inscription
Portail d'information géographique

Résultats de la recherche (414 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre
  • The influence of sea-level change and geologic structure on cave development in west-central Florida
  • Carbonate dissolution ; Carbonate rock ; Cave development ; Florida ; Karst ; Karst filling ; Sea level ; Tectonics ; United States ; Vertical movement
  • The formation of caves in a portion of Citrus County, Florida is controlled structurally by northwest-southeast-trending joints that formed in the Suwannee Limestone during the uplift of Ocala Arch in the Miocene Epoch. The caves developed in a zone
  • where saline water from the Gulf of Mexico and fresh water from the Ocala uplift mixed. Further uplift elevated the caves above the mixing zone. Erosion caused sections of caves passages to collapse and/or be filled with sediment. The caves are fossil
  • segments of a formerly larger, interconnected cave system.
  • Palaeolithic stratigraphy of Sodmein Cave (Red Sea Mountains, Egypt)
  • Archaeology ; Archeological site ; Cave ; Egypt ; Geomorphology ; Palaeogeography ; Palaeolithic ; Stratigraphy
  • Cave. - (H.N.).
  • Late Holocene widening of karst voids by marine processes in partially submerged coastal caves (Northeastern Adriatic Sea)
  • Adriatic Sea ; Applied geomorphology ; Cave ; Coastal geomorphology ; Collapse structures ; Croatia ; Holocene ; Italy ; Karst ; Limestone ; Marine abrasion ; Sea level
  • The coastal scenery of the Northeastern Adriatic sea is widely interested by caves and related coastal features, which are developed in correspondence of geological weaknesses of sea cliffs. We present the preliminary surveying of five partially
  • submerged coastal caves cut in limestone cliffs, relating the dissolutionally widened vadose karst voids and the present-day forms. The analysis pointed out two well-defined morphological zones inside the caves. The boundary between the zones roughly
  • coincides with the mean sea level. The submerged zone is mainly affected by abrasion processes on the bottom and the lateral walls, while the emerged zone is interested by karst processes and collapse of blocks from the roof. Their effects produce a bell
  • -shaped cross-section, in which the submerged part of the caves is significantly larger than the emerged one. - (NF)
  • Last interglacial sea levels and coastal caves in the Cape Province, South Africa
  • The dating of the 6 to m shoreline in southern Africa as early Pleistocene prompted a reassessment of evidence from archaeological cave sites on the south coast of the Cape Province which had suggested that this shoreline is of last interglacial age
  • . The successions in the caves at Klasies River Mouth and Die Kelders have been misinterpreted. In fact, they confirm a pre-last interglacial age for this feature. These sites, together with Herolds Bay Cave, indicate that in southern Africa the only last
  • interglacial shoreline above present sea level is at about 4 m, and that it dates from isotope substage 5.
  • Rapid entrenchment of stream profiles in the salt caves of Mount Sedom, Israel
  • Arid area ; C 14 dating ; Dead Sea ; Diapir ; Fluvial erosion ; Groundwater ; Holocene ; Israel ; Karst ; Longitudinal section ; Rift ; Salt ; Stream
  • This paper focuses on downcutting rates and stream profile development measured in rock salt cave stream passages in the Mount Sedom salt diapir, Dead Sea rift valley, Israel. Although the area is very arid, the diapir contains extensive karst
  • The flank margin model for dissolution cave development in carbonate platforms
  • The flank margin model presented here invokes a water-mixing mechanism to explain rapid development of caves of unusual morphology in the Bahama Islands. The mixing of discharging freshwater with tide-pulsed incoming marine water under the flank
  • of emergent dune ridges may have produced the conditions necessary. Freshwater lens position is controlled by sea level, which in stable carbonate platforms like the Bahamas is a function of glacioeustatic sea level still stands.
  • Basalt ; Cave ; Coastal environment ; Marine erosion ; Pyroclastic ; Volcanic rock ; Volcanism
  • Also influenced by marine erosion, the dimensions and morphology of sea caves principally depend on the structural behaviour of the enclosing basaltic lavas and pyroclastics. In basalt volcanic areas sea caves can form in columnar and irregularly
  • ; in basaltic dyke; along the border of a basaltic dyke and thick hydrovolcanic tuff and in basaltic tuff. The aim of the study is to demonstrate that how and in which form sea caves develop in structurally different basaltic lavas and pyroclastics. - (AM)
  • Cathedral Cave, Wellington Caves, New South Wales, Australia. A multiphase, non-fluvial cave
  • Australia ; Cave ; Geomorphology ; Inventory ; Karst ; Karstification ; New South Wales ; Palaeokarst ; Stratigraphy
  • Cathedral Cave is an outstanding example of a class of multiphase caves with largely non-fluvial origins. It is possible to recognize at least 10 significant phases of speleogenesis by morphostratigraphy, in addition to the 4 generations of cave
  • -filling palaeokarst deposits intersected by the cave. The cave we see today results from the progressive integration of a number of previously disconnected or poorly connected solution cavities.
  • Constraining Holocene sea levels using U-Th ages of phreatic overgrowths on speleothems from coastal caves in Mallorca (Western Mediterranean)
  • Baleares ; Cave ; Coastal environment ; Holocene ; Mallorca ; Palaeo-environment ; Sea level ; Spain ; Speleothem ; Th/U dating
  • are in accord with an archaeologically estimated age for a drowned prehistoric construction at a depth of 1 m below current sea level in a cave from the same area. Speleothem δ13C and δ18O and chemical composition of cave pools provide supportive evidence
  • The U-Th ages of calcite and aragonite overgrowths collected from the modern water table in coastal caves on Mallorca (Cova de Cala Varques A and Cova des Pas de Vallgornera) were determined using high-precision MC-ICPMS techniques. The results
  • Formation of phreatic caves in an eogenetic karst aquifer by CO2 enrichment at lower water tables and subsequent flooding by sea level rise
  • most likely formed at lower water tables during lower sea levels. Consideration of the hydrological and geochemical constraints posed by the upper Floridan aquifer leads to the conclusion that cave formation was most likely driven by dissolution
  • Analyzing morphological data and water chemistry from caves in the Suwannee River Basin in north-central Florida and water chemistry from wells in the central Florida carbonate platform indicates that phreatic caves within the Suwannee River Basin
  • of vadose CO2 gas into the groundwater. Phreatic caves in the Suwannee River Basin are thus relict and have no causal relationship with modern surficial drainage systems. Dissolution at water tables, potentially driven by vadose CO2 gas, offers
  • Sequence of sediments at Locality 1 in Zhoukoudian and correlation with loess stratigraphy in northern China and with the chronology of deep-sea cores
  • According to recent dating by several methods, the impressive cave sediments at Locality 1 at Zhoukoudian, about 40 m thick, have not only allowed the age of Peking Man to be established, but have calibrated the general course of cave development
  • , permitted correlation with events both within China and farther afield, and placed the sequence in the global framework of late Cenozoic climatic change. The cave deposits can be divided into 17 layers which are correlated with the great loess sequences (L9
  • -L4) in China and with deep-sea-core oxygen-isotope stages 16-6. The 14th layer upward (730,000-230,000 yr B.P.) represents at least four glacial cycles.
  • Effect of the 2004 Asian tsunami in the sea cave of Tham Phaya Nak (Koh Phi Phi archipelago, Thailand) and possible evidence of a prehistoric event
  • Archipelago ; Coastal environment ; Coral reef ; Impact ; Karst ; Sea cave ; Sediment transport ; Speleothem ; Thailand ; Tsunami
  • . Limestone cliffs of Koh Phi Islands and the marine cave of Phi Phi Leh have been poorly affected, but a prehistoric-event has provoked the deposit of a layer of coral fragments into the cave. This damage could be attributed to a tsunami but a storm cannot
  • Eogenetic caves in Pleistocene carbonate in Slovenia
  • Cave ; Cave development ; Classification ; Conglomerate ; Diagenesis ; Karst ; Pleistocene ; Slovenia ; Speleology
  • This paper focuses on caves in Pleistocene carbonate conglomerates in Slovenia and for the first time defines them as eogenetic. The conglomerates show no deep burial that would resemble the mezogenetic stage of diagenesis and are still in the phase
  • of early diagenesis (i.e. eogenetic stage). Based on speleological analysis the eogenetic caves were grouped into four types; (1) linear stream caves, (2) shelter caves, (3) breakdown caves, and (4) vadose shafts. - (IKR)
  • Jeskyne a propasti v Ceskoslovensku.. (Caves and chasms in Czechoslovakia)
  • Distribution of karst, features, karst regions, chasms and caves in Czechoslovakia, including the show caves. Czechoslovak speleology, protection of caves and other karst features in Czechoslovakia. (MS).
  • A new history of cave development at Bungonia, N.S.W.
  • This paper presents a new developmental history of Bungonia caves based on cave morphology, clastic sediments in the caves and geological observations in the caves and their surroundings. Karst development at Bungonia can be traced back to at least
  • Magnetostratigraphy of cave sediments, Wyandotte Ridge, Crawford County, Indiana: towards a regional correlation
  • Cave ; Geochronology ; Indiana ; Kentucky ; Palaeomagnetism ; Polarization ; Stratigraphic correlation ; Stratigraphy ; United States
  • The polarity of 42 sediment samples obtained from 21 sites in Wyandotte Cave and five smaller satellite caves in Wyandotte Ridge, southern Indiana, is used as a basis for a magnetostratigraphic correlation with sediments in Mammoth Cave, Kentucky.
  • Punkva a jeji jeskynni systém v Amatérské jeskyni.. (Punkva River and its cave system of Amateur Cave)
  • The newly discovered cave system of the Punkva River in the Moravian Karst offered favourable conditions for the study of its relations to the environment. The Amateur Cave belongs to the longest in Europe and enables to complete the hydrogeological
  • Cave ; Cave development ; Erosion ; Karst ; Slovenia
  • The paper presents a denuded cave in the area of Podbojev laz, on the NW side of the Rakov Škocjan. The morphological properties of several sections of the denuded cave and its surroundings are described. It developed from an epiphreatic cave system
  • which used to function as an outflow cave system from the Rak valley. Morphometrical analysis of the slopes show that the denuded cave was developed in stages. As the surrounding surface is not flattened, the cave roof has been denuded gradually. - (L'A.).
  • Cave development under the influence of Pleistocene glaciation in the Dinarides - an example from Štirovača Ice Cave (Velebit Mt., Croatia)
  • Cave development ; Croatia ; Glacial features ; Glaciation ; Karst ; Karstification ; Palaeo-environment ; Pleistocene ; Records
  • The aim of this study is to examine the effect of Pleistocene glaciations on the speleogenesis of Štirovača Ice Cave, based on analyses of surface and cave morphology and of cave sediments, since it is well known that caves, and particularly clastic
  • sediments in caves, contain abundant information on speleogenesis and on the conditions of karstification. The AA. assume that Štirovača Ice Cave represents an important archive in regard to tha glacial history of the Velebit Mt.
  • Magyarirszag barlangjai.. (Caves of Hungary)
  • There are almost 2000 caves in Hungary. The first part of the volume reviews the history of their exploration and the second presents the major caves, their origin, description of passages, geographical environment and touristic importance. The book