Pub Date : 2014-03-07DOI: 10.2174/1874425701405010010
E. Stefano, A. Incarbona, R. Sprovieri, S. Ferraro
The geographical location, the shape and the circulation pattern makes the Mediterranean Sea an ideal laboratory to study the interplay between different climatic systems, abrupt climate changes and the response of marine ecosystems. The Ocean Drilling Program Site 963 was drilled in the Northwestern part of the Sicily Channel, the sill that divides the western from the eastern Mediterranean Sea. Numerous papers have been published on Site 963 sediments in the last decade, investigating Mediterranean paleoceanographic themes. Here we offer a synthetic framework of these investigations carried out by sub-centennial resolution. We present the whole sequence of suborbital climatic oscillations over the last 130 kyr, that is since the last interglacial period, and we claim that teleconnection with Greenland and North Atlantic regions is the most likely phenomenon to explain our results. Furthermore we show the high sensitivity of marine planktonic (planktonic foraminifera and coccolithophores) ecosystems to Stadial/Interstadial fluctuations. We conclude that a three-steps scenario may describe productivity variations during each high-frequency oscillation, from Interstadial 24 to the last deglaciation (from 110 to 15 kiloyears ago): surface oligotrophy and a deep nutricline in the lower part of Interstadials; increased productivity, through a deep chlorophyll maximum and winter/spring coccolithophore blooms, during the upper part of Interstadials; a shallow nutricline during Stadials and possibly reduced productivity levels with respect to the upper Interstadial phase. Results from Site 963 investigations provide key information for very high- resolution paleoceanographic research in the Mediterranean Sea.
{"title":"Ten Years of Paleoceanographic Studies at ODP Site 963 (Central Mediterranean Sea)","authors":"E. Stefano, A. Incarbona, R. Sprovieri, S. Ferraro","doi":"10.2174/1874425701405010010","DOIUrl":"https://doi.org/10.2174/1874425701405010010","url":null,"abstract":"The geographical location, the shape and the circulation pattern makes the Mediterranean Sea an ideal laboratory to study the interplay between different climatic systems, abrupt climate changes and the response of marine ecosystems. The Ocean Drilling Program Site 963 was drilled in the Northwestern part of the Sicily Channel, the sill that divides the western from the eastern Mediterranean Sea. Numerous papers have been published on Site 963 sediments in the last decade, investigating Mediterranean paleoceanographic themes. Here we offer a synthetic framework of these investigations carried out by sub-centennial resolution. We present the whole sequence of suborbital climatic oscillations over the last 130 kyr, that is since the last interglacial period, and we claim that teleconnection with Greenland and North Atlantic regions is the most likely phenomenon to explain our results. Furthermore we show the high sensitivity of marine planktonic (planktonic foraminifera and coccolithophores) ecosystems to Stadial/Interstadial fluctuations. We conclude that a three-steps scenario may describe productivity variations during each high-frequency oscillation, from Interstadial 24 to the last deglaciation (from 110 to 15 kiloyears ago): surface oligotrophy and a deep nutricline in the lower part of Interstadials; increased productivity, through a deep chlorophyll maximum and winter/spring coccolithophore blooms, during the upper part of Interstadials; a shallow nutricline during Stadials and possibly reduced productivity levels with respect to the upper Interstadial phase. Results from Site 963 investigations provide key information for very high- resolution paleoceanographic research in the Mediterranean Sea.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"22 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133260859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-24DOI: 10.2174/1874425701405010001
Tenger Borjigin, L. Yin, L. Bian, Xunlai Yuan, Chuanming Zhou, F. Meng, Xiaomin Xie, F. Bao
Exceptionally preserved nano-scale spheroids derived from microbial processes and nano-scale fossils have been discovered from the black shales of the Jijiawan section of the Ediacaran Doushantuo Formation in the Yangtze Gorge area of Hubei Province, southern China. The numerous soccer ball-like spheroids are pyritized. Their morphology and abundant preservation may suggest that they could possibly be related to larger spheroids, regardless of the tremendous dimensional gap found in the phosphorite and cherts of the Doushantuo Formation, including those recognized as ‘embryos’. The colony-like spheroids preserved in situ and obtained by acid maceration are compared with known Neoproterozoic microfossils—Bavlinella faveolata (or Sphaerocongregus variabilis). Additionally, nano-scale fossil bodies, characterized by morphological features comparable to living cyanobacteria, fungi and possible unicellular heterotrophic protists were observed in different minor laminae of the black shale samples. This study aims to reveal the aspects of nano-scale biota preserved in the black shale of the Ediacaran Doushantuo Formation, and highlight the taphonomy of microorganisms during the key transition from the anoxic deeper oceans to the oxygenated oceans of the early Ediacaran interval.
{"title":"Nano-Scale Spheroids and Fossils from the Ediacaran Doushantuo Formation in China","authors":"Tenger Borjigin, L. Yin, L. Bian, Xunlai Yuan, Chuanming Zhou, F. Meng, Xiaomin Xie, F. Bao","doi":"10.2174/1874425701405010001","DOIUrl":"https://doi.org/10.2174/1874425701405010001","url":null,"abstract":"Exceptionally preserved nano-scale spheroids derived from microbial processes and nano-scale fossils have been discovered from the black shales of the Jijiawan section of the Ediacaran Doushantuo Formation in the Yangtze Gorge area of Hubei Province, southern China. The numerous soccer ball-like spheroids are pyritized. Their morphology and abundant preservation may suggest that they could possibly be related to larger spheroids, regardless of the tremendous dimensional gap found in the phosphorite and cherts of the Doushantuo Formation, including those recognized as ‘embryos’. The colony-like spheroids preserved in situ and obtained by acid maceration are compared with known Neoproterozoic microfossils—Bavlinella faveolata (or Sphaerocongregus variabilis). Additionally, nano-scale fossil bodies, characterized by morphological features comparable to living cyanobacteria, fungi and possible unicellular heterotrophic protists were observed in different minor laminae of the black shale samples. This study aims to reveal the aspects of nano-scale biota preserved in the black shale of the Ediacaran Doushantuo Formation, and highlight the taphonomy of microorganisms during the key transition from the anoxic deeper oceans to the oxygenated oceans of the early Ediacaran interval.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"265 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121065898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-02-15DOI: 10.2174/1874425701204010001
Krista R. Smilek, Daniel I. Hembree
While the fossil record of holothurians extends from the Cambrian to the Holocene, adequately evaluating their temporal and spatial distribution is difficult due to their poor preservation potential. Several extant holothurians, however, produce abundant shallow burrows that a have a high preservation potential. Neoichnological experiments allow for the direct observation of burrowing behaviors and the resulting biogenic structures. Data obtained from these experiments are invaluable to the interpretation of ichnofossils lacking associated body fossils. The burrowing behaviors of the holothurian Thyonella gemmata were studied in a laboratory setting under varying environmental conditions. Specimens were exposed to variations in grain size, salinity, and water temperature to assess their behavioral response to environmental change and any resulting biogenic structures. Thyonella gemmata burrows by intruding itself into the sediment using muscular contractions and limited use of tube feet. Thyonella gemmata contracts its body into a U-shape and maintains contact with the sediment surface. The resulting burrow is a wide, U-shaped concentration of disrupted sediment with or without spreite. Sediment size had the greatest effect on burrowing activity and morphology; individuals were able to easily burrow into fine- and medium-grained sand, but experienced difficulty in coarse-grained sand. Altering water temperature yielded no significant results. While increasing salinity had no effect, lowering salinity had an adverse physiological effect on the specimens and inhibited burrowing. Studying the varying burrow morphologies produced in these experiments will aid in the interpretation of potential holothurian ichnofossils and the interpretation of paleoenvironmental conditions.
{"title":"Neoichnology of Thyonella gemmata: A Case Study for Understanding Holothurian Ichnofossils","authors":"Krista R. Smilek, Daniel I. Hembree","doi":"10.2174/1874425701204010001","DOIUrl":"https://doi.org/10.2174/1874425701204010001","url":null,"abstract":"While the fossil record of holothurians extends from the Cambrian to the Holocene, adequately evaluating their temporal and spatial distribution is difficult due to their poor preservation potential. Several extant holothurians, however, produce abundant shallow burrows that a have a high preservation potential. Neoichnological experiments allow for the direct observation of burrowing behaviors and the resulting biogenic structures. Data obtained from these experiments are invaluable to the interpretation of ichnofossils lacking associated body fossils. The burrowing behaviors of the holothurian Thyonella gemmata were studied in a laboratory setting under varying environmental conditions. Specimens were exposed to variations in grain size, salinity, and water temperature to assess their behavioral response to environmental change and any resulting biogenic structures. Thyonella gemmata burrows by intruding itself into the sediment using muscular contractions and limited use of tube feet. Thyonella gemmata contracts its body into a U-shape and maintains contact with the sediment surface. The resulting burrow is a wide, U-shaped concentration of disrupted sediment with or without spreite. Sediment size had the greatest effect on burrowing activity and morphology; individuals were able to easily burrow into fine- and medium-grained sand, but experienced difficulty in coarse-grained sand. Altering water temperature yielded no significant results. While increasing salinity had no effect, lowering salinity had an adverse physiological effect on the specimens and inhibited burrowing. Studying the varying burrow morphologies produced in these experiments will aid in the interpretation of potential holothurian ichnofossils and the interpretation of paleoenvironmental conditions.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126962235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-14DOI: 10.2174/1874425701003010001
Matthew Burton-Kelly, J. M. Erickson
Late Cambrian arthropod trackways from the Potsdam Sandstone have been known since the 1850s. A site in Clinton County, New York, USA, exposes Protichnites in fine-grained, quartz-rich, rippled, micro-laminated Potsdam Sandstone. The study area includes evidence of microbial mat growth on the original surface where the trackways were produced. Ripple marks presumably underlie, and therefore were generated prior to, the microbial mat. Trackway preservation is variable over the outcrop and depositional setting indicates a high intertidal or a low supratidal environment with growth of benthic microbial mats. At least eleven distinguishable trackways of multi-legged, telson- bearing individuals show a range of widths. The trackways consist of repetitive sets of seven pairs of tracks converging in the direction of motion of the organism. A telson impression, either discontinuous or continuous, divides the trackways longitudinally and is nearly centered throughout the lengths of the trackways. The trackways are consistent in number of tracks per series, arrangement, and stride lengths with the ichnospecies holotype from the original description of Protichnites septemnotatus Owen, 1852. Variable preservation probably resulted from varying thickness of the microbial mat and/or varying water depth or wind and wave action in an intertidal pool.
{"title":"A New Occurrence of Protichnites Owen, 1852, in the Late Cambrian Potsdam Sandstone of the St. Lawrence Lowlands~!2009-12-12~!2010-02-08~!2010-04-09~!","authors":"Matthew Burton-Kelly, J. M. Erickson","doi":"10.2174/1874425701003010001","DOIUrl":"https://doi.org/10.2174/1874425701003010001","url":null,"abstract":"Late Cambrian arthropod trackways from the Potsdam Sandstone have been known since the 1850s. A site in Clinton County, New York, USA, exposes Protichnites in fine-grained, quartz-rich, rippled, micro-laminated Potsdam Sandstone. The study area includes evidence of microbial mat growth on the original surface where the trackways were produced. Ripple marks presumably underlie, and therefore were generated prior to, the microbial mat. Trackway preservation is variable over the outcrop and depositional setting indicates a high intertidal or a low supratidal environment with growth of benthic microbial mats. At least eleven distinguishable trackways of multi-legged, telson- bearing individuals show a range of widths. The trackways consist of repetitive sets of seven pairs of tracks converging in the direction of motion of the organism. A telson impression, either discontinuous or continuous, divides the trackways longitudinally and is nearly centered throughout the lengths of the trackways. The trackways are consistent in number of tracks per series, arrangement, and stride lengths with the ichnospecies holotype from the original description of Protichnites septemnotatus Owen, 1852. Variable preservation probably resulted from varying thickness of the microbial mat and/or varying water depth or wind and wave action in an intertidal pool.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123634151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-18DOI: 10.2174/1874425700902010010
Youxing Li, Suna Zhang, Jie Zhang
Tintinnids are very common in all marine water and even fresh water. The oldest fossils of Tintinnids are not only appeared in Neoproterozoic Era, but also in Mesoproterozoic Calymmian. Eight species of six genera Tintinnids of Mesoproterozoic Calymmian, from Huangmailing Phosphoric Ore in Hubei Province of Central China, are illustrated in this paper. They are the oldest ancestor of Tintinnids. Tintinnids had about 1600 million years history.
{"title":"Mesoproterozoic Calymmian Tintinnids from Central China","authors":"Youxing Li, Suna Zhang, Jie Zhang","doi":"10.2174/1874425700902010010","DOIUrl":"https://doi.org/10.2174/1874425700902010010","url":null,"abstract":"Tintinnids are very common in all marine water and even fresh water. The oldest fossils of Tintinnids are not only appeared in Neoproterozoic Era, but also in Mesoproterozoic Calymmian. Eight species of six genera Tintinnids of Mesoproterozoic Calymmian, from Huangmailing Phosphoric Ore in Hubei Province of Central China, are illustrated in this paper. They are the oldest ancestor of Tintinnids. Tintinnids had about 1600 million years history.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129549531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-04-28DOI: 10.2174/1874425700902010001
C. Diedrich
Rare Late Pleistocene porcupine remains of Hystrix (Atherurus) brachyura Linnaeus 1758 are described from the Fuchsluken Cave, a small gypsum karst cavity at the Rote Berg on the Giebelstein near Saalfeld (Thuringia, Central Germany). The cave was used during the Eemian and mainly Early Weichselian (around 120.000-75.000 BP) by spotted hyena clans of Crocuta crocuta spelaea (Goldfuss 1823), which imported prey that resulted in a large bone accumulation in and around the cave. It was also used in the short term by porcupines as their den, such as proven for several Eemian to Early Weichselian cave faunas in Central Europe, especially Germany and Czech Republic, recently. In the cave recycled-by-hyenas cracked megafauna bones were found, on which they had chewed all around. These typically nibbled bones with parallel bite scratches were also found at other European caves such as presented here for two more new Hystrix cave sites in the Moravian Karst (Czech Republic) and indirectly prove their presence at more and more cave sites in Central Europe. Here, the recently learned 21 Late Pleistocene porcupine sites with skeletal material and more often the indirect proof by chewed bones are presented in an overview. Nearly all are cave localities, often being small cavities or the entrance parts of small caves were used as porcupine dens, as is proved here in the Fuchsluken Cave near Saalfeld. In many cases the porcupines used hyena dens and recycled their accumulated bone rubbish.
{"title":"Late Pleistocene Hystrix (Acanthion) brachyura Linnaeus 1758 from the Fuchsluken Cave Near Saalfeld (Thuringia, Germany) - A Porcupine and Hyena Den and Contribution to their Palaeobiogeography in Europe","authors":"C. Diedrich","doi":"10.2174/1874425700902010001","DOIUrl":"https://doi.org/10.2174/1874425700902010001","url":null,"abstract":"Rare Late Pleistocene porcupine remains of Hystrix (Atherurus) brachyura Linnaeus 1758 are described from the Fuchsluken Cave, a small gypsum karst cavity at the Rote Berg on the Giebelstein near Saalfeld (Thuringia, Central Germany). The cave was used during the Eemian and mainly Early Weichselian (around 120.000-75.000 BP) by spotted hyena clans of Crocuta crocuta spelaea (Goldfuss 1823), which imported prey that resulted in a large bone accumulation in and around the cave. It was also used in the short term by porcupines as their den, such as proven for several Eemian to Early Weichselian cave faunas in Central Europe, especially Germany and Czech Republic, recently. In the cave recycled-by-hyenas cracked megafauna bones were found, on which they had chewed all around. These typically nibbled bones with parallel bite scratches were also found at other European caves such as presented here for two more new Hystrix cave sites in the Moravian Karst (Czech Republic) and indirectly prove their presence at more and more cave sites in Central Europe. Here, the recently learned 21 Late Pleistocene porcupine sites with skeletal material and more often the indirect proof by chewed bones are presented in an overview. Nearly all are cave localities, often being small cavities or the entrance parts of small caves were used as porcupine dens, as is proved here in the Fuchsluken Cave near Saalfeld. In many cases the porcupines used hyena dens and recycled their accumulated bone rubbish.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124208331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-09-10DOI: 10.2174/1874425700801010024
Curtis R. Congreve, B. Lieberman
Cladistic parsimony analysis of the trilobite family Homalonotidae Chapman 1980 produced a hypothesis of re- latedness for the group. The family consists of three monophyletic subfamilies, one containing Trimerus Green 1832, Platycoryphe Foerste 1919, and Brongniartella Reed 1918; one containing Plaesiacomia Hawle and Corda 1847 and Col- pocoryphe Novak in Perer 1918; and one containing Eohomalonotus Reed 1918 and Calymenella Bergeron 1890. All genera are monophyletic, except Brongniartella, which is paraphyletic; as it was originally defined it "gives rise" to Trimerus and Platycoryphe. A modified Brooks Parsimony Analysis using the phylogentic hypothesis illuminates patterns of biogeography, in particu- lar, vicariance and geodispersal of homalonotids, during the late Ordovician. The analysis yields three major conclusions about homalonotid biogeography: homalonotids originated in Gondwana; Avalonia and Laurentia were close enough dur- ing the late Ordovician to exchange taxa, especially when sea level rose sufficiently; and long distance dispersal events occurred between Armorica and Florida, and also between Arabia and a joined Laurentia-Avalonia.
{"title":"Phylogenetic and Biogeographic Analysis of Ordovician Homalonotid Trilobites","authors":"Curtis R. Congreve, B. Lieberman","doi":"10.2174/1874425700801010024","DOIUrl":"https://doi.org/10.2174/1874425700801010024","url":null,"abstract":"Cladistic parsimony analysis of the trilobite family Homalonotidae Chapman 1980 produced a hypothesis of re- latedness for the group. The family consists of three monophyletic subfamilies, one containing Trimerus Green 1832, Platycoryphe Foerste 1919, and Brongniartella Reed 1918; one containing Plaesiacomia Hawle and Corda 1847 and Col- pocoryphe Novak in Perer 1918; and one containing Eohomalonotus Reed 1918 and Calymenella Bergeron 1890. All genera are monophyletic, except Brongniartella, which is paraphyletic; as it was originally defined it \"gives rise\" to Trimerus and Platycoryphe. A modified Brooks Parsimony Analysis using the phylogentic hypothesis illuminates patterns of biogeography, in particu- lar, vicariance and geodispersal of homalonotids, during the late Ordovician. The analysis yields three major conclusions about homalonotid biogeography: homalonotids originated in Gondwana; Avalonia and Laurentia were close enough dur- ing the late Ordovician to exchange taxa, especially when sea level rose sufficiently; and long distance dispersal events occurred between Armorica and Florida, and also between Arabia and a joined Laurentia-Avalonia.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125198316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-08-28DOI: 10.2174/1874425700801010018
M. Yamasaki, M. Matsui, C. Shimada, S. Chiyonobu, Tokiyuki Sato
We made shell size measurements of the planktic foraminifer Neogloboquadrina pachyderma (sinistral) using samples from IODP Site U1304, the North Atlantic. We found that mean and maximum shell sizes began to increase around 1.1 Ma, and that several episodic changes in test size occurred during 0.6 - 0.35 Ma. Test size reached a maximum during the late Quaternary. Based on correlation with previous investigations, we have confirmed that these changes in fo- raminiferal shell size occurred on an inter-ocean scale.
{"title":"Timing of Shell Size Increase and Decrease of the Planktic Foraminifer Neogloboquadrina pachyderma (Sinistral) During the Pleistocene, IODP Exp. 303 Site U1304, the North Atlantic Ocean","authors":"M. Yamasaki, M. Matsui, C. Shimada, S. Chiyonobu, Tokiyuki Sato","doi":"10.2174/1874425700801010018","DOIUrl":"https://doi.org/10.2174/1874425700801010018","url":null,"abstract":"We made shell size measurements of the planktic foraminifer Neogloboquadrina pachyderma (sinistral) using samples from IODP Site U1304, the North Atlantic. We found that mean and maximum shell sizes began to increase around 1.1 Ma, and that several episodic changes in test size occurred during 0.6 - 0.35 Ma. Test size reached a maximum during the late Quaternary. Based on correlation with previous investigations, we have confirmed that these changes in fo- raminiferal shell size occurred on an inter-ocean scale.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122799598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-08-01DOI: 10.2174/1874425700801010007
R. Poore
Marine records from the northern Gulf of Mexico indicate that significant multidecadaland century-scale variability was common during the Holocene. Mean annual sea-surface temperature (SST) during the last 1,400 years may have varied by 3C, and excursions to cold SST coincide with reductions in solar output. Broad trends in Holocene terrestrial climate and environmental change along the eastern portion of the northern Gulf Coast are evident from existing pollen records, but the high-frequency details of climate variability are not well known. Continuous and well-dated records of climate change and climate variability in the western portion of the northern Gulf Coast are essentially lacking. Information on Holocene floods, droughts, and storm frequency along the northern Gulf Coast is limited. Records of floods may be preserved in continental shelf sediments, but establishing continuity and chronologies for sedimentary sequences on the shelf presents challenges due to sediment remobilization and redeposition during storms. Studies of past storm deposits in coastal lakes and marshes show promise for constructing records of past storm frequency. A recent summary of sea-level history of the northern Gulf Coast indicates sea level was higher than modern sea level several times during the last few thousand years.
{"title":"Holocene Climate and Climate Variability of the Northern Gulf of Mexico and Adjacent Northern Gulf Coast: A Review","authors":"R. Poore","doi":"10.2174/1874425700801010007","DOIUrl":"https://doi.org/10.2174/1874425700801010007","url":null,"abstract":"Marine records from the northern Gulf of Mexico indicate that significant multidecadaland century-scale variability was common during the Holocene. Mean annual sea-surface temperature (SST) during the last 1,400 years may have varied by 3C, and excursions to cold SST coincide with reductions in solar output. Broad trends in Holocene terrestrial climate and environmental change along the eastern portion of the northern Gulf Coast are evident from existing pollen records, but the high-frequency details of climate variability are not well known. Continuous and well-dated records of climate change and climate variability in the western portion of the northern Gulf Coast are essentially lacking. Information on Holocene floods, droughts, and storm frequency along the northern Gulf Coast is limited. Records of floods may be preserved in continental shelf sediments, but establishing continuity and chronologies for sedimentary sequences on the shelf presents challenges due to sediment remobilization and redeposition during storms. Studies of past storm deposits in coastal lakes and marshes show promise for constructing records of past storm frequency. A recent summary of sea-level history of the northern Gulf Coast indicates sea level was higher than modern sea level several times during the last few thousand years.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115398564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-03-11DOI: 10.2174/1874425700801010001
Hanako Domitsu, M. Oda
Using an age model based on magnetostratigraphic and tephrostratigraphic control points, we assigned ages to two planktic foraminiferal events from the Pleistocene sequence in the northwest Pacific: the first occurrence of Neogloboquadrina pachyderma at 1.25 ± 0.04 Ma and the last occurrence of Neogloboquadrina inglei at 0.73 ± 0.05 Ma.
{"title":"Pleistocene Planktic Foraminiferal Events in the Northwest Pacific Near Japan","authors":"Hanako Domitsu, M. Oda","doi":"10.2174/1874425700801010001","DOIUrl":"https://doi.org/10.2174/1874425700801010001","url":null,"abstract":"Using an age model based on magnetostratigraphic and tephrostratigraphic control points, we assigned ages to two planktic foraminiferal events from the Pleistocene sequence in the northwest Pacific: the first occurrence of Neogloboquadrina pachyderma at 1.25 ± 0.04 Ma and the last occurrence of Neogloboquadrina inglei at 0.73 ± 0.05 Ma.","PeriodicalId":448881,"journal":{"name":"The Open Paleontology Journal","volume":"PP 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114108120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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