Pennsylvanian (Namurian and Westphalian) miospore assemblages from the west coast of Scotland

McLean, Donald; Owens, Bernard; Pendleton, Janine L.; Bodman, David J.

doi:10.1016/j.revpalbo.2012.11.005

Cited by 4 publications

(3 citation statements)

References 24 publications

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“…We placed a caveat on the selection of the fossil with the highest coverage. Fossil prepollen of Potonieisporites D.C.Bhardwaj, a monosaccate type that was produced by walchian conifers, is known from at least as early as the Langsettian (Upper Carboniferous >313–314 Ma) from Scotland [43] while macrofossils of the walchian conifer Hermitia Kerp and Clement-Westerhof are known from at least as early as the Asturian ( = Westphalian D, 308–306 Ma) of the Netherlands [44] . Extant conifer families have fossil records extending from the Triassic [45] , [46] providing an expectation on the ‘upper’ distribution of reasonable S i values.…”

Section: Methodsmentioning

confidence: 99%

Evolutionary Diversification of New Caledonian Araucaria

et al. 2014

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New Caledonia is a global biodiversity hotspot. Hypotheses for its biotic richness suggest either that the island is a ‘museum’ for an old Gondwana biota or alternatively it has developed following relatively recent long distance dispersal and in situ radiation. The conifer genus Araucaria (Araucariaceae) comprises 19 species globally with 13 endemic to this island. With a typically Gondwanan distribution, Araucaria is particularly well suited to testing alternative biogeographic hypotheses concerning the origins of New Caledonian biota. We derived phylogenetic estimates using 11 plastid and rDNA ITS2 sequence data for a complete sampling of Araucaria (including multiple accessions of each of the 13 New Caledonian Araucaria species). In addition, we developed a dataset comprising 4 plastid regions for a wider taxon sample to facilitate fossil based molecular dating. Following statistical analyses to identify a credible and internally consistent set of fossil constraints, divergence times estimated using a Bayesian relaxed clock approach were contrasted with geological scenarios to explore the biogeographic history of Araucaria. The phylogenetic data resolve relationships within Araucariaceae and among the main lineages in Araucaria, but provide limited resolution within the monophyletic New Caledonian species group. Divergence time estimates suggest a Late Cretaceous-Cenozoic radiation of extant Araucaria and a Neogene radiation of the New Caledonian lineage. A molecular timescale for the evolution of Araucariaceae supports a relatively recent radiation, and suggests that earlier (pre-Cenozoic) fossil types assigned to Araucaria may have affinities elsewhere in Araucariaceae. While additional data will be required to adequately resolve relationships among the New Caledonian species, their recent origin is consistent with overwater dispersal following Eocene emersion of New Caledonia but is too old to support a single dispersal from Australia to Norfolk Island for the radiation of the Pacific Araucaria sect. Eutacta clade.

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Section: Methodsmentioning

confidence: 99%

Evolutionary Diversification of New Caledonian Araucaria

et al. 2014

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“…15; Love & Neves 1963). Here 90-150 m of Westphalian aged sedimentary rocks consisting of sandstones, sandy shales and conglomerates are preserved, along with more organic rich horizons which include coal lenticles, impure fireclay and a thin (1-2 cm thick) coal seam (Love & Neves, 1963;Johnstone & Mykura, 1989;Cleal & Thomas, 1996;McLean et al, 2013). This outcrop is spatially limited (~5 km 2 ) due to faulting and unconformities, but its existence confirms the presence of Carboniferous rocks, including organic rich horizons, in the northwest of Scotland (Love & Neves, 1963).…”

Section: Carboniferousmentioning

confidence: 99%

Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore NW Scotland

Fyfe

Schofield

Holford

et al. 2021

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The Sea of Hebrides Basin and Minch Basin are late Palaeozoic-Mesozoic rift basins located to the northwest of the Scottish mainland. The basins were the target of small-scale petroleum exploration from the late 1960s to the early 1990s, with a total of three wells drilled within the two basins between 1989 and 1991. Although no commercially viable petroleum discoveries were made, numerous petroleum shows were identified within both basins, including a gas show within the Upper Glen 1 well in Lower Jurassic limestones. Organic rich shales have been identified throughout the Jurassic succession within the Sea of Hebrides Basin, with one Middle Jurassic (Bajocian-Bathonian) shale exhibiting a Total Organic Carbon content of up to 15 wt%. The focus of this study is to review the historic petroleum exploration within these basins, and to evaluate whether the conclusions drawn in the early 1990s of a lack of prospectivity remains the case. This was undertaken by analysis of seismic reflection data, gravity and aeromagnetic data and sedimentological data, from both onshore and offshore wells, boreholes and previously published studies. The key findings from our study suggest that there is a low probability of commercially sized petroleum accumulations within either the Sea of Hebrides Basin or the Minch Basin. Ineffective source rocks, likely due to low maturities (due to lack of burial) and the fact that the encountered Jurassic and Permian-Triassic reservoirs are of poor quality (low porosity and permeability) has led to our interpretation of future exploration being high risk, with any potential accumulations being small in size. While petroleum accumulations are unlikely within the basin, applying the knowledge obtained from the study could provide additional datasets and insight into petroleum exploration on other northeast Atlantic margin basins, such as the Rockall Trough and the Faroe-Shetland Basin.

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“…O primeiro constitui gênero de grão de pólen monossacado, conhecido em estratos pennsilvanianos (di Pasquo, 1999) e permianos (Bharadwaj, 1962;Stephenson, 2008) do Gondwana. Já o gênero de esporo Spackmanites parece ser restrito a estratos pennsilvanianos euroamericanos (Habib, 1966;Ravn, 1986;McLean et al, 2013). Contudo, nenhum aprofundamento taxonômico foi possível principalmente em razão de tratar-se de apenas um espécime de cada um destes táxons.…”

Section: Palinologia E Biostratigrafiaunclassified

Palinomorfos e associações de fácies da Formação Lagoa Azul (Grupo Itararé, Pennsilvaniano da Bacia do Paraná) no sudeste do Estado do Paraná, Brasil

Kipper

Souza

Vesely³

2017

Pesq Geoc

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No sudeste do Estado do Paraná, o Grupo Itararé assenta-se por meio de discordância angular sobre o substrato pré-glacial, que é composto de unidades precambrianas a devonianas, cada vez mais velhas para o sudeste. Devido a esta configuração estratigráfica, tem-se interpretado que os estratos aflorantes na região de Porto Amazonas representam os níveis mais inferiores do Grupo Itararé, enquanto aqueles da região de Campo do Tenente, localizados mais ao sul da área, representam seções mais jovens. Este artigo apresenta o resultado da análise palinológica e faciológica realizada em sete afloramentos da porção basal do Grupo Itararé (Formação Lagoa Azul), nas regiões de Porto Amazonas, Lapa e Campo do Tenente, visando ao posicionamento palinoestratigráfico. Nove fácies sedimentares foram identificadas compondo, na maior parte, depósitos de transporte de massa e turbiditos, acumulados em ambiente marinho relativamente profundo sob influência glacial. Associações palinológicas foram registradas em todas as três regiões, incluindo escassos elementos indígenas, compreendendo esporos e grãos de pólen monossacados, com grau de preservação variado. As características palinológicas gerais das associações e a presença de determinadas espécies de esporos e grãos de pólen sugerem posicionamento na Zona Ahrensisporites cristatus, correspondente à porção inferior do Grupo Itararé (Formação Lagoa Azul), de idade pennsilvaniana (Neobashkiriano a Kasimoviano). Os resultados obtidos confirmam a ocorrência de estratos glaciais da parte inferior do Grupo Itararé na faixa de afloramentos. Além disso, demonstram a importância do estudo dos processos de retrabalhamento e ressedimentação de palinofósseis pré-pennsilvanianos.

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Pennsylvanian (Namurian and Westphalian) miospore assemblages from the west coast of Scotland

Cited by 4 publications

References 24 publications

Evolutionary Diversification of New Caledonian Araucaria

Evolutionary Diversification of New Caledonian Araucaria

Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore NW Scotland

Palinomorfos e associações de fácies da Formação Lagoa Azul (Grupo Itararé, Pennsilvaniano da Bacia do Paraná) no sudeste do Estado do Paraná, Brasil

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