Stephen Culver - Academia.edu (original) (raw)
Papers by Stephen Culver
Smithsonian contributions to the marine sciences, 1981
In the context of warming climate and rising sea level, records from the early-to-mid Holocene pr... more In the context of warming climate and rising sea level, records from the early-to-mid Holocene provide important analogues to investigate how the environment responds to such changes. The Sunda shelf provides favourable conditions to reconstruct past environmental change as the presence of numerous large paleo-valley systems and high sedimentation rates allow transgressive deposits from the early-mid Holocene sea-level rise to accumulate continuously in topographic depressions. To this end, we analysed the sedimentological, geochemical and micropaleontological characteristics of a sediment core (GRBH03) to investigate early-to-mid Holocene environmental changes in southern Singapore. We constrained the chronology with ten radiocarbon dates that were placed in Bchron age-depth model. Using a multi-proxy approach (e.g., grain size distribution, loss on ignition and XRF core-scanning), supported by benthic foraminifera, three sedimentary units were identified in GRBH03. Sedimentary un...
Barrier Dynamics and Response to Changing Climate, 2018
Barrier islands and associated back-barrier estuaries and lagoons interact via hydrodynamic and s... more Barrier islands and associated back-barrier estuaries and lagoons interact via hydrodynamic and sedimentary processes, affecting the evolution of both systems. Understanding coupled dynamic processes between both systems is vital to forecasts of future coastal morphologic and hydrodynamic changes in response to such factors as sea-level rise and storm patterns. The Pamlico Sound and the Outer Banks barrier islands of North Carolina, USA have co-evolved in response to Holocene climate and sea-level change, and autogenic processes. Recent data and models illustrate the dynamic response of this system to minor, but rapid, climate changes occurring throughout the Holocene, including the Medieval Climate Anomaly and Little Ice Age. Periods of extreme barrier segmentation occurred during times of rapid climate change, affecting tidal energy and salinity conditions within the Pamlico Sound. Hydrodynamic models aid in understanding the magnitude of changes, and the impact on barrier morphology. Future changes to coastal systems may be anticipated based upon changes that have occurred in the past.
Notes for a Short Course: Studies in Geology, 1982
Biogeography is concerned with recording and explaining the distribution of organisms in space an... more Biogeography is concerned with recording and explaining the distribution of organisms in space and time. In their search for patterns of distribution, biogeographers have classified the surface of the earth into a hierarchical scheme of ecological units (e.g. Kauffman and Scott, 1976). The basic biogeographic units are realms and provinces. A faunal realm is a large area about the size of a continent while provinces are subdivisions within a realm. An appreciation of the scale involved is gained by considering a current classification of the terrestial world (Udvardy, 1975) which contains 8 realms and 172 provinces.
The Journal of Foraminiferal Research, 2016
The frequency of anthropogenic seasonal hypoxia on the continental shelf west of the Mississippi ... more The frequency of anthropogenic seasonal hypoxia on the continental shelf west of the Mississippi Delta (the Louisiana Bight) has increased since the middle of the 20 th century. This study applies the PEB index, a proxy for hypoxia, to four ,2 m kasten cores taken southwest of Southwest Pass of the Mississippi Delta. The PEB index is defined as the cumulative percent of Protononion atlanticum (5 Nonionella atlantica of this study), Nonionella opima, Epistominella vitrea and Buliminella morgani. The PEB index varies little in the shallowest core, KC4 (59 m water depth). Assemblages were strongly dominated by PEB taxa (average 95%), due mainly to the dominance of E. vitrea (average 76%). In core KC3 (75 m), an average PEB value of 84% is also due mainly to E. vitrea (61%). The PEB index of KC3 was consistently higher above 90 cm, a level dated at 1955-1960 (210 Pb age estimate), and could reflect an increased influence of hypoxia or an increased rate of sediment accumulation associated with delta progradation. A similar trend characterizes core KC2 (87 m). The PEB index is 18% from 240 cm to 140 cm, increasing up core as the abundance of E. vitrea increases, likely due to delta progradation. Other PEB taxa, B. morgani and N. opima, increase in the top 30 cm of the core, probably due to increased hypoxia between 1952 and 1968 (210 Pb age estimate). Core KC1 (473 m) differed from shallower cores in its higher species diversity. Bolivina lowmani, Cassidulina neocarinata, and Bolivina ordinaria each comprise ,15% of assemblages and PEB taxa are rare (average 5%) but increase to 19% in a 30 cm interval attributed to off-shelf transport. We conclude that the PEB index is a useful indicator of anthropogenic hypoxia but dominance of E. vitrea may also be attributable to sedimentological factors related to delta progradation.
![Research paper thumbnail of Corrigendum to “Micropaleontologic record of Pliocene and Quaternary paleoenvironments in the southern Albemarle Embayment, North Carolina, U.S.A.” [PALAEO: 457 (1 September 2016); pages 360-379]](https://attachments.academia-assets.com/120231234/thumbnails/1.jpg)
](Palaeogeography, Palaeoclimatology, Palaeoecology, 2016
The Journal of Foraminiferal Research, 2014
Foraminifera, grain size, and carbon and nitrogen isotope ratios and abundances were analyzed in ... more Foraminifera, grain size, and carbon and nitrogen isotope ratios and abundances were analyzed in surface-sediment samples collected from three floating fish-cage complexes to address how aquaculture has influenced the Setiu estuary and lagoon of northeast peninsular Malaysia. Two currently active floating fish-cage complexes, SET11-S43 and SET11-S40, are located in the semi-enclosed Setiu lagoon, within four km of an inlet connecting to the South China Sea. The sampling areas experience salinities in the 20s, and sediments have mixed agglutinated and calcareous foraminiferal [total] assemblages, generally dominated by Ammonia aff. A. aoteana and Ammobaculites exiguus. The majority of live foraminifera at these sites belong to agglutinated species; percent of live specimens is greater around the SET11-S43 fish-cage complex, likely related to the presence of aquaculture-related organic-rich mud. Percent agglutinated specimens in total assemblages (live + dead) decrease towards the inlet as total assemblage density and diversity increase due to increased salinity. At a recently (1-3 years) abandoned fishcage complex, SET11-S9A, located in a low salinity (,5) estuarine setting, Miliammina fusca and Am. exiguus dominate total assemblages. Surface-sediment grain-size data indicate that fish-cagerelated organic-rich mud underlies SET11-S43 and extends tens of meters to the north with a surrounding sandier substrate, typical of most of the Setiu estuary and lagoon system. SET11-S40 is underlain by generally sandy sediment; organic-rich mud characterizes the lagoon immediately to the north of this fish-cage complex. Percent carbon and nitrogen in sediment exhibit distributional patterns that strongly correlate with the distribution of fish-cage mud. Greater amounts of mud, carbon, and nitrogen in sediment are found to the north of the active lagoonal fish-cage complexes. The d 13 C and d 15 N signatures of the organic matter in this area are attributed to input from the surrounding mangrove forest, whereas their distribution is a result of the interaction of tidal currents with the physical presence of fish-farm complexes. The environmental influence of the active fish cages at lagoonal site SET11-S40 is minimal as a result of the flushing effects of tidal currents from a nearby inlet. Further north at the SET11-S43 lagoonal fish-cage complex, which receives less marine influence (lower salinity and reduced tidal currents), organic-rich mud has accumulated beneath and to the north of the complex. Foraminiferal and sedimentological data from abandoned estuarine fish-farm complex SET11-S9A are indistinguishable from those of adjacent estuarine sites indicating a rapid return to pre-fish-farm conditions following abandonment.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2015
Sea-level reconstructions based on foraminiferal assemblage data are common for temperate salt-ma... more Sea-level reconstructions based on foraminiferal assemblage data are common for temperate salt-marsh settings. In comparison, the widespread mangrove swamps of equatorial to subtropical settings have received considerably less attention due to enhanced taphonomic loss of specimens, extensive bioturbation, abundant infaunal foraminifera and irregular intertidal topography. The tropics, however, provide the best possible estimate of "eustatic function" and thus are important for testing earth-ice models. In this paper, we use foraminiferal data, in a chronologic framework provided by optically stimulated luminescence, radiocarbon and Pb-210 age estimates, to determine coastal evolution and rates of sea-level rise in the Setiu wetland of northeastern peninsular Malaysia on the western margin of the southern South China Sea over the past ca. 200 years. Foraminiferal data from three surface transects across fringing mangrove swamps were used to interpret four cores from mid to high mangrove swamp settings. Patterns of foraminiferal distribution were determined by correspondence analysis, canonical correspondence analysis and detrended canonical correspondence analysis of dead assemblage data. We used weighted averaging as the transfer function model to reconstruct sea-level curves for the cores and to provide a composite reconstruction for the last ca. 200 years. Based on one C-14 estimate, sea level rose during the 19 th century at 1.26 mm yr-1. The rate increased to 3.2 ±0.6 mm yr 1 .around 1900 CE, roughly coincident with rate increases recorded globally. However, the 20 th century rate in the Setiu wetland is considerably greater than that of global estimates (ca.1.8 mm yr-1) for this period. Rates of sea-level rise in the Gulf of Thailand (immediately to the north of the Setiu wetland) determined from GPS-corrected tide gauge data and multi-satellite altimetry are geographically variable but also greater than the global rate. The data from the Setiu wetland
Stratigraphy, 2010
ABSTRACT Foraminiferal and sedimentologic data were collected by vibracoring a small, relict, sho... more ABSTRACT Foraminiferal and sedimentologic data were collected by vibracoring a small, relict, short-lived, migrating inlet (New Inlet) and its flood-tide delta on the Outer Banks, North Carolina. These data, placed in the context of geospatial data derived from ground penetrating radar, were developed into a stratigraphic model for this sedimentary environment. The model was applied to vibracores collected from two additional barrier island segments within which historic inlets had not been recorded to investigate whether inlets had existed in these segments in the past. Five foraminiferal biofacies were recognized within the three barrier island segments. Biofacies 1 through 5 are all associated with interior and back-barrier depositional environments but Biofacies 4 and 5 contained foraminifera indicating a sediment source on the shoreface or shallow inner shelf. Biofacies 4 and 5 thus represent overwash or flood-tide delta depositional settings. Utilizing the model as an interpretive tool, we recognized a previously undocumented inlet and flood-tide delta that existed prior to 962-662 cal. yrs BP, a few kilometers north of Rodanthe, NC. However, at a barrier island segment between Avon and Buxton, NC, the lack of information on stratal geometry and foraminiferal assemblages meant that it could not be determined whether this sedimentary succession was influencedmore by overwash or inlet dynamics. Given the similarity of foraminiferal assemblages in overwash and flood-tide delta sediments, it is clear that additional lines of evidence (lithologic and geospatial) are required to recognize small-scale flood-tide delta deposits in the subsurface.
Smithsonian contributions to the marine sciences, 1987
Distribution of Recent Benthic Foraminifera off the Pacific Coast of Mexico and Central America. ... more Distribution of Recent Benthic Foraminifera off the Pacific Coast of Mexico and Central America. Smithsonian Contributions to the Marine Sciences, number 30, 184 pages, 115 figures, 1987.-A computer file of all published distributional data (presence or absence) on the recent, living and dead benthic foraminifera off the Mexican and Central American Pacific coast was constructed from 21 papers published since 1896. Manipulation of this file produced 5 catalogs and 115 maps. Catalog | lists alphabetically species names with publication and locality information as recorded in the literature (i.e., unsynonymized). Catalog 2 lists synonymized species names with publication and locality information. Catalogs 3 and 4 list alphabetically all unsynonymized and synonymized species names, respectively. Catalog 5 lists synonymized names by increasing latitude and longitude. Over the past 90 years, 447 names have been used to record benthic foraminifera in the study area. Through synonymization, this number was reduced to 377, of which 114 occur at 5 or more of the 119 sample localities. Computer-generated maps were drawn for the 114 most commonly recorded species. Species were grouped by depth and geographic (latitudinal) distribution through visual examination of the maps. Thirty-two species are restricted to depths of less than 200 m, 22 occur mainly at depths of less than 2000 m, 22 at depths of greater than 200 m, 5 at depths of greater than 2000 m, 11 are found between 200 and 2000 m, and 22 are ubiquitous with depth.
Geological Society of America Abstracts with Programs
Journal of Foraminiferal Research
The distributions of modern foraminiferal species represent an important tool for petroleum geolo... more The distributions of modern foraminiferal species represent an important tool for petroleum geologists to characterize paleoenvironments. This paper documents the distribution of benthic foraminifera on the inner shelf (<40 m water depth) immediately offshore of the Terengganu River mouth, one of the three major drainages on the east coast of peninsular Malaysia. Sediment substrate type primarily controls the distribution of species; temperature, salinity, dissolved oxygen, and pH vary little in the study area and have little influence. Sandy substrates (mostly coarse and very coarse sand) from 20 to 40 m water depth are characterized by abundant specimens of the larger foraminifera Amphistegina spp. Muddy substrates immediately adjacent to the Terengganu River mouth from 12 to 20 m water depth are characterized by higher diversity assemblages dominated by several smaller calcareous taxa and the agglutinated species Ammobaculites exiguus. The latter species has been documented in...
PALAIOS
ABSTRACTThe presence/absence and abundance of benthic foraminifera in successive discrete beds (S... more ABSTRACTThe presence/absence and abundance of benthic foraminifera in successive discrete beds (Shattuck “zones”) of the Miocene Calvert and Choptank formations, exposed at the Calvert Cliffs, Maryland, USA, allows for investigation of community dynamics over space and time. The stratigraphic distribution of benthic foraminifera is documented and interpreted in the context of sea-level change, sequence stratigraphy, and the previously published distribution of mollusks. Neritic benthic foraminiferal communities of four sea-level cycles over ∼4 million years of the middle Miocene, encompassing the Miocene Climatic Optimum and the succeeding middle Miocene Climate Transition, are dominated by the same abundant species. They differ in the varying abundance of common species that occur throughout most of the studied section and in the different rare species that appear and disappear. Transgressive systems tracts (TSTs) have higher species diversity than highstand systems tracts (HSTs) b...
Journal of Foraminiferal Research, 2020
The content and scope of the Cushman Laboratory and Cushman Foundation Special Publications are b... more The content and scope of the Cushman Laboratory and Cushman Foundation Special Publications are briefly described and summarized in four tables. Seventy-seven Special Publications have been produced over the past 90+ years. Most are taxonomic works, of variable length (up to 661 pages) with copious illustrations (up to 389 plates) in the form of images of foraminiferal taxa (six Special Publications are on radiolaria and one on thecamoebians). The Special Publications underpin all other aspects of micropaleontological (particularly foraminiferal) research ranging from biostratigraphy to paleoceanography to evolutionary studies.
Smithsonian contributions to the marine sciences, 1981
In the context of warming climate and rising sea level, records from the early-to-mid Holocene pr... more In the context of warming climate and rising sea level, records from the early-to-mid Holocene provide important analogues to investigate how the environment responds to such changes. The Sunda shelf provides favourable conditions to reconstruct past environmental change as the presence of numerous large paleo-valley systems and high sedimentation rates allow transgressive deposits from the early-mid Holocene sea-level rise to accumulate continuously in topographic depressions. To this end, we analysed the sedimentological, geochemical and micropaleontological characteristics of a sediment core (GRBH03) to investigate early-to-mid Holocene environmental changes in southern Singapore. We constrained the chronology with ten radiocarbon dates that were placed in Bchron age-depth model. Using a multi-proxy approach (e.g., grain size distribution, loss on ignition and XRF core-scanning), supported by benthic foraminifera, three sedimentary units were identified in GRBH03. Sedimentary un...
Barrier Dynamics and Response to Changing Climate, 2018
Barrier islands and associated back-barrier estuaries and lagoons interact via hydrodynamic and s... more Barrier islands and associated back-barrier estuaries and lagoons interact via hydrodynamic and sedimentary processes, affecting the evolution of both systems. Understanding coupled dynamic processes between both systems is vital to forecasts of future coastal morphologic and hydrodynamic changes in response to such factors as sea-level rise and storm patterns. The Pamlico Sound and the Outer Banks barrier islands of North Carolina, USA have co-evolved in response to Holocene climate and sea-level change, and autogenic processes. Recent data and models illustrate the dynamic response of this system to minor, but rapid, climate changes occurring throughout the Holocene, including the Medieval Climate Anomaly and Little Ice Age. Periods of extreme barrier segmentation occurred during times of rapid climate change, affecting tidal energy and salinity conditions within the Pamlico Sound. Hydrodynamic models aid in understanding the magnitude of changes, and the impact on barrier morphology. Future changes to coastal systems may be anticipated based upon changes that have occurred in the past.
Notes for a Short Course: Studies in Geology, 1982
Biogeography is concerned with recording and explaining the distribution of organisms in space an... more Biogeography is concerned with recording and explaining the distribution of organisms in space and time. In their search for patterns of distribution, biogeographers have classified the surface of the earth into a hierarchical scheme of ecological units (e.g. Kauffman and Scott, 1976). The basic biogeographic units are realms and provinces. A faunal realm is a large area about the size of a continent while provinces are subdivisions within a realm. An appreciation of the scale involved is gained by considering a current classification of the terrestial world (Udvardy, 1975) which contains 8 realms and 172 provinces.
The Journal of Foraminiferal Research, 2016
The frequency of anthropogenic seasonal hypoxia on the continental shelf west of the Mississippi ... more The frequency of anthropogenic seasonal hypoxia on the continental shelf west of the Mississippi Delta (the Louisiana Bight) has increased since the middle of the 20 th century. This study applies the PEB index, a proxy for hypoxia, to four ,2 m kasten cores taken southwest of Southwest Pass of the Mississippi Delta. The PEB index is defined as the cumulative percent of Protononion atlanticum (5 Nonionella atlantica of this study), Nonionella opima, Epistominella vitrea and Buliminella morgani. The PEB index varies little in the shallowest core, KC4 (59 m water depth). Assemblages were strongly dominated by PEB taxa (average 95%), due mainly to the dominance of E. vitrea (average 76%). In core KC3 (75 m), an average PEB value of 84% is also due mainly to E. vitrea (61%). The PEB index of KC3 was consistently higher above 90 cm, a level dated at 1955-1960 (210 Pb age estimate), and could reflect an increased influence of hypoxia or an increased rate of sediment accumulation associated with delta progradation. A similar trend characterizes core KC2 (87 m). The PEB index is 18% from 240 cm to 140 cm, increasing up core as the abundance of E. vitrea increases, likely due to delta progradation. Other PEB taxa, B. morgani and N. opima, increase in the top 30 cm of the core, probably due to increased hypoxia between 1952 and 1968 (210 Pb age estimate). Core KC1 (473 m) differed from shallower cores in its higher species diversity. Bolivina lowmani, Cassidulina neocarinata, and Bolivina ordinaria each comprise ,15% of assemblages and PEB taxa are rare (average 5%) but increase to 19% in a 30 cm interval attributed to off-shelf transport. We conclude that the PEB index is a useful indicator of anthropogenic hypoxia but dominance of E. vitrea may also be attributable to sedimentological factors related to delta progradation.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2016
The Journal of Foraminiferal Research, 2014
Foraminifera, grain size, and carbon and nitrogen isotope ratios and abundances were analyzed in ... more Foraminifera, grain size, and carbon and nitrogen isotope ratios and abundances were analyzed in surface-sediment samples collected from three floating fish-cage complexes to address how aquaculture has influenced the Setiu estuary and lagoon of northeast peninsular Malaysia. Two currently active floating fish-cage complexes, SET11-S43 and SET11-S40, are located in the semi-enclosed Setiu lagoon, within four km of an inlet connecting to the South China Sea. The sampling areas experience salinities in the 20s, and sediments have mixed agglutinated and calcareous foraminiferal [total] assemblages, generally dominated by Ammonia aff. A. aoteana and Ammobaculites exiguus. The majority of live foraminifera at these sites belong to agglutinated species; percent of live specimens is greater around the SET11-S43 fish-cage complex, likely related to the presence of aquaculture-related organic-rich mud. Percent agglutinated specimens in total assemblages (live + dead) decrease towards the inlet as total assemblage density and diversity increase due to increased salinity. At a recently (1-3 years) abandoned fishcage complex, SET11-S9A, located in a low salinity (,5) estuarine setting, Miliammina fusca and Am. exiguus dominate total assemblages. Surface-sediment grain-size data indicate that fish-cagerelated organic-rich mud underlies SET11-S43 and extends tens of meters to the north with a surrounding sandier substrate, typical of most of the Setiu estuary and lagoon system. SET11-S40 is underlain by generally sandy sediment; organic-rich mud characterizes the lagoon immediately to the north of this fish-cage complex. Percent carbon and nitrogen in sediment exhibit distributional patterns that strongly correlate with the distribution of fish-cage mud. Greater amounts of mud, carbon, and nitrogen in sediment are found to the north of the active lagoonal fish-cage complexes. The d 13 C and d 15 N signatures of the organic matter in this area are attributed to input from the surrounding mangrove forest, whereas their distribution is a result of the interaction of tidal currents with the physical presence of fish-farm complexes. The environmental influence of the active fish cages at lagoonal site SET11-S40 is minimal as a result of the flushing effects of tidal currents from a nearby inlet. Further north at the SET11-S43 lagoonal fish-cage complex, which receives less marine influence (lower salinity and reduced tidal currents), organic-rich mud has accumulated beneath and to the north of the complex. Foraminiferal and sedimentological data from abandoned estuarine fish-farm complex SET11-S9A are indistinguishable from those of adjacent estuarine sites indicating a rapid return to pre-fish-farm conditions following abandonment.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2015
Sea-level reconstructions based on foraminiferal assemblage data are common for temperate salt-ma... more Sea-level reconstructions based on foraminiferal assemblage data are common for temperate salt-marsh settings. In comparison, the widespread mangrove swamps of equatorial to subtropical settings have received considerably less attention due to enhanced taphonomic loss of specimens, extensive bioturbation, abundant infaunal foraminifera and irregular intertidal topography. The tropics, however, provide the best possible estimate of "eustatic function" and thus are important for testing earth-ice models. In this paper, we use foraminiferal data, in a chronologic framework provided by optically stimulated luminescence, radiocarbon and Pb-210 age estimates, to determine coastal evolution and rates of sea-level rise in the Setiu wetland of northeastern peninsular Malaysia on the western margin of the southern South China Sea over the past ca. 200 years. Foraminiferal data from three surface transects across fringing mangrove swamps were used to interpret four cores from mid to high mangrove swamp settings. Patterns of foraminiferal distribution were determined by correspondence analysis, canonical correspondence analysis and detrended canonical correspondence analysis of dead assemblage data. We used weighted averaging as the transfer function model to reconstruct sea-level curves for the cores and to provide a composite reconstruction for the last ca. 200 years. Based on one C-14 estimate, sea level rose during the 19 th century at 1.26 mm yr-1. The rate increased to 3.2 ±0.6 mm yr 1 .around 1900 CE, roughly coincident with rate increases recorded globally. However, the 20 th century rate in the Setiu wetland is considerably greater than that of global estimates (ca.1.8 mm yr-1) for this period. Rates of sea-level rise in the Gulf of Thailand (immediately to the north of the Setiu wetland) determined from GPS-corrected tide gauge data and multi-satellite altimetry are geographically variable but also greater than the global rate. The data from the Setiu wetland
Stratigraphy, 2010
ABSTRACT Foraminiferal and sedimentologic data were collected by vibracoring a small, relict, sho... more ABSTRACT Foraminiferal and sedimentologic data were collected by vibracoring a small, relict, short-lived, migrating inlet (New Inlet) and its flood-tide delta on the Outer Banks, North Carolina. These data, placed in the context of geospatial data derived from ground penetrating radar, were developed into a stratigraphic model for this sedimentary environment. The model was applied to vibracores collected from two additional barrier island segments within which historic inlets had not been recorded to investigate whether inlets had existed in these segments in the past. Five foraminiferal biofacies were recognized within the three barrier island segments. Biofacies 1 through 5 are all associated with interior and back-barrier depositional environments but Biofacies 4 and 5 contained foraminifera indicating a sediment source on the shoreface or shallow inner shelf. Biofacies 4 and 5 thus represent overwash or flood-tide delta depositional settings. Utilizing the model as an interpretive tool, we recognized a previously undocumented inlet and flood-tide delta that existed prior to 962-662 cal. yrs BP, a few kilometers north of Rodanthe, NC. However, at a barrier island segment between Avon and Buxton, NC, the lack of information on stratal geometry and foraminiferal assemblages meant that it could not be determined whether this sedimentary succession was influencedmore by overwash or inlet dynamics. Given the similarity of foraminiferal assemblages in overwash and flood-tide delta sediments, it is clear that additional lines of evidence (lithologic and geospatial) are required to recognize small-scale flood-tide delta deposits in the subsurface.
Smithsonian contributions to the marine sciences, 1987
Distribution of Recent Benthic Foraminifera off the Pacific Coast of Mexico and Central America. ... more Distribution of Recent Benthic Foraminifera off the Pacific Coast of Mexico and Central America. Smithsonian Contributions to the Marine Sciences, number 30, 184 pages, 115 figures, 1987.-A computer file of all published distributional data (presence or absence) on the recent, living and dead benthic foraminifera off the Mexican and Central American Pacific coast was constructed from 21 papers published since 1896. Manipulation of this file produced 5 catalogs and 115 maps. Catalog | lists alphabetically species names with publication and locality information as recorded in the literature (i.e., unsynonymized). Catalog 2 lists synonymized species names with publication and locality information. Catalogs 3 and 4 list alphabetically all unsynonymized and synonymized species names, respectively. Catalog 5 lists synonymized names by increasing latitude and longitude. Over the past 90 years, 447 names have been used to record benthic foraminifera in the study area. Through synonymization, this number was reduced to 377, of which 114 occur at 5 or more of the 119 sample localities. Computer-generated maps were drawn for the 114 most commonly recorded species. Species were grouped by depth and geographic (latitudinal) distribution through visual examination of the maps. Thirty-two species are restricted to depths of less than 200 m, 22 occur mainly at depths of less than 2000 m, 22 at depths of greater than 200 m, 5 at depths of greater than 2000 m, 11 are found between 200 and 2000 m, and 22 are ubiquitous with depth.
Geological Society of America Abstracts with Programs
Journal of Foraminiferal Research
The distributions of modern foraminiferal species represent an important tool for petroleum geolo... more The distributions of modern foraminiferal species represent an important tool for petroleum geologists to characterize paleoenvironments. This paper documents the distribution of benthic foraminifera on the inner shelf (<40 m water depth) immediately offshore of the Terengganu River mouth, one of the three major drainages on the east coast of peninsular Malaysia. Sediment substrate type primarily controls the distribution of species; temperature, salinity, dissolved oxygen, and pH vary little in the study area and have little influence. Sandy substrates (mostly coarse and very coarse sand) from 20 to 40 m water depth are characterized by abundant specimens of the larger foraminifera Amphistegina spp. Muddy substrates immediately adjacent to the Terengganu River mouth from 12 to 20 m water depth are characterized by higher diversity assemblages dominated by several smaller calcareous taxa and the agglutinated species Ammobaculites exiguus. The latter species has been documented in...
PALAIOS
ABSTRACTThe presence/absence and abundance of benthic foraminifera in successive discrete beds (S... more ABSTRACTThe presence/absence and abundance of benthic foraminifera in successive discrete beds (Shattuck “zones”) of the Miocene Calvert and Choptank formations, exposed at the Calvert Cliffs, Maryland, USA, allows for investigation of community dynamics over space and time. The stratigraphic distribution of benthic foraminifera is documented and interpreted in the context of sea-level change, sequence stratigraphy, and the previously published distribution of mollusks. Neritic benthic foraminiferal communities of four sea-level cycles over ∼4 million years of the middle Miocene, encompassing the Miocene Climatic Optimum and the succeeding middle Miocene Climate Transition, are dominated by the same abundant species. They differ in the varying abundance of common species that occur throughout most of the studied section and in the different rare species that appear and disappear. Transgressive systems tracts (TSTs) have higher species diversity than highstand systems tracts (HSTs) b...
Journal of Foraminiferal Research, 2020
The content and scope of the Cushman Laboratory and Cushman Foundation Special Publications are b... more The content and scope of the Cushman Laboratory and Cushman Foundation Special Publications are briefly described and summarized in four tables. Seventy-seven Special Publications have been produced over the past 90+ years. Most are taxonomic works, of variable length (up to 661 pages) with copious illustrations (up to 389 plates) in the form of images of foraminiferal taxa (six Special Publications are on radiolaria and one on thecamoebians). The Special Publications underpin all other aspects of micropaleontological (particularly foraminiferal) research ranging from biostratigraphy to paleoceanography to evolutionary studies.