Geology Commons^™

Modeling The Construction And Evolution Of Distributed Volcanic Fields On Earth And Mars, Jacob Armstrong Richardson

USF Tampa Graduate Theses and Dissertations

Magmatism is a dominant process on Earth and Mars that has significantly modified and evolved the lithospheres of each planet by delivering magma to shallow depths and to the surface. Two common modes of volcanism are present on both Earth and Mars: central-vent dominated volcanism that creates large edifices from concentrating magma in chambers before eruptions and distributed volcanism that creates many smaller edifices on the surface through the independent ascent of individual magmatic dikes. In regions of distributed volcanism, clusters of volcanoes develop over thousands to millions of years. This dissertation explores the geology of distributed volcanism on Earth …

Recent Increases In Arctic Freshwater Flux Affects Labrador Sea Convection And Atlantic Overturning Circulation, Qian Yang, Tim Dixon, Paul G. Myers, Jennifer Bonin, Don Chambers, M.R. Van Den Broeke, Mads H. Ribergaard, John Mortensen

School of Geosciences Faculty and Staff Publications

The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland’s ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from …

Encrustation Of Inarticulate Brachiopods On Scaphitid Ammonites And Inoceramid Bivalves From The Upper Cretaceous U. S. Western Interior, Neil H. Landman, Joshua S. Slattery, Peter J. Harries

School of Geosciences Faculty and Staff Publications

The inarticulate brachiopod Discinisca is a rare faunal element in the Upper Cretaceous of the U.S. Western Interior. We report two occurrences of encrustation of Discinisca on a scaphitid ammonite (scaphite) and several inoceramids from the lower Maastrichtian Baculites baculus/Endocostea typica Biozones of the Pierre Shale at two localities. Six specimens of Discinisca are present on a single specimen of Hoploscaphites crassus from east-central Montana. They occur along the furrow at the mature apertural margin. Because the brachiopods are restricted to the margin and do not occur on the rest of the shell, it is likely that they …

A Fossilized Energy Distribution Of Lightning, Matthew A. Pasek, Marc Hurst

School of Geosciences Faculty and Staff Publications

When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per …

Geochemistry Of Upper Cretaceous Sediments Of Bozeş Formation (Apuseni Mts., Romania) – Provenance Implications, Luminiţa Zaharia, Romona Bălc, Cosmin C. Stremţan, Adriana Socaciu

School of Geosciences Faculty and Staff Publications

A whole-rock geochemical study was carried out on sandstones from the Upper Cretaceous Bozeş Formation in the southeastern part of the Apuseni Mountains (Romania) in order to constrain their provenance and depositional setting. The geochemical results were compared and integrated with previously reported provenance indicators, such as framework composition and heavy mineral assemblages. The chemical composition is similar for all samples investigated, with limited ranges for both major oxides and trace elements. The sandstones are potassic (Na₂O/K₂O < 1) and can be classified mainly as arenites with a few greywackes. Their immature to relatively mature character is revealed by the SiO₂/Al₂O₃ ratios, ranging between 3.90 and 11.25, as well as their high Sr/Rb ratios. The …

Geographically Isolated Wetlands Are Part Of The Hydrological Landscape, Mark Rains, S. G. Leibowitz, M. J. Cohen, I. F. Creed, H. E. Golden, J. W. Jawitz, P. Kalla, C. R. Lane, M. W. Lang, D. L. Mclaughlin

School of Geosciences Faculty and Staff Publications

No abstract provided.

Apparent Glacially Induced Structural Controls On Limestone Conduit Development In Ohio Caverns, United States, Adrienne M. Watts, Ira D. Sasowsky

International Journal of Speleology

Rock discontinuities such as bedding planes and joints are important controls on the form that caves take. We examined structural controls on the development of Ohio Caverns. The cave formed in Devonian limestone underlying a small bedrock knob (Mt. Tabor) within the Interior Lowland province, United States. The area has been overridden by continental glaciation multiple times. The bedrock is pervasively fractured, with many curved and wavy near-vertical fractures showing many different orientations. In the case of Ohio Caverns, it appears that the controlling fractures in map view may not be joints sensu stricto, but rather some combination of …

The Genesis Of A Lava Cave In The Deccan Volcanic Province (Maharashtra, India), Nikhil R. Pawar, Amod H. Katikar, Sudha Vaddadi, Sumitra H. Shinde, Sharad N. Rajaguru, Sachin V. Joshi, Sanjay P. Eksambekar

International Journal of Speleology

Lava tubes and channels forming lava distributaries have been recognized from different parts of western Deccan Volcanic Province (DVP). Openings of smaller dimension have been documented from the pāhoehoe flows around Pune, in the western DVP. A small lava cave is exposed in Ghoradeshwar hill, near Pune. Detailed field studies of the physical characteristics, structure and morphology of the flows hosting the lava tube has been carried out. This is the first detailed documentation of a lava cave from the DVP. The lava cave occurs in a compound pāhoehoe flow of Karla Formation, characterized by the presence of lobes, toes …

Multiple Scales Of Beach Morphodynamic Processes: Measurements And Modelling, Jun Cheng

USF Tampa Graduate Theses and Dissertations

Multiple scales of beach morphodynamic processes ranging from those of wave-breaking induced turbulence, individual wave, storm, seasonal, to inter-annual are examined in this dissertation based on both laboratory and field data. These processes were simulated using process-based numerical models and data-driven models.

At a microscale, separating turbulence from orbital motion under breaking waves in the surf zone is essential to understanding wave-energy dissipation. Velocity data under monochromatic and random waves in the large-scale sediment transport facility (LSTF) were analyzed. Moving averaging provides a simple method for extracting turbulence from velocity measurements under random breaking waves collected at a reasonably high …

Investigation Of The Mechanisms For Mobilization Of Arsenic In Two Asr Systems In Southwest Central Florida, Gregg William Jones

USF Tampa Graduate Theses and Dissertations

Aquifer storage and recovery (ASR) is a strategy in which water is injected into an aquifer when it is plentiful and pumped from the aquifer when water is scarce. An impediment to ASR in Florida is leaching of naturally-occurring arsenic from limestone of the Upper Floridan Aquifer System (UFAS) into stored water. The concentration of arsenic in surface water, which serves as the recharge water for many ASR systems, and native groundwater is usually much less than 3.0 µ/L. However, data from ASR wells in Florida show that arsenic in recovered water frequently exceeded the 10 µg/L maximum contaminant level …

Phosphorus Sorption Dynamics In Shallow Groundwater, Coastal Everglades, Florida, Usa, Hilary Flower

USF Tampa Graduate Theses and Dissertations

For this dissertation I studied phosphorus (P) sorption dynamics in the shallow groundwater of the southern Everglades. In particular, I examined how the ambient water type governs soluble reactive P (SRP) availability through adsorption/desorption reactions with the aquifer matrix. Chapter 2 investigated how P sorption dynamics of the mangrove root zone sediment are affected by high bicarbonate brackish groundwater compared to both fresh groundwater and saltwater. The results from chapter 2 show that the sediment exhibited exceptionally low sorption efficiency in the high bicarbonate brackish water, which would allow ambient water SRP concentration to be maintained at a higher level. …

Geophysical Evidence For Mid-Crustal Magma Reservoirs In The Lassen Volcanic Region, California, Samantha Catherine Tavarez

USF Tampa Graduate Theses and Dissertations

Regional-scale complete Bouguer gravity anomalies underlying the Lassen and Shasta -Medicine Lake regions in northern California and southern Oregon are associated with subduction of the Gorda plate beneath North America. These generally negative anomalies reflect where underplating has deepened to form the mantle wedge, and where subduction has given rise to a series of Quaternary volcanoes comprising the southernmost end of the Cascade range. Multiple conductive bodies were identified by Park and Ostos (2013) in their magnetotelluric (MT) study of the broader Lassen volcanic region. Their broadband and long period measurements were conducted along a 250 km profile spanning from …

Is Nubia Plate Rigid? A Geodetic Study Of The Relative Motion Of Different Cratonic Areas Within Africa., Mary Wambui Njoroge

USF Tampa Graduate Theses and Dissertations

The Nubia plate is normally considered to be a rigid plate and as such used in the realization of terrestrial reference frame. Gondwana breakup plate reconstruction, the Cameroon volcanic line, seismicity, and the morphology of the Okavango rift zone (ORZ) suggest the presence of internal deformation within the Nubia plate. To test this hypothesis, six different reference frames were developed from the velocity field of three individual regions (West, Central and South), and of different combinations of them (West+Central, South+Central, and Nubia as a whole). The residual velocities with respect to these references frame help us understand the presence of …

A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary

USF Tampa Graduate Theses and Dissertations

Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ¹⁵N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …

Hydrothermal Speleogenesis In Carbonates And Metasomatic Silicites Induced By Subvolcanic Intrusions: A Case Study From The Štiavnické Vrchy Mountains, Slovakia, Pavel Bella, Ľudovít Gaál, Vladimír Šucha, Peter Koděra, Rastislav Milovský

International Journal of Speleology

Several caves of hydrothermal origin in crystalline limestones and metasomatic silicites were investigated in the central zone of the Štiavnica stratovolcano, Štiavnické vrchy Mountains, central Slovakia. Evidence of hydrothermal origin includes irregular spherical cave morphology sculptured by ascending thermal water, occurrence of large calcite crystals and hydrothermal alteration of host rocks, including hydrothermal clays. The early phases of speleogenesis in the crystalline limestone near Sklené Teplice Spa were caused by post-magmatic dissolution linked either to the emplacement of subvolcanic granodiorite intrusions during Late Badenian time or to the spatially associated Late Sarmatian epithermal system. Speleogenesis in metasomatic silicites in the …

Ocean Forcing Of Quaternary East Antarctic Ice Sheet Evolution: An Ice-Proximal Sedimentary Perspective, Michelle E. Guitard

USF Tampa Graduate Theses and Dissertations

Antarctica and the Southern Ocean play a critical role in Earth’s climate system. Antarctica’s ice sheets contain enough ice to raise global sea level by ~58 m, and the Southern Ocean distributes climate signals and nutrients to the major ocean basins and the deep ocean. Antarctica’s largest ice sheet, the East Antarctic Ice Sheet (EAIS), was considered stable compared to those in West Antarctica and the Antarctic Peninsula because it was thought to be grounded above sea level. However, subglacial topography now reveals vast submarine basins and measurements of ice velocity in the Pacific sector indicate marine-terminating outlet glacier thinning …

Millennial-Scale Variability Of A Major East Antarctic Outlet Glacier During The Last Glaciation, Michelle Guitard

USF Tampa Graduate Theses and Dissertations

Ongoing retreat of Antarctica’s marine-based glaciers is associated with warm (~2° C) modified Circumpolar Deep Water intrusion onto the continental shelf, suggesting that Southern Ocean temperatures may influence Antarctic ice sheet stability. Understanding past cryosphere response to environmental forcing is crucial to modeling future ice sheet behavior. Of particular interest is the response of the East Antarctic Ice Sheet (EAIS), which stands to contribute ~20 m to global sea level. However, marine sediment sequences recording timing and variability of EAIS fluctuations through the last major climate shift, the Last Glacial Maximum (LGM), are either missing from the margin or have …

Numerical Simulation Of Spring Hydrograph Recession Curves For East Yorkshire Chalk Aquifer, Uk, Nozad Hasan Azeez, Landis Jared West, Simon H. Bottrell

Sinkhole Conference 2015

The Cretaceous Chalk aquifer is the most important in the UK for the provision of water to public supply and agriculture. The Chalk has both matrix and fracture porosity and is thus best considered as a dual porosity aquifer system. Although the matrix porosity is large, typically around 0.35 in the study area of East Yorkshire, UK (ESI, 2010), pore diameters are typically very small, and the water contained in them is virtually immobile. The high permeability fracture network is responsible for the ability of water to drain; spatial variations in fracture network properties mean conventional approaches to aquifer characterization …

Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Mike Marasa

Sinkhole Conference 2015

On February 12th, 2014, a sinkhole occurred at the National Corvette Museum in Bowling Green, Kentucky. The collapse happened inside part of the building known as the Skydome and eight Corvettes on display were lost into the void that opened in the concrete floor. In this region of Kentucky, known as the Pennyroyal sinkhole plain, subsidence and cover collapse sinkholes are commonly found throughout the landscape. This iconic karst region in the United States is also home to Mammoth Cave, the longest cave in the world, and thousands of other caves and karst features. Investigation of the sinkhole collapse began …

The Cost Of Karst Subsidence And Sinkhole Collapse In The United States Compared With Other Natural Hazards, David J. Weary

Sinkhole Conference 2015

Rocks with potential for karst formation are found in all 50 states. Damage due to karst subsidence and sinkhole collapse is a natural hazard of national scope. Repair of damage to buildings, highways, and other infrastructure represents a significant national cost. Sparse and incomplete data show that the average cost of karst-related damages in the United States over the last 15 years is estimated to be at least $300,000,000 per year and the actual total is probably much higher. This estimate is lower than the estimated annual costs for other natural hazards; flooding, hurricanes and cyclonic storms, tornadoes, landslides, earthquakes, …

Hydrochemical Characteristics And Formation Mechanism Of Groundwater In The Liulin Karst System, Min Yang, Feng'e Zhang, Sheng Zhang, Miying Yin, Guoqing Wu

Sinkhole Conference 2015

The Liulin karst system is typical of hydrogeological systems in northwestern China, with a group of springs as the dominant mechanism for regional groundwater discharge. To reveal the hydrochemical formation mechanism of the Liulin karst groundwater system, we studied the hydrogeochemical processes of karst groundwater in aquifers at the base of the hydrogeological investigation. Then starting from the chemical composition of karst groundwater together with the recharge-runoff - discharge process of groundwater systems, we analyzed the solutes origin and the dissolved mineral facies of the groundwater chemical composition. The results showed that the anionic and cationic compositions of karst water …

Finding Springs In The File Cabinet, Mason Johnson, Ashley Ignatius

Sinkhole Conference 2015

The Minnesota Pollution Control Agency (MPCA), in partnership with other agencies, is currently undertaking comprehensive sub-basin assessments statewide over a ten-year period. Southeast Minnesota has over 17,500 kilometers of perennial and intermittent streams, making the task of comprehensive sub-basin assessment challenging; the task is further complicated by karst geology. In the summer of 2014, a pilot project began between the MPCA and Minnesota Department of Natural Resources (DNR) to digitally preserve paper documents which capture qualitative and quantitative data about the hydrology, water chemistry, geomorphology, biology, land use and karst features of southeast Minnesota streams. The paper documents in file …

A Method Of Mapping Sinkhole Susceptibility Using A Geographic Information System: A Case Study For Interstates In The Karst Counties Of Virginia, Alexandra L. Todd, Lindsay Ivey-Burden

Sinkhole Conference 2015

Karst terrain is landscape underlain by limestone that has been chemically dissolved by acidic groundwater, producing subsurface voids that pose risks for sinkholes if the overlaying soils can no longer support their own weight and collapse. The western counties of Virginia are heavy in karst due to their natural, geographic boundary of the western Ridge Province and the eastern Blue Ridge Mountain Range. As a result, the Commonwealth of Virginia Hazard Mitigation Plan recommends that the Virginia Department of Transportation (VDOT) develop a method to determine the roadways and regions most susceptible to experiencing sinkholes, in an effort to reduce …

History And Future Of The Minnesota Karst Feature Database, Robert Tipping, Mathew Rantala, E. Calvin Alexander Jr., Yongli Gao, Jeffrey Green

Sinkhole Conference 2015

Since the 1990s, the University of Minnesota and the Minnesota Department of Natural Resources have maintained a karst features database that is used to conduct research on karst processes and inventory karst features. Originally designed as a tabular database only, the karst features database developed into a spatial database in 2002, with tabular data stored in Microsoft Access and a spatial component managed in ESRI ArcView. In 2012, the database was converted to a single, relational database platform, PostgreSQL, with both tabular and spatial components edited in ESRI ArcMap. Custom editing forms are written in Visual Basic and are accessed …

A Semi-Automated Tool For Reducing The Creation Of False Closed Depressions From A Filled Lidar-Derived Digital Elevation Model, John Wall, Daniel H. Doctor, Silvia Terziotti

Sinkhole Conference 2015

Closed depressions on the land surface can be identified by ‘filling’ a digital elevation model (DEM) and subtracting the filled model from the original DEM. However, automated methods suffer from artificial ‘dams’ where surface streams cross under bridges and through culverts. Removal of these false depressions from an elevation model is difficult due to the lack of bridge and culvert inventories; thus, another method is needed to breach these artificial dams. Here, we present a semi-automated workflow and toolbox to remove falsely detected closed depressions created by artificial dams in a DEM. The approach finds the intersections between transportation routes …

Sinkhole Vulnerability Mapping: Results From A Pilot Study In North Central Florida, Clint Kromhout, Alan E. Baker

Sinkhole Conference 2015

At the end of June in 2012, Tropical Storm Debby dropped a record amount of rainfall across Florida which triggered hundreds, if not thousands, of sinkholes to form which resulted in tremendous damage to property. The Florida Division of Emergency Management contracted with the Florida Department of Environmental Protection’s Florida Geological Survey to produce a map depicting the state’s vulnerability to sinkhole formation. The three-year project began with a pilot study in three northern Florida counties: Columbia, Hamilton and Suwannee. Utilizing the statistical modeling method Weights of Evidence, results from the pilot study yielded a 93 percent success rate of …

Shallow Depressions In The Florida Coastal Plain: Karst And Pseudokarst, Sam B. Upchurch, Thomas M. Scott, Michael C. Alfieri, Thomas L. Dobecki

Sinkhole Conference 2015

In Florida, shallow depressions (i.e., depressions <1-2 m in depth) on the land surface are often attributed to sinkhole development. However, it has become evident that there are at least six different mechanisms through which these depressions can form in geologically young cover sediments. These mechanisms include: 1. Cover-subsidence sinkholes over shallow limestone; 2. Suffosion sinkholes over shallow limestone; 3. Cover settlement over shallow shell beds; 4. Large, aeolian deflation areas that resemble “Carolina bays;” 5. Depressions that mimic landforms developed on a shallow paleosol; and 6. Depressions created by pedodiagenesis (i.e., conversion of smectite to kaolinite) in a soil-forming environment. Of these, only the first two appear to represent traditional mechanisms for sinkhole development in eogenetic karst. Cover settlement over shell beds is poorly understood and incorrectly attributed to sinkhole development processes. This type of depression has serious limitations in terms of cover thickness and shell content of the substrate. The last three mechanisms are pseudokarst created by aeolian and soil-forming processes. In this paper we present examples of each and discuss their constraints and evidence.

Creation Of A Map Of Paleozoic Bedrock Springsheds In Southeast Minnesota, Jeffrey A. Green, E. Calvin Alexander Jr.

Sinkhole Conference 2015

Springs are groundwater discharge points that serve as vital coldwater sources for streams in southeast Minnesota. The springs generally emanate from Paleozoic carbonate and siliciclastic bedrock aquifers. Use of systematic dye tracing began in the 1970s and continues through the present as a standard method for investigating karst hydrology and to map springsheds,. The work was accelerated in 2007 because of increased funding from the State of Minnesota’s Environment and Natural Resources Trust Fund. A compilation springshed map of dye traces conducted over the last several decades has been assembled for the region. In southeast Minnesota, the springs are the …

Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea

Sinkhole Conference 2015

Much of the Driftless Area of southeastern Minnesota is underlain by karstified carbonate bedrock. Land use in this karst terrain is dominated by agriculture, including row crop and dairy operations. The karst in this region is often mantled with up to 15 m of soil and unconsolidated sediments. As a result, underlying karst hazards such as incipient sinkholes are often hidden until they are suddenly revealed by the collapse of subsurface voids. Regionally, the economics of the dairy industry is causing a trend toward the consolidation and expansion of existing operations. As concentrated animal feeding operations (CAFO) or feedlots expand, …

Pre-Event And Post-Formation Ground Movement Associated With The Bayou Corne Sinkhole, Cathleen E. Jones, Ronald Blom

Sinkhole Conference 2015

We discuss measurements of the precursory and post-formation ground displacement in the vicinity of the Bayou Corne, Louisiana, sinkhole made using interferometric synthetic aperture radar (InSAR) and data from the L-band UAVSAR instrument. Large precursory movement was observed at the sinkhole site and shown to be predominantly horizontal in direction, in contrast to sinkhole precursors previously detected with InSAR, all of which indicated vertical deformation. Here we discuss how two opposing imaging directions were used to determine the precursory horizontal movement, and use the same technique to look at the progression of post-formation ground displacement around the expanding sinkhole during …