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 terrace is a flat surface bounded by steplike steep slopes [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 tropical (Keyword) returned 219 results for the whole karstbase:
Showing 1 to 15 of 219
Paleoclimate and location of the border between Mediterranean climate region and the Saharo-Arabian Desert as revealed by speleothems from the northern Negev Desert, Israel, , Vaks A. , Barmatthews M. , Ayalon A. , Matthews A. , Frumkin A. , Dayan U. , Halicz L. , Mogilabin A. , Schilman B. ,
Speleothem bearing karstic caves of the northern Negev Desert, southern Israel, provides an ideal site for reconstructing the paleoclimate and paleo-location of the border between Mediterranean climate region and the Saharo-Arabian Desert. Major periods of speleothem deposition (representing humid periods) were determined by high resolution 230Th-U dating and corresponding studies of stable isotope composition were used to identify the source of rainfall during humid periods and the vegetation type. Major humid intervals occurred during glacials at 190-150[no-break space]ka, 76-25[no-break space]ka, 23-13[no-break space]ka and interglacials at 200-190[no-break space]ka, 137-123[no-break space]ka and 84-77[no-break space]ka. The dominant rainfall source was the Eastern Mediterranean Sea, with a possible small contribution from southern tropical sources during the interglacial periods. When the interglacial interval rainfall was of Eastern Mediterranean origin, the minimum annual rainfall was ~ 300-350[no-break space]mm; approximately twice than of the present-day. Lower minimum amounts of precipitation could have occurred during glacial periods, due to the cooler temperatures and reduced evaporation. Although during most of the humid periods the vegetation remained steppe with mixed C3 C4 vegetation, Mediterranean C3 type steppe-forest vegetation invaded southward for short periods, and the climate in the northern Negev became closer to Mediterranean type than at present. The climate was similar to present, or even more arid, during intervals when speleothem deposition did not occur: 150-144[no-break space]ka, 141-140[no-break space]ka, 117-96[no-break space]ka, 92-85[no-break space]ka, 25-23[no-break space]ka, and 13[no-break space]ka-present-day.Precipitation increase occurred in the northern Negev during the interglacial monsoonal intensity maxima at 198[no-break space]ka, 127[no-break space]ka, 83[no-break space]ka and glacial monsoonal maxima at 176[no-break space]ka, 151[no-break space]ka, 61[no-break space]ka and 33[no-break space]ka. However, during interglacial monsoonal maxima at 105[no-break space]ka and 11[no-break space]ka, the northern Negev was arid whereas during glacial monsoonal minima it was usually humid. This implies that there is not always synchroneity between monsoonal activity and humidity in the region.Oxygen isotopic values of the northern Negev speleothems are systematically lower than contemporaneous speleothems of central and northern Israel. This part is attributed to the increased rainout of the heavy isotopes by Rayleigh fractionation processes, possibly due to the farther distance from the Mediterranean coast

The `human revolution' in lowland tropical Southeast Asia: the antiquity and behavior of anatomically modern humans at Niah Cave (Sarawak, Borneo), , Barker G, Barton H, Bird M, Daly P, Datan I, Dykes A, Farr L, Gilbertson D, Harrisson B, Hunt C,
Recent research in Europe, Africa, and Southeast Asia suggests that we can no longer assume a direct and exclusive link between anatomically modern humans and behavioral modernity (the `human revolution'), and assume that the presence of either one implies the presence of the other: discussions of the emergence of cultural complexity have to proceed with greater scrutiny of the evidence on a site-by-site basis to establish secure associations between the archaeology present there and the hominins who created it. This paper presents one such case study: Niah Cave in Sarawak on the island of Borneo, famous for the discovery in 1958 in the West Mouth of the Great Cave of a modern human skull, the `Deep Skull,' controversially associated with radiocarbon dates of ca. 40,000 years before the present. A new chronostratigraphy has been developed through a re-investigation of the lithostratigraphy left by the earlier excavations, AMS-dating using three different comparative pre-treatments including ABOX of charcoal, and U-series using the Diffusion-Absorption model applied to fragments of bones from the Deep Skull itself. Stratigraphic reasons for earlier uncertainties about the antiquity of the skull are examined, and it is shown not to be an `intrusive' artifact. It was probably excavated from fluvial-pond-desiccation deposits that accumulated episodically in a shallow basin immediately behind the cave entrance lip, in a climate that ranged from times of comparative aridity with complete desiccation, to episodes of greater surface wetness, changes attributed to regional climatic fluctuations. Vegetation outside the cave varied significantly over time, including wet lowland forest, montane forest, savannah, and grassland. The new dates and the lithostratigraphy relate the Deep Skull to evidence of episodes of human activity that range in date from ca. 46,000 to ca. 34,000 years ago. Initial investigations of sediment scorching, pollen, palynomorphs, phytoliths, plant macrofossils, and starch grains recovered from existing exposures, and of vertebrates from the current and the earlier excavations, suggest that human foraging during these times was marked by habitat-tailored hunting technologies, the collection and processing of toxic plants for consumption, and, perhaps, the use of fire at some forest-edges. The Niah evidence demonstrates the sophisticated nature of the subsistence behavior developed by modern humans to exploit the tropical environments that they encountered in Southeast Asia, including rainforest

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

Unusual speleothems resembling giant mushrooms occur in Cueva Grande de Santa
Catalina, Cuba. Although these mineral buildups are considered a natural heritage, their
composition and formation mechanism remain poorly understood. Here we characterize
their morphology and mineralogy and present a model for their genesis. We propose that
the mushrooms, which are mainly comprised of calcite and aragonite, formed during four
different phases within an evolving cave environment. The stipe of the mushroom is an
assemblage of three well-known speleothems: a stalagmite surrounded by calcite rafts
that were subsequently encrusted by cave clouds (mammillaries). More peculiar is the
cap of the mushroom, which is morphologically similar to cerebroid stromatolites and
thrombolites of microbial origin occurring in marine environments. Scanning electron
microscopy (SEM) investigations of this last unit revealed the presence of fossilized
extracellular polymeric substances (EPS)—the constituents of biofilms and microbial
mats. These organic microstructures are mineralized with Ca-carbonate, suggesting that
the mushroom cap formed through a microbially-influenced mineralization process. The
existence of cerebroid Ca-carbonate buildups forming in dark caves (i.e., in the absence
of phototrophs) has interesting implications for the study of fossil microbialites preserved
in ancient rocks, which are today considered as one of the earliest evidence for life on
Earth.


Breeding Caves and Maternity Colonies of the Bent-Winged Bat In South-Eastern Australia, 1966, Dwyer P. D. , Hamiltonsmith E.

Eight breeding Caves of Miniopterus schreibersi (Kuhl) are described from South Australia, Victoria, New South Wales and Southern Queensland, in terms of their structure, the location of nursery areas at which juveniles are deposited after birth, and their physical environments. Maternity colonies are found at these caves through spring, summer and early autumn. Established colonies range from about 15,000 to 200,000 bats at peak size. These individuals are predominantly adult females and their young. Adult males are conspicuous only at the single South Australian breeding cave. Births occur from approximately the beginning of December to mid-January at all colonies except that in South Australia, where a birth period is evident between mid-October to late-November. Artificial warming, as a consequence of bat activity, appears to be characteristic of these Miniopterus schreibersi breeding caves. It is suggested that this may have functional significance in facilitating adequate development of juveniles, and that the habit could be a reflection of the tropical ancestry of this species.


Essays to Edward Aubrey Glennie - La Faune Souterraine de l'Afrique Tropicale. (in French), 1969, Vandel A.

A Study of Limestone Solution under Tropical Conditions in North-East Tanzania, 1971, Cooke H. J.

Seminar on Karst Denudation - Comparative morphogenetical study of Karst Regions in the Tropical and Temperate Zones, 1972, Balazs D.

Comparative Morphogenetic Study of Karst Regions in Tropical and Temperate Areas, 1973, Balazs D.

Observations on the aquatic subterranean fauna of Cuba., 1973, Botosaneanu Lazare
A short account on some achievements of the cubano-romanian biospeleological expeditions to Cuba in the study of the aquatic subterranean faunas. The following divisions of the aquatic subterranean realm are reviewed together with their most characteristic faunal elements: "guano pools" and rimstone pools in the vadose zone of the caves; underground streams; water table (and other) lakes in the caves; "pozzos" carved in the limestone, and "grietas" which are vertical clefts in the limestone of marine terraces, giving access to fresh- or to brackish water; the interstitial of the marine beaches; the underflow of running waters. At present, thorough biospeleological research is being carried out almost everywhere in Central America; Cuba, which remained until recently rather poorly investigated, proves to be one of the most remarkable areas from this point of view. A few of the most interesting problems rose in the course of the study of the underground aquatic fauna of Cuba are listed. An interesting biogeographical problem is the following: some of the subterranean aquatic elements prove to be related to elements belonging to the fauna of the other Antilles and of Mexico, but not to the South-American fauna (as is the case for some terrestrial groups). The research undertaken will be a contribution to the problem of the divisions of the aquatic subterranean realm and of their reciprocal relations, in a warm and humid climate; it will also contribute an answer to the problem of the differences between temperate and tropical cave communities; finally, it allows one to perceive in its very progress the process of colonization of the subterranean freshwaters by elements of marine origin, either through the interstitial realm or through the fissures of the littoral limestones.

The Spider communities in tropical caves (Aranaea)., 1973, Brignoli Paolo Marcello
The so called "tropical" caves (most of which are also geographically "tropical") are distinguished from the "temperate" caves by the much larger trophic resources. Spiders are common in both kinds of caves, but the groups present in one kind are mostly absent in the other (notwithstanding that many families are distributed over at least one temperate and one tropical region). As in all temperate caves more or less the same groups of spiders can be found, so the tropical caves have a typical spider fauna, composed of different groups (often also more than those present in the temperate caves). In the temperate caves the most typical groups are the Leptonetidae, the Dysderidae, many Araneoidea and some Agelenidae; these groups are either absent or rare in the tropical caves. In these the typical groups are some Orthognatha and many primitive spiders of the Haplogynae (Oonopidae, Tetrablemmidae, Ochyroceratidae, Scytodidae, Pholcidae, Telemidae) with a few Araneoidea (Theridiosomatidae and Symphytognathidae). From an ecological point of view, the detriticolous groups are not common in temperate caves, but are exceedingly common in tropical caves. In these live also often some groups which could be considered not strictly detriticolous, but more exactly "microcavernicolous" (i.e. living "normally" in more or less permanent crevices etc. of soil and rocks). In temperate caves are on the other hand more common groups living typically on vegetation, not very close to the soil. Ethologically, in tropical caves the existence of groups is possible which either ambush their prey or search for it actively whereas most spiders of temperate caves capture it with a web.

Temperate preference responses of some aquatic, cave-adapted Crustaceans from Central Texas and Northeastern Mexico., 1973, Elliot William R. , W. Mitchell Robert
The temperature preference responses of five species of troglobite crustaceans were studied in a 15-30C gradient. Stygonectes hadenoecus, S. russelli and Asellus reddelli had no discernible temperature preferenda. Speocirolana bolivari had a weak preference for 20-30C. Cirolanides texensis had a pronounced preference for 20-30C, temperatures much warmer than that of its habitat. The lack of temperature preferenda in three species agrees with the hypothesis that imprisoned troglobites tend to lose responses to those environmental variables which are constant in caves. S. bolivari may retain its temperature selectivity because of a slow rate of cave-adaptation. It is hypothised that C. texensis is recently descended from a tropical, epigean, freshwater ancestor.

Ecological and evolutive aspects of the communities of temperate and tropical caves: observations on the biological cycles of some species of Ptomaphagus (Coleoptera Catopidae)., 1973, Sbordoni Marina Cobolli, Sbordoni Valerio
Differences between tropical and temperate cave communities are an important topic in the actual biospeleological thinking. Among the most striking differences is the paucity of terrestrial troglobites in tropical caves. This fact may depend on the higher energy input into tropical caves which lessens the selection pressures for energy-economizing troglobite adaptations. Consequently evolutionary rates would be slowed in tropical caves and, in a date group, troglobites would appear later in such caves than in temperate ones with lower energy input. In order to investigate this point the authors studied the degree of adaptation to the cave environment in two species of Mexican Ptomaphagus which, being phylogenetically related, probably descend from the same epigean ancestor. Among these species the first one, P. troglomexicanus Peck, lives in a typical temperate cave (i.e. cold, high altitude cave, with scarce food supply) in the Sierra de Guatemala (Tamaulipas), the other one, P. spelaeus (Bilimek), populates tropical caves (i.e. warm, lowland cave, with rich food supply) in the State of Guerrero. In addition a comparison is made with P. pius Seidlitz, an epigean species from southern Europe. The results show a striking difference between P. troglomexicanus on a side and the other two species. Differences chiefly concern morphological features such as relative antenna length, structural complexity (i.e. the number of sensilla) of the antenna chemioreceptor organs in the 70, 90, 100 segments, degree of reduction of eye, wing and pigmentation and physiological ones such as the length of the life cycle. The possible causes of these differences are discussed. According to the authors these differences appear due to the different selection pressures acting in the two types of caves. In addition a comparison between the "tropical cave" species, P. spelaeus, with the epigean one, P. pius, does not point out the differences that one could expect by the diverse ecology of these species. These observations support the idea that evolutionary rates in cavernicoles are strongly affected by the ecology of the cave, mainly depending on the degree of energy input, and are poorly consistent with the hypothesis that mutations affecting degenerative processes are selectively neutral.

Present state of the knowledge on hypogean Histeridae., 1973, Vomero Vincenzo
The author makes some considerations on troglobitic and endogeous world Histeridae. All these species present extreme reduction of eyes or are completely blind; all are wingless and only one is brachipterous. The Histeridae described here belong to the following genera: Speleacritus Jeannel and Spelaeabraeus Moro (Abraeinae), Sardulus Patrizi, Bacanius Le Conte, Troglobacanius Vomero and Geoculus Wenzel. (Dendrophilinae, Bacanius group). Finally some considerations on troglophylic and guanobitic Histeridae are made, reporting the recent discovery of a new genus and of some new species belonging to guanobitic biocoenosis of Mexican tropical caves.

Observations on the aquatic subterranean fauna of Cuba., 1973, Botosaneanu Lazare
A short account on some achievements of the cubano-romanian biospeleological expeditions to Cuba in the study of the aquatic subterranean faunas. The following divisions of the aquatic subterranean realm are reviewed together with their most characteristic faunal elements: "guano pools" and rimstone pools in the vadose zone of the caves; underground streams; water table (and other) lakes in the caves; "pozzos" carved in the limestone, and "grietas" which are vertical clefts in the limestone of marine terraces, giving access to fresh- or to brackish water; the interstitial of the marine beaches; the underflow of running waters. At present, thorough biospeleological research is being carried out almost everywhere in Central America; Cuba, which remained until recently rather poorly investigated, proves to be one of the most remarkable areas from this point of view. A few of the most interesting problems rose in the course of the study of the underground aquatic fauna of Cuba are listed. An interesting biogeographical problem is the following: some of the subterranean aquatic elements prove to be related to elements belonging to the fauna of the other Antilles and of Mexico, but not to the South-American fauna (as is the case for some terrestrial groups). The research undertaken will be a contribution to the problem of the divisions of the aquatic subterranean realm and of their reciprocal relations, in a warm and humid climate; it will also contribute an answer to the problem of the differences between temperate and tropical cave communities; finally, it allows one to perceive in its very progress the process of colonization of the subterranean freshwaters by elements of marine origin, either through the interstitial realm or through the fissures of the littoral limestones.

Temperate preference responses of some aquatic, cave-adapted Crustaceans from Central Texas and Northeastern Mexico., 1973, Elliot William R. , W. Mitchell Robert
The temperature preference responses of five species of troglobite crustaceans were studied in a 15-30C gradient. Stygonectes hadenoecus, S. russelli and Asellus reddelli had no discernible temperature preferenda. Speocirolana bolivari had a weak preference for 20-30C. Cirolanides texensis had a pronounced preference for 20-30C, temperatures much warmer than that of its habitat. The lack of temperature preferenda in three species agrees with the hypothesis that imprisoned troglobites tend to lose responses to those environmental variables which are constant in caves. S. bolivari may retain its temperature selectivity because of a slow rate of cave-adaptation. It is hypothised that C. texensis is recently descended from a tropical, epigean, freshwater ancestor.

Results 1 to 15 of 219
You probably didn't submit anything to search for