Geology and geography.
Vice-chair: James Starnes, MS Department of Environmental Quality
Hunter Henry Brunson
9:00 HYDROGEOLOGIC ASSESSMENT OF A PROPOSED RESERVOIR SITE, SMITH COUNTY, MISSISSIPPI
Jason A. McIlwain*, Darrel W. Schmitz, and James H. May, Mississippi State University, Mississippi State, MS 39762
The Oakohay Creek watershed in Smith County, Mississippi, is a proposed site for the development of a reservoir intended to boost the county's economy. The site is being assessed for suitability based on the hydrogeology of the area. There are three components to the site assessment. The first component involves examining the hydrologic characteristics of the drainage basin. Stream discharge is monitored at eight locations along Oakohay Creek and its tributaries. Stage-discharge hydrographs are constructed based on the obtained data. The second component of the study is based on studying the site's geology. The geology is being studied through field reconnaissance, surface mapping, and examination of geophysical well log data from the MDEQ as well as drillers' logs from seismic exploration. Cross-sections have been constructed based on the available data. Surface mapping of the Glendon/Marianna formations (limestones and marls) of the Vicksburg Group is being conducted. Outcrops of the Glendon/Marianna formations are present along Oakohay Creek near the proposed dam site. Potential dissolution of the Glendon/Marianna formations could cause leakage and instability of the dam. Currently, drilling, along with coring of the Glendon/Marianna formations, is taking place that will provide information for the project. The third component of the study involves the assessment of water quality within the basin. Samples are taken for analysis by the Mississippi State Chemical Laboratory.
9:20 DETERMINING THE POTENTIAL FOR DIRECT RECHARGE IN THE MISSISSIPPI RIVER ALLUVIAL AQUIFER USING SOIL CORE ANALYSES, WASHINGTON CO., MS
Claire E. Rose (1), Jeannie Bryson (2), and Stan Galicki (1), (1) Millsaps College, Jackson, MS 39210 and (2) USGS, Pearl, MS 39208
The potential for water and chemical transport to the Mississippi River Alluvial Aquifer in the Bogue Phalia watershed via vertical recharge was investigated by determining the hydraulic conductivity of sediment in the upper 6 m. Three methods were used; direct measurement of core segments using a falling head permeameter, bulk density and sediment composition data in conjunction with the Rosetta Stone software, and the Hazen method using particle size distribution data. The upper 3 m of topostratum consists of a clay loam with vertical hydraulic conductivity values ranging from [10.sup.-5] to as low as [10.sup.-7] cm/s. The interval from 3 m to approximately 6 m was a sandy loam with hydraulic conductivity values ranging from [10.sup.-3] to [10.sup.-4] cm/s. The sediment composition, bulk density values, and vertical hydraulic conductivity values in the upper 3 m indicate that a relatively homogenous blanket of lower permeability clay loam persists in the area and that that the potential for vertical recharge is low. Appreciable lateral recharge from the nearby Bogue Phalia River is likely as the river incises through the clay loam to the higher conductivity fine, sandy loam interval.
9:40 NON-POINT SOURCE CONTAMINATION OF WETLAND SEDIMENT, LEFLUER'S BLUFF STATE PARK, JACKSON, MS
Becky D. McDole and Stan Galicki, Millsaps College, Jackson, MS 39210
Runoff and overland flow from the 40 hectare Lefluer's Bluff Golf Course contribute to Eubanks Creek and the Pearl River within the Jackson Watershed. The area of study is situated in a cypress-tupelo alluvial swamp adjacent to the golf course. Two sediment cores were dated using [210.sup.Pb] and [137.sup.Cs]. One core was immediately adjacent to the golf course drainage; the second was at a remote location in the floodplain. Carbon, nitrogen, and phosphorus concentrations were determined at regular intervals from the cores. Based on a calculated sediment accumulation rate of approximately 2 cm/yr, element concentration profiles were constructed for each core. Phosphorus and N concentrations in the core adjacent to the golf course are typically greater overall, but also display a notable increase in concentration from horizons that post date golf course construction; nutrient concentration increases in the remote core are more gradual. Correlations between nutrient concentrations in each sample also reflect a difference; values in the remote core typically maintain higher correlation coefficients which range from 0.77 to 0.93, while correlation coefficients from the remote core only range from 0.17 to 0.54. A similar relationship is also observed for pre and post construction intervals in the core most influenced by runoff. The difference observed between cores is attributed to the increased availability of N and P in stormwater in the area most heavily influenced by runoff.
10:00 THE GEOLOGY AND HYDROLOGY OF A PROPOSED IMPOUNDMENT OF THE UPPER SAND CREEK, CHOCTAW COUNTY, MISSISSIPPI
Jonathan R McMillin*, Darrel W. Schmitz, and James H. May, Mississippi State University, Mississippi State, MS 39762
The Sand Creek watershed, Choctaw County, Mississippi, constitutes a proposed site for a recreational and water management reservoir. Prior to the development of the site, the geology and hydrogeology of the watershed must be investigated to determine suitability for impoundment. The proposed site is located within the Wilcox Group, a sequence of interbedded sands, silts, clays and lignites of Eocene age. Geological cross sections derived from geophysical logs and field exploration provides information regarding facies distributions within the proposed site area. Discharge characteristics of both perennial and ephemeral streams at seven locations provide data concerning surface runoff that can then be related to infiltration into the Lower Wilcox Aquifer. These measurements will aid in determining if there is sufficient water flow for impoundment. All data collected and the characteristics of the reservoir are mapped using ArcGIS 9.1 software. Analysis of the study area suggests that the proposed site is suitable for the location of a reservoir. Mitigation of permeable sands should be accomplished by the construction of a levee at the mouth of the reservoir.
10:40 THE TOMBIGBEE RIVER TERRACE SYSTEM E.
Russell and D. Schmitz*, Mississippi State University, Mississippi State, MS 39762
The Tombigbee River in Mississippi has three to four well developed and one poorly preserved terrace deposits. Near Amory the relatively flat surface of the modern alluvium ranges from 190 to 200 feet MSL. The terrace surfaces are progressively more dissected with age and the average elevation of the basal gravels in the first terrace deposit is ~230 feet MSL, the second at ~260 feet MSL, third at ~290 feet MSL, and the fourth at ~320 feet MSL. The uppermost fifth terrace deposit outcrop has no topographic expression. Downstream the base of the terrace deposits decrease in elevation. Typically, the Tombigbee River alluvium is about 30 feet (9 meters) thick as are the first four terrace deposits. The basal horizon consists of iron stained, poorly sorted chert gravel with small rounded pebbles of quartzite and fine- to coarse-grained quartz sands that grade upward into quartz sand that, in turn, grades upward into yellowish-orange, sandy silts and clays, a typical meandering stream deposit. The fifth terrace deposit consists locally of remnants of quartz sand with small, well-rounded, chert pebbles, and rare quartzite pebbles in the basal beds. Like the alluvium, the gravels in the terrace deposits diminish down stream away from the source beds, the Gordo Formation. The terraces are best developed where the chert gravels defend the terraces below the confluence of Bull Mountain Creek and Buttahatchie River.
11:00 PRE-POST KATRINA BACTERIAL POLLUTION OF THE MISSISSIPPI SOUND
David F. Ufnar, University of Southern Mississippi, Hattiesburg, MS 39406
Microbial source tracking efforts have traditionally focused on the input of fecal bacteria from sources such as storm drains, sewers, and runoff. Fecal coliform levels in the Mississippi Sound have been analyzed and compared to physical factors in an attempt to characterize possible non-point sources of pollution. Results from this study show that a primary factor in elevated levels of fecal coliforms is barometric pressure and the resulting changes in wind direction. Fecal coliform counts collected from monitoring stations along the Harrison County, Mississippi coast during May-August, 2005 prior to Hurrican Katrina, 8/29/05, and following Katrina (9/24/05--present) have been compared with barometric pressure readings over that time interval. The occurrence of high fecal coliform counts can be qualitatively correlated with low barometric pressure. Statistically, there is a correlation between high barometric pressure (>1019 mb) and low bacterial counts. The low bacterial counts are most likely to occur when the winds are from a northerly direction. The passage of warm and cold fronts through the northern Gulf of Mexico cause excursions in barometric pressure, and numerous 90[degrees]-180[degrees] shifts in wind directions over a period of 6-8 days. Commonly, a rise in fecal coliform counts is observed at coastal monitoring stations after an abrupt change in barometric pressure, and a shift in wind directions and wind speeds. When these trends of increased fecal coliform levels occur prior to rainfall, it is inferred that the sediment may be a source of the fecal coliform bacteria observed in the water column. The changes in wind direction and speed may induce more energetic conditions at the shoreline (e.g. increased wave heights, and increased nearshore current velocities).
LOESS CAVES OF VICKSBURG
Amber L. Bufk in and Danny Harrelson*, U.S. Army Engineer Research and Development Center (ERDC), Vicksburg, MS 39180
The loess caves of Vicksburg were made famous during the Siege of Vicksburg in the American Civil War. They were not true caves in the geologic sense because none were naturally formed subterranean openings. The caves uniqueness lies in the fact that they were made in loess materials as shelters to avoid artillery bombardments during the Vicksburg Campaign. Because of loess's ability to hold a vertical cut, the material made easily excavated bombardment shelters with walls that could stand for many years without slumping. However, a few of the caves did become unstable during constant bombardment and it was reported some collapsed and buried alive some unfortunate souls. Loughborough, 1990, describes in details life in these caves and recounts how many persons tried to live their lives "normally" in a loess cave during the siege operations. Contemporary accounts reported the caves to be large enough for several humans to enter and some even large enough to accommodate 200 people. Because of the ability to hold stable vertical slopes, loess caves are still a popular form of dwelling that is still in use today in many countries (e.g. China) for human habitation.
Hunter Henry Brunson
1:30 HOUSING THE STATE GEOLOGICAL SURVEY
Michael B. E. Bograd, Mississippi Office of Geology, Jackson, MS 39289
The Mississippi Geological Survey, now the Office of Geology, Mississippi Department of Environmental Quality (MDEQ), has been housed in several locations since 1850. Some moves followed changes in enabling legislation. The first location was a prominent second-floor room in the Lyceum at the University of Mississippi (UM) where the State Geologist was professor of geology. State Geologist Lewis Harper moved the Survey to the State Penitentiary in Jackson and had a prisoner on staff. Dr. Eugene Hilgard, who is credited with convincing Union troops not to burn the UM campus, had offices at UM and in the State Capitol. After a hiatus during Reconstruction, the Survey was reestablished in 1906 with State Geologist Albert Crider at Biloxi, and his staff Calvin Brown at UM and William Logan at Mississippi A & M College. From 1909 to 1924 the Survey was in the New and then Old Capitol at Jackson. From 1924 to 1963 the Survey was housed at UM's Old Library Building, the most attractive building on campus. In 1960 the Survey opened a core and sample library at 2525 North West Street in Jackson to better serve the state's oil industry; the entire agency moved to that building in 1963. Most staff moved in 1991 to the MDEQ headquarters in Southport Center at Ellis Avenue and Highway 80 in Jackson. MDEQ hopes new quarters off the flood plain of Lynch Creek will be found soon.
1:50 THE GEOLOGY OF MISSISSIPPI; A DVD PUBLICATION STATUS REPORT
David T. Dockery III, Mississippi Office of Geology, Jackson, MS 39289
The Geology of Mississippi text is an 891-page (single-spaced) WordPerfect file containing 462,606 words and over 4,000 references. A separate file contains several hundred captioned illustrations in tiff format to accompany the text. These files will be merged, with connecting links, in a DVD publication. An abridged version is planned for a color hardcopy publication. Both the DVD and hardcopy publications will contain many illustrations of historical value, depicting outcrops no longer exposed today. The book contains introductory chapters, the largest of which are on groundwater, physiographic provinces, and ecoregions, followed by a systematic discussion of the state's geology from the oldest to the youngest rocks. Discussions of global time-rock units and the geologic column contain important references published in Nature and Science, as well as information on global boundary stratotypes. The discussion of Mississippi's local geology is based on personal experience, institutional knowledge, and a review of relevant literature, including a complete review of the following: all publications of the Mississippi Geological Survey (now Office of Geology), all publications of the Mississippi Mineral Resources Institute, all volumes of Gulf Coast Association of Geological Societies Transactions, and all issues of Geology and the Journal of Paleontology. The societal impact of the state's geology is reflected in the citation of numerous newspaper articles. Significant geologic outcrops in the state are described as Mississippi Geological Survey (MGS) localities 1-166.
2:10 THE DEFINING OF CITRONELLE SURFACES IN SOUTH MISSISSIPPI AND THE SURFACE EXPRESSION OF RUTH SALT DOME
James E. Starnes* and Patricia Mason, Mississippi Office of Geology, Jackson, Mississippi 39289 and Mississippi Office of Land and Water Resources, Jackson, MS 39289
The use of the Mississippi Automated Resource Information Systems (MARIS) 10-meter Digital Elevation Model (DEM) allows for accurate identification and mapping of Pliocene age alluvial surfaces of the Citronelle Formation. These surfaces consist predominantly of tan to yellow silt with a minor constituent of fine sand, which is indicative of a floodplain depositional environment. The highest of these surfaces is 550 feet MSL in southwestern Simpson County and is typified at the Magee Municipal Airport in Section 3, Township 10 North, Range 18 West. The next highest, for which remnants can be found capping much of Lincoln County, is about 500 feet MSL. This is typified near Brookhaven in Section 5, Township 7 North, Range 8 East. Centered in the northwest 1/4 of Section 22, Township 5 North, Range 9 East, in southeastern Lincoln County, a roughly circular area approximately 1 mile in diameter is expressed above the local Citronelle alluvial surface, with a hilltop reaching an elevation of 570 feet MSL. This is 70 feet above the local Citronelle alluvial surface at 500 feet MSL. Gravity data centers this feature directly above Ruth Salt Dome, a shallow piercement type salt dome. Radial drainage off this feature and coarse sand and gravel exposed on the hilltop also support the presence of a geological structure.
2:30 GRAVEL PETROLOGY OF THE PRE-LOESS TERRACE DEPOSITS
James E. Starnes, Mississippi Office of Geology, Jackson, MS 39289
The Pre-loess Terrace Deposits are early Pleistocene sand and gravel deposits overlain by loess that border the current floodplain of the Mississippi River in Mississippi and are probably equivalent to the Mounds Gravel Fm. of Missouri. The gravel portion of the deposits are dominantly composed of chert commonly containing Paleozoic fossils of crinoids, brachiopods, corals, bryozoans, gastropods, stromatolites, stromotoporids, and rare trilobites. Chert varieties include oolitic, chalcedony, cornelian, lace agate, jasper, banded chert, and tripolitic chert. Chert breccias and conglomerates are also common. In addition to chert and its varieties, the following gravel clasts have been identified in Pre-loess Terrace Deposits: Sioux and Baraboo Quartzite (fine to coarse-grained, pink to purple and often banded, occasionally brecciate, pebble to boulder size), St. Francis Mountain rhyolite (fine to coarse-grained; pink, red, green, gray; massive or flow banded, pebble to cobble size), Keokuk geodes (cauliflower cherts lined inside with rock crystal quartz, quartz druse, or chalcedony; pebble to large cobble size), sandstone (fine to coarse-grained; white, pink, red, green, gray; cobble to boulder size; some sandstones are loosely cemented as a result of quartz overgrowths displaying prismatic crystal faces on individual grains and commonly containing authigenic feldspars), Arkose and weathered granite (pink, coarse-grained, pebble to cobble size, very rare), quartz (milky, pink, clear, gray; pebble to large cobble size). Authogentic and allogentic silicified wood, including fossil palm, is common.
3:10 LATE CRETACEOUS ECHINODERMS IN THE CENTRAL GULF STATES: AN UPDATE
George E. Phillips* and Charles N. Ciampaglio, Mississippi Museum of Natural Science, Jackson, MS 39202, and Wright State University, Celina, OH 45822
With the recent discovery of new species and new species occurrences, Late Cretaceous echinoderm paleontology in Mississippi, Alabama, and Arkansas is in need of significant updating. Given that no one has looked at any particular echinoderm group in the region in the last 50 years, a closer examination of echinoderms in the north-central Gulf is long overdue. For example, several new species of the cassiduloid Hardouinia have recently been identified in Santonian and Campanian deposits in the region. A pair of small burrowing spatangoids is abundant in a sandy marl horizon just above the b asal lag of the Maastrichtian Prairie Bluff Formation in Pontotoc County, Mississippi. The crinoid Uintacrinus socialis, an important stratigraphic marker for Late Santonian deposits in the Western Interior and Europe, has now been found in the Tombigbee Sand Member of the Eutaw Formation in Mississippi. The bourgueticrinid Dunnicrinus, published from Late Maastrichtian deposits in Mississippi, the Netherlands, and Delaware, is now recorded from earlier Gulfian deposits in Mississippi. The type of Bourgueticrinus alabame nsis, the only specimen known to exist of this species, is now officially lost, requiring a search for a neotype. Asteroids, never before described from Mississippi or Alabama, are now documented. Articulated goniasterids have been recovered from the Campanian Mooreville Formation of Alabama, and Maastrichtian units in the north-central Gulf have yielded individual goniasterid ossicles.
3:30 EARLY CENOMANIAN PALEOCLIMATOLOGY AND PEDOGENIC PROCESSES IN THE NORTH AMERICAN WESTERN INTERIOR BASIN
David F. Ufnar, University of Southern Mississippi, Hattiesburg, MS 39406
Stable isotope mass balance modeling results of meteoric [[delta].sup.18]O values from the Cenomanian Stage of the Cretaceous Western Interior Basin (KWIB) suggest that precipitation and evaporation fluxes were greater than that of the present. Sphaerosiderite meteoric [[delta].sup.18]O values have been compiled from the Lower Tuscaloosa Formation of Mississippi (25[degrees]N paleolatitude), The Dakota Formation of Nebraska (35[degrees]N) and the Dunvegan Formation of British Columbia (55[degrees]N paleolatitude). These paleosol siderite [[delta].sup.18]O values define a paleolatitudinal gradient ranging from -4.2 [per thousand] VPDB at 25[degrees]N to -12.5 [per thousand] VPDB at 55[degrees]N. This trend is significantly steeper and more depleted than a Holocene meteoric calcite trend (27[degrees]N: -3.6 [per thousand]; 67[degrees]N: -7.4 [per thousand] VPDB). The steep latitudinal trend in meteoric [[delta].sup.18]O values may be the result of increased precipitation and evaporation fluxes (amount effects) under a more vigorous greenhouse-world hydrologic cycle. A stable-isotope mass balance model has been used to generate estimates of Cenomanian precipitation rates that range from 1500 mm/yr at 25[degrees]N paleolatitude to 3200 mm/yr at 45[degrees]N paleolatitude. Comparisons between Cenomanian siderite and Holocene calcite latitudinal trends show an amplification of Cretaceous low-latitude moisture deficits between 5-25[degrees]N paleolatitude and moisture surpluses between 40-60[degrees]N paleolatitude. The low latitude moisture deficits correlate with a mean annual average heat loss of 71 W/[m.sup.2] at 10[degrees]N paleolatitude (present, 16 W/[m.sup.2]). The increased precipitation flux and moisture surplus in the mid-latitudes corresponds to a mean average annual heat gain of 160 W/m2 at 50[degrees]N paleolatitude (present, 21 W/[m.sup.2]). The heat transferred to the atmosphere via latent heat of condensation was 7.0 x that of the present at 50[degrees]N. The intensified hydrologic cycle of the mid-Cretaceous greenhouse warming may have played a significant role in the poleward transfer of heat and more equable global conditions.
3:50 Divisional Business Meeting
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|Publication:||Journal of the Mississippi Academy of Sciences|
|Date:||Jan 1, 2007|
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