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Kathleen A. Campbell - One of the best experts on this subject based on the ideXlab platform.
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lucinid bivalves from miocene Hydrocarbon Seep sites of eastern north island new zealand with comments on miocene new zealand Seep faunas
Acta Palaeontologica Polonica, 2018Co-Authors: Kazutaka Amano, Crispin T. S. Little, Kathleen A. CampbellAbstract:Three new fossil species of lucinids, Meganodontia haunuiensis, Elliptiolucina neozelandica, and Lucinoma saetheri, are described from lower to middle Miocene Hydrocarbon Seep carbonates from north and south of Hawke Bay, eastern North Island, New Zealand. Of these taxa Meganodontia haunuiensis is confined to Seep sites south of Hawke Bay, while Elliptiolucina neozelandica comes only from the Seep sites north of Hawke Bay. Using ecological information from modern bivalve species, we suggest the southern area Seep sites formed in shallower waters than the northern sites. Among the lucinids, Meganodontia haunuiensis is one of the oldest records of the genus, and its distribution has shrunk from worldwide in the Miocene times to only around Taiwan today. Elliptiolucina neozelandica is the second oldest species in the genus. Since the Miocene the distribution of Elliptiolucina has narrowed but its habitat range has increased to both Seeps and sandy environments, mainly around the Philippines.
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systematics and palaeoecology of a new fossil limpet patellogastropoda pectinodontidae from miocene Hydrocarbon Seep deposits east coast basin north island new zealand with an overview of known fossil Seep pectinodontids
2012Co-Authors: Kristian P Saether, Bruce A Marshall, Crispin T. S. Little, Kathleen A. CampbellAbstract:‘Serradonta’ kimberleyae n. sp. is described from Miocene-age Hydrocarbon Seep deposits in northern Hawke’s Bay, North Island, New Zealand. Pectinodontid limpets from fossil and modern hydrothermal vents and Hydrocarbon Seeps are reviewed and shell morphological distinctions are outlined between the two pectinodontid genera known from Seeps: Bathyacmaea and Serradonta. It is suggested that the diagnosis of Bathyacmaea be emended to be more consistent with the shell morphology of the species currently included in it. The shell microstructure of ‘Serradonta’ kimberleyae is similar to that of modern pectinodontid shells from the Hikurangi margin Seeps, which may be congeneric. The palaeoecology of the new Miocene species is found to be similar to other fossil vent–Seep patellogastropods, as well as species of Pectinodontidae that inhabit these environments today.
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fossil vesicomyid bivalves from miocene Hydrocarbon Seep sites north island new zealand
Acta Palaeontologica Polonica, 2012Co-Authors: Kazutaka Amano, Kristian P Saether, Crispin T. S. Little, Kathleen A. CampbellAbstract:Two fossil species of vesicomyids are described from Lower to Middle Miocene Hydrocarbon Seep carbonates in eastern North Island, New Zealand. One elongate species is proposed as a new genus and species: Notocalyptogena neozelandica. The other species probably belongs to the genus Pliocardia, but due to poor preservation is not identified further. The composition of this Miocene vesicomyid Seep fauna differs from that found in modern New Zealand Seeps located on the offshore Hikurangi convergent margin, which contain the genera Calyptogena, Archivesica, and Isorropodon. The fossil fauna went extinct locally after the Middle Miocene and has been since replaced by the modern vesicomyid taxa.
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a new fossil provannid gastropod from miocene Hydrocarbon Seep deposits east coast basin north island new zealand
Acta Palaeontologica Polonica, 2010Co-Authors: Kristian P Saether, Crispin T. S. Little, Kathleen A. CampbellAbstract:Provanna marshalli sp. nov. is described from Early to Middle Miocene-age fossil Hydrocarbon Seep localities in the East Coast Basin, North Island, New Zealand, adding to 18 modern and three fossil species of the genus described. Modern species are well represented at hydrothermal vent sites as well as at Hydrocarbon Seeps and on other organic substrates in the deep sea, including sunken wood and whale falls. Described fossil Provanna species have been almost exclusively reported from Hydrocarbon Seep deposits, with a few reports of suspected fossil specimens of the genus from other chemosynthetic environments such as sunken wood and large vertebrate (whale and plesiosaurid) carcasses, and the oldest occurrences are dated to the Middle Cenomanian (early Late Cretaceous). The New Zealand fossil species is the most variable species of the genus described to date, and its shell microstructure is reported and found to be comparable to the fossil species Provanna antiqua and some modern species of the genus.
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new fossil mussels bivalvia mytilidae from miocene Hydrocarbon Seep deposits north island new zealand with general remarks on vent and Seep mussels
Zootaxa, 2010Co-Authors: Kristian P Saether, Bruce A Marshall, Crispin T. S. Little, Kathleen A. Campbell, Michael G Collins, Andrea C AlfaroAbstract:Bathymodiolus (sensu lato) heretaunga sp. nov. and Gigantidas coseli sp. nov. are described from Miocene-age Hydrocarbon Seep carbonates of North Island, New Zealand, adding to only four described fossil Hydrocarbon Seep mussel species. Both new species are small compared to their modern congeners, and it is suggested that an evolutionary trend toward gigantism occurred in vent and Seep mussels since the first known fossil species of the group appeared in the Middle Eocene. Bathymodiolus heretaunga is highly variable in morphology, potentially reflecting population variation over a wide geographic area. Gigantidas coseli is the first named species, fossil or modern, of its genus known from Hydrocarbon Seeps, although several closely related species in the same group, the Bathymodiolus childressi clade, have been reported from these environments.
Duofu Chen - One of the best experts on this subject based on the ideXlab platform.
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tracing fluid sources and formation conditions of miocene Hydrocarbon Seep carbonates in the central western foothills central taiwan
Journal of Asian Earth Sciences, 2017Co-Authors: Qinxian Wang, Duofu Chen, Hongpeng Tong, Chiyue HuangAbstract:Abstract Hydrocarbon-Seep carbonates were discovered to be hosted within Miocene marine mudstone in the central Western Foothills near the Kuohsing area, Central Taiwan. Here, we present field observations, petrography, mineralogy, stable carbon isotope data, as well as rare earth element compositions. We evaluate the role of diagenetic alteration on the Kuohsing Seep carbonates and constrain their fluid sources and formation conditions. Four main morphologies in the field were observed, including cylindrical columns, massive forms, lenticular nodules, and stratiform bodies. Petrographically, the carbonates are predominantly composed of partially recrystallized calcite and dolomite, with abundant amounts of biogenic detritus, pyrite aggregations and unidentified filaments. Isotopic analyses show that carbon isotope values inversely vary with oxygen isotope values, indicating substantial modification of the carbon isotope compositions of the carbonates by diagenetic processes. Extremely negative δ13C values as low as −47.6‰ recognized as a near-primary isotopic signature recorded in the carbonates, an end member of the trend, reveals that methane was incorporated during the carbonate precipitation. On the other hand, the carbonates have well preserved primary REE compositions, exhibiting MREE enrichment, no La and Ce anomalies, and supra-chondritic Y/Ho ratios. These REE patterns suggest that the Kuohsing authigenic carbonates were precipitated from reducing Seep fluids with limited admixture of seawater.
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in situ and on line measurement of gas flux at a Hydrocarbon Seep from the northern south china sea
Continental Shelf Research, 2014Co-Authors: Dong Feng, Duofu ChenAbstract:Natural Hydrocarbon Seeps in the marine environment are important sources of methane and other greenhouse gases to the ocean and the atmosphere. Accurate quantification of methane flux at Hydrocarbon Seeps is therefore necessary to evaluate their influence on the global methane budget and climate change. Hydrocarbon Seeps on the seabed produce a near-shore gas bubble zone along the shallow western coast of Hainan Island, northern South China Sea. An in-situ and on-line gas flux measuring device was deployed over a Hydrocarbon Seep to quantify the gas flux by equal volume exchange venting from the seabed offshore of Ledong Town, Hainan Island, over 19 days. The physiochemical parameters and the dissolved methane concentration of the bottom water at the Hydrocarbon Seep were also measured. The gas flux from the Hydrocarbon Seep varied from 22 to 771/day with the tidal period and was strongly negatively correlated with water depth. The flux data from the Seep suggests that the variation in hydrostatic pressure induced by tidal forcing and ocean swell may control the variation of the gas flux. The bottom water dissolved methane concentration, ranging from 26 to 74 nmol/L, was negatively correlated with temperature and water depth at the seabed and positively with the gas flux. The total gas volume released from the Hydrocarbon Seep was 30.5 m(3) for the 19-day period, providing an estimated gas flux of 600 m(3)/yr. The 120 known Hydrocarbon Seeps along the eastern edge of the Yinggehai Basin could vent a large quantity of methane from the seafloor, which suggests that Hydrocarbon Seeps on the continental margin of the northern South China Sea may be an important natural source of methane to the atmosphere. (C) 2014 Elsevier Ltd. All rights reserved.
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rare earth elements in Seep carbonates as tracers of variable redox conditions at ancient Hydrocarbon Seeps
Terra Nova, 2009Co-Authors: Dong Feng, Duofu Chen, Jörn PeckmannAbstract:Marine Hydrocarbon Seeps are dynamic systems, which are typically reflected in complex lithologies of limestones forming at these sites. In order to test if Seep limestones with their multiple generations of carbonate phases reflect variable redox conditions, the rare earth element (REE) patterns of limestones from five ancient Hydrocarbon-Seep localities, Hollard Mound (Middle Devonian), Iberg (Mississippian), Beauvoisin (Oxfordian), Canyon and Satsop River (Oligocene), and Marmorito (Miocene) have been investigated. The total REE contents vary widely (0.3‐43.7 p.p.m.). Early microcrystalline phases tend to show higher contents than spatially associated later phases (microspar, sparite, and blocky cement). The shale-normalized REE patterns of the carbonates show both negative and positive Ce anomalies even for individual deposits, suggesting that the redox conditions varied significantly. It is apparent that in addition to anoxic conditions, oxic conditions were common in some ancient Seep environments. Intermittent oxygenation is presumed to have resulted from abrupt changes in fluid flow.
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Seep carbonates and preserved methane oxidizing archaea and sulfate reducing bacteria fossils suggest recent gas venting on the seafloor in the northeastern south china sea
Marine and Petroleum Geology, 2005Co-Authors: Duofu Chen, Yong Yang Huang, Xunlai Yuan, Lawrence M CathlesAbstract:Seep carbonates, formed by the synergistic metabolism of methane oxidizing archaea (MOA) and sulfate reducing bacteria (SRB), have been found in many places worldwide but have not been found to date in the South China Sea. Mud volcanoes and shale diapirs have been reported in the South China Sea however, and microscope and geochernical analysis of carbonates dredged where bottom simulating reflectors (BSR) suggest the presence of gas hydrate on the northeastern continental slope of the South China Sea suggest that the carbonates are Hydrocarbon Seep-related carbonates. The carbonates we dredged are chimney-like and preserve MOA/SRB fossils. Their very light carbon isotopic compositions (- 51.25 to - 51.76 parts per thousand) suggest that their carbon was derived from microbial methane oxidization. These Seep carbonates and their preserved MOA/SRB fossils imply gas venting has occurred recently on the seafloor in the northeastern continental slopes in the South China Sea. (c) 2005 Elsevier Ltd. All rights reserved.
Crispin T. S. Little - One of the best experts on this subject based on the ideXlab platform.
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lucinid bivalves from miocene Hydrocarbon Seep sites of eastern north island new zealand with comments on miocene new zealand Seep faunas
Acta Palaeontologica Polonica, 2018Co-Authors: Kazutaka Amano, Crispin T. S. Little, Kathleen A. CampbellAbstract:Three new fossil species of lucinids, Meganodontia haunuiensis, Elliptiolucina neozelandica, and Lucinoma saetheri, are described from lower to middle Miocene Hydrocarbon Seep carbonates from north and south of Hawke Bay, eastern North Island, New Zealand. Of these taxa Meganodontia haunuiensis is confined to Seep sites south of Hawke Bay, while Elliptiolucina neozelandica comes only from the Seep sites north of Hawke Bay. Using ecological information from modern bivalve species, we suggest the southern area Seep sites formed in shallower waters than the northern sites. Among the lucinids, Meganodontia haunuiensis is one of the oldest records of the genus, and its distribution has shrunk from worldwide in the Miocene times to only around Taiwan today. Elliptiolucina neozelandica is the second oldest species in the genus. Since the Miocene the distribution of Elliptiolucina has narrowed but its habitat range has increased to both Seeps and sandy environments, mainly around the Philippines.
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late jurassic early cretaceous Hydrocarbon Seep boulders from novaya zemlya and their faunas
Palaeogeography Palaeoclimatology Palaeoecology, 2015Co-Authors: Crispin T. S. Little, Andrzej Kaim, Krzysztof Hryniewicz, Oyvind Hammer, Jonas Hagstrom, Hans Arne NakremAbstract:The paper describes Late Jurassic–Early Cretaceous Seep carbonate boulders from the Russian Arctic island of Novaya Zemlya, collected in 1875 by A.E. Nordenskiold during his expedition to Siberia. The carbonates are significantly depleted in heavy carbon isotopes (δ13C values as low as ca. − 40‰) and show textures typical for carbonates formed under the influence of Hydrocarbons, such as fibrous carbonate cements and corrosion cavities. The rocks contain index fossils of Late Oxfordian–Early Kimmeridgian, Late Tithonian (Jurassic) and latest Berriasian–Early Valanginian (Cretaceous) age. The fossil fauna is species rich and dominated by molluscs, with subordinate brachiopods, echinoderms, foraminifera, serpulids and ostracods. Most of the species, including two chemosymbiotic bivalve species, likely belong to the ‘background’ fauna. Only a species of a hokkaidoconchid gastropod, and a possible abyssochrysoid gastropod, can be interpreted as restricted to the Seep environment. Other Seep faunas with similar taxonomic structure are suggestive of rather shallow water settings, but in case of Novaya Zemlya Seep faunas such structure might result also from high northern latitude.
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the palaeoecology of the latest jurassic earliest cretaceous Hydrocarbon Seep carbonates from spitsbergen svalbard
Lethaia, 2015Co-Authors: Krzysztof Hryniewicz, Crispin T. S. Little, Michael R. Sandy, Hans Arne Nakrem, Andrzej Kaim, Oyvind Hammer, Jorn H HurumAbstract:Latest Jurassic–earliest Cretaceous Hydrocarbon Seeps from Spitsbergen, Svalbard, are known to contain unusual fauna, lacking most of the species characteristic for roughly coeval Seep deposits. This study summarizes and analyses the fauna from 16 Seep carbonate bodies from Spitsbergen to explain its composition. The Seeps formed in a shallow epicontinental sea with widespread deposition of fine-grained, organic-rich sediments. They are spread over a relatively large area and are positioned roughly in the same interval, indicating Seepage over extensive areas of the palaeo-Barents Sea. The Seep fauna is very species rich and with low dominance, comprising 54 species, with a composition similar to that of Jurassic–Cretaceous normal-marine environments of other Boreal seas. Seep-restricted fauna is not abundant and is represented by four species only. Hokkaidoconchids and possible siboglinid worm tubes characteristic for high sulphide fluxes are rare. Apart from Seep-restricted sulphide-mining lucinid and thyasirid bivalves, chemosymbiosis was also a source of nourishment for background solemyid and nucinellid bivalves, all of which take sulphide from infaunal sources. This all suggests a relatively weak sulphide flux. The high diversity and low dominance of the fauna and significant richness and abundance of background species is typical for shallow water Seeps.
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brachiopods from late jurassic early cretaceous Hydrocarbon Seep deposits central spitsbergen svalbard
Zootaxa, 2014Co-Authors: Michael R. Sandy, Hans Arne Nakrem, Krzysztof Hryniewicz, Oyvind Hammer, Crispin T. S. LittleAbstract:Late Jurassic–Early Cretaceous (Late Volgian–latest Ryazanian) rhynchonellate brachiopods are described from eight out of 15 Hydrocarbon Seep deposits in the Slottsmoya Member of the Agardhfjellet Formation in the Janusfjellet to Knorringfjellet area, central Spitsbergen, Svalbard. The fauna comprises rhynchonellides, terebratulides (terebratuloids and loboidothyridoids) and a terebratellidine. The rhynchonellides include: Pseudomonticlarella varia Smirnova; Ptilorhynchia mclachlani sp. nov.; and Ptilorhynchia obscuricostata Dagys. The terebratulides belong to the terebratuloids: Cyrtothyris? sp.; Cyrtothyris aff. cyrta (Walker); Praelongithyris? aff. borealis Owen; and the loboidothyridoids: Rouillieria cf. michalkowii (Fahrenkohl); Rouillieria aff. ovoides (Sowerby); Rouillieria aff. rasile Smirnova; Uralella? cf. janimaniensis Makridin; Uralella? sp.; Pinaxiothyris campestris? Dagys; Placothyris kegeli? Harper et al.; and Seductorithyris septemtrionalis gen. et sp. nov. The terebratellidine Zittelina? sp. is also present. Age determinations for all but one of the brachiopod-bearing Seeps are based on associated ammonites. Five of the Seep carbonates have yielded Lingularia similis?, and it is the only brachiopod species recorded from two of the Seeps. Other benthic invertebrate taxa occurring in the Seeps include bivalves, gastropods, echinoderms, sponges, and serpulid and non-serpulid worm tubes. The brachiopod fauna has a strong Boreal palaeobiogeographic signature. Collectively, the Spitsbergen Seep rhynchonellate brachiopods exhibit high species richness and low abundance (<100 specimens from 8 Seeps). This contrasts markedly with other Palaeozoic–Mesozoic brachiopod-dominated Seep limestones where brachiopods are of low diversity (typically monospecific) with a super-abundance of individuals. The shallow water environmental setting for the Spitsbergen Seeps supported a diverse shelf fauna, compared to enigmatic Palaeozoic–Mesozoic brachiopod-dominated Seeps.
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bivalves from the latest jurassic earliest cretaceous Hydrocarbon Seep carbonates from central spitsbergen svalbard
Zootaxa, 2014Co-Authors: Krzysztof Hryniewicz, Crispin T. S. Little, Hans Arne NakremAbstract:The bivalve fauna from the latest Jurassic–earliest Cretaceous Hydrocarbon Seep deposits from central Spitsbergen, Svalbard comprises at least 17 species, four of which belong to chemosymbiotic taxa often found at Seeps. These are the solemyid Solemya ( Petrasma ) cf. woodwardiana ; Nucinella svalbardensis sp. nov., which belongs to a group of large Nucinella species known from Seeps and deep water environments; the lucinid bivalve, Tehamatea rasmusseni sp. nov., included in a genus widely distributed in other Jurassic–Cretaceous Seeps; and Cretaxinus hurumi gen. et sp. nov., which is the oldest known thyasirid and is discussed in relation to other large Seep-restricted genera in this family. The remaining species in the fauna belong to ‘background’ genera known from coeval normal marine sediments, mostly from the Boreal area. These include the nuculid Dacromya chetaensis , two new malletiids ( Mesosaccella rogovi sp. nov. and M. toddi sp. nov.), the oxytomiid Oxytoma octavia , at least three Buchia species, at least two pectinids, including Camptonectes ( Costicamptonectes ) aff. milnelandensis and Camptonectes ( Camptochlamys ) clatrathus , the limid Pseudolimea arctica , the arcticid Pseudotrapezium aff. groenlandicum , and the pholadomyid Goniomya literata . The large number of ‘background’ species in the bivalve fauna is probably a reflection of the shallow-water setting of the Svalbard Seeps. This might also explain the lack of the Seep-restricted modiomorphid bivalve Caspiconcha from the fauna. With solemyids, Nucinella , lucinids and thyasirids, the latest Jurassic–earliest Cretaceous bivalve Seep fauna of Svalbard contains typical representatives of the Mesozoic bivalve Seep faunas, both long established and young evolutionary colonists.
Jörn Peckmann - One of the best experts on this subject based on the ideXlab platform.
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First report of the megathyridid (Terebratellidina) brachiopod Argyrotheca from a Hydrocarbon Seep deposit, middle Eocene Humptulips Formation, Washington State, USA
PalZ, 2021Co-Authors: James L. Goedert, Michael R. Sandy, Jörn PeckmannAbstract:A single terebratulide brachiopod valve found in a middle Eocene limestone deposit in the Humptulips Formation in western Washington State is the first record of a megathyridid brachiopod in a Hydrocarbon Seep deposit, the first fossil record of the genus Argyrotheca in western North America, and the northernmost record for Argyrotheca from the north-eastern Pacific Ocean.
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Mineral authigenesis within chemosynthetic microbial mats: Coated grain formation and phosphogenesis at a Cretaceous Hydrocarbon Seep, New Zealand
'Wiley', 2021Co-Authors: Jennifer Zwicker, Steffen Kiel, Daniel Smrzka, Florian Steindl, Michael E. Böttcher, Eugen Libowitzky, Jörn PeckmannAbstract:Abstract Marine Hydrocarbon Seeps are sites of chemosynthetic microbial activity and authigenic carbonate formation. Seep limestones are typified by a range of geochemical signatures of microbial Hydrocarbon oxidation, but only few Seep deposits reveal mesofabrics that can be regarded as evidence of microbial activity. A Cretaceous methane‐Seep limestone from Waipiro Bay, New Zealand, exhibits a fabric composed of cryptocrystalline carbonate fluorapatite between carbonate coated grains and spheroidal calcite. To understand the unusual Waipiro deposit, a paragenetic sequence has been derived for coated grains, spheroidal calcite and carbonate fluorapatite using thin section petrography, scanning electron microscopy, Fourier‐transform infrared spectroscopy and stable isotope geochemistry. The formation of 13C‐depleted coated grains (δ13C values as low as −15.8‰ Vienna‐Pee Dee Belemnite) and spheroidal calcite (δ13C values as low as −21.3‰) was favoured by Hydrocarbon oxidation. Fibrous banded and botryoidal cement, a typical early diagenetic phase of Hydrocarbon‐Seep deposits, features δ13C values as low as −22.9‰. Coated grains and spheroidal calcite grew by displacive growth in a gel‐like medium, probably a microbial mat. Phosphorus is a mobile element and marine pore waters are typically undersaturated with respect to carbonate fluorapatite. Specific conditions are consequently required to retain sufficient concentrations to precipitate carbonate fluorapatite. Possible sources of phosphorus for the formation of the 13C‐depleted Waipiro carbonate fluorapatite (mean δ13C value of −15.4‰) include (a) the oxidation of sedimentary organic matter by organoclastic sulphate reduction, (b) the degradation of the microbial mat itself and (c) the active release of polyphosphate by sulphide‐oxidizing bacteria. This study suggests that the formation of the Cretaceous Waipiro Seep limestone involved an interplay of biogeochemical processes including sulphate‐driven anaerobic oxidation of methane, organoclastic sulphate reduction and possibly nitrate‐dependent sulphide oxidation. It further demonstrates that coated grains resembling oncoids are not restricted to shallow water, photosynthesis‐dependent ecosystems
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the early cretaceous brachiopod peregrinella from tibet a confirmed Hydrocarbon Seep occurrence for a Seep restricted genus
PalZ, 2016Co-Authors: Michael R. Sandy, Jörn PeckmannAbstract:An occurrence of the dimerelloid brachiopod Peregrinella from northern Tibet is confirmed as associated with a Hydrocarbon-Seep deposit based on petrographic textures and microfabrics, 13C-depleted authigenic carbonate phases, and paleontology. This is the first confirmed association of a rhynchonellide brachiopod with a Mesozoic Seep paleoenvironment located outside of Europe and North America. In addition, we consider aspects of the taxonomy of Peregrinella: (a) several species names have been proposed for specimens of Peregrinella from northern Tibet, but these species may all be referable to P. cheboensis Sun, 1986, the senior subjective synonym; (b) the subgenus Peregrinellina was previously erected based on specimens of Peregrinella from southern Tibet. The subgenus is considered a junior subjective synonym of Peregrinella.
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rare earth elements in Seep carbonates as tracers of variable redox conditions at ancient Hydrocarbon Seeps
Terra Nova, 2009Co-Authors: Dong Feng, Duofu Chen, Jörn PeckmannAbstract:Marine Hydrocarbon Seeps are dynamic systems, which are typically reflected in complex lithologies of limestones forming at these sites. In order to test if Seep limestones with their multiple generations of carbonate phases reflect variable redox conditions, the rare earth element (REE) patterns of limestones from five ancient Hydrocarbon-Seep localities, Hollard Mound (Middle Devonian), Iberg (Mississippian), Beauvoisin (Oxfordian), Canyon and Satsop River (Oligocene), and Marmorito (Miocene) have been investigated. The total REE contents vary widely (0.3‐43.7 p.p.m.). Early microcrystalline phases tend to show higher contents than spatially associated later phases (microspar, sparite, and blocky cement). The shale-normalized REE patterns of the carbonates show both negative and positive Ce anomalies even for individual deposits, suggesting that the redox conditions varied significantly. It is apparent that in addition to anoxic conditions, oxic conditions were common in some ancient Seep environments. Intermittent oxygenation is presumed to have resulted from abrupt changes in fluid flow.
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paleoecology and evolutionary significance of an early cretaceous peregrinella dominated Hydrocarbon Seep deposit on the crimean peninsula
PALAIOS, 2008Co-Authors: Steffen Kiel, Jörn PeckmannAbstract:An isolated limestone deposit preserving thousands of specimens of the dimerelloid brachiopod Peregrinella multicarinala is exposed in fossil-poor Hauterivian strata northwest of the town of Planerskoje on the Crimean Peninsula in southern Ukraine. The limestone consists of micrite that encloses abundant detrital components, mostly brachiopod shell fragments, and also contains authigenic, framboidal pyrite. Cavities are rare; a few have been filled by a sequence of anhedral yellow calcite, seam micrite, banded and botryoidal cement, and equant calcite spar. The limestone preserves a diverse mollusk fauna of low abundance, including modiomorphid, lucinid, and buchiid bivalves and abyssochrysoid, ampullinid, and neritid gastropods. The negative delta(13)C values of the micrite (as low as -13.6 parts per thousand) and the character of the associated mollusk fauna indicate that this limestone formed at an ancient Hydrocarbon Seep. This evidence supports the earlier interpretation of Peregrinella as a Seep-restricted brachiopod. The new Ukrainian records of some of the mollusk taxa-notably Caspiconcha and Paskentana-significantly extend the geographic range of these apparently Seep-restricted mollusks, suggesting that mollusks at Early Cretaceous Seeps had a wider geographical distribution than previously appreciated.
Ira Leifer - One of the best experts on this subject based on the ideXlab platform.
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long term atmospheric emissions for the coal oil point natural marine Hydrocarbon Seep field offshore california
Atmospheric Chemistry and Physics, 2021Co-Authors: Ira Leifer, Christopher Melton, D R BlakeAbstract:Abstract. In this study, we present a novel approach for assessing nearshore Seepage atmospheric emissions through modeling of air quality station data, specifically, a Gaussian plume inversion model. Three decades of air quality station meteorology and total Hydrocarbon concentration, THC, data were analysed to study emissions from the Coal Oil Point marine Seep field offshore California. THC in the Seep field directions was significantly elevated and Gaussian with respect to wind direction, θ. An inversion model of the Seep field anomaly, THC’(θ), derived atmospheric emissions. The model inversion is for the far field, which was satisfied by gridding the sonar Seepage and treating each grid cell as a separate Gaussian plume. This assumption was validated by offshore in situ offshore data that showed major Seep area plumes were Gaussian. Plume air sample THC was 85 % methane, CH4, and 20 % carbon dioxide, CO2, similar to seabed composition, demonstrating efficient vertical plume transport of dissolved Seep gases. Air samples also measured atmospheric alkane plume composition. The inversion model used observed winds and derived the three-decade-average (1990–2021) field-wide atmospheric emissions of 83,500 ± 12,000 m3 THC day−1. Based on a 50:50 air to seawater partitioning, this implies seabed emissions of 167,000 m3 THC dy−1. Based on atmospheric plume composition, C1-C6 alkane emissions were 19, 1.3, 2.5, 2.2, 1.1, and 0.15 Gg yr−1, respectively. The approach can be extended to derive emissions from other dispersed sources such as landfills, industrial sites, or terrestrial Seepage if source locations are constrained spatially.
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Geologic control of natural marine Hydrocarbon Seep emissions, Coal Oil Point Seep field, California
Geo-Marine Letters, 2010Co-Authors: Ira Leifer, Marc J. Kamerling, Bruce P. Luyendyk, Douglas S. WilsonAbstract:High-resolution sonar surveys, and a detailed subsurface model constructed from 3D seismic and well data allowed investigation of the relationship between the subsurface geology and gas-phase (methane) Seepage for the Coal Oil Point (COP) Seep field, one of the world’s largest and best-studied marine oil and gas Seep fields, located over a producing Hydrocarbon reservoir near Santa Barbara, California. In general, the relationship between terrestrial gas Seepage, migration pathways, and Hydrocarbon reservoirs has been difficult to assess, in part because the detection and mapping of gas Seepage is problematic. For marine Seepage, sonar surveys are an effective tool for mapping Seep gas bubbles, and thus spatial distributions. Seepage in the COP Seep field occurs in an east–west-trending zone about 3–4 km offshore, and in another zone about 1–2 km from shore. The farthest offshore Seeps are mostly located near the crest of a major fold, and also along the trend of major faults. Significantly, because faults observed to cut the fold do not account for all the observed Seepage, Seepage must occur through fracture and joint systems that are difficult to detect, including intersecting faults and fault damage zones. Inshore Seeps are concentrated within the hanging wall of a major reverse fault. The subsurface model lacks the resolution to identify specific structural sources in that area. Although to first order the spatial distribution of Seeps generally is related to the major structures, other factors must also control their distribution. The region is known to be critically stressed, which would enhance hydraulic conductivity of favorably oriented faults, joints, and bedding planes. We propose that this process explains much of the remaining spatial distribution.
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beach tar accumulation transport mechanisms and sources of variability at coal oil point california
Marine Pollution Bulletin, 2007Co-Authors: Tonya S Del Sontro, Ira Leifer, Bruce P. Luyendyk, Bernardo R BroitmanAbstract:A new field method for tar quantification was used at Coal Oil Point (COP), California to study the mechanisms transporting oil/tar from the nearby COP natural marine Hydrocarbon Seep field. This method segregates tar pieces into six size classes and assigns them an average mass based on laboratory or direct field measurements. Tar accumulation on the 19,927 m 2 survey area was well resolved spatially by recording tar mass along twelve transects segmented into 4-m 2 blocks and then integrating over the survey area. A seasonal trend was apparent in total tar in which summer accumulations were an order of magnitude higher than winter accumulations. Based on multiple regression analyses between environmental data and tar accumulation, 34% of tar variability is explained by a combination of onshore advection via wind and low swell height inhibiting slick dispersion. � 2007 Elsevier Ltd. All rights reserved.
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the acoustic signature of marine Seep bubbles
Journal of the Acoustical Society of America, 2007Co-Authors: Ira Leifer, Dajun TangAbstract:Observations of seabed bubbles (62m depth) at a natural marine Hydrocarbon Seep by passive acoustic and optical approaches are compared. The acoustic and optical methods observed a bimodal distribution with peaks at 1500 and 1750Hz, and 2200 and 2800μm radius, respectively. Radii were ~20% lower than predicted by the Minnaert formula. Frequency shifts were observed for bubbles emitted within a few milliseconds and were attributed to coupling between nearby bubbles. Surfactants also may have played a role.
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natural marine Seepage blowout contribution to atmospheric methane
Global Biogeochemical Cycles, 2006Co-Authors: Ira Leifer, Bruce P. Luyendyk, Jim Boles, Jordan F ClarkAbstract:The release of methane sequestered within deep-sea methane hydrates is postulated as a mechanism for abrupt climate change; however, whether emitted seabed methane reaches the atmosphere is debatable. We observed methane emissions for a blowout from a shallow (22 m) Hydrocarbon Seep. The emission from the blowout was determined from atmospheric plume measurements. Simulations suggest a 1.1% gas loss to dissolution compared to ∼ 10% loss for a typical low-flux bubble plume. Transfer to the atmosphere primarily was enhanced by the rapid upwelling flows induced by the massive discharge. This mechanism could allow methane suddenly released from deeper (>250 m) waters to contribute significantly to atmospheric methane budgets. Copyright 2006 by the American Geophysical Union.