Here we present teiid lizard fossils from Gruta do Urso, Aurora do Tocantins, Tocantins State, northern Brazil. We describe a left lower jaw of a "Cnemidophorinae" indet. and a right dentary attributed to Tupinambis sp. These materials share with extant Teiidae a heterodont dentition with subpleurodont tooth implantation, and are assigned to Teiinae and Tupinambinae based on dental characteristics. The paleofaunal assemblage from Gruta do Urso suggests a late Pleistocene/early Holocene age. These records add to our knowledge of the Quaternary fauna of northern Brazil.

Three questions were asked during this research. 1) Does the Sr content of Caribbean speleothems have a direct relationship with the age of the host rock at the time of speleothem precipitation?; 2) do older speleothems contain less Sr than younger speleothems in the same climatic setting?; and 3) will speleothems record the change in Sr concentration of eogenetic carbonates as a faster depletion in climates of higher precipitation as opposed to drier climates? The speleothems and cave rocks in this study were analyzed with various methods in an attempt to understand the rock processes that affect speleothem Sr concentrations. Evidence to support the hypothesis that younger host rock contributes higher concentrations of Sr to speleothems was found in the stalagmites of Curacao while Bahamian stalagmites indicated climatic variations. The results have implications for using stalagmites from relatively young, eogenetic limestone as a proxy for Sr-related paleoclimate data.

Dissolutional features called karst exist on the surface, and in the subsurface as caves. In glaciated regions caves were thought to be post-glacial in origin. Work in the 1970s demonstrated that pre-glacial caves existed, but did not answer if a cave could form post-glacially. A model proposed by Mylroie and Carew (1987) states that a post-glacial cave would be controlled entirely by glacial features and the deranged drainage of glaciated terrains. Caves known as maze caves form at maximum rates, and could form to navigable size in the time since deglaciation. Maze caves form in the shallow subsurface, allowing them to be removed in subsequent glaciations. GIS water flow analysis, and calculation of formation times using cross-section data demonstrates that maze caves in the glaciated region of New York are post-glacial in origin fitting in the deranged drainage and forming in the time since deglaciation.

The Mariana Islands are a volcanic island chain in the western Pacific Ocean composed of Eocene volcanic cores with a carbonate mantle. Others have classified the cave and karst features into the cave types described in the CIKM, but no comprehensive GIS has been developed. For this project, a comprehensive GIS of the cave and karst features was developed. The cave and karst features were divided by cave type, physiographic province, and island. The karst features in the GIS were hyperlinked to a series of HTML pages, one for each island, and a set of HTML navigation pages mirroring the GIS layers were also created. LANDSAT images and Digital Raster Graphics were draped over the Digital Elevation Models for visualization. Attempts were made to remotely sense the vegetation and exposed soils and rocks from the LANDSAT images with the goal of producing a theoretical subsurface limestone/volcanic contact. Although the overall remote sensing aspect was unsuccessful, the GIS inventory was a success.

The purpose of this project was to distinguish between the karst and pseudokarst caves throughout Mississippi, create an inventory and survey of representative caves and karst features, identify the geology of the rocks hosting the caves, and produce a GIS-based digital karst map. The State of Mississippi is not known for its karst features, yet there are three distinct limestone units that contain dissolution caves: 1) Paleozoic (Mississippian) Tuscumbia Formation limestone; 2) Mesozoic carbonate units; and 3) Cenozoic limestone, Marianna Formation. There are a total of 44 caves known within the state based on past documentation, however the caves listed are not always differentiated between karst or pseudokarst features. This study located and mapped 20 caves, of which 18 were karst caves from eight counties and two were pseudokarst caves from two counties. Four of these caves were newly discovered karst caves, increasing the state total to 48; however two separate karst caves were connected, which makes the final state total 47 caves. Of the remaining 28 caves not surveyed, 11 were pseudokarst caves from eight counties and were not studied because the focus was on dissolutional karst caves. The remaining 17 missing karst caves either had been destroyed, access permission could not be obtained, or the caves could not be located. No active caving organizations exist in Mississippi to preserve cave location data or the caves themselves. Mining, deforestation, and other land use procedures have altered the landscape, resulting in concealment of some caves, and completely or partially destroying other caves.

<p>This study was undertaken to provide supporting evidence for the late presence of Neanderthals in Iberia at the end of the Middle Paleolithic. This period is almost impossible to date accurately by the conventional radiocarbon method. Accordingly electron spin resonance (ESR) was used to obtain ages for four Spanish sites. They were EI Pendo in the Cantabrian north, Carihuela in Andalusia and Gorham's and Vanguard caves at Gibraltar. The sites were chosen to allow the greatest variety in geographic settings, latitudes and sedimentation. They were either under excavation or had been excavated recently following modem techniques. A multidisciplinary approach to dating the archaeological contexts was being proposed for all the sites except EI Pendo whose deposits had been already dated but only on the basis of sedimentological and faunal analyses. This was the first research program to apply ESR to such a variety of sites and compare its results with that of such a variety of other archaeometric dating techniques.</p> <p>The variety allowed a further dimension to the research that is the opportunity of appraising first hand the applicability and advantages of a new dating technique and determining its accuracy as an archaeological dating method in comparison with other techniques.</p> <p>Test samples for the research were collected at the sites as well as at the Museo de Ciencias Naturales in Madrid and the Gibraltar Museum.</p> <p>The ESR results for EI Pendo provide a terminus post quem of 31 Ka for the presence of the Neanderthal at the site. Those for Carihuela permit the Neanderthal skeletal remains found in layers Vand VI to be dated between 45 ka and 74 ka and between 67 ka and 86 ka respectively. The data also confirm the late presence of the Neanderthals in Andalusia. The results for the Gibraltar final Mousterian layer also confirm the presence of Neanderthals in southern Spain at 36.9 ±5 to 40.3 ±5 ka.</p> <p>While there are a number of secure dates for early Aurignacian deposits in Spain the results of the present research provide the first solid evidence of the late presence of Homo sapiens neanderthalensis in the Iberian Peninsula.</p> <p>Furthermore, from the data collected it can also be concluded that the ESR method is accurate and eminently suitable for dating archaeological contexts.</p> / Doctor of Philosophy (PhD)

Thesis (M.A.(Geography & Environmental Studies)) -- University of the Witwatersrand, Arts Faculty, 1973 / The Sterkfontein Cave System is a karst cave developed on the dolomites of the Transvaal system, fifty kilometres north-west of Johannesburg in South Africa. It lies beneath a small hill and was first exploited as a source of lime. Later it became a tourist and scientific attraction of world renown when some of the first australopithecine remains were recovered from a deposit within it. [Abbreviated abstract. Open document to view full version] / WS2017

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2017 / During the Plio-Pleistocene, the Earth experienced a period of gradual cooling, leading to a decrease in atmospheric temperature and increased seasonality. This resulted in the aridification of large parts of Africa, and this is believed to have encouraged human evolution and innovation. Palaeoenvironmental analyses using sediment deposits as palaeoclimate proxies in the Cradle of Humankind have been used to understand the timing and intensity of this aridification by determining how changes in environmental conditions and seasonal cycles affected the South African landscape. These changes are recorded within the carbon and oxygen isotopic signatures of speleothems, which have precipitated within the Sterkfontein Caves system. The aim of this study is to understand the degree to which modern speleothems represent the modern climate and environment, and thereby deduce the reliability of speleothem deposits in the Sterkfontein Caves system as palaeoclimate proxies. Samples of modern speleothems were collected from different chambers of the Sterkfontein Caves, along with the collection of modern drip water samples bi-weekly over a period of 14 months. Oxygen and carbon stable light isotope analyses of these modern speleothem and drip water samples were used to obtain modern temperature, precipitation and vegetation data. These data were then compared to modern climatic and environmental records for atmospheric temperatures and precipitation from weather stations around the Sterkfontein Caves area. The δ13C trends produced from the modern speleothem samples reflected the current vegetation distribution in terms of C4 and C3 vegetation very well, while the temperatures calculated from the δ18O values of the modern speleothem and drip water samples displayed variations related to kinetic fractionation effects, rendering these data less useful in reflecting the current atmospheric temperatures. The δ18O values of the drip water samples, along with the measured drip rate reflected current precipitation seasonality, taking into account groundwater residence time and recharge rate. The conditions within the cave conducive to formation of the speleothems was well reflected by the pH and electro-conductivity values produced from the drip water samples. These values also provided further insight into the exterior climatic conditions. Overall, the carbon and oxygen stable light isotope data revealed patterns present in the modern speleothem and drip water samples, which could be further related to changes in local climate during the precipitation of these modern speleothems from drip water sources. This, to a certain degree, provides evidence of the reliability of speleothems in the Sterkfontein Caves system as suitable palaeoclimate proxies with regards to vegetation and precipitation interpretations, over a longer term scale and at higher sampling resolution. / MT 2018

Thesis (M.Sc. Earth and Ocean Sciences and Chemistry)--University of Waikato, 2009. / Title from PDF cover (viewed October 2, 2009). Includes bibliographical references (p. 161-170)

Radon is a naturally occurring radioactive element in the 238U decay series that is found in high concentrations in certain geological formations such as Caves. Exposure to high concentrations of radon has been positively linked to the incidence<br /> of lung cancer. This study used Electret ion chambers and the RAD7 continuous radon monitor to measure radon concentrations in the Cango Caves in the Western Cape Province, South Africa. Measurements were taken during summer i.e. February 2004 and March 2005. The results for the radon activity concentrations range from the minimum of<br /> about 800 Bq.m-3 to a maximum of 2600 Bq.m-3. The two techniques give very similar results, though the Electret ion chamber results appear to be consistently higher by a few percent where measurements were taken at the same locations. A<br /> mathematical model has been developed to investigate the radon concentrations in the Cave. Diffusion and ventilation have been considered as mechanisms for explaining the distribution of radon concentrations. The ventilation rate in the Cave has been estimated under certain assumptions, and it is found to be about 7 &times / 10&minus / 6 s&minus / 1 for the Van Zyl hall which is the first large chamber in the Cave. The radon concentration increases as one goes deeper into the Cave, but then becomes fairly constant for the deeper parts. The annual effective dose that the guides are exposed to in the Cave as a result of the radon concentrations, depends strongly on the time that they spend in the Cave and in which, halls they spend most of their time in the Cave. The initial results indicate an annual effective dose of 4-10 mSv, but this needs to be further investigated.