Geology and Hydrology of Karst in West-Central and North-Central Florida

The state of Florida is blessed with the highest density of large springs in North America and hundreds of smaller springs where the water from limestone aquifers returns to the surface (Scott et al., 2004). Spectacular underwater caves supply water to these springs. Lesser known are the equally fantastic air-filled caves of Florida and South Georgia (Florea, 2006; Lane, 1986). This paper features these underwater and airfilled caves, explores the impact of changes in sea level on karst in this near-coastal environment, and establishes several geologic and hydrologic characteristics that distinguish karst in the limestones of the southeast from karst elsewhere in the U.S

Isotopes of Carbon in a Karst Aquifer of the Cumberland Plateau of Kentucky, USA

In this study, the concentration and isotopic composition of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) are measured in the karst groundwater of the Otter Creek watershed of the Cumberland Plateau of Kentucky, USA. Comparisons among these data and with the geochemistry of carbonate and gypsum equilibrium reactions reveal that DOC concentration is inversely related to discharge, multiple reaction pathways provide DIC with isotopic enrichment that may be directly related to mineral saturation, and oxidation of reduced sulfur is possible for dissolution. DOC is derived from C3 vegetation with an average δ13CDOC of ‒27‰. DIC in groundwater is derived from both pedogenic CO2 and HCO3- from dissolved carbonate. At input sites to the karst aquifers DIC concentrations are expectedly low, less than 1 mmol/L, in waters that are undersaturated with respect to calcite. At the output of these karst aquifers DIC concentrations reach 3 mmol/L in waters that are at or above calcite saturation. Values of δ13CDIC range between ‒6.3 and ‒12.4‰ with CO2 degassing and calcite precipitation at some sites obfuscating a simple relationship between δ13CDIC, discharge, and mineral saturation. In addition, concentrations of DIC in sulfur seeps within the watershed range between 2–7 mmol/L with δ13CDIC values in some samples skewed more toward the anticipated value of carbonate bedrock than would be expected from reactions with carbonic acid alone. This suggests that the oxidation of reduced sulfur from shallow oilfield brines liberates bedrock DIC through reactions with sulfuric acid.Keywords: dissolved organic carbon, dissolved inorganic carbon, sulfur redox, ion geochemistry, saturation index.Keywords: dissolved organic carbon, dissolved inorganic carbon, sulfur redox, ion geochemistry, saturation index.DOI: 10.3986/ac.v42i2-3.668

I Sinkholes nella Letteratura Scientifica Internazionale: una Breve Rassegna, con Particulare Riferimento Agli Stati Uniti D\u27America

Fenomeni di sinkholes sono diffusi in moltissimi paesi del mondo, in ambiti geologici e morfologici alquanto differenziati, e coinvolgono svariate litologie, sia nelle successioni di copertura che in quelle direttamente affioranti alla superficie. Il presente contributo intende fornire una breve rassegna, certamente non esaustiva, sullo stato dell’arte delle ricerche relative ai sinkholes in ambito internazionale. Esso consiste in una descrizione della più aggiornata e diffusa classificazione dei sinkholes e, a seguire, in descrizioni delle più tipiche casistiche di sinkholes nei vari paesi. Tra questi, viene dato particolare risalto agli Stati Uniti d’America (e, più in particolare, alla Florida), dove le ricerche su tali fenomeni sono state avviate da tempo e risultano estremamente approfondite

Everglades National Park – Surveying the southernmost cave in the continental United States

Everglades National Park encompasses 1.5 million acres of grassland glades, tree islands, cypress strands, and mangrove marshes and is world renowned for natural vistas and wonders at the surface. The cave and karst resources in this park, however, are little known even though much of the park is underlain by limestone. In a recent communication to the authors, Alan Cressler (U.S. Geological Survey, written communication, 2006) described his visit to Palma Vista Cave in Everglades National Park last November that he originally explored and described over 13 years ago (Cressler, 1993)

International, cooperative research in the Apuseni Mountains of western Romania

In May of 2006, nine American scientists and cavers from the Karst Research Group at the University of South Florida traveled to western Romania to attend and present at an international conference on records of climate change in caves in the historic Roman town of Baile Hurculane. The conference, co-sponsored by the “Emil Racoviţă” Speleological Institute of Romania and the Karst Waters Institute, drew more than 100 experts in the field of climate change and karst, and was a wonderful time spent alongside the thermal springs and Austro-Hungarian bathhouses nestled within the massive limestone canyon of the Cerna River. Following the conference and post-conference field trips in early June of 2006, six members of the American team joined with several Romanian colleagues to conduct paleoclimate research in the caves of the Apuseni Mountains of Transylvania. A follow-up trip in July of 2007 by a smaller research team completed the projects started the previous year. The NSS provided partial funding for the work in both 2006 and 2007 though an International Participation Grant. The Romanian Science Foundation and the Romanian Ministry of Education and Research provided much of the remaining funds

Cave Levels, Marine Terraces, Paleoshorelines, and the Water Table in Peninsular Florida

Levels of passages are a common feature of many cave systems around the world. Likewise, coastal and marine terraces are common in coastal plain settings. This paper extends the discussion of cave levels from traditional research sites in the interior lowlands of the United States to the Atlantic Coastal Plains, namely peninsular Florida. Are there levels in Florida caves, and is there a link between the elevation of cave levels, marine terraces, paleoshorelines, and thus the water table, above and below present sea level in peninsular Florida