for use elsewhere, and we present a detailed statistical analysis of our data as a guide toward interpreting charcoal concentrations in karst and non-karst deposits.


Historic inscriptions in Predjama cave system and high floods in 2010, 2012, Sebela, S.

High floods of September 2010 partly ruined historic inscription made by charcoal »Slovenski gadje 1882« in Predjama cave system. Regarding studied historic records the September 2010 floods were the highest in Predjama at least since 1882. If we thrust the well-documented floods in 1826 they can even be higher than ones in 2010. In 2010 the water reached 489.60 m above the sea level at entrance parts of the cave and about 485 m at Vetrovna Luknja causing that the old inscription from 1882 was under water and partly destroyed. Another old inscription »Nagel 1748«, probably done by more resistant pencil, did not suffer from the 2010 floods. Contrary, it was twice partly destroyed by carless visitors, first in 1991 and secondly in the period 1991 – 2005.


Historic inscriptions in Predjama cave system and high floods in 2010, 2012, ebela, Stanka

High floods of September 2010 partly ruined historic inscription made by charcoal »Slovenski gadje 1882« in Predjama cave system. Regarding studied historic records the September 2010 floods were the highest in Predjama at least since 1882. If we thrust the well-documented floods in 1826 they can even be higher than ones in 2010. In 2010 the water reached 489.60 m above the sea level at entrance parts of the cave and about 485 m at Vetrovna Luknja causing that the old inscription from 1882 was under water and partly destroyed. Another old inscription »Nagel 1748«, probably done by more resistant pencil, did not suffer from the 2010 floods. Contrary, it was twice partly destroyed by carless visitors, first in 1991 and secondly in the period 1991 – 2005.


Characterizing moldic and vuggy pore space in karst aquifers using borehole-wall, slabbed-core and thin-section images, 2013, Manda A. K. , Culpepper A. R.

Carbonate aquifers are prolific and important sources of potable water in many parts of the world owing toenlarged dissolution features that enhance porosity and interconnectivity. To better understand the variationsof pore space in different karst aquifers, image and geospatial analyses are used to analyze pore attributes(i.e., pore area and perimeter) in images of vuggy aquifers. Pore geometry and 2D porosity derivedfrom images of the moldic Castle Hayne and vuggy Biscayne aquifers are analyzed at three scales of observation:borehole televiewer, core and thin-section. The Castle Hayne and Biscayne aquifers are the foci of thisstudy because the pore spaces that control the hydrologic properties in each of these aquifers are markedlydifferent even though both of these carbonate reservoirs are prolific aquifers. Assessments of pore area,perimeter and shape index (a measure of shape complexity) indicate that pore geometries and pore complexitiesvary as a function pore type and scale of observation. For each aquifer type, the areas, perimetersand complexities of pores are higher at the larger scale of observation (e.g., borehole) than the smallerscale of observation (e.g., thin section). When the complexity of the moldic pores is compared to the complexityof vuggy pores, the results indicate that moldic pores are generally more complex than vuggy poresat the same scale of observation. Whereas estimates of 2D porosity from the borehole televiewer image ofthe vuggy aquifer are higher than those derived from the moldic aquifer, the range of 2D porosities is largerin core and thin section images for the vuggy aquifer than themoldic aquifer. A model for the development ofpores is presented that suggests that the coalescence of small pores with simple shapes leads to the growth oflarger pores with more complex shapes. The model suggests that the younger Biscayne aquifer is a moremature karst than the Castle Hayne aquifer.


The hydrogeology and hydrochemistry of the thermal waters at Taffs Well, South Wales, UK, 2013, Farr G. , Bottrell S. H

Taffs Well is the only thermal spring in Wales, with an average temperature of 21.6°C ± 0.5°C. The River Taff is adjacent to the spring and removal of a weir and work on flood defences has reduced mixing with flood water from the river. This has enabled data to be gathered that more closely represent the thermal water end-member than previously possible. Limited interaction with modern waters is confirmed by tritium, nitrate, CFC and SF6concentrations below or close to lower detection limits, showing at most 6% mixing with modern waters. 14C dating suggests a conservative age estimate of at least 5000 years.
Values for dissolved noble gases suggest that the waters originate as rainfall at an altitude several hundred metres higher than the spring. The northern Carboniferous Limestone outcrop is proposed, which would then require recharged waters to flow to a depth of 400m and distance of 25km, following the synclinal structure of the South Wales Coalfield, to discharge at the spring. Sr isotope data suggest interaction with the Marros Group (formerly known as the Millstone Grit), the waters flowing within or close to the contact between the Carboniferous Limestone and Marros Group before rising via the Tongwynlais Fault.


PALEOKARST CRUST OF ORDOVICIAN LIMESTONE AND ITS CAPABILITY IN RESISTING WATER INRUSHES IN COAL MINES OF NORTH CHINA, 2013, Mou L. , Li G.

With increase in mining depth of the Carboniferous-Permian coal seams in North China, it is particularly important to study the heterogeneity of karst development in the underlying Middle Ordovician limestone and determine any impermeable strata that may prevent the pressurized karst water from bursting into coal mines. Detailed analysis of the exploratory borehole data suggests presence of a paleokarst crust at the top of Middle Ordovician Fengfeng Formation. Because of its mechanical strength and low permeability to water, the paleokarst crust can function as an additional water-resisting layer. This paper takes Sihe Mine of Shanxi Province as an example to study the geotechnical and hydrogeological characteristics of the paleokarst crust. Incorporation of this additional hydrological barrier led to more minable coal seams in the coalmine.


Characteristics of gas disaster in the Huaibei coalfield and its control and development technologies, 2014, Wang L. , Cheng Y. , An F, Zhou H. , Kong S. , Wang W.

The Huaibei coalfield is in the East China Economic Area, which is rich in coal and gas resources. However, hundreds of coal and gas outburst accidents have occurred because of the complex geological structures of the coalfield. Based on theoretical analysis and field statistics, the characteristics of regional geological structures and the coal measure strata evolution in the Huaibei coalfield were researched, and gas resource distribution and gas parameters were statistically analyzed to determine the dominant controlling factors of gas occurrence and gas dynamic disaster. The results indicated that the Huaibei coalfield has undergone complex tectonic evolution, causing obvious differences in gas storage in different blocks of different mining areas, which exhibits a pattern of high amounts of gas in the south and east, and low amounts of gas in the north and west. The coal seam and gas occurrence have a bipolar distribution in the coalfield caused by multiple tectonic movements, and they are deeply buried. Horizontal tectonic stress plays a dominant role in gas outburst, and the thermal evolution and trap effects of magma intrusion increase the possibility and extent of gas outburst. Considering coal seam and gas occurrence characteristics in the coalfield, we propose a new technology for deep coal reservoir reconstruction which combined present underground regional gas control methods and surface well extraction methods. The technology has three effects: developing gas resources, improving coal mining safety level and reducing greenhouse gas emissions, which has been practiced to be effective in coal mines in the Huaibei coalfield.


The formation of the pinnacle karst in Pleistocene aeolian calcarenites (Tamala Limestone) in southwestern Australia, 2015,

A spectacular pinnacle karst in the southwestern coastal part of Western Australia consists of dense fields of thousands of pinnacles up to 5 m high, 2 m wide and 0.5–5 m apart, particularly well exposed in Nambung National Park. The pinnacles have formed in the Pleistocene Tamala Limestone, which comprises cyclic sequences of aeolian calcarenite, calcrete/microbialite and palaeosol. The morphology of the pinnacles varies according to the lithology in which they have formed: typically conical in aeolianite and cylindrical in microbialite. Detailed mapping and mineralogical, chemical and isotopic analyses were used to constrain the origin of the pinnacles, which are residual features resulting mainly from solutional widening and coalescence of solution pipeswithin the Tamala Limestone. The pinnacles are generally joined at the base, and the stratigraphy exposed in their sides is often continuous between adjacent pinnacles. Some pinnacles are cemented infills of solution pipes, but solution still contributed to their origin by removing the surrounding material. Although a number of pinnacles contain calcified plant roots, trees were not a major factor in their formation. Pinnacle karst in older, better-cemented limestones elsewhere in theworld is similar inmorphology and origin to the Nambung pinnacles, but is mainly influenced by joints and fractures (not evident at Nambung). The extensive dissolution associatedwith pinnacle formation at Nambung resulted in a large amount of insoluble quartz residue, which was redeposited to often bury the pinnacles. This period of karstification occurred at aroundMIS 5e, and therewas an earlier, less intense period of pinnacle development duringMIS 10–11. Both periods of pinnacle formation probably occurred during the higher rainfall periods that characterise the transition from interglacial to glacial episodes in southern Australia; the extensive karstification around MIS 5e indicates that the climate was particularly humid in southwestern Australia at this time.


Results 76 to 84 of 84
You probably didn't submit anything to search for