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Emma Sheldon - One of the best experts on this subject based on the ideXlab platform.
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identification and characterisation of the oligocene miocene boundary base neogene in the eastern north sea basin based on dinocyst stratigraphy micropalaeontology and δ13c isotope data
Palaeogeography Palaeoclimatology Palaeoecology, 2012Co-Authors: Karen Dybkjær, Chris King, Emma SheldonAbstract:Abstract For the first time a combined palynological and δ13C-isotope study has identified the Oligocene–Miocene boundary — and thus the base of the Neogene — within the North Sea Basin. The type section, the Lemme–Carrosio section in northern Italy, is correlated with the Frida-1 well in the eastern (Danish) part of the North Sea Basin using a combination of data from a previous dinocyst stratigraphic study and new δ13C-isotope data. The results show that the Oligocene–Miocene boundary is located at a depth of 1440 m in the Frida-1 well. The Frida-1 δ13C-isotope curve further reflects the Mi-1 glaciation event also recorded in the Lemme–Carrosio section. The dinocyst events bracketing the boundary in Frida-1 are; the last occurrence (LO) of Distatodinium biffii at 1630 m, below the boundary, the LO of Chiropteridium spp. at 1370 m and first occurrence (FO) of Ectosphaeropsis burdigalensis at 1330 m, both above the boundary. An influx of Deflandrea phosphoritica is found in an interval immediately below the boundary (1532–1490 m), while the genus Homotryblium occurs abundantly in a broader interval (1650–1330 m) encompassing the boundary. Hitherto unpublished data combined with new data provide a series of stratigraphically important nanno- and micropalaeontological events that frame/characterise the Oligocene–Miocene boundary within the North Sea Basin; an almost monospecific assemblage of Reticulofenestra bisecta at 1630 m, the LO of Elphidium subnodosum at 1625 m, the LO of Aulacodiscus insignis quadrata (Diatom sp. 3 of King, 1983) at 1610 m, the LO of Karreriella seigliei at 1580 m and the LO of Pararotalia canui at 1570 m, all below the boundary, and the FO of Aulacodiscus aemulans (Diatom sp. 5 of King, 1983) at 1410 m and the LO of Aulacodiscus aemulans at 1250 m, both above the boundary. The dinocyst, nanno- and micropalaeontological studies thus provide a series of bioevents and abundance variations which can be used to locate and to correlate the Oligocene–Miocene boundary within the eastern North Sea Basin more precisely than was previously possible.
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Identification and characterisation of the Oligocene–Miocene boundary (base Neogene) in the eastern North Sea Basin — based on dinocyst stratigraphy, micropalaeontology and δ13C-isotope data
Palaeogeography Palaeoclimatology Palaeoecology, 2012Co-Authors: Karen Dybkjær, Chris King, Emma SheldonAbstract:Abstract For the first time a combined palynological and δ13C-isotope study has identified the Oligocene–Miocene boundary — and thus the base of the Neogene — within the North Sea Basin. The type section, the Lemme–Carrosio section in northern Italy, is correlated with the Frida-1 well in the eastern (Danish) part of the North Sea Basin using a combination of data from a previous dinocyst stratigraphic study and new δ13C-isotope data. The results show that the Oligocene–Miocene boundary is located at a depth of 1440 m in the Frida-1 well. The Frida-1 δ13C-isotope curve further reflects the Mi-1 glaciation event also recorded in the Lemme–Carrosio section. The dinocyst events bracketing the boundary in Frida-1 are; the last occurrence (LO) of Distatodinium biffii at 1630 m, below the boundary, the LO of Chiropteridium spp. at 1370 m and first occurrence (FO) of Ectosphaeropsis burdigalensis at 1330 m, both above the boundary. An influx of Deflandrea phosphoritica is found in an interval immediately below the boundary (1532–1490 m), while the genus Homotryblium occurs abundantly in a broader interval (1650–1330 m) encompassing the boundary. Hitherto unpublished data combined with new data provide a series of stratigraphically important nanno- and micropalaeontological events that frame/characterise the Oligocene–Miocene boundary within the North Sea Basin; an almost monospecific assemblage of Reticulofenestra bisecta at 1630 m, the LO of Elphidium subnodosum at 1625 m, the LO of Aulacodiscus insignis quadrata (Diatom sp. 3 of King, 1983) at 1610 m, the LO of Karreriella seigliei at 1580 m and the LO of Pararotalia canui at 1570 m, all below the boundary, and the FO of Aulacodiscus aemulans (Diatom sp. 5 of King, 1983) at 1410 m and the LO of Aulacodiscus aemulans at 1250 m, both above the boundary. The dinocyst, nanno- and micropalaeontological studies thus provide a series of bioevents and abundance variations which can be used to locate and to correlate the Oligocene–Miocene boundary within the eastern North Sea Basin more precisely than was previously possible.
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Microfossil biostratigraphy of the Palaeogene succession in the Davis Strait, offshore West Greenland
Marine and Petroleum Geology, 2003Co-Authors: Jan A. Rasmussen, Emma SheldonAbstract:Abstract A new microfossil based biostratigraphy of the Paleocene and Lower Eocene sediments of the Hellefisk-1, Ikermiut-1, Kangâmiut-1, Nukik-1, and Nukik-2 boreholes offshore West Greenland has been established. In general, the five boreholes contain fairly well-preserved, diverse microfossil faunas and floras consisting mainly of foraminifera, radiolaria, ostracods and diatoms. The studied interval was subdivided into three foraminiferid biostratigraphic intervals, in ascending stratigraphic order, the Stensioeina beccariiformis , Praeglobobulimina ovata and Pseudohastigerina wilcoxensis intervals and five biostratigraphic intervals based on additional microfossil groups (the Thalassiosiropsis wittiana , Fenestrella antiqua–Coscinodiscus morsianus , Ostracod, Aulacodiscus hirtus and Cenodiscus–Cenosphaera intervals). The intervals are more easily recognised in the two basinal boreholes, Ikermiut-1 and Kangâmiut-1, than in the three more nearshore boreholes, Nukik-1, Nukik-2 and Hellefisk-1, due to a higher microfossil diversity and abundance.
Victor A Gallardo - One of the best experts on this subject based on the ideXlab platform.
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first report of a surf zone diatom accumulation in the eastern south pacific Aulacodiscus kittonii arnott ex ralfs bacillariophyta as the dominant and exclusive species
Gayana Botanica, 2016Co-Authors: Patricio Rivera, Fabiola Cruces, Victor A GallardoAbstract:Las diatomeas de la zona de rompiente de las olas constituyen un grupo reducido de especies que producen acumulaciones masivas sobre playas arenosas con fuerte oleaje, a menudo como unicas dominantes de la comunidad. Se unen a las burbujas generadas por el oleaje y forman masas flotantes de color marron o verde, de forma irregular, las que luego con la marea se depositan sobre la playa formando franjas largas. En mayo de 2015 una de estas acumulaciones, de color verde, fue detectada en la Bahia de Coquimbo. El analisis de las muestras mediante microscopia optica y electronica de barrido demostro la presencia de la diatomea Aulacodiscus kittonii, un taxon muy conocido por participar en este tipo de eventos. Este es el primer registro para Chile y para el Pacifico Sur Oriental, evento en el cual A. kittonii fue la especie dominante, como tambien el primer registro para Chile de A. kittonii como una especie viviente. Se entrega una descripcion de los especimenes chilenos y se comenta e ilustra la variabilidad de algunas de sus caracteristicas morfologicas.
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first report of a surf zone diatom accumulation in the eastern south pacific Aulacodiscus kittonii arnott ex ralfs bacillariophyta as the dominant and exclusive species primera cita de una acumulacion de diatomeas de la zona de rompiente de las olas
2016Co-Authors: Patricio Rivera, Fabiola Cruces, Victor A GallardoAbstract:ABSTRACT The so-called “surf diatoms” constitute a small group of species that are present with great abundance in the surf zones of some sandy beaches where often the accumulations are dominated only for one of these species. They adhere to air bubbles generated by wave action forming green or brown patches that float in the surf zone, remaining as long streaks on the beach. In May 2015 a green accumulation was detected in Coquimbo Bay in northern Chile. The study of samples with light and electron microscopy techniques showed the presence of Aulacodiscus kittonii , a well-known surf diatom. This is the first report of this kind for Chile and for the whole coast of the Eastern South Pacific Ocean with A. kittonii as the dominant species. It is also the first report for Chile as a living taxon. A description of the Chilean specimens is given with comments and photographs on the variation of some of its morphological features. K EYWORDS : Surf diatoms, sandy beaches, diatom bloom, morphology, Chile.
Karen Dybkjær - One of the best experts on this subject based on the ideXlab platform.
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identification and characterisation of the oligocene miocene boundary base neogene in the eastern north sea basin based on dinocyst stratigraphy micropalaeontology and δ13c isotope data
Palaeogeography Palaeoclimatology Palaeoecology, 2012Co-Authors: Karen Dybkjær, Chris King, Emma SheldonAbstract:Abstract For the first time a combined palynological and δ13C-isotope study has identified the Oligocene–Miocene boundary — and thus the base of the Neogene — within the North Sea Basin. The type section, the Lemme–Carrosio section in northern Italy, is correlated with the Frida-1 well in the eastern (Danish) part of the North Sea Basin using a combination of data from a previous dinocyst stratigraphic study and new δ13C-isotope data. The results show that the Oligocene–Miocene boundary is located at a depth of 1440 m in the Frida-1 well. The Frida-1 δ13C-isotope curve further reflects the Mi-1 glaciation event also recorded in the Lemme–Carrosio section. The dinocyst events bracketing the boundary in Frida-1 are; the last occurrence (LO) of Distatodinium biffii at 1630 m, below the boundary, the LO of Chiropteridium spp. at 1370 m and first occurrence (FO) of Ectosphaeropsis burdigalensis at 1330 m, both above the boundary. An influx of Deflandrea phosphoritica is found in an interval immediately below the boundary (1532–1490 m), while the genus Homotryblium occurs abundantly in a broader interval (1650–1330 m) encompassing the boundary. Hitherto unpublished data combined with new data provide a series of stratigraphically important nanno- and micropalaeontological events that frame/characterise the Oligocene–Miocene boundary within the North Sea Basin; an almost monospecific assemblage of Reticulofenestra bisecta at 1630 m, the LO of Elphidium subnodosum at 1625 m, the LO of Aulacodiscus insignis quadrata (Diatom sp. 3 of King, 1983) at 1610 m, the LO of Karreriella seigliei at 1580 m and the LO of Pararotalia canui at 1570 m, all below the boundary, and the FO of Aulacodiscus aemulans (Diatom sp. 5 of King, 1983) at 1410 m and the LO of Aulacodiscus aemulans at 1250 m, both above the boundary. The dinocyst, nanno- and micropalaeontological studies thus provide a series of bioevents and abundance variations which can be used to locate and to correlate the Oligocene–Miocene boundary within the eastern North Sea Basin more precisely than was previously possible.
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Identification and characterisation of the Oligocene–Miocene boundary (base Neogene) in the eastern North Sea Basin — based on dinocyst stratigraphy, micropalaeontology and δ13C-isotope data
Palaeogeography Palaeoclimatology Palaeoecology, 2012Co-Authors: Karen Dybkjær, Chris King, Emma SheldonAbstract:Abstract For the first time a combined palynological and δ13C-isotope study has identified the Oligocene–Miocene boundary — and thus the base of the Neogene — within the North Sea Basin. The type section, the Lemme–Carrosio section in northern Italy, is correlated with the Frida-1 well in the eastern (Danish) part of the North Sea Basin using a combination of data from a previous dinocyst stratigraphic study and new δ13C-isotope data. The results show that the Oligocene–Miocene boundary is located at a depth of 1440 m in the Frida-1 well. The Frida-1 δ13C-isotope curve further reflects the Mi-1 glaciation event also recorded in the Lemme–Carrosio section. The dinocyst events bracketing the boundary in Frida-1 are; the last occurrence (LO) of Distatodinium biffii at 1630 m, below the boundary, the LO of Chiropteridium spp. at 1370 m and first occurrence (FO) of Ectosphaeropsis burdigalensis at 1330 m, both above the boundary. An influx of Deflandrea phosphoritica is found in an interval immediately below the boundary (1532–1490 m), while the genus Homotryblium occurs abundantly in a broader interval (1650–1330 m) encompassing the boundary. Hitherto unpublished data combined with new data provide a series of stratigraphically important nanno- and micropalaeontological events that frame/characterise the Oligocene–Miocene boundary within the North Sea Basin; an almost monospecific assemblage of Reticulofenestra bisecta at 1630 m, the LO of Elphidium subnodosum at 1625 m, the LO of Aulacodiscus insignis quadrata (Diatom sp. 3 of King, 1983) at 1610 m, the LO of Karreriella seigliei at 1580 m and the LO of Pararotalia canui at 1570 m, all below the boundary, and the FO of Aulacodiscus aemulans (Diatom sp. 5 of King, 1983) at 1410 m and the LO of Aulacodiscus aemulans at 1250 m, both above the boundary. The dinocyst, nanno- and micropalaeontological studies thus provide a series of bioevents and abundance variations which can be used to locate and to correlate the Oligocene–Miocene boundary within the eastern North Sea Basin more precisely than was previously possible.
Patricio Rivera - One of the best experts on this subject based on the ideXlab platform.
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first report of a surf zone diatom accumulation in the eastern south pacific Aulacodiscus kittonii arnott ex ralfs bacillariophyta as the dominant and exclusive species
Gayana Botanica, 2016Co-Authors: Patricio Rivera, Fabiola Cruces, Victor A GallardoAbstract:Las diatomeas de la zona de rompiente de las olas constituyen un grupo reducido de especies que producen acumulaciones masivas sobre playas arenosas con fuerte oleaje, a menudo como unicas dominantes de la comunidad. Se unen a las burbujas generadas por el oleaje y forman masas flotantes de color marron o verde, de forma irregular, las que luego con la marea se depositan sobre la playa formando franjas largas. En mayo de 2015 una de estas acumulaciones, de color verde, fue detectada en la Bahia de Coquimbo. El analisis de las muestras mediante microscopia optica y electronica de barrido demostro la presencia de la diatomea Aulacodiscus kittonii, un taxon muy conocido por participar en este tipo de eventos. Este es el primer registro para Chile y para el Pacifico Sur Oriental, evento en el cual A. kittonii fue la especie dominante, como tambien el primer registro para Chile de A. kittonii como una especie viviente. Se entrega una descripcion de los especimenes chilenos y se comenta e ilustra la variabilidad de algunas de sus caracteristicas morfologicas.
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first report of a surf zone diatom accumulation in the eastern south pacific Aulacodiscus kittonii arnott ex ralfs bacillariophyta as the dominant and exclusive species primera cita de una acumulacion de diatomeas de la zona de rompiente de las olas
2016Co-Authors: Patricio Rivera, Fabiola Cruces, Victor A GallardoAbstract:ABSTRACT The so-called “surf diatoms” constitute a small group of species that are present with great abundance in the surf zones of some sandy beaches where often the accumulations are dominated only for one of these species. They adhere to air bubbles generated by wave action forming green or brown patches that float in the surf zone, remaining as long streaks on the beach. In May 2015 a green accumulation was detected in Coquimbo Bay in northern Chile. The study of samples with light and electron microscopy techniques showed the presence of Aulacodiscus kittonii , a well-known surf diatom. This is the first report of this kind for Chile and for the whole coast of the Eastern South Pacific Ocean with A. kittonii as the dominant species. It is also the first report for Chile as a living taxon. A description of the Chilean specimens is given with comments and photographs on the variation of some of its morphological features. K EYWORDS : Surf diatoms, sandy beaches, diatom bloom, morphology, Chile.
Chris King - One of the best experts on this subject based on the ideXlab platform.
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identification and characterisation of the oligocene miocene boundary base neogene in the eastern north sea basin based on dinocyst stratigraphy micropalaeontology and δ13c isotope data
Palaeogeography Palaeoclimatology Palaeoecology, 2012Co-Authors: Karen Dybkjær, Chris King, Emma SheldonAbstract:Abstract For the first time a combined palynological and δ13C-isotope study has identified the Oligocene–Miocene boundary — and thus the base of the Neogene — within the North Sea Basin. The type section, the Lemme–Carrosio section in northern Italy, is correlated with the Frida-1 well in the eastern (Danish) part of the North Sea Basin using a combination of data from a previous dinocyst stratigraphic study and new δ13C-isotope data. The results show that the Oligocene–Miocene boundary is located at a depth of 1440 m in the Frida-1 well. The Frida-1 δ13C-isotope curve further reflects the Mi-1 glaciation event also recorded in the Lemme–Carrosio section. The dinocyst events bracketing the boundary in Frida-1 are; the last occurrence (LO) of Distatodinium biffii at 1630 m, below the boundary, the LO of Chiropteridium spp. at 1370 m and first occurrence (FO) of Ectosphaeropsis burdigalensis at 1330 m, both above the boundary. An influx of Deflandrea phosphoritica is found in an interval immediately below the boundary (1532–1490 m), while the genus Homotryblium occurs abundantly in a broader interval (1650–1330 m) encompassing the boundary. Hitherto unpublished data combined with new data provide a series of stratigraphically important nanno- and micropalaeontological events that frame/characterise the Oligocene–Miocene boundary within the North Sea Basin; an almost monospecific assemblage of Reticulofenestra bisecta at 1630 m, the LO of Elphidium subnodosum at 1625 m, the LO of Aulacodiscus insignis quadrata (Diatom sp. 3 of King, 1983) at 1610 m, the LO of Karreriella seigliei at 1580 m and the LO of Pararotalia canui at 1570 m, all below the boundary, and the FO of Aulacodiscus aemulans (Diatom sp. 5 of King, 1983) at 1410 m and the LO of Aulacodiscus aemulans at 1250 m, both above the boundary. The dinocyst, nanno- and micropalaeontological studies thus provide a series of bioevents and abundance variations which can be used to locate and to correlate the Oligocene–Miocene boundary within the eastern North Sea Basin more precisely than was previously possible.
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Identification and characterisation of the Oligocene–Miocene boundary (base Neogene) in the eastern North Sea Basin — based on dinocyst stratigraphy, micropalaeontology and δ13C-isotope data
Palaeogeography Palaeoclimatology Palaeoecology, 2012Co-Authors: Karen Dybkjær, Chris King, Emma SheldonAbstract:Abstract For the first time a combined palynological and δ13C-isotope study has identified the Oligocene–Miocene boundary — and thus the base of the Neogene — within the North Sea Basin. The type section, the Lemme–Carrosio section in northern Italy, is correlated with the Frida-1 well in the eastern (Danish) part of the North Sea Basin using a combination of data from a previous dinocyst stratigraphic study and new δ13C-isotope data. The results show that the Oligocene–Miocene boundary is located at a depth of 1440 m in the Frida-1 well. The Frida-1 δ13C-isotope curve further reflects the Mi-1 glaciation event also recorded in the Lemme–Carrosio section. The dinocyst events bracketing the boundary in Frida-1 are; the last occurrence (LO) of Distatodinium biffii at 1630 m, below the boundary, the LO of Chiropteridium spp. at 1370 m and first occurrence (FO) of Ectosphaeropsis burdigalensis at 1330 m, both above the boundary. An influx of Deflandrea phosphoritica is found in an interval immediately below the boundary (1532–1490 m), while the genus Homotryblium occurs abundantly in a broader interval (1650–1330 m) encompassing the boundary. Hitherto unpublished data combined with new data provide a series of stratigraphically important nanno- and micropalaeontological events that frame/characterise the Oligocene–Miocene boundary within the North Sea Basin; an almost monospecific assemblage of Reticulofenestra bisecta at 1630 m, the LO of Elphidium subnodosum at 1625 m, the LO of Aulacodiscus insignis quadrata (Diatom sp. 3 of King, 1983) at 1610 m, the LO of Karreriella seigliei at 1580 m and the LO of Pararotalia canui at 1570 m, all below the boundary, and the FO of Aulacodiscus aemulans (Diatom sp. 5 of King, 1983) at 1410 m and the LO of Aulacodiscus aemulans at 1250 m, both above the boundary. The dinocyst, nanno- and micropalaeontological studies thus provide a series of bioevents and abundance variations which can be used to locate and to correlate the Oligocene–Miocene boundary within the eastern North Sea Basin more precisely than was previously possible.
