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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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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. ...

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That open traverse is a traverse which does not close onto a survey point of known coordinates and orientation or onto itself [25].?

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Your search for flank margin caves (Keyword) returned 29 results for the whole karstbase:
Showing 1 to 15 of 29
The exposed carbonates of the Bahamas consist of late Quaternary limestones that were deposited during glacio-eustatic highstands of sea level. Each highstand event produced transgressive-phase, stillstand-phase, and regressive-phase units. Because of slow platform subsidence, Pleistocene carbonates deposited on highstands prior to the last interglacial (oxygen isotope substage 5e, circa 125,000 years ago) are represented solely by eolianites. The Owl's Hole Formation comprises these eolianites, which are generally fossiliferous pelsparites. The deposits of the last interglacial form the Grotto Beach Formation, and contain a complete sequence of subtidal intertidal and eolian carbonates. These deposits are predominantly oolitic. Holocene deposits are represented by the Rice Bay Formation, which consists of intertidal and eolian pelsparites deposited during the transgressive-phase and stillstand-phase of the current sea-level highstand. The three formations are separated from one another by well-developed terra-rossa paleosols or other erosion surfaces that formed predominantly during intervening sea-level lowstands. The karst landforms of San Salvador consist of karren, depressions, caves, and blue holes. Karren are small-scale dissolutional etchings on exposed and soil-covered bedrock that grade downward into the epikarst, the system of tubes and holes that drain the bedrock surface. Depressions are constructional features, such as swales between eolian ridges, but they have been dissolutionally maintained. Pit caves are vertical voids in the vadose zone that link the epikarst to the water table. Flank margin caves are horizontal voids that formed in the distal margin of a past fresh-water lens; whereas banana holes are horizontal voids that developed at the top of a past fresh-water lens, landward of the lens margin. Lake drains are conduits that connect some flooded depressions to the sea. Blue holes are flooded vertical shafts, of polygenetic origin, that may lead into caves systems at depth. The paleokarst of San Salvador is represented by flank margin caves and banana holes formed in a past fresh-water lens elevated by the last interglacial sea-level highstand, and by epikarst buried under paleosols formed during sea-level lowstands. Both carbonate deposition and its subsequent karstification is controlled by glacio-eustatic sea-level position. On San Salvador, the geographic isolation of the island, its small size, and the rapidity of past sea level changes have placed major constraints on the production of the paleokarst

History of the Guano Mining Industry, Isla de Mona, Puerto Rico, 1998, Frank, E. F.
Isla de Mona, Puerto Rico is ringed by hundreds of flank margin caves (Frank 1993; Mylroie et al. 1995). In the late 1800s and early 1900s, ~150,000 metric tons of phosphorite, altered bat guano, were mined from the caves. A high phosphate content made the phosphorite a valuable fertilizer (Wadsworth 1973). Briggs (1974) indicates the guano deposits have been exhausted from seven of the eight largest known cave systems on the island. Many relics from the guano mining days are still present in the caves and surrounding areas today.

Karst Development and Speleogenesis, Isla de Mona, Puerto Rico, 1998, Frank, E. F. , Mylroie, J. , Troester, Jo. , Alexander, Jr. , E. C. , Carew, J.
Isla de Mona consists of a raised table-top Miocene-Pliocene reef platform bounded on three sides by vertical cliffs, up to 80 m high. Hundreds of caves ring the periphery of the island and are preferentially developed in, but not limited to, the Lirio Limestone/Isla de Mona Dolomite contact. These flank margin caves originally formed at sea level and are now exposed at various levels by tectonic uplift of the island (Frank 1983; Mylroie et al. 1995b). Wall cusps, a characteristic feature of flank margin caves, are ubiquitous features. Comparisons among similar caves formed in the Bahamas and Isla de Mona reveal the same overall morphology throughout the entire range of sizes and complexities. The coincidence of the primary cave development zone with the Lirio Limestone/Isla de Mona Dolomite contact may result from syngenetic speleogenesis and dolomitization rather than preferential dissolution along a lithologic boundary. Tectonic uplift and glacioeustatic sea level fluctuations produced caves at a variety of elevations. Speleothem dissolution took place in many caves under phreatic conditions, evidence these caves were flooded after an initial period of subaerial exposure and speleothem growth. Several features around the perimeter of the island are interpreted to be caves whose roofs were removed by surficial denudation processes. Several large closed depressions and dense pit cave fields are further evidence of surficial karst features. The cliff retreat around the island perimeter since the speleogenesis of the major cave systems is small based upon the distribution of the remnant cave sections.

Geology of Isla de Mona, Puerto Rico, 1998, Frank, E. F. , Wicks, C. , Mylroie, J. , Troester, J. , Alexander, Jr. , E. C. , Carew, J.
Isla de Mona is a carbonate island located in the Mona Passage 68 km west of Puerto Rico. The tectonically uplifted island is 12 km by 5 km, with an area of 55 km?, and forms a raised flat-topped platform or meseta. The meseta tilts gently to the south and is bounded by near vertical cliffs on all sides. These cliffs rise from 80 m above sea level on the north to 20 m above the sea on the southern coast. Along the southwestern and western side of the island a three- to six-meter-high Pleistocene fossil reef abuts the base of the cliff to form a narrow coastal plain. The meseta itself consists of two Mio-Pliocene carbonate units, the lower Isla de Mona Dolomite and the upper Lirio Limestone. Numerous karst features, including a series of flank margin caves primarily developed at the Lirio Limestone/Isla de Mona Dolomite contact, literally ring the periphery of the island.

Field assessment of the microclimatology of tropical flank margin caves., 2000, Gamble D. W. , Dogwiler J. T. , Mylroie J. E.

Field assessment of the microclimatology of tropical flank margin caves, 2000, Gamble Dw, Dogwiler Jt, Mylroie J,
Temperature observations were collected inside 2 caves in the Bahamas and 1 cave in Puerto Rico to characterize the microclimatology of tropical flank margin cave systems. Three aspects of these tropical cave temperatures agree with temperate cave microclimate theory. Specifically, external atmospheric disturbances can affect temperatures inside tropical flank margin cave systems, tropical flank margin caves are warmer than the exterior temperatures during winter, and water can impact temperatures deep into a tropical flank margin cave system. The temperature observations collected also indicate potential differences between the microclimatology of tropical and temperate cave systems. In particular, the temperate 3-zone cave microclimate model may not be applicable to tropical flank margin caves, diurnal fluctuations were not apparent in tropical flank margin cave systems, and the existence of a temperature inversion in a down-sloping cave may not be applicable to all tropical flank margin caves. The potential differences in temperate and these tropical cave systems can be linked to the physical dimensions of the tropical flank margin cave systems and the unique hydrology of small carbonate islands. Specifically, tropical flank margin caves have a width greater than length while temperate fluvio-karst caves have a length greater than width and tidal water can exist in the pits and depressions of tropical flank margin caves as opposed to flowing streams in temperate cave systems

Speleogenesis in coastal and oceanic settings, 2000, Mylroie J. E. , Carew J. L.
Carbonate islands and coasts are directly influenced by the chemistry of mixing marine and fresh water, and by the migration of sea level in response to Quaternary glacio-eustasy. Carbonate islands are unique in particular because they are limited in recharge to their own areal extent, whereas carbonate coasts can obtain recharge from adjacent, non-carbonate areas. Carbonate islands fall into three categories: Simple carbonate islands which are entirely carbonate from the land surface to a depth exceeding the lowest Quaternary glacio-eustatic sea-level lowstand (approximately -125 m); carbonate-cover islands which are entirely carbonate, but a carbonate/non-carbonate contact exists within the range of Quaternary glacio-eustasy; and carbonate-rimmed islands where non-carbonate rocks are present at the surface. Simple carbonate islands have only autogenic recharge and develop pit caves in the epikarst, banana holes at the top of the fresh-water lens, and flank margin caves at the margin of the freshwater lens. Carbonate-cover islands develop additional caves at the carbonate/non-carbonate contact, and carbonate-rimmed islands form stream caves from non-carbonate allogenic recharge. Blue holes and large conduit caves exist on carbonate islands and coasts. They are overprinted by Quaternary glacio-eustasy, and their development is linked to processes not operating at their locations today.

Karst genetic model for the French Bay Breccia deposits, San Salvador, Bahamas., 2001, Florea L. , Mylroie J. , Carew J.
On the Island of San Salvador in the Bahama archipelago 30 breccia deposits can be found along the French Bay sea cliffs on the southeastern coast of the island. Breccia deposits of this type have not been observed on any other location on the island. These deposits have traditionally been interpreted as paleo-talus deposits from an eroding sea cliff formed on a transgressive eolianite deposited at the start of the oxygen isotope substage 5e sea-level highstand (ca. 125,000 years before present). New evidence supports a karst genesis. A survey of several deposits revealed a vertical restriction of +2 to +7 meters above sea level consistent with flank margin caves developed during the substage 5e still-stand. The morphologies of the features were found to be globular and contain distinct caliche boundaries, overhung lips, and smooth undulating bases. Petrographic results support a model in which voids are created and then infilled with a soil breccia. It can be concluded from these results that the deposits reflect qualities of a lithified soil breccia filling in breached flank margin caves. karst breccia, paleokarst, San Salvador

Eogenetic karst from the perspective of an equivalent porous medium, 2002, Vacher H. L. , Mylroie J. E. ,
The porosity of young limestones experiencing meteoric diagenesis in the vicinity of their deposition (eogenetic karst) is mainly a double porosity consisting of touching-vug channels and preferred passageways lacing through a matrix of interparticle porosity. In contrast, the porosity of limestones experiencing subaerial erosion following burial diagenesis and uplift (telogenetic karst) is mainly a double porosity consisting of conduits within a network of fractures. The stark contrast between these two kinds of karst is illustrated by their position on a graph showing the hydraulic characteristics of an equivalent porous medium consisting of straight, cylindrical tubes (n-D space, where n is porosity, D is the diameter of the tubes, and log n is plotted against log D). Studies of the hydrology of small carbonate islands show that large-scale, horizontal hydraulic conductivity (K) increases by orders of magnitude during the evolution of eogenetic karst. Earlier petrologic studies have shown there is little if any change in the total porosity of the limestone during eogenetic diagenesis. The limestone of eogenetic karst, therefore, tracks horizontally in n-D space. In contrast, the path from initial sedimentary material to telogenetic karst comprises a descent on the graph with reduction of n during burial diagenesis, then a sideways shift with increasing D due to opening of fractures during uplift and exposure, and finally an increase in D and n during development of the conduits along the fractures. Eogenetic caves are mainly limited to boundaries between geologic units and hydrologic zones: stream caves at the contact between carbonates and underlying impermeable rocks (and collapse-origin caves derived therefrom); vertical caves along platform-margin fractures; epikarst; phreatic pockets (banana holes) along the water table; and flank margin caves that form as mixing chambers at the coastal freshwater-saltwater 'interface'. In contrast, the caverns of telogenetic karst are part of a system of interconnected conduits that drain an entire region. The eogenetic caves of small carbonate islands are, for the most part, not significantly involved in the drainage of the island

Blow Hole Cave: An unroofed cave on San Salvador Island, the Bahamas, and its importance for detection of paleokarst caves on fossil carbonate platforms, 2002, Bosá, K Pavel, Mylroie John E. , Hladil Jindrich, Carew James L. , Slaví, K Ladislav

The comparative study of a Quaternary carbonate platform (San Salvador Island, the Bahamas) and a Devonian Carbonate Platform (Krásná Elevation, Moravia) indicates a great similarity in karst evolution. Caves on both sites are interpreted as flank margin caves associated with a freshwater lens and halocline stabilised during sea-level highstands. The sedimentary fill of both caves is genetically comparable - beach and aeolian sediments with bodies of breccias.

Karst development on carbonate islands, 2003, Mylroie J. E. , Carew J. L.

Karst development on carbonate platforms occurs continuously on emergent portions of the platform. Surficial karst processes produce an irregular pitted and etched surface, or epikarst. The karst surface becomes mantled with soil, which may eventually result in the production of a resistant micritic paleosol. The epikarst transmits surface water into vadose pit caves, which in turn deliver their water to a diffuse-flow aquifer. These pit caves form within a 100,000 yr time frame. On islands with a relatively thin carbonate cover over insoluble rock, vadose flow perched at the contact of carbonate rock with insoluble rock results in the lateral growth of vadose voids along the contact, creating large collapse chambers that may later stope to the surface.
Carbonate islands record successive sequences of paleosols (platform emergence) and carbonate sedimentation (platform submergence). The appropriate interpretation of paleosols as past exposure surfaces is difficult, because carbonate deposition is not distributed uniformly, paleosol material is commonly transported into vadose and phreatic voids at depth, and micritized horizons similar in appearance to paleosols can develop within existing carbonates.
On carbonate islands, large dissolution voids called flank margin caves form preferentially in the discharging margin of the freshwater lens from the effects that result from fresh-water/salt-water mixing. Similarly, smaller dissolution voids also develop at the top of the lens where vadose and phreatic fresh-waters mix. Independent of fluid mixing, oxidation of organic carbon and oxidation/reduction reactions involving sulfur can produce acids that play an important role in phreatic dissolution. This enhanced dissolution can produce caves in fresh-water lenses of very small size in less than 15,000 yr. Because dissolution voids develop at discrete horizons, they provide evidence of past sea-level positions. The glacio-eustatic sea-level changes of the Quaternary have overprinted the dissolutional record of many carbonate islands with multiple episodes of vadose, fresh-water phreatic, mixing zone, and marine phreatic conditions. This record is further complicated by collapse of caves, which produces upwardly prograding voids whose current position does not correlate with past sea level positions.
The location and type of porosity development on emergent carbonate platforms depends on the degree of platform exposure, climate, carbonate lithology, and rate of sea-level change. Slow, steady, partial transgression or regression will result in migration of the site of phreatic void production as the fresh-water lens changes elevation and moves laterally in response to sea-level change. The result can be a continuum of voids that may later lead to development solution-collapse breccias over an extended area.

Hoga island, Sulawesi, Indonesia: geomorphology and groundwater resources of a small tropical carbonate island, 2006, Dykes A. P. , Gunn J.
This paper provides the first report of the geomorphology and hydrogeology of Hoga island, a small tropical carbonate island in southeast Sulawesi, Indonesia, based on reconnaissance field explorations and surveys. Hoga is being developed as a specialist ecotourism destination, and a sustainable water supply is one of the important development issues. The island comprises 3.42km2 of low-lying hard, but highly karstified, coral limestone covered with dense scrub forest and coconut plantations. It displays dissolution features typical of similar tropical islands, including pit caves and flank margin caves. A freshwater aquifer exists with a water table 1.57m above MSL near the centre of the less karstified western two-thirds of the island, where surface elevations locally exceed 6m above MSL. All occurrences of potable freshwater, i.e. having electrical conductivity < 1500 mS cm-1, are also within this main part of the island. Complex hydrogeological conditions are indicated by the patterns of tidal influences on water levels in existing wells and natural dissolution holes. Using published studies and empirical relationships, it is estimated that Hoga contains a potable freshwater lens at least 2m thick (total volume c.300,000m3) and that annual recharge may exceed 500,000m3. As actual annual demand for freshwater since 2001 was < 2800m3, it is concluded that Hoga contains an aquifer that could sustain the present and likely future freshwater demands of residents and seasonal ecotourist populations, subject to satisfactory water quality assessment and management.

Development of the carbonate island karstmodel, 2007, Mylroie J. R. And Mylroie J. E.
The development of a comprehensive conceptual model for carbonate island karst began in the Bahamas in the 1970s. The use, initially, of cave and karst models created for the interior of continents, on rocks hundreds of millions of years old, was not successful. Models developed in the 1980s for the Bahamas, that recognized the youthfulness of the carbonate rock, the importance of fresh-water mixing with sea water, and the complications introduced by glacioeustatic sea-level change produced the first viable model, the flank margin cave model. This model explains the largest caves in carbonate islands as being the result of mixing zone dissolution in the distal margin of the fresh-water lens, under the flank of the enclosing land mass. The flank margin model, taken from the Bahamas to Isla de Mona, Puerto Rico, in the early 1990s, provided the first viable explanation for the very large caves there. Field work in the geologicallycomplex Mariana Islands in the late 1990s resulted in the development of the Carbonate Island Karst Model, or CIKM, which integrated the various components controlling cave and karst development on carbonate islands. These components are: 1) Mixing of fresh and salt water to create dissolutional aggressivity; 2) Movement of the fresh-water lens, and hence the mixing environments, by 100+ m as a result of Quaternary glacioeustasy; 3) The overprinting of glacioeustatic changes by local tectonic movements, where present; 4) The unique behavior of eogenetic (diagenetically immature) carbonate rocks; and 5) The classification of carbonate islands into simple, carbonate cover, composite, and complex categories. Current research involves the use of flank margin caves as predictors of past and present fresh-water lens configuration, the analysis of flank margin cave morphology as a measure of the processes that create them, and the CIKM as an indicator of paleokarst distribution.

The Caves of Abaco Island, Bahamas: keys to geologic timelines, 2008, Walker L. N. , Mylroie J. E. , Walker A. D. , Mylroie J. R.

Abaco Island, located on Little Bahama Bank, is the most northeastern island in the Bahamian archipelago. Abaco exhibits typical carbonate island karst features such as karren, blue holes, pit caves, banana holes and flank margin caves. Landforms that resemble tropical cone karst and pseudokarst tafoni caves are also present. The three cave types of Abaco—flank margin caves, pit caves, and tafoni caves—are abundant, but each forms by very different mechanisms. Flank margin caves are hypogenic in origin, forming due to mixing dissolution at the margin of the freshwater lens. Since the lens margin is concordant with sea level, flank margin caves record the position of sea level during their formation. Flank margin caves exhibit phreatic dissolutional features such as bell holes, dissolutional cusps and spongework. Pit caves form as vadose fast-flow routes to the freshwater lens and are common on the Pleistocene eolianite ridges of the Bahamas. Pit caves are characterized by their near-vertical or stair-step profiles. Because pit caves form in the vadose zone, their position is not tied to sea level. Tafoni caves are pseudokarst features that form when the soft interior of an eolianite ridge is exposed to subaerial erosion. Since tafoni caves form by mechanical processes, they do not exhibit phreatic dissolutional features. Tafoni caves may be mistaken as flank margin caves by the untrained observer, which may cause problems when using caves as sea-level indicators. Each of Abaco’s unique cave types may preserve depositional and erosional features that are useful to the researcher in creating general geologic timelines. While these timelines may not give exact dates, they are useful in the field for understanding depositional boundaries and determining sequences of geologic events.

Flank Margin Cave Development in Telogenetic Limestones of New Zealand, 2008, Mylroie J. E. , Mylroie J. R. , Nelson C. S.

Coastal limestone outcrops, typically with advanced levels of diagenetic maturity (i.e., are telogenetic carbonates), were examined on North Island (Raglan Harbour, Kawhia Harbour, Napier, and Waipu Cove) and South Island (Pohara, Paturau River, Punakaiki, Kakanui, and Kaikoura), New Zealand, to determine if flank margin caves, produced by mixing dissolution, were present. In coastal settings, caves in carbonate rock can be the outcome of pseudokarst process, primarily wave erosion, as well as karst processes not associated with fresh and sea-water mixing such as epikarst features and conduit-flow stream caves. Flank margin caves were successfully differentiated from other cave types by the following criteria: phreatic dissolutional morphologies at the wall rock and chamber scales; absence of high- velocity, turbulent-flow wall sculpture and sediment deposits; and lack of integration of adjacent caves into a continuous flow path. The active tectonics of New Zealand creates a variable sea- level situation. The relatively short time of sea-level stability limits the size of the New Zealand flank margin caves compared to tectonically-stable environments, such as the Bahamas, where glacioeustasy alone controls sea-level stability. Uplift events can be identified as slow and steady when the flank margin caves are uniformly elongated in the vertical direction, and episodic when the flank margin caves show widening and tube development at discrete horizons that cut across rock structure. New Zealand flank margin caves contain information on uplift duration and rates independent of other commonly used measures, and therefore can provide a calibration to other methods.

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