Geology Research
Below are recent and/or current Geology research projects at the GRC (updated November 2016).
To download a PDF list of all past Geology projects, please click HERE.
| Number | Project Title, Researcher, & Abstract |
|---|---|
| G-102 | Karst Geology & Pleistocene History Through Sealevel Events, John Mylroie
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| G-105 | Amino Acid Racemization Dating of Cerion, Chione, Lucina and Assorted Corals and other taxa on San Salvador as a Tool for Unravelling the Geochronology of Late Pleistocene/ Holocene Deposition, backed up by some U-series dating and mapping. This study has since been expanded to include Cerion Morphology, James Carew
This project involves amino acid racemization dating of Cerion, Chione, Lucina, and assorted corals (and other taxa) on San Salvador and other Bahamian islands as a tool for unravelling the geochronology of Late Pleistocene/Holocene deposition; backed up by some U-series dating and mapping. This work is done in collaboration with that of G-120 and G-180. In 1988, this study was expanded to include Cerion morphology, and to include islands other than San Salvador. The study is currently stressing usefulness of morphology for environmental and stratigraphic purposes. Collaboration continues between myself and Dr. Sally Walker (Univ. of Georgia) on Cerion morphology and ecology. A new addition to this research was initiated in 2005 to allow study of stable isotope study of Cerion to determine its usefulness for paleoclimate information. |
| G-120 | Study of the detailed Quaternary Pleistocene Holocene History of San Salvador and all of the Bahamas, with Special Emphasis on Sea Level Position and its Effects on Deposition, Diagenesis, Karstification, and Denudation, James Carew and John Mylroie
Study of the detailed Quaternary (Pleistocene-Holocene) history of San Salvador Island and all of the Bahamas, with special emphases on: sea level position and the effects on deposition, diagenesis, karstification, and denudation. |
| G-174 | Hydrology of San Salvador: Relationships between inland lakes, conduits, the ocean and groundwater, R. Lawrence Davis
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| G-180 | Geological investigation of Long Island, New Providence Island, South Andros, Eleuthera Island, Crooked Island, Acklins Island, North Andros, Great Inagua Islands, Abaco Island, Cat Island, Exuma Island, Mayaguana Island, and Rum Cay, John Mylroie and Joan Mylroie
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| G-213 | A Field Evaluation of San Salvador Island's Climatology, Douglas W. Gamble
A meteorological observation network was established on San Salvador in 2001. Initially, a Metdata One weather station was placed at the GRC, a WS-2000 Wireless weather station was placed on Storrs Lake, and a total of four tipping bucket rain gauges were placed at Hog Cay, Grotto Beach, Ocean House, and Six Pack Pond. Currently, an Onset weather station is deployed at the GRC and a tipping bucket rain gage is at Storr's Lake. The purpose of this network is to record baseline meteorological data and assess spatial variability of precipitation across the island. All of the data collected for this research is available to the other GRC researchers. In particular, data will be provided to Dr. Larry Davis for his research of island hydrology, Dr. John Mylroie for his study of island karst, and Dr. John Rogers for his research of island biogeography. |
| G-225 | Post-depositional dissolution of carbonate minerals: Origins of Secondary Porosity in Modern Carbonate Platforms, Jon Martin
We are testing the hypothesis that elevated pCO2 caused by remineralization of organic matter is a major driver of dissolution of carbonate platforms through extensive observations, sampling, chemical analyses, and modeling of saturation states of carbonate minerals in ground and surface water of two neighboring islands (Rum Cay and San Salvador Island) in the Bahamian Archipelago. These islands have nearly identical sizes and climates, but different groundwater salinities. Water will be sampled in depth transects at blue holes during day and night and during different seasons to observe the role photosynthesis, a CO2 sink, and respiration, a CO2 source, have on pCO2 and saturation state of the water. Water will also be sampled from abandoned well fields to observe spatiotemporal variations in pCO2 compared to salinity in groundwater and their relationships to saturation state and dissolution. Additional well observations will include long-term monitoring of specific conductivity as a proxy for dissolution changes through seasons and with storms. |
| G-226 | The distribution of modern-day attached benthic foraminifera from shore to shelf edge, San Salvador, Bahamas, Ron Lewis
The current phase of research focuses on those benthic foraminifera that are fixed to solid substrates by organic adhesive or, more commonly, by calcium-carbonate precipitation. These foram species are most common in low-light settings such as the undersides of cobbles in reef rubble. The two-fold research of my team focuses on their biology, especially rates of growth in different environmental settings, and their rates of calcium-carbonate production. To test the hypothesis that environmental differences leads to differences in growth rates (fastest near-shore, slowest at the wall), concrete blocks with travertine tiles attached were deployed in water depths ranging from 1.5 to 31.4 meters. The results are combined with those of similar previous experiments. In our study of calcium-carbonate production, ImageJ is used to determine the area of each (permanently) attached species of foraminifera and of higher-level taxa for non-foraminifera. Our findings to date show that attached foraminifera play a substantial role in calcium-carbonate production in the shallow warm-water regime. This has been largely overlooked in former research on production rates of foraminifera. The assessment of their contribution can enhance our understanding of carbonate systems, providing a baseline for anticipated global changes. |
| G-231 | Microbial abundance and identification in rocks and water and their role in the formation of secondary porosity (including caves) in the Bahamas, Stephanie Schwabe
The objective of this project is to continue to isolate and identify the bacterial floras found in meteoric water and in the subsurface, and to identify the environmental changes they generate. Continuing to collect and identify more of the environmental components will help to explain some of the changes we may see. It is also necessary to try and identify the organic budget that sustains these bacteria populations. Are they only waiting for the rains or are they removing organic material locked in the composite grains, which make up the rock. We will also be looking closely at the water that is already sitting in some of the vertical cave systems and the drip waters to see what the organic content might be. There is interest as well to determine how much CO2 is being released out of the walls and floor sediments, particularly in Altar Cave. |
| G-234 | Exploring records of anthropogenic and Climate Change - San Salvador Island, Bahamas, Lisa Park-Boush
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| G-235 | Creation and testing of an Ostracode-based transfer function for past climate reconstruction: San Salvador, Bahamas, Lisa Park-Boush
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| G-236 | Biogenic sedimentray structures produced by polychaetes and decapods on tropical beaches, San Salvador Island, Bahamas, Koji Seike and H. Allen Curran
The goal of this project is to characterize the morphologies of burrows of decapod shrimp (callianassids) and fiddler crabs that inhabit sandy supratidal, intertidal, and shallow subtidal zones around San Salvador Island. Better understanding of such modern burrows will permit more detailed paleoenvironmental interpretation of similar fossil burrows in Pleistocene marine rocks throughout the Bahamas and beyond. With our initial field research conducted in Jan-Feb 2011, we established 3 study sites: a supratidal-intertidal site on the north arm of Pigeon Creek, a shallow offshore site in Graham's Harbour, and a shallow offshore site in Long Bay, a short distance north of Lindsay's Reef. We determined that there are at least three distinctive callianassid burrow forms present in the intertidal and shallow subtidal, sandy substrate zones around San Salvador. One burrow-maker species is known (Glypterus acanthochirus), but the other two remain undetermined. In the future, we plan to make additional burrow casts in Graham's Harbour and Long Bay, capture more shrimp specimens for identification, and investigate fiddler crab burrows in the Pigeon Creek area. We also plan to expand this research to investigate other burrow forms of our study areas and on the sandy substrate zone off Bamboo Point. |
| G-237 | Middle to Late Holocene marine history of San Salvador: Does evidence exist for short-term sea level highstands within the island's coastal and interior lake stratigraphy?, Michael Savarese
The rate of sea-level rise is forecast to accelerate as a result of global climate change, and this will have a significant impact on the distribution of environments and coastal geomorphologic change of the Bahama Islands. The Bahamas have been influenced by comparable high rates of sea-level rise in the recent past, particularly in the last 7000 years of history through the Holocene Epoch. The islands have undergone net progradation through the deposition and lithification of dune and beach sediments over most of this interval, though evidence for coastal erosion does exist. The work completed to date has demonstrated the following: (1) Dune strand plains were particularly productive during the middle to late Holocene, however, their role in island progradation is predicted to stop once a critical sea-level rise rate is achieved. These dune plains support a palm-forested coastal coppice that would become threatened during a different sea-level rise regime. (2) Lithified late Holocene beach deposits are common throughout the islands studied thus far (San Salvador, Eleuthera, and the lower Exuma Islands). These sit as much as 2 meters above current sea level, suggesting short-lived sea-level highstands existed in the recent past. However, these high beach deposits can be explained by local anomalously high tides driven by routine oceanographic processes. (3) Middle to late Holocene dune ridges and beach deposits are influential in the formation and perpetuation of coastal lakes and lagoons, which add to the islands' mosaic of natural habitats. Accelerated sea-level rise threatens these features as well. These results will be augmented by documenting these 3 effects on other islands. Research activities will include visiting outcrops of appropriate age around the periphery of a number of islands. Standard practices of sedimentology, stratigraphy, and paleontology will be employed including: the measuring and describing of strata; documenting the occurrence of fossils and sedimentary structures; collecting fossil and rocks for petrographic description; and the collecting of rocks and fossils for radiocarbon dating. |
| G-240a | Investigation of the Hurricane Storm Surge and Possible Tsunami Deposits along the Coast of San Salvador Island, The Bahamas, Tina Niemi
The UMKC group is studying the coastal damage and recovery of hurricanes (2004 Frances, 2011 Irene) along the San Salvador coastal environments and the depositional record of this and other storms in lakes. We have documented storm surge deposition, damage, and recovery to the beach and backbeach environments, and dune erosion and overwash sedimentation in coastal lakes. We have also mapped large boulder fields in rocky coastal areas and on Green Cay. The basic research questions for this study include: What is the sedimentologic and geomorphic character of hurricane storm deposits? Has the frequency of hurricanes changed over time on San Salvador island? It has been hypothesized that hurricane intensity has increased since 2 ka in the Bahamas (Bourrouilh-Le Jan, 2007). Can we differentiate storm-deposits from tsunami deposits? Recently beachrock at higher-than-present elevations has been interpreted as deposited in a single catastrophic event like a tsunami (Vogt et al., 2010). Is there evidence for this along the northeast side of San Salvador island? We will also continue to work along the beach rock outcrop from Barker's Point south to Triangle Pond. |
| G-240b | Coastal Morphology, Human Impact, and Paleoenvironmental Reconstruction of San Salvador Island, Tina Niemi
This project focuses on the paleoenvironmental reconstruction of the area around habitation sites based on coastal geomorphic mapping and stratigraphic, petrographic, and geochemical analyses of sediment cores and coastal beachrock. We plan to continue to investigate Triangle Pond and North Storr's Lake and the coast adjacent to the habitation sites near these and other lakes to determine how the coastal environment and landscape have evolved over time in response to natural changes and land use practices such as soil erosion and degradation in the watershed. Our preliminary interpretations of the Salt Pond data suggest that Al and Fe increase in concentration at about the time of the prehistoric settlement of the island possibly due to soil erosion, and we will continue to see how lake sediment and surface sediment in their watershed vary. Our project looks at howthe coastal landforms correlate to the stratigraphic changes found in the lakes. Many coastal lakes were clearly once open to the sea. When did they become isolated and how did that process evolve? Did the development of beachrock form the barrier that closed the inlets from the sea as hypothesized in our 2010 and 2012 GRC conference papers? |
| G-241 | Biomineralization of carbonates in modern microbialites and its application in CO2 sequestration, David Wronkiewicz and Varun Paul
Storr's Lake in San Salvador Island, Bahamas, is an inland, hypersaline lake, harboring lithified, organo-sedimentary structures called microbialites. Our goal was to identify and characterize these microbialites and investigate the conditions in the lake that allow their growth. Five different microbialites, described morphologically as calcerous knobs, plateau, pinnacle mound, sharpy and mushroom shaped, respectively, were collected from different depths. Salinity, pH, redox chemistry, dissolved oxygen, alkalinity, and chemical composition of the lake were measured either on-site, or in the laboratories at GRC and Missouri S&T. Suspended planktonic material including algae, bacteria, dinoflagellates and organic material contribute to the turbidity of the lake, while also restricting light penetration. Scanning electron microscopy investigations revealed the presence of angular, blocky and needle shaped Mg-calcite and possibly aragonite. X-ray diffraction analysis of the microbialites indicated the presence of Mg-calcite as the dominant mineral constituent in all types, while aragonite was present only in the pinnacle mound and plateau types. A depth-wise profile of these two microbialite types indicated that the aragonite/calcite ratio increased from the top of these microbialites to the bottom. Light measurements revealed that in spite of the turbidity, sunlight reaches the bottom of the lake water, though at very low intensities. |
| G-242 | Ostracode and Bird Biogeographic Patterns Within the Bahamian Archipeligo - A Model for Diversity and Dispersal Mechanisms As Related to Climate Change, Lisa Park-Boush
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| G-243 | Characteristics and Causes of Coastal Boulder Lines on San Salvador Island, Bahamas, Bosiljka Glumac and H. Allen Curran
Lines of boulders that parallel the inland edge of rocky coasts are prominent geomorphic features in many areas around the world, including San Salvador and other islands of The Bahamas. Two contrasting rocky-coast, boulder-lines on San Salvador have been chosen for initial study: an area on the protected north coast bordering Graham's Harbour, west of Singer Bar Point, and a high wave-energy site along cliffs of island's south coast between The Gulf and The Cut. Goals of this study are to characterize in detail features of the boulder lines of San Salvador and to determine mechanisms for their origin. Measurements of boulder line height and length will be made in both areas, and size, shape, composition, and orientation of individual boulders will be determined at selected sites evenly spaced along the full extent of each line. We will use a protocol for recording data modified from previously published sources. Once field data sets are complete, we will compare our data with results from previously studied areas in order to develop a best hypothesis for formation of Bahamian boulder lines. Increased knowledge of where boulder lines are and how they formed is important for future coastal development planning throughout The Bahamas. |
| G-244 | Investigating the quality of the fossil record in carbonate platform settings, Simon Darroch
This project aims to examine how community composition and live/dead fidelity in benthic foraminiferal assemblages change along environmental gradients. Both community composition and fidelity indices are mapped onto facies distributions, along with quantitative surveys of Callianassid burrows, in order to assess the relative impacts of current velocity and deep-tier bioturbation on the fidelity of the proto-fossil record. The results of this project will help determine: 1) the preservation potential of communities along environmental gradients (beta diversity); 2) the extent of spatial averaging in different carbonate sedimentary facies; and 3) the principal controls on live/dead fidelity and quality of the fossil record of benthic foraminifera. |
| G-245 | Experimental testing of Ediacaran taphonomic scenarios, Simon Darroch
The microbial 'death-mask' model proposed for terminal Neoproterozoic Lagerstatte hypothesizes the precipitation of authigenic iron sulfide minerals on, and around, decaying carcasses in association with microbial mats, cementing the sediment as a sole veneer and retaining the external morphology of the organism (Gehling, 1999). Taphonomic experiments using arthropod larvae and cyanobacterial mats have replicated 'death mask'-style preservation in a preliminary fashion (see Darroch et al., 2012), demonstrating higher preservational fidelity in experiments using microbial mats, as well as the precipitation of iron sulfides around carcasses. However, a major limitation of these experiments was the use of freshwater, rather than marine, microbial mats. This project will collect and use the microbial mats present in both Storr's and Stout's lake to effectively simulate, and thereby isolate the chemical and biological controls on, 'death-mask'-style preservation. |
| G-246 | Utilizing multiple marine proxies to determine the extent of disturbance along anthropogenically-developed coastlines: San Salvador, Bahamas, Kelsey Feser
Fidelity analyses comparing live and subfossil accumulations are an established method of documenting anthropogenically-induced changes. Groups consisting of skeletonized organisms are typically selected as proxies because of their preservation potential. However, little work has been performed to assess the relative performance of different taxonomic groups in the same locations in terms of their ability to exhibit correlative fidelity signals. The goal of this research is to utilize three independent subfossil proxies: foraminifera (Simon Darroch), corals (Amelinda Webb) and mollusks (myself) in order to better understand, a) how well each group preserves fidelity, b) to what degree specific components of each of these communities has changed over the course of the interval studied, and c) the relative degree to which each of the study locations has been impacted by anthropogenic modification. We anticipate that the three proxies, because of their relative similarity in terms of life mode and trophic groups, will exhibit similar patterns of live/dead fidelity. In order to achieve this objective, samples were collected from three locations around San Salvador including: Dump Reef, Snow Bay, and Bone Fish Bay. Samples from the latter two sites will also be compared to previous collections from the same locations to directly assess taxonomic changes. |
| G-247 | Mapping Ooid Distribution at Pigeon Creek Delta, San Salvador, The Bahamas, Kiara Gomez
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| G-248 | Drilling predation by cassid gastropods on echinoid prey in a tropical marine setting, Michal Kowalewski and Troy Dexter
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| G-249 | Eolian sedimentary architecture preserved in Quaternary calcarenites on San Salvador island, Bahamas: A standard for comparison with carbonate and non-carbonate deposits of eolian origin, Mario Caputo
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| G-250 | Wet-dry weather cycles - An alternate hypothesis for the origin of calcareous crusts and associated plant-root casts preserved in Pleistocene and Holocene eolian strata on San Salvador and other Bahamian islands , Mario Caputo and Bosiljka Glumac
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| G-251 | Seasonal weather and stormy vs. fair weather episodes preserved in cross-bedded eolian calcarenites of the Holocene North Point Member, Rice Bay Formation, San Salvador Island: A new hypothesis, Mario Caputo and Bosiljka Glumac
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| G-252 | News Tools for Conservation Paleobiology: Taphonomic Mismatch to Identify Degraded Habitats and Trait-Based Paleoenvironmental Inference Models, Andrew Michelson
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| G-253 | Radon studies in selected caves on San Salvador Island, Bahamas, Bogdan Onac
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| G-254 | Imaging of freshwater resources along the coast of a young carbonate island using shallow geophysical methods, Lee Florea
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| G-255 | Evaluating the Geomorphology of Sandy Hook using Ground-penetrating Radar and Precision Topographic Surveying
, C. Robin Mattheus
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| G-256 | Geochemistry and hydro-geomicrobiology investigations in caves and blueholes of San Salvador Island, Bahamas , Bogdan Onac
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| G-257 | Functional Diversity of Chemosymbiosis in Lucinid Bivalves from Coastal Biomes , Annette Engel
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| G-258 | Testing Mantle Viscosity Assumptions in Glacial Isostatic Adjustment Models of Past Sea Level Change, Maureen Raymo
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| G-259 | Impact of Permeability Extremes on Carbonate Island Hydrology, Jason Gulley
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| G-260 | Petrographic and cathodoluminescence study of San Salvador Stratigraphy, Ann Holmes
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| G-261 | The Relationship of Pre-Columbian and Historic Land Use to Sedimentation Patterns and Landscape Geomorphology, Lisa Park-Boush
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| G-262 | Microbial 'death masks' and the roots of the animal family tree, Brandt Gibson
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