MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

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 percent saturation is the ratio, expressed as a percentage, of (a) the volume of some fluid (water, gas, or oil) to (b) the total volume of intergranular space (voids) in a given porous medium. synonymous with degree of saturation [22].?

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 floridan (Keyword) returned 41 results for the whole karstbase:
Showing 31 to 41 of 41
Vertical migration of municipal wastewater in deep injection well systems, South Florida, USA, 2007, Maliv R. G. , Guo W. , Missimer T.

Deep well injection is widely used in South Florida, USA for wastewater disposal largely because of the presence of an injection zone (“boulder zone” of Floridan Aquifer System) that is capable of accepting very large quantities of fluids, in some wells over 75,000m 3 / day. The greatest potential risk to public health associated with deep injection wells in South Florida is vertical migration of wastewater, containing pathogenic micro-organisms and pollutants, into brackish-water aquifer zones that are being used for alternative water-supply projects such as aquifer storage and recovery. Upwards migration of municipal wastewater has occurred in a minority of South Florida injection systems. The results of solute-transport modeling using the SEAWAT program indicate that the measured vertical hydraulic conductivi-ties of the rock matrix would allow for only minimal vertical migration. Fracturing at some sites increased the equivalent average vertical hydraulic conductivity of confining zone strata by approximately four orders of magnitude and allowed for vertical migration rates of up 80m/year. Even where vertical migration was rapid, the documented transit times are likely long enough for the inactivation of pathogenic microorganisms. 


SEISMIC-SAG STRUCTURAL SYSTEMS IN TERTIARY CARBONATE ROCKS BENEATH SOUTHEASTERN FLORIDA, USA: EVIDENCE FOR HYPOGENIC SPELEOGENESIS?, 2009, Cunningham K. , Walker C.

High-resolution, multichannel seismic-re?ection data recently acquired mostly in Biscayne Bay, southeastern Florida, exhibit disturbances in parallel seismic re?ections that correspond to the carbonate rocks of the Floridan aquifer system and lower part of the overlying intermediate con?ning unit. These disruptions in seismic re?ections are indicative of structural characteristics in carbonate rocks of Eocene to middle Miocene age that are interpreted to be related to collapsed paleocaves or collapsed paleocave systems, and include (1) fractures; (2) faults; (3) narrow (hundreds-of-m- scale wide) seismic-sag structural systems; and (4) broad (km-scale wide) seismic-sag structural systems. Commonly, the seismic-sag structural systems are multistoried, re?ecting a vertical arrangement of cyclic zones of structural sags that exhibit a progressive evolution from cave formation; cave collapse; suprastratal sag; and in some cases, ?nal in?ll of the upward termination of sag zones. In the study area, these structural systems are buried by upper Miocene-to-Holocene sedimentary rocks and sediments; however, they may manifest as well-documented, hundreds-of-m-scale wide, sinkholes along the submarine surface of the continental margin in the Straits of Florida. The potential link between the seismic sags and submarine sinkholes suggests the sea?oor sinkholes began to form as early as during the Eocene. We will discuss, speleogenic mechanisms dominating the formation of the narrow, seismic-sag structures that include: vadose, water-table, regional mixing zone corrosive, and ?ank-margin processes. Further, three mechanisms are postulated for the speleogenesis of the paleocave systems associated with the broad seismic-sag structural systems: (1) corrosion by an Eocene mixed fresh-saltwater zone associated with a regional groundwater ?ow system beneath the southern part of the paleo-Florida Platform, (2) hypogenic speleogenesis associated with upward groundwater ?ow driven by Kohout convection and dissolution by mixed fresh and saline groundwater, or (3) hypogenic spelogenesis associated with the upward ascension of hydrogen-sul?de-bearing groundwater charged by dissolution and the reduction of calcium sulfates in deeper Eocene or Paleocene rocks. We will contrast and compare our theories on the timing and processes involved in the formation of seismic-sag structural systems with those proposed in the existing literature for the submarine sinkholes on the continental margin in the Straits of Florida, and discuss how the seismic-sag structural systems and submarine sinkholes may be linked. Future marine seismic data acquisition and interpretation is planned to help develop more accurate timing of formation of paleocaves and paleocave systems, their collapse, and structural impact on suprastratal rocks, and more decisive insight into the speleogenic processes that proceed during the evolution of these seismic-sag structural systems within the Florida Platform.


Geochemical and statistical evidence of recharge, mixing, and controls on spring discharge in an eogenetic karst aquifer, 2009, Moore Paul J. , Martin Jonathan B. , Screaton Elizabeth J.

Information about sources of recharge, distributions of flow paths, and the extent of water–rock reactions in karst aquifers commonly result from monitoring spring chemistry and discharge. To investigate the relationship between spring characteristics and the complexities of karst aquifers, we couple variations in surface- and groundwater chemistry to physical conditions including river stage, precipitation, and  evapotranspiration (ET) within a sink-rise system through a 6-km portion of the Upper Floridan aquifer (UFA) in north-central Florida. Principal component analysis (PCA) of time series major-element compositions suggests that at least three sources of water affect spring discharge, including allogenic recharge into a swallet, diffuse recharge through a thin vadose zone, and water upwelling from deep within the aquifer. The deep-water source exerts the strongest influence on water chemistry by providing a majority of Na+, Mg2+, K+, Cl, and SO2 4 to the system. Anomalously high temperature at one of several monitoring wells reflects vertical flow of about 1 m/year. Mass-balance calculations suggest diffuse recharge and deep-water upwelling can provide up to 50% of the spring discharge; however, their contributions depend on head gradients between the conduit and surrounding aquifer matrix, which are influenced
by variations in precipitation, ET, and river stage. Our results indicate that upwelling from deep flow paths may provide significant contributions of water to spring discharge, and that monitoring only springs limits interpretations of karst systems by masking critical components of the aquifer, such as water sources and flow paths. These results also suggest the matrix in eogenetic aquifers is a major pathway for flow even in a system dominated by conduits.


Iron Oxide and Calcite Associated with Leptothrix sp. Biofilms within an Estavelle in the Upper Floridan Aquifer, 2011, Florea Lee J. , Stinson Chasity L. , Brewer Josh, Fowler Rick, Kearns B Joe, Greco Anthony M.

In Thornton’s Cave, an estavelle in west-central Florida, SEM, EDS, and XRD data reveal biofilms that are predominantly comprised of FeOOH-encrusted hollow sheaths that are overgrown and intercalated with calcite. Fragments of this crystalline biofilm adhere to the walls and ceiling as water levels vary within the cave. Those on the wall have a ‘cornflake’ appearance and those affixed to the ceiling hang as fibrous membranes. PCR of DNA in the active biofilm, combined with morphologic data from the tubes in SEM micrographs, point to Leptothrix sp., a common Fe-oxidizing bacteria, as the primary organism in the biofilm. Recent discoveries of ‘rusticles’ in other Florida caves suggest that Fe-oxidizing bacteria may reside elsewhere in Florida groundwater and may play a role in the mobility of trace metals in the Upper Florida aquifer.
SEM micrographs from two marble tablets submerged for five months, one exposed to microbial activity and a second isolated from microbial action, revealed no visible etchings or borings and very limited loss of mass. EDS data from the electron micrographs of the unfiltered tablet document the same FeOOH-encrusted hollow sheaths and similar deposits of calcite as seen in the ‘cornflakes’. These results, combined with water chemistry data imply that the biofilm may focus or even promote calcite precipitation during low-water level conditions when CO2 degasses from the cave pools.


River reversals into karst springs: A model for cave enlargement in eogenetic karst aquifers, 2011, Gulley J. , Martin J. B. , Screaton E. J. , Moore P. J.

Revised Hydrogeologic framework for the Floridan Aquifer System in the Northern Coastal Areas of Georgia and Parts of South Carolina, 2011, Gill H. E. , Williams L. J.

The hydrogeologic framework for the Floridan aquifer system was revised for eight northern coastal counties in Georgia and five coastal counties in South Carolina (fig. 1) as part of a regional assessment of water resources by the U.S. Geological Survey (USGS) Groundwater Resources Program. In this study, selected well logs were compiled and analyzed to determine the vertical and horizontal continuity of permeable zones that make up the aquifer system, and define more precisely the thickness of confining beds that separate individual aquifer zones. The results of the analysis indicate that permeable zones in the Floridan aquifer system can be divided into (1) an upper group of extremely transmissive zones that correlate to the Ocala Limestone in Georgia and the Parkers Ferry Formation in South Carolina, and (2) a lower group of zones of relatively lower transmissivity that correlates to the middle part of the Avon Park formation in Georgia and updip clastic equivalent units of South Carolina (fig. 2). This new subdivision simplifies the hydrogeologic framework originally developed by the USGS in the 1980s and helps to improve the understanding of the physical geometry of the system for future modeling efforts. Revisions to the framework in the Savannah–Hilton Head area are particularly important where permeable beds control the movement of saltwater contamination. The revised framework will enable water-resource managers in Georgia and South Carolina to assess groundwater resources in a more uniform manner and help with the implementation of sound decisions when managing water resources in the aquifer system


Horizontal Bedding-Plane Conduit Systems in the Floridan Aquifer System and Their Relation to Saltwater Intrusion in Northeastern Florida and Southeastern Georgia, 2011, Williams L. J. , Spechler R. M.

Acoustic televiewer (ATV) images, flowmeter, and borehole geophysical logs obtained from the open intervals of deep test wells were used to develop a revised conceptual model of groundwater flow for the Floridan aquifer system in northeastern Florida and southeastern Georgia. Borehole information was used to identify and map the types and distribution of highly-transmissive production zones in the Floridan aquifer system. The ATV images and flowmeter traverses indicate that water produced from most wells is largely derived from a system of highly-transmissive solution zones formed along bedding planes and major formational contacts. These “horizontal bedding-plane conduit systems” may locally influence the movement of brackish and saline water in the Floridan aquifer system. A modified conceptual model of regional flow in the Floridan aquifer system is proposed that incor-porates locally interconnected horizontal conduit systems within the largely porous matrix rock (fig. 1). Each of the conduit systems represents a highly-transmissive zone along which water can move preferentially through the aquifer system. These may or may not be laterally continuous across the area. Flow paths within the system are restricted vertically by local or regional confining units except where these are breached by collapse features or vertical fractures. Near major pumping centers, water probably moves preferentially along the horizontal conduits to reach the discharging well. The source of water moving into the transmissive open conduits is either derived from upward migration along vertical discontinuities in the rock or from diffuse leakage from adjacent porous rock units. Some trapped relict water in adjacent lower-permeability units may locally contribute to the higher chloride concentrations observed in some wells 


Comparative study of specific groundwater vulnerability of a karst aquifer in central Florida, 2012, Van Beynen P. E. , Niedzielski M. A. , Bialkowskajelinska E. , Alsharifa K. , Matusick J.

The Floridan aquifer system (FAS) is known to be one of the most productive aquifer systems in the USA. With the FAS being a karst aquifer, it presents unique challenges to land use planners because of inherent vulnerabilities to contamination through direct connections between the aquifer and the surface. In this study a new Geographic Information Systems (GIS) -based index, the Karst Aquifer Vulnerability Index (KAVI), incorporates geologic layers used in intrinsic groundwater vulnerability models (GVMs) plus an epikarst layer specific to karst, with land use coverages to create a specific groundwater vulnerability model. The KAVI model was compared to another specific vulnerability model, the Susceptibility Index (SI). Tabulation of the percentage areas of vulnerability classes reveals major differences between the two models with SI suggesting greater vulnerability for the study area than KAVI. Validation of these two models found that KAVI vulnerability levels best reproduced spatially varying concentrations of nitrate in the aquifer. Sensitivity analysis, the application of a variation index and measuring the effective weights for each parameter included in KAVI confirmed the importance of closed depressions but also aquifer hydraulic conductivity. The inclusion of land use was justified; however, effective weight analysis determined its assigned weight was too high as used in the initial calculation of KAVI.


Biological Control on Acid Generation at the Conduit-Bedrock Boundary in Submerged Caves: Quantification through Geochemical Modeling, 2013, Herman Janet S. , Hounshell Alexandria G. , Franklin Rima B, Mills Aaron L.

No-mount Cave, located in wekiwa Springs State Park in central Florida, USA, is an aphotic, submerged, freshwater cave in which large colonies of sulfur-oxidizing bacteria live in filamentous microbial mats. Upwardly discharging groundwater enters the cave from the Upper Floridan aquifer, specifically the Eocene-aged Ocala Limestone. we undertook a combined field, laboratory, and modeling study in which we sought to determine the amount of calcite dissolution attributable to the generation of protons by microbially mediated sulfide oxidation. The chemical compositions of groundwater within the limestone formation collected through a newly designed sampling device and of water in the cave conduit were used in geochemical modeling. we used the reaction-path model PHREEqCI to quantify the amount of calcite dissolution expected under various plausible scenarios for mixing of formation water with conduit water and extent of bacterial sulfide oxidation. Laboratory experiments were conducted using flow-through columns packed with crushed limestone from the study site. Replicate columns were eluted with artificial groundwater containing dissolved HS- in the absence of microbial growth. without biologically mediated sulfide oxidation, no measurable calcite dissolution occurred in laboratory experiments and no additional amount of speleogenesis is expected as formation water mixes with conduit water in the field. In contrast, significant calcite dissolution is driven by the protons released in the biological transformation of the aqueous sulfur species. Although a range of results were calculated, a plausible amount of 158 mg Ca2+ released to conduit water per liter of groundwater crossing the formation-conduit boundary and mixing with an equal volume of conduit water was predicted. Our modeling results indicate that significant cave development can be driven by microbially mediated sulfide oxidation under these hydrogeochemical conditions


Integration of Seismic-Reflection and Well Data to Assess the Potential Impact of Stratigraphic and Structural Features on Sustainable Water Supply from the Floridan Aquifer System, Broward County, Florida, 2014, Cunningham, K. J.

The U.S. Geological Survey and Broward County water managers commenced a 3.5-year cooperative study in July 2012 to refine the geologic and hydrogeologic framework of the Floridan aquifer system (FAS) in Broward County. A lack of advanced stratigraphic knowledge of the physical system and structural geologic anomalies (faults and fractures originating from tectonics and karst-collapse structures) within the FAS pose a risk to the sustainable management of the resource.

The principal objective of the study is to better define the regional stratigraphic and structural setting of the FAS in Broward County. The objective will be achieved through the acquisition, processing, and interpretation of new seismic-reflection data along several canals in Broward County. The interpretation includes integration of the new seismic-reflection data with existing seismic-reflection profiles along Hillsboro Canal in Broward County and within northeast Miami-Dade County, as well as with data from nearby FAS wellbores. The scope of the study includes mapping the geologic, hydrogeologic, and seismic-reflection framework of the FAS, and identifying stratigraphic and structural characteristics that could either facilitate or preclude the sustainable use of the FAS as an alternate water supply or a treated effluent repository. In addition, the investigation offers an opportunity to: (1) improve existing groundwater flow models, (2) enhance the understanding of the sensitivity of the groundwater system to well-field development and upconing of saline fluids, and (3) support site selection for future FAS projects, such as Class I wells that would inject treated effluent into the deep Boulder Zone.


Quantitative hermeneutics: Counting forestructures on a path from W. M. Davis to the concept of multiple-permeability karst aquifers., 2015,

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20th century; a period, up to around the turn of this century, when karst science and mainstream hydrogeology were on different tracks; and a period of convergence, now intertwining, beginning roughly in the last quarter of the 20th century. Two influential players in our story are M.K. Hubbert, whose introduction of the Eulerian perspective of flow was a force for divergence, and R.M. Garrels, whose founding of the field of sedimentary geochemistry was a force for convergence. Other key players include F.T. Mackenzie, J.E. Mylroie, V.T. Stringfield, the U.S. Geological Survey, the Bermuda Biological Station, and the Gerace Research Center in the Bahamas, along with the historical accounts of W.B. White. Our narrative ends with the broader acceptance of the concept of multiple-permeability karst aquifers. We flag in our construction a total of 43 forestructures distributed amongst the categories of hermeneutic theory: 14 in the category of preconceptions; 9 in goals; 14 in tools such as skills; and 6 in tools such as institutions. These counts are an example of the concept of social construction of statistics, and we discuss the implications in terms of the huge number of potential combinations of forestructures that could shape alternative historical narratives of this subject over this time frame.


Results 31 to 41 of 41
You probably didn't submit anything to search for