Journal of Foraminiferal Research最新文献

{"title":"Benthic Foraminiferal Assemblages from the Laurentian Channel in the Lower Estuary and Gulf of ST. Lawrence, Eastern Canada: Tracers of Bottom-Water Hypoxia","authors":"T. Audet, A. de Vernal, A. Mucci, M. Seidenkrantz, C. Hillaire‐Marcel, Vladislav Carnero-Bravo, Y. Gélinas","doi":"10.2113/gsjfr.53.1.57","DOIUrl":"https://doi.org/10.2113/gsjfr.53.1.57","url":null,"abstract":"\u0000 Over the past century, an increase in temperatures and a decrease in dissolved oxygen concentrations have been observed in the bottom waters of the Laurentian Channel (LC), throughout the Lower St. Lawrence Estuary (LSLE) and the Gulf of St. Lawrence (GSL), eastern Canada. To document the impact of these changes, we analyzed the benthic foraminiferal assemblages and geochemical signatures of four sediment cores taken in the LC. Radiometric measurements (210Pb, 226Ra, 137Cs) indicate that the studied cores encompass the last 50 years of sedimentation in the LSLE and the last ∼160 years in the GSL. The sedimentary record shows a 60 to 65% decrease in benthic foraminiferal taxonomic diversity in the LC since the 1960s. An accelerated change in the foraminiferal assemblages is observed at approximately the same time at all studied sites, around the late 1990s and the early 2000s, towards populations dominated by the hypoxia-tolerant indicator taxa Brizalina subaenariensis, Eubuliminella exilis, and Globobulimina auriculata. This evolution of assemblages reflects incursions of the hypoxic zone into the western GSL over the last decades. The results of our multivariate analyses highlight the potential of benthic foraminiferal assemblages as a proxy of bottom-water hypoxia.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46558088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2022 Joseph A. Cushman Award: Professor Rajiv Nigam, National Institute of Oceanography (NIO), Goa, India","authors":"","doi":"10.2113/gsjfr.53.1.90","DOIUrl":"https://doi.org/10.2113/gsjfr.53.1.90","url":null,"abstract":"","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42821437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stable Isotopic Variability in Individual Benthic Foraminifera from the Continental Shelf of Tropical Brazil","authors":"K. Billups, P. Eichler, C. Ravelo, Luzia Liniane do Nascimento, H. Vital, M. Gomes","doi":"10.2113/gsjfr.52.4.212","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.212","url":null,"abstract":"\u0000 We analyzed nine benthic foraminiferal species from the Açu Reef belonging to the orders Rotaliida and Miliolida, symbiont-bearing (Rotaliida: Amphistegina gibbosa, Heterostegina depressa; Miliolida: Peneroplis carinatus, Archaias angulatus, Amphisorus hemprichii, and Archaias compressus) and symbiont-barren (Rotaliida: Buccella peruviana, Pseudononion atlanticum; Miliolida: Quinqueloculina lamarckiana). Stable isotopes measured on individual tests display a large intraspecific variability (δ18O: ∼1–1.5‰; δ13C: ∼2–3.5‰) that is not associated with site location, sampling season, or water depth. Positive correlation between δ13C and δ18O values is significant in three of the species (A. gibbosa, B. peruviana, and Q. lamarckiana), with a regression slope similar to other marine calcifiers (∼2‰ δ13C/‰ δ18O), perhaps related to the carbonate chemistry of the calcifying fluid. With the exception of A. gibbosa, offsets from δ18O equilibrium, when distinct, tend to be positive. Offsets from δ13C of ΣCO2 of sea water are negative for two of the rotaliids (A. gibbosa and H. depressa) and positive for three of the miliolids (P. carinatus, A. angulatus, A. hemprichii), with non-symbiont-bearing species of both orders being close to the sea water values (∼ 1.3–2‰). These δ13C differences are consistent with calcification pathways of rotaliids versus miliolids, with the former drawing carbon from an internal pool and the latter from ambient seawater. Our study contributes a large data set that illustrates the importance of vital and abiotic effects on the stable isotopic composition of large benthic foraminifera in a tropical continental shelf, limiting their applicability as paleoenvironmental tracers.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43692590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution and Diversity of Benthic Foraminifera in the Coastal Area of Al-Bawadi Island, Southern Red Sea","authors":"Ahmed Badreldin, Mohamed Mohamed Abdu Makbool, Mohamed Abdu ElSabrouti, Pamela M. Hallock","doi":"10.2113/gsjfr.52.4.264","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.264","url":null,"abstract":"\u0000 The coastal areas of the southern Red Sea islands are non-urbanized, relatively pristine environments and are located on the main migration pathway of Indo-Pacific foraminiferal species to the northern Red Sea and to the Mediterranean Sea via the Suez Canal. Studying the foraminiferal composition, structure, and distribution in the Red Sea is essential to understanding how Indo-Pacific species can migrate to and survive in the Mediterranean Sea. Al-Bawadi, an uninhabited island located in the southern Red Sea, is an ideal location for such study. The coastal waters are oligotrophic, hypersaline, and very warm, overlying carbonate-rich, sandy-bottom and coral-reef substrata. In 25 sediment samples collected from water depths <6 m, 79 foraminiferal species were recorded. Rotaliids dominated the assemblages, followed by miliolids; agglutinated foraminifers were scarce, and planktic species were not found. The larger-benthic, symbiont-bearing Neorotalia calcar dominated except in very shallow water, where smaller, free-living miliolid species dominated. The FoRAM Index (FI) was calculated for all samples; the symbiont-bearing group included seven genera comprising more than half of the total assemblage such that the FI>4 for most samples from depths >3 m, indicating that water quality is suitable for coral-reef growth and recovery. Diversity indices reflected prevailing normal marine to hypersaline conditions. Depth, presence of coral reefs, and hydrodynamics are the main factors controlling the spatial distribution of the foraminiferal assemblages. Occurrences of aberrant tests in the tidal flat area could be related to naturally occurring stresses, such as rapid changes in temperature and salinity, or to breakage and repair. Monitoring studies of unthreatened environments are essential to understand reef-related assemblages and to predict the migration pathways of thermo-tolerant and thermo-sensitive foraminiferal species.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44300309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ObituaryMarcelle K. Boudagher-Fadel, B.Sc., M.Sc., Ph.D. 1956-2022","authors":"G. D. Price","doi":"10.2113/gsjfr.52.4.197","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.197","url":null,"abstract":"","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43075359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reply to Comment on “Larger Benthic Foraminifera and Microfacies of Late Paleocene - Early Eocene Sections in Meghalaya, Northeast India” by Hadi, M. (2022)","authors":"Christer Dominique Pereira, S. Khanolkar, Santanu Banerjee, E. Özcan, P. Saraswati","doi":"10.2113/gsjfr.52.4.210","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.210","url":null,"abstract":"","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41489064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Index to Volume 52, 2022","authors":"","doi":"10.2113/gsjfr.52.4.310","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.310","url":null,"abstract":"","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46720715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Biostratigraphic Analysis and Age Estimates of Middle Cretaceous Sequences in The Baltimore Canyon Trough, Offshore Mid-Atlantic U.S. Margin","authors":"L. Jordan, J. Browning, Kenneth G. Miller, W. Schmelz","doi":"10.2113/gsjfr.52.4.229","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.229","url":null,"abstract":"\u0000 We applied quantitative methods to previously published biostratigraphic data from the Baltimore Canyon Trough (offshore of the Mid-Atlantic U.S.A.) to provide an improved chronostratigraphic framework for Cretaceous sequences. Here, we successfully used graphic correlation of 228 planktonic foraminifera, nannofossil, and palynological events spanning 22 wells to define assemblage and interval zones as well as major paleoenvironmental changes in the Dawson Canyon, Logan Canyon (three sequences), and Missisauga Formations (two sequences, undifferentiated here). Ranking and scaling techniques were not successful because of the of the limited number of usable biostratigraphic markers. The ages of the sequences previously identified using well logs and seismic profiles were temporally constrained based on chronostratigraphically significant biostratigraphic markers that we identified: the late Cenomanian to Turonian DCx sequence (Rotalipora cushmani and Thalmanninella greenhornensis); the early Cenomanian LC1 sequence; the middle and late Albian LC2 sequence (Braarudosphaera africana, Planomalina buxtorfi, and Spinidinium vestitum); the late Aptian LC3 sequence (Cyclonephelium tabulatum); and the early Aptian to Barremian Missisauga sequences (Aptea anaphrissa, Pseudoceratium pelliferum, and Muderongia simplex). These five biostratigraphic associations are correlated with six prominent seismic reflectors and sequence boundaries that can be traced across the basin. Duration of hiatuses associated with these sequence boundaries are uncertain, though our Monte Carlo analysis allows extraction of age estimates from broad and sometimes contradictory ranges and suggests correlation of hiatuses with global sea-level falls. Together, these seismic and biostratigraphic interpretations can be applied (1) to evaluate reservoir continuity and the viability of offshore carbon storage reservoirs in the Baltimore Canyon Trough, (2) to better define the tectonostratigraphic evolution of the basin, and (3) to contribute to the understanding of regional and global variations in Cretaceous sea level.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48982635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plio-Pleistocene Planktic Foraminiferal Biochronology of ODP Site 762B, Exmouth Plateau, Southeast Indian Ocean","authors":"Ashutosh Kumar Singh, D. K. Sinha","doi":"10.2113/gsjfr.52.4.248","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.248","url":null,"abstract":"\u0000 The Indonesian Throughflow region connects the tropical Pacific Ocean with the eastern Indian Ocean, and variability of the Throughflow during the Plio-Pleistocene has been related to major climate shifts at the global level. Planktic foraminiferal biostratigraphy integrated with magnetochronology provides a robust time framework for assigning age control to major paleoceanographic events. Understanding of the coupled histories of the El Niño Southern Oscillation, Western Pacific Warm Pool, Indonesian Throughflow, and the eastern Indian Ocean has greatly benefitted from the chronological framework provided by planktic foraminiferal biostratigraphies from these regions. Ocean Drilling Program (ODP) Hole 762 lies under the influence of the Leeuwin Current, originating from the Indonesian Throughflow. Multiproxy data have been collected from Hole 762B and other nearby sites for paleoceanographic interpretation. However, a detailed planktic foraminiferal biostratigraphy integrated with magnetochronology is not available from this site. We provide here the sequential order of planktic foraminiferal First Occurrence (FO) and Last Occurrence (LO) events, which allowed us to divide the examined section into seven biostratigraphic zones. The biostratigraphy was integrated with magnetostratigraphy using revised ages of magnetochrons, which yielded biochronological age estimates for planktic foraminiferal events. A major planktonic faunal turnover between 3.4 and 2.7 Ma is probably related to the onset of the Northern Hemisphere glaciation and related changes in the Indonesian Throughflow. We have compared our numerical age estimates with published ages from other parts of the world. The diachronism observed probably is related to the local oceanographic setting of ODP Hole 762B, which has been alternatively influenced by changing strengths of the warm Leeuwin Current and the cold west Australian Current. The biochronology established here will be useful for correlating paleoceanographic events in the region.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47519241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benthic Foraminiferal and Sedimentologic Changes in the Pliocene Yorktown Formation, Virginia, USA","authors":"W. Spivey, S. Culver, D. Mallinson, H. Dowsett, M. Buzas","doi":"10.2113/gsjfr.52.4.278","DOIUrl":"https://doi.org/10.2113/gsjfr.52.4.278","url":null,"abstract":"\u0000 The Pliocene Yorktown Formation consists of four lithologic units that record three marine transgressive sequences along the U.S. mid-Atlantic margin. These units were deposited during a time when average sea-level and mean global temperatures were ∼25 m and ∼3°C higher than the pre-industrial, respectively, and global atmospheric CO2 concentrations were similar to present. Forty-five samples were collected along the James River near Rushmere, Virginia, and Spring Grove, Virginia, and were analyzed for benthic foraminifera community and sedimentological changes between each member of the formation. These data are useful for developing boundary conditions for shallow, near-shore environments for paleoclimate modeling. Foraminiferal analysis distinguishes six biofacies across the entire formation. The most notable change in grain-size occurs at the conformable boundary between the Rushmere and Morgarts Beach members, where the average percentage of sand decreases from ∼60% in the Rushmere Member to <40% in the Morgarts Beach Member.","PeriodicalId":54832,"journal":{"name":"Journal of Foraminiferal Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43569051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}