Diss.--Technische Hochschule, Hanover. / Bibliography: p. 144-161.

Limestone dissolution in karst environments is likely due to geochemistry of the water, the actions of microbial communities, and the effect of water flow. We explored the rate of limestone dissolution and will examine here the microbial communities associated with the limestone. A conduit within the brackish cave, Double Keyhole Spring, on the coast of central west Florida was the site of the experiment. PVC pipes (5cm x 16cm) were filled with crushed limestone that was screened to a 1.9cm – 2.54cm size range. There were three treatments (5 replicates each): Control - sealed autoclaved controls with limestone and conduit water; Low Flow – sealed at one end, with a screen on the other so water contacts the limestone but cannot flow through; High Flow – screen mesh at both ends to allow the flow of conduit water over the limestone in the tube. After 9 months, the samples were retrieved. The Controls showed a loss of 0.33% ± 0.10, Low Flow samples showed a loss of 1.63% ± 0.71, and High Flow samples lost 2.28% ±0.29. Other studies in freshwater conditions found an average mass loss of 2.25% over the same time period under conditions similar to the High Flow sample in this experiment. Q-PCR and LH-PCR were used to estimate microbial density and species richness. The microbial community growing on the limestone samples were found to be significantly different from sediment or water column samples in both diversity and richness. The conclusion of this study is that the archaeal community growing on the limestone is the main biological driver of limestone dissolution in Double Keyhole Spring.

"This thesis discusses the archaeological literature concerning karst features: what information is available, the sites previously studied, the people who researched karst sites, and historic and prehistoric remains recovered from karst features. It describes specific sites, settlement studies related to karst features, and environmental reconstruction. As background, this thesis also describes geological and hydrological information concerning karst features, such as their sediment history, causes, and formation processes. It then presents geological information specific to one karst feature called Promise Sink. It also suggests a possible method to date sinkhole formation through pollen and floral analysis. Another facet of this thesis presents the results of a preliminary survey of a karst feature called Promise Sink. Through survey and excavation, the archaeological potential of Promis Sink is evaluated. A mapping gram provides documentation of Promise Sink on many levels: the surrounding area, surface features, physiology, and depth profile. An underwater survey of the sink also included subsurface testing which produced evidence of a prehistoric cultural component"--Introduction. / Typescript. / "Summer Semester, 1993." / "Submitted to the Department of Anthropology in Partial fulfillment of the requirements for the degree of Master of Arts." / Advisor: Rochelle Marrinan, Professor Directing Thesis. / Vita. / Includes bibliographical references (leaves 116-130).

Understanding the mechanisms that control sedimentation in the anchialine caves of the Yucatan Peninsula, Mexico is vital for interpreting the sedimentary deposits therein. External forcing mechanisms of varying scales, such as eustatic sea-level rise and large storm events, can have a significant influence on the rate and composition of sediment transported and deposited in the cave. Using sediment cores, high resolution radiocarbon dating, cave mapping and continuous aquifer attribute data, it was shown that sedimentation patterns in the cave were not controlled by sea-level rise/fall alone. Overlying vegetation and cave physiography were controlling factors which resulted in sedimentation in the cave being transient in time and space. The coastal aquifer responded to seasonal variations in precipitation but also showed a broad regional response to intense rainfall associated with Hurricane Ingrid in 2013. Due to the extensive hydraulic conductivity of the aquifer, the hydrologic response to Hurricane Ingrid was shorted lived (weeks) while its effect on sedimentation in the cave lasted for months. Sedimentation rates in the cave did not respond to elevated precipitation alone but showed a link with overlying vegetation. In regions of the cave with overlying mangrove forest, sedimentation was significantly higher than areas with tropical forest coverage. Mangrove forests baffled sediment creating an aquitard which resulted in the ponding of meteoric waters and subsequent enrichment in nutrients. Nutrient rich meteoric waters were funneled into cenotes increasing primary productivity for organic matter sediment production. Sedimentary deposits in anchialine caves are subject to punctuated sedimentation as a result of external forcing mechanisms or triggers. In the case of Yax Chen the trigger for sedimentation was not contemporaneous with Holocene sea-level rise. This has important implications for the use of cave sediments as proxies for sea-level research and paleo hurricane studies. / Thesis / Candidate in Philosophy

<p> This is the first study of the karst features found at Moira River karst. This study intends to investigate a number of different karst features of the area rather than concentrating on one highly specific problem. Hopefully this will enable the reader to appreciate the wide diversity of karst able to form within a small area such as Moira karst.</p> <p> The variation in karst features encountered at Moira River ranged from a relatively rare form of karst, called a draped karst, to dissolution patterns (scallops), found within a cave. The draped karst dominates much of the area and is formed by the preferential removal of thin, recessive limestone beds. The overlying, massive bedded unit remains and is "draped" over an underlying massive unit.</p> <p> The river plays a dominant role in the formation of karst features at Moira Karst. It floods quite frequently as evidenced by the number of runoff channels found in the area. The caves at Moira River karst have developed as a short cut across a bend in the river and are fully inundated when the river reaches high flow rates. Karst development does not extend much beyond a range of 300 m from either bank of the river and is concentrated on the east side of the river.</p> / Thesis / Bachelor of Science (BSc)

<p> In the summer of 1976 a study was undertaken of the Woodville/Codroy gypsum karst plain, an area of about 4 km^2 in southwest Newfoundland. Geology of the gypsum is revised and the general geomorphology described. Sinkholes were surveyed and classifications based on several criteria are presented. Hydro-chemistry is reported in some detail from field and laboratory analyses. It is shown that the gypsum karst system evolves in much the same \'Jay as that of limestone but at a greater rate, permitting comprehensive study of morphologic evolution within post-glacial karst areas. Processes at work in the gypsum may be initially simpler than those in carbonates but complexities of rock characteristics complicate the picture. Some water measurements indicate diffuse flow conditions in the aquifer, while others suggest conduit flow; it is demonstrated that both diffuse and conduit flow systems may operate in conjunction. </p> / Thesis / Master of Arts (MA)

<p>This thesis describes the geomorphology and hydrogeology of karst systems in portions of the northeastern Canyon Ranges of the Mackenzie Mountains and the Norman Range of the Franklin Mountains, N.W.T. In the region, mean annual temperatures are -6 to -8°C, total annual precipitation is 325 to 500 mm, and permafrost has a widespread to continuous distribution. The area was glaciated in the Late Wisconsinan by the Laurentide Ice Sheet.</p> <p>The Canyon Ranges and Norman Range are composed of a sequence of faulted and folded miogeoclinal sedimentary rocks that span the Proterozoic to Eocene. The geology is reviewed with an emphasis on strata that display karst. Included are several dolomite and limestone formations, two of which are interbedded with evaporites in the subsurface. The principal groundwater aquifer is the Lower Devonian Bear Rock Formation. In subcrop, the Bear Rock Formation is dolomite and anhydrite, outcrops are massive calcareous solution breccias. This is the primary karst rock.</p> <p>The regional distribution and range of karst landforms and drainage systems are described. Detailed mapping is presented from four field sites. These data were collected from aerial photography and ground surveys. The karst has examples of pavement, single and compound dolines, subsidence troughs, polje,sinking streams and lakes, and spring deposits. The main types of depressions are subsidence and collapse dolines. Doline density is highest on the Bear Rock Formation. Surficial karst is absent or less frequent in the zone of continuous permafrost or outside the glacial limit.</p> <p>At the field sites, water samples were collected at recharge and discharge locations. Samples were analyzed for a full range of ionic constituents and many for natural isotopes. In addition, several springs were monitored continuously for discharge, temperature, and conductivity. Dye tracing established linkages between recharge and discharge at some sites. These data are summarized for each site, as is the role of permafrost in site hydrology.</p> <p>The relationships between geological structure, topography, and groundwater systems are described. Conduit aquifers are present in both dolomite and limestone. These systems are characterized by discharge waters of low hardness and dissolved ion content. Aquifers in the Bear Rock Formation have a mixed flow regime and often have highly mineralized discharge. At the principal field site, there was a time lag of 40 to 60 days between infiltration and discharge in this unit. At a second site, flow through times were on the order of years. Variability in these systems is attributed to bedrock properties and boundary conditions.</p> <p>Preliminary rates of denudation are calculated from the available hydrochemical data. Total solutional denudation at the primary field site is approximately 45 m³ km^-2 a^-1 (mm ka^-l). The majority is attributed to the subsurface dissolution of halite and anhydrite. The predominance of subsurface dissolution is linked to the high frequency of collapse and subsidence dolines and depressions.</p> <p>The karst features and drainage systems of the northern Mackenzie Mountains date to the Tertiary. Glaciation has had a stimulative effect on karst development through the subglacial degradation of permafrost and the altering of boundary conditions by canyon incision.</p> / Doctor of Philosophy (PhD)

O carste pode ser entendido como um sistema aberto, uma forma de relevo que resulta de processos que operam em conjunto nos subsistemas hidrológico e geoquímico. Os mecanismos de gênese e desenvolvimento de aquíferos cársticos levam à formação de meios anisotrópicos altamente descontínuos e heterogêneos, na sua estrutura espacial e no seu funcionamento temporal, podendo apresentar estrutura de permeabilidade hierárquica com fluxo turbulento. Apesar das limitações impostas pela anisotropia do meio, a descarga de aquíferos cársticos tende a concentrar-se em uma única ressurgência, permitindo, para entender suas propriedades, o uso da análise de sistemas baseada em estatística de séries temporais. O arranjo espacial complexo da drenagem subterrânea tem implicações no sinal hidrológico do exutório do sistema, de forma que a correta interpretação dos espectros obtidos prescindem de uma adequada caracterização da estrutura da drenagem, por meio testes com traçadores. Neste contexto, este trabalho teve como objetivo investigar o sinal hidrológico e sua relação com os padrões de recarga e a geometria e distribuição espacial das drenagens subterrâneas dos aquíferos do planalto cárstico Alambari-Ouro Grosso, localizados na região cárstica do Vale do Ribeira, município de Iporanga, São Paulo. Os métodos e técnicas utilizados envolveram análises por meio de fotointerpretação, morfometria de depressões poligonais, identificação e tipificação in situ e em gabinete das feições de recarga e descarga do sistema, testes qualitativos e quantitativos com traçadores corantes, obtenção de séries históricas de parâmetros hidrológicos e estatística descritivas exploratórias em séries temporais. Os resultados obtidos a partir de testes com traçadores corantes e análises morfométricas demonstraram a existência, no mesmo sinclinal, de dois sistemas independentes e funcionalmente distintos: i) Sistema Alambari, responsável por drenar quase 80% da área das depressões poligonais do planalto e a maior área da contribuição alóctone aos sistemas (65,9%), apresentando assinaturas hidrológicas típicas de um carste bem desenvolvido; e ii) Ouro Grosso, composta por depressões poligonais menos expressivas, recargas difusas, armazenamento epicárstico/pedológico e comportamento mais inercial. O sistema Alambari apresenta ainda depressões poligonais com as maiores declividades e a maior amplitude altimétrica, o que representa recargas potencialmente mais energéticas que no sistema Ouro Grosso. As séries temporais demonstraram que, em qualquer estação climática, o sistema Ouro Grosso é mais inercial que o sistema Alambari e o efeito memória da vazão menos variável em Alambari, característica provavelmente associada a maior capacidade de drenagem do sistema. Comportamento semelhante ao da vazão foi observado na condutividade elétrica, com exceção no inverno de 2017 (o mais seco), onde observou-se uma subida gradativa da mesma, demonstrando que a memória da condutividade elétrica pode refletir a resposta rápida do sistema a impulsos de chuva ou o comportamento de longo prazo associado à lenta e constante mineralização das águas do sistema. O comportamento da condutividade elétrica no sistema Ouro Grosso é anômalo, uma vez que as injeções de água meteórica no sistema resultam em picos de saturação e não diluição. Este fenômeno foi explicado a partir da noção de \"efeito pistão\", ou seja, um impulsionamento de águas saturadas na rede fraturada e nos reservatórios epicársticos/pedológicos, resultando na disponibilização de água mineralizada ao sistema. A análise das correlações cruzadas mostrou que na relação chuva versus condutividade elétrica, nos períodos relativamente mais secos, a desmineralização da água é menor. As análises também evidenciaram o comportamento dos reservatórios dinâmicos cujo fluxo de água mineralizada aumenta quando a recarga é mais intensa. / Karsts can be understood as an open system, a form of relief resulting from processes that operate together in the hydrological and geochemical subsystems. The mechanisms of genesis and development of karst aquifers lead to the formation of highly discontinuous and heterogeneous anisotropic media, in their spatial structure and in their temporal functioning, being able to present a hierarchical permeability structure with turbulent flow. Despite the limitations imposed by the environmental anisotropy, the discharge of karst aquifers tends to concentrate in a single resurgence, allowing, to understand its properties, the use of systems analysis based on time series statistics. The complex spatial arrangement of the underground drainage has implications in the hydrological signal of the exudate of the system, so that the correct interpretation of the obtained spectra doesn\'t have an adequate characterization of the structure of the drainage, through tests with tracers. In this context, the objective of this work was to investigate the hydrological sign and its relation with the recharge patterns and the geometry and spatial distribution of the subterranean drainage of the aquifer of the Alambari-Ouro Grosso karst plateau, located in the karst region of the Ribeira Valley, southeastern Brazil. The methods and techniques used involved analysis through photointerpretation, morphometry of polygonal depressions, in situ identification and typing, and in the recharge and discharge characteristics of the system, qualitative and quantitative tests with dye tracers, obtaining historical series of hydrological parameters and descriptive statistics in time series. The results obtained from tests with dye tracers and morphometric analysis showed the existence, in the same syncline, of two independent and functionally distinct systems: i) Alambari System, responsible for draining almost 80% of the area of the polygonal depressions of the plateau and the largest area of the allochthonous contribution to the systems (65.9%), presenting hydrological signatures typical of a well developed karst; and ii) Ouro Grosso, composed of less expressive polygonal depressions, diffuse refills, epikarst/pedological storage and more inertial behavior. The Alambari system also has polygonal depressions with the highest slopes and the highest altimetric amplitude, which represents potentially more energetic recharges than in the Ouro Grosso system. The time series showed that, in any weather season, the Ouro Grosso system is more inertial than Alambari system and the flow memory effect is less variable in Alambari, a characteristic probably associated to the greater drainage capacity of the system. Similar behavior to the flow rate was observed in the electrical conductivity, except in the winter of 2017 (the driest), where it was observed a gradual increase, demonstrating that the electrical conductivity memory can reflect the rapid response of the system to impulses of rainfall or the long-term behavior associated with the slow and steady mineralization of the system\'s waters. The behavior of the electrical conductivity in the Ouro Grosso system is anomalous, since the injections of meteoric water into the system result in saturation and non-dilution peaks. This phenomenon was explained by the notion of \"piston effect\", a saturated water propulsion in the fractured network and in the epikarst/pedological reservoirs, resulting in the availability of mineralized water to the system. The analysis of the cross correlations showed that in the relationship between rainfall versus electrical conductivity, in the relatively drier periods, water demineralization is lower. The analyzes also showed the behavior of the dynamic reservoirs whose mineralized water flow increases when the recharge is more intense.

Thesis (M.Sc.(Environmental and Engineering Geology))--University of Pretoria, 2008. / Abstract in English. Includes bibliographical references (leaves 94-106).

Entre o Planalto de Guapiara e a Serra de Paranapiacaba ocorrem sistemas cársticos que estão sob constante pressão do avanço antrópicodas mais variadas naturezas, como mineração de rochas carbonáticas, silviculturas, agriculturas e a própria ocupação humana. Este estudo apresenta primeiramente um levantamento detalhado de aspectos geológicos e geomorfológicos do carste da região, baseado em fotointerpretação, geoprocessamento e trabalhos de campo. Os sistemas cársticos se desenvolvem de forma distinta em ambos os compartimentos geomorfológicos. No Planalto de Guapiara o carste é pouco expressivo com feições cársticas dispersas e raras em todos os corpos carbonáticos abordados. O relevo mais suavizado, com gradientes hidráulicos relativamente baixos e o pouco tempo de exposição das rochas carbonáticas não permitiram o desenvolvimento de umsistema cárstico pleno no planalto. Na Serra de Paranapiacaba, o relevo mais acidentado, associado a altos gradientes hidráulicos, carbonatos mais puros, e maior tempo de exposição das rochas carbonáticas, permite que as feições sejam mais concentradas e apresentem maior desenvolvimento em relação ao planalto. A partir dadeterminação da configuração do carste foi possível se determinar a vulnerabilidadee a delimitação de um zoneamento ambiental do sistema cárstico com a utilização de dois métodos: EPIK e KDI. Na região do Planalto de Guapiara a vulnerabilidade do carsteé baixa e a ocupação humana é mais expressiva, com poucos riscos ao sistema e à população que ali se estabeleceu. Na região da Serra de Paranapiacaba a presença de feições cársticas mais constantes e mais concentradas indica vulnerabilidade muito alta, porém a presença de Unidades de Conservação garante a preservação deste tipo de sistema e a baixa ocupação e interferência humana. Espera-se que este estudo venha a contribuir para políticas públicas de ordenamento territorial futuro, minimizando os eventuais impactos no carste da região. / Between the Guapiara Plateau and the Paranapiacaba Range there are karst systems that are under constant pressure from anthropic advancement of various natures, such as mining of carbonate rocks, forestry, agricultureand human settlement itself. This study presents a detailed survey of geologic and geomorphologic aspects based on photo interpretation, GIS and fieldwork observations. Karst systems develop differently in both geomorphological compartments. At the Guapiara Plateau is not very expressive with scattered and rare karst features in all carbonate bodies covered by this study. The most cushioned relief, with relatively low hydraulic gradients and the short time of exposure of the carbonate rocks did not allow the full development of a karst system at the plateau. At Paranapiacaba Range, the most rugged relief, associated with high hydraulic gradients, purer carbonates and longer exposure of the carbonate rocks, allows karst features to be more concentrated and greater development in relation to the plateau. From the determination of the karst setting was possible to determine the vulnerability and delimitation of an environmental zoning of karst system using two methods: EPIK and KDI. At the Guapiara Plateau the karst vulnerability is low and human settlement is more expressive, with little risk to the system and the people who settled there. At Paranapiacaba Range the presence of karst features is more constant and more concentrated so the vulnerability is very high, but the presence of protected areas to guarantee the preservation of this type ofsystem and the low occupancy and human interference . It is hoped that this study will contribute to public policies for future land use, minimizing any impacts on the karst region.