Cameron Parish Research Articles

Property Risk Assessment of Sinkhole Hazard in Louisiana, U.S.A

Sinkholes (or dolines) are an often-overlooked environmental hazard. The processes that lead to their formation are slow and insidious, which encourage a lack of awareness or concern for the potential danger, until the sudden, climactic formation leads to unexpected property damage and possibly human casualties. This research identifies the risk to residential properties to the sinkhole hazard, using Louisiana, United States as a case study. Risk is defined as the product of the hazard intensity and the loss to structure and contents within the building resulting from the hazard-related disaster. Results suggest that risk is highly scale-dependent. Although the risk due to sinkholes is small on a per capita basis statewide, especially when compared to the per capita risk of other natural hazards, the property risk for census tracts or census blocks partially or completely overlying a salt dome is substantial. At finer scales, Terrebonne Parish, in coastal southeastern Louisiana, has the greatest concentration of salt domes, while Madison Parish, which is east of Monroe, has the highest percentage of area at risk for sinkhole formation, and St. Mary Parish—immediately west of Terrebonne—has the greatest risk of property loss. An Acadia Parish census tract has the maximum annual property losses in 2050 projected at $40,047 (2010$), and the highest projected annual per building ($43) and per capita ($18) property loss are in the same St. Mary Parish census tract. At the census block level, maximum annual property loss ($7,040) is projected for a census block within Cameron Parish, with maximum annual per building loss ($85 within West Baton Rouge Parish), and maximum per capita annual property loss ($120 within Plaquemines Parish). The method presented in this paper is developed generally, allowing application for risk assessment in other locations. The results generated by the methodology are important to local, state, and national emergency management efforts. Further, the general public of Louisiana, and other areas where the developed method is applied, may benefit by considering sinkhole risk when purchasing, remodeling, and insuring a property, including as a basis of comparison to the risk from other types of hazard.

Relationship between Growth Faults, Subsidence, and Land Loss: An Example from Cameron Parish, Southwestern Louisiana, USA

O'Leary, M. and Gottardi, R., 2020. Relationship between growth faults, subsidence, and land loss: An example from Cameron Parish, Southwestern Louisiana, USA. Journal of Coastal Research, 36(4), 812–827. Coconut Creek (Florida), ISSN 0749-0208.This study investigates the relationship between faulting, subsidence, and land loss in coastal Louisiana. A methodology that integrates three-dimensional (3D) seismic data, well logs, high-resolution topographic mapping (LIDAR), and historical aerial photography is successfully developed to identify fault-related geomorphic changes in southwestern Louisiana's Chenier Plain. Analysis of a 3D seismic survey and well logs reveals the presence of 10 normal faults that form an east-west graben in the middle of the study area. Well logs were used to further constrain the geometry of the faults. Shallow water well logs were used to map the faults at shallow depth, below the resolution of the seismic survey. Fault traces were extrapolated to the surface by maintaining constant dip and projected on LIDAR data. Elevation profiles derived from the LIDAR were conducted across the different faults, and results show that a distinct difference between the upthrown and downthrown sides of the faults occurs. Historical aerial photographs were used to investigate any change in geomorphology from 1953 to 2017 within the study area. Results reveal the occurrence of water bodies on the immediate downthrown sides of suspected fault traces. These findings suggest that faulting influences and focuses areas where subsidence is happening and subsequent land loss may occur, and detailed understanding of active shallow faulting in coastal areas can be used to identify regions that are at risk of land loss.

Ratooning as an adaptive management tool for climatic change in rice systems along a north-south transect in the southern Mississippi valley

The effect of climate change on recent and projected increases in surface temperatures is well-documented. For agriculture, such changes can impact crop phenology and production, but the degree of impact will depend, in part, on contemporaneous changes in crop management. In the current study, we quantified recent (last 40 years) and projected (to 2095) changes in air temperature and associated changes in growing season duration for rice along a latitudinal north-south gradient of the lower Mississippi valley. Recent and projected climate data indicated an ongoing increase in air temperature and growing season length with latitudes above ∼31 °N. We then applied the DD50 growing degree day model to these data to determine if ratooning, a management practice that produces a second rice harvest with minimal resource input, could be employed. The model results were analyzed and used relative to the southernmost location, Cameron Parish, where the season length and daily temperatures currently allow for ratooning to be a common practice for long-grain cultivars (e.g., Cocodrie, Catahoula). The recent and projected increases in temperature and seasonality indicate that ratooning could already be adopted in Avoyelles Parish, and is potentially possible as far north as Cape Girardeau County (37 °N) by the end of the 21 st century. While additional information regarding possible effects of heat stress, water availability, rising carbon dioxide (CO2) levels, and other factors will be necessary to fully assess ratooning potential, our research indicated that ongoing increases in temperature and season length may allow agronomic management practices, such as ratooning, to help adapt rice production to climatic uncertainty.

Herpetofaunal Diversity and Seasonality from a Remnant Coastal Chenier Forest in Southwestern Louisiana

Cheniers are ancient beach ridges in southwestern Louisiana that are often characterized by coastal forest surrounded by marshland. Coastal chenier forests (CCFs) are considered an imperiled habitat in Louisiana because many forest remnants are considerably impacted due to human activities and recent hurricanes. Because little is known about the herpetofaunal community of CCFs, I initiated a seasonal herpetofaunal diversity and abundance study on a privately-owned, remnant CCF in eastern Cameron Parish, Louisiana. Utilizing coverboards and drift fence arrays with pitfall and funnel traps, I documented 12 species (4 anuran, 4 snake, 3 lizard, and 1 turtle) comprising CCF obligate and facultative species, as well as one marsh transient species. Species-accumulation curves indicate the sample was representative of the small herpetofaunal community. Three amphibian (Incilius nebulifer [Gulf Coast Toad], Lithobates sphenocephalus utricularius [Coastal Plains Leopard Frog], and Gastrophryne carolinensis [Eastern Narrow-mouthed Toad]) and 2 reptile (Scincella lateralis [Little Brown Skink] and Thamnophis p. proximus [Orangestriped Ribbonsnake]) species comprised 94% of the captures. Diversity was highest during the spring, with 3 months (March–May) of sampling detecting 92% of the total diversity observed. Sampling during single months only yielded 42–75% of the diversity. Amphibian abundance varied by month (highest June to September) and with the presence of rain, whereas reptile abundance only varied by month (highest in March). Funnel traps were more effective and quantified diversity better than pitfall traps or coverboards. The herpetofaunal diversity at the site was low and comprised of mostly generalist species; regional specimen records also exhibit a modest herpetofaunal community. This data will provide baseline information to determine the impacts of future hurricanes on the herpetofaunal community, analyze recolonization dynamics following hurricanes, and make comparisons to other CCF remnants in the region. I also provide recommendations for improving herpetofauna sampling methodology in coastal settings.

First Nesting Records in Southwestern Louisiana for American Oystercatchers (Haematopus palliatus) and Reddish Egrets (Egretta rufescens), with Implications for Dredge Spoil Island Restoration

American Oystercatchers (Haematopus palliatus) and Reddish Egrets (Egretta rufescens) are coastal species of conservation concern known to nest along most of the Gulf of Mexico’s coastline. However, there is a distributional gap in breeding records for both species between southeastern Louisiana and eastern Texas. Herein, we report on the first breeding records for each species from southwestern Louisiana at Rabbit Island (Cameron Parish, Louisiana), a small, marsh island in Calcasieu Lake. Suitable nesting habitat for American Oystercatchers (1 nesting pair) was present on the island via shell rake and for Reddish Egrets (6–12 pairs, min) in clumps of Juncus roemerianus; this is the first report of Reddish Egrets utilizing this plant species for nesting. A large scale island restoration project is slated for Rabbit Island and therefore, we provide restoration recommendations for conservation planners to improve habitat suitability for multiple bird guilds at this and other potential dredge spoil island projects.

Surveillance of Enteric Viruses and Microbial Indicators in the Eastern Oysters (Crassostrea virginica) and Harvest Waters along Louisiana Gulf Coast.

Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter-feeding molluscan shellfish exposed to sewage-contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male-specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log10 genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P < 0.05); however, weak correlations were found in oysters (r < 0.45) and between oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences.

Short-Term Response of Brown Pelicans (Pelecanus occidentalis) to Oil Spill Rehabilitation and Translocation

Abstract Translocation of wildlife is a valuable tool for managers to alleviate impacts of human/wildlife conflicts, habitat fragmentation, and small population sizes. Pelecanus occidentalis (Brown Pelican) were previously successfully translocated into Louisiana in 1960–1980s and had rebounded significantly prior to the Deepwater Horizon Oil Spill in April 2010. The Deepwater Horizon Oil Spill had a dramatic impact on southeastern Louisiana, including the people, wildlife, and coastal habitats of the region. We translocated 182 oil-rehabilitated Brown Pelicans from southeastern Louisiana to an area non-impacted by the oil spill in southwestern Louisiana (Rabbit Island, Cameron Parish). Daily surveys were conducted at the island for six weeks and documented mortality, movements, integration with local pelican flocks, persistence of pelicans at the island, and the role of supplemental feeding. We documented no mortality of rehabilitated birds and found that translocated Brown Pelicans readily integrated wi...

An Extralimital Record of a Louisiana-Banded Mottled Duck Recovered in South Dakota

Anas fulvigula (Mottled Duck) primarily occupy coastal marshes along the western Gulf of Mexico and Florida. Previous extralimital records of Mottled Ducks have been recorded in Great Plains states and in some states along the Atlantic Coast. We report on a female Mottled Duck that was banded in 2007 on Rockefeller Wildlife Refuge (Cameron Parish, LA) and harvested near Alpena, SD (Sanborn County). This minimum movement of 1680 km is highly unusual in a species where individuals rarely stray more than 160 km from the coast. Among recent and reliably documented reports (since 1980), this observation represents the northernmost documented record for this species. We presume that this individual migrated north with wintering Anas platyrhynchos (Mallard) it associated with in coastal Louisiana.

Relative Nest Density, Nest Success, and Site Occupancy of King Rails in Southwestern Louisiana Rice Fields

Abstract King Rail (Rallus elegans) populations are listed as threatened or endangered in 13 states. One remaining area of relative abundance is the rice-growing region of southwestern Louisiana. Rice fields are flooded for much of the year and support thick emergent vegetation, potentially providing high-quality habitat for King Rails. The objectives of this study were to determine: 1) relative nest density of King Rails in rice; 2) which local and landscape factors influence relative nest densities; 3) nest survival of King Rails in rice fields; 4) effectiveness of callback surveys in indicating King Rail breeding activity; and 5) site occupancy of King Rails in rice fields. In the summers of 2004 and 2005, King Rail surveys and nest searches were conducted in Cameron, Jefferson Davis, Vermilion, and Acadia Parishes in southwestern Louisiana. In 2004, 42 fields were searched for nests and 30 of those were surveyed with callback survey techniques. In 2005, 40 fields were searched and 60 were surveyed. A ...

Survey for West Nile Virus Infection in Free-ranging American Alligators in Louisiana

West Nile virus (WNV) is an endemic arboviral pathogen that occurs throughout most of the United States and is typically maintained through a bird-mosquito-bird transmission cycle. The ecological significance of the virus is high due to its ability to infect and cause disease in humans, livestock, and wildlife. West Nile virus infection of many vertebrate species causes signs of viral illness, including encephalitis that may result in mortality. Infection by WNV has recently been detected in captive Alligator mississippiensis (American Alligators) in Georgia and Louisiana, and in both captive and free-ranging alligators in Florida. However, additional surveys for WNV in populations of free-ranging alligators within the southeastern USA have not been conducted. The purpose of this study was to survey free-ranging alligators in south Louisiana for active WNV infection. Blood samples were collected from 93 alligators captured at Rockefeller Wildlife Refuge in Cameron Parish, LA, during May 2006 and were screened for WNV using reverse transcriptase polymerase chain reaction (RT-PCR). All samples (100%) tested negative for WNV, indicating a lack of detectable active infection in these animals. Additional surveys of the occurrence of WNV in alligators throughout the southeastern USA are needed to determine the susceptibility of these reptiles to the virus, effects on the health of infected populations, and the potential role of alligators in the maintenance and transmission of the virus.

The Effects of Hurricane Rita on the Aquatic Vascular Flora in a Large Fresh-Water Marsh in Cameron Parish, Louisiana

In June 2005, a large fresh-water marsh in Cameron Parish, Louisiana was surveyed for aquatic vascular plants. This marsh is bisected by the Intracoastal Waterway into a northern sector contained within the Lacassine National Wildlife Refuge and a southern sector. In September 2005, Hurricane Rita made landfall in Cameron Parish, Louisiana as a Category 3 storm. In June 2006, nine months after the storm, another survey of the marsh was made. Results from that survey indicate that the vascular flora of the northern sector were largely undamaged. In contrast, most of the plant species of the southern sector have been extirpated. It appears that violent wave action and salt poisoning from the storm surge caused this destruction. Additionally, it appears that the Intracoastal Waterway acted as a barrier to the storm surge and thus protected the northern sector of the marsh.

John Warner Smith

John Warner Smith with Charles Henry Rowell Click for larger view Figure 1 John Warner Smith Photo by Dave Herman, © 2006 [End Page 1389] ROWELL: How much, in pre-Katrina days, did the state of Louisiana depend upon the economy of the city of New Orleans? How much did New Orleans depend upon the economy of the state? My asking these questions assumes that each economy depended upon the other. Did they? SMITH: Absolutely. Before Katrina we had a civilian labor force of roughly two million workers. About six hundred thousand of those jobs were in the New Orleans metropolitan statistical area. Nearly a third of the state's labor force was basically in that region. Of that six hundred thousand or so jobs, nearly half were wiped out by Hurricane Katrina. The jobs that were lost were in sectors that were the engine of New Orleans. When you knock out the tourism business, you cripple New Orleans and the state of Louisiana. For example, just the other day hotels in New Orleans had a ninety percent occupancy rate, but the occupants were different than they were before Katrina. They aren't tourists. They are mostly evacuees, construction workers, and other folks working on the recovery. These are not the people who come as tourists who eat, drink, sleep, and spend millions of dollars in New Orleans every year. There is a saying that, "So goes New Orleans, so goes the state of Louisiana." In the rebuilding process, we have held job fairs all over the state of Louisiana. We held a couple of job fairs in New Orleans for the Louisiana Restaurant Association. The restaurants were trying to come back. They were trying to open the doors, even though they had limited menus and limited food service, but they struggled to find workers. Our agency partnered with the State Department of Transportation and started a free bus service from Baton Rouge to New Orleans for anyone who wanted to get on it and look for work, go to work, or just go to New Orleans to inspect their property. Fortunately, we were able to link some workers with job opportunities. We've been doing this for a couple of months now. The ridership is probably about six hundred or so a day—not a big number, but for those three hundred to get on, come back, and be able to hold a job, it's certainly helpful. Don't forget that we were also hit in southwestern Louisiana by Hurricane Rita a month after Katrina. I am talking about Lake Charles, the Cameron Parish area, and, to some extent, Jefferson Davis Parish and Beauregard Parish. Those parishes were very dependent on the petrochemical industry and there were some job losses there. Much of that area has recovered, but the lower part of the region, Cameron Parish in particular, is probably similar in devastation to St. Bernard Parish in the southeast. Cameron Parish is going to [End Page 1390] be a long time recovering. The economy there was heavily dependent upon the fisheries and seafood processing industry. There are still some challenges in the service sector in general, with businesses struggling to find workers. Many of those workers went to Texas. Many of them ended up in Houston and Dallas, and are still there because they can't find housing in their home parishes. So, the impact of the storm is still being felt in that corner of the state, even though the petrochemical industry has bounced back somewhat. ROWELL: What can the federal government do at this time to assist the state of Louisiana? SMITH: We are receiving federal funds for workforce training. The U.S. Department of Labor has given us sixty-two million dollars of National Emergency Grant funds. This grant will initially provide temporary job assistance to evacuees, and then provide more comprehensive training that will move trainees into permanent jobs. Federal community development block grant funding might be available at some point. The federal government has...

Structure and Stratigraphy of the Calcasieu Lake Salt-Withdrawal Minibasin, Onshore Louisiana

ABSTRACT The Calcasieu Lake salt-withdrawal minibasin, central Cameron Parish, Louisiana, forms an E-W elliptical shape of ~15 mi by 10 mi. Complex normal-fault systems occur along the basin's periphery, commonly down-to-the-basin and flanking adjacent salt-cored uplifts, including Hackberry, Big Lake, Sweet Lake and Creole. Calcasieu Lake salt dome, a comparatively small piercement structure, occupies the basin's center. Sub-salt exploration is currently a major play offshore, yet sub-salt production beneath prominent overhangs of the Calcasieu Lake salt dome was established nearly a quarter century ago in October, 1966, producing ~6.0 BCFG and 300 MBO. Calcasieu Lake minibasin formation was preceded by emplacement of an allochthonous salt sheet into Upper Eocene Jackson strata, probably similar to the modern salt canopy offshore. Rapid sedimentary loading in the Oligocene caused salt remobilization, forming or enhancing peripheral salt uplifts, and an eventual salt weld to form. The Middle Miocene marked renewed sedimentation and basin formation, likely related to formation of the now-detached Calcasieu Lake salt dome by remobilization of salt from a central residual mound. In particular, a sandrich depositional sequence, up to 3,000 ft or more in thickness, is confined to the basin itself, without equivalent strata on peripheral highs. Local upturning of Middle Miocene basinal strata by the Calcasieu Lake salt dome allowed for the sub-salt production at Calcasieu Lake. The paucity of wells drilled along the basin's flanks leaves open many exploration opportunities to test these sand-rich strata as they onlap and pinch-out up the flanks. End_of_Record - Last_Page 409-------

Abstract: Magnitude, Distribution and Impacts of Accidental Brine Spills in the Louisiana Coastal Wetland Conservation Plan Area&amp;nbsp;

ABSTRACT Accidental brine spills cause varying degrees of environmental damage in ecologically sensitive areas of coastal Louisiana. The objectives of this study were to determine the location, frequency, and causes of brine spills in coastal Louisiana, and to identify areas most susceptible to spills. The study was limited to the Louisiana Coastal Wetlands Conservation Plan Area (Conservation Area) as defined by the Louisiana Department of Natural Resources. I obtained digital spill report data the Louisiana Department of Environmental Quality (LADEQ), Water Quality Management Division in Baton Rouge. This database contained spill reports from 1990 through the early part of 1998, and included spill date, quantity, location (parish, oil and gas field), source, facility, and receiving water. I also obtained the locations and volumes of saltwater disposal wells from the Louisiana Department of Natural Resources, Office of Conservation. LADEQ field investigators with the Southwest, Southeast, and Lafourche regional offices were interviewed. Based on their recommendations, twenty-two spill sites were selected for field investigations. These spill sites represented a diversity of ages, quantities, and affected habitats. I documented the condition of each site with photographs, and detailed field notes. The history of each spill and clean-up efforts was also included. Five hundred sixty-seven spills were reported, or discovered by the LADEQ between 1990 and the first half of 1998. Eighty percent of the spills were concentrated in eight parishes. St. Mary and Vermilion parishes each had 14%, while Terrebonne, St. Martin, Plaquemines, Lafourche, Iberia, and Cameron parishes had between 8% and 9%. Fifty-nine percent of the spills resulted from line ruptures and 19% resulted from other equipment failures. Over two hundred sixty million barrels of produced water were injected into disposal wells in the seventeen-parish region located in the Conservation Area in 1996. Plaquemines, Cameron, Terrebonne, and Lafourche parishes made up 60% of the total. Forty-three percent of the wells were located in open water, 23% in marsh, 20% in uplands, and 13% in either cypress or deciduous forest. Visible ecological impacts at the spill sites that I visited ranged from small areas of dead vegetation to hundreds of acres of dead cypress trees. Some of the sites were impacted by chronic exposure to leaking lines and other sites were impacted by isolated events. Figure 1 is a photograph of a brine spill site in a bottomland hardwood forest in St. James Parish that is approximately five years old. A line rupture between the gathering facilities and the injection well caused this spill, and most of the other spills I investigated. Figure 1. Brine spill site in St. James Parish. The spill was approximately five years old at the time the photograph was taken. The findings in this study can be practically applied to spill prevention and detection by focusing inspection efforts in sensitive habitats where high volume injection wells are located. End_of_Record - Last_Page 10-------

Abstract: Foraminiferal Biofacies, Local Zonation and Paleobathymetry of the Hackberry Sequence (Middle Oligocene Frio) of Southwestern Louisiana&amp;nbsp;

ABSTRACT The Hackberry Sequence is a Middle Oligocene (Frio) wedge of deepwater sediments characterized by the Hackberry foraminiferal assemblage. Reevaluation of foraminiferal faunas through high-resolution biostratigraphic studies has increased the known diversity to over 200 species, one of the richest microfaunas in the Gulf Coast Paleogene. Careful evaluation of these diverse assemblages allows recognition of ten foraminiferal biofacies within the Hackberry Sequence. Each biofacies, characterized by distinctive assemblages of key and secondary foraminiferal taxa, has been recognized from recent work in the downdip portion of the Hackberry in Cameron and Calcasieu parishes of southwestern Louisiana. The time of Hackberry deposition also serves as the point of origin or arrival for many long-ranging foraminifera within the Gulf Coast Basin fossil record. Hackberry foraminiferal biofacies are useful for subdividing this sequence into a local zonation scheme, each indicative of a particular paleobathymetric regime. Analysis suggests that the basal to lower biofacies were deposited in depths ranging from lower to middle bathyal. Transported downdip shelf sands in the lower Hackberry are marked by influxes of inner shelf taxa, especially Amphistegina floridana and Elphidium rota. This suggests a correlation of the lower Hackberry to the updip Chickasawhay Formation. Middle and upper Hackberry biofacies range from middle bathyal to deep middle neritic, indicating a gradual in-filling and environmental shallowing throughout deposition of the Middle Oligocene Hackberry Sequence. The biostratigraphic and paleoenvironmental nature of the Pre-Hackberry unconformity is also addressed.

Abstract: 3-D Seismic Revives Kings Bayou

ABSTRACT Shell and Union Pacific Resources have drilled seven successful gas wells in 11 attempts based on their 3-D seismic survey of the greater Kings Bayou area in southern Cameron Parish, Louisiana. The 3-D seismic data helped resolved complex structure, explained apparent stratigraphic inconsistencies, and identified several amplitude anomalies thereby defining significant exploration and development opportunities in a mature area. Newly discovered recoverable volumes of 65 BCF have been found in lower Miocene reservoirs increasing field production from 0.6 MMCFD in 1993, prior to the acquisition of the 3-D survey, to 41 MMCFD. This new-found gas has revived a dying field and returned it to full production capacity. End_of_Record - Last_Page 568-------

Evolution of Salt and Hydrocarbon Migration: Sweet Lake Area, Cameron Parish, Louisiana: ABSTRACT

ABSTRACT The interpretation of seismic, gravity, and well data in northern Cameron Parish, Louisiana suggests that lateral salt flow has influenced the area's structural evolution, depositional patterns, and hydrocarbon migration. Sweet Lake field has produced over 46 MMBO and 15 BCFG from middle Miocene deltaic sands. The productive structural closure is a faulted downthrown anticline controlled by the underlying salt feature. Sweet Lake field overlies a allochthonous salt mass that was probably once part of an ancestral salt ridge extending from Hackberry to Big Lake. Nine wells encountering top of salt and several seismic lines define a detached salt feature of more than 44 square kilometers (17 square miles) at depths from 8,560'-18,000'. Salt withdrawal in the East Hackberry-Big Lake area influenced the depositional patterns of the Oligocene lower Hackberry channel systems. Progradation of thick middle Oligocene Camerina (A) andMiogypsinoides sands into the area caused salt thinning and withdrawal, resulting in the development and orientation of the large Marginulina-Miogypsinoides growth fault northwest of Sweet Lake. Additional evidence for the southeast trend of the salt is a well, approximately 10 kilometers (6 miles) southeast of Sweet Lake, which encountered salt at approximately 19,800'. High quality 2-D and 3-D seismic data will continue to enhance the regional understanding of the evolving salt structures in the onshore Gulf Coast and the local understanding of hydrocarbon migration. Additional examples of lateral salt flow in the onshore area will be recognized and some may prove to have subsalt hydrocarbon potential.

Depositional Patterns and Structural Styles--Hackberry Salt Dome, Cameron Parish, Louisiana: ABSTRACT

ABSTRACT The West and East Hackberry fields of north-central Cameron Parish, Louisiana, are associated with a large southeast-plunging salt ridge. Episodes of salt movement influenced the depositional patterns and reservoir trap styles of the Oligocene- and Miocene-age sedimentary section. The Oligocene lower Hackberry channels were influenced by the salt structure, resulting in the Manchester-Holmwood channel system flanking the east and south sides of the salt dome and the Choupique channel system flanking the west side of the salt dome. The depositional patterns and structural bed dips of the younger Oligocene Camerina A to Marginulina section demonstrate a major period of salt movement and erosion. The resulting truncation of the Camerina A sandstones, sealed by overlying shales, provides the dominant trap style for the majority of the reservoirs. This same general period of salt movement influenced the orientation of the Oligocene Marginulina to Miogypsinoides expansion fault system to the east. The Sweet Lake salt dome, downthrown to this expansion system, probably represents a southeast extension of this ancestral salt ridge.

Taxonomy and Paleoecology of the Marginulina Zone, Cameron and Calcasieu Parishes

ABSTRACT A total of 168 benthonic foraminifera are noted from five wells in Cameron and Calcasieu Parishes with the intention of interpreting the paleoecology and taxonomy of the Upper Oligocene in age Marginulina zone. Sixteen undescribed benthonic species or morphotypes of previously described species are present. Well cuttings from the five wells were analyzed at 30 foot intervals. The study wells are oriented in a north-east-southwest transect approximately paralleling the paleo-coast line. Paleoecological interpretations were made by analyzing nonspecific (species diversity; planktonic:benthonic ratio; etc.) and specific (morphological variation; species predominance; etc.) faunal characteristics. These quantitative and qualitative faunal characteristics indicate that deposition of the Marginulina sediments occurred at a minimum depth indicative of present day outer neritic environments. Deposition may have occurred at greater depths because nonspecific and specific faunal characteristics are only indicative of upper depth limits. The taxonomic study was fundamental to the paleoecologic analysis.

Depletion and Recovery Behavior of the Gladys McCall Geopressured Geothermal Reservoir

Abstract Many sedimentary basins throughout the world contain sealed fault blocks in which the pore fluids are at higher pressures and temperatures than normal as a consequence of their depositional environment. The U.S. Department of Energy has drilled, completed, and tested four deep research wells in selected geopressured geothermal prospects in the Texas-Louisiana Gulf Coast region to evaluate the recov-erabiliry of the thermal, hydraulic, and chemical (methane) energy in this potential energy resource. The wells are expensive and the specific energy of the fluids is relatively small, but the total recoverable energy from a single well can be extremely large. Long-term testing of the Gladys McCall No. I research well, located in Cameron Parish, Louisiana, U.S.A., has defined an impressively large geopressured geothermal reservoir. An integrated analysis of the test data is presented, and a numerical model is constructed that matches the available data for the 6.5-year test history of the well.