Small round holes, Oichnus Bromley, are a locally common feature of crinoid pluricolumnals in the Mississippian of the British Isles. Numerous examples have been found from mudrocks in the Brigantian (Mississippian) Blackhall Limestone, Lower Limestone Formation, at Trearne Quarry, near Beith, north Ayrshire, all assigned to Oichnus simplex Bromley. These trace fossils are typically associated with growth deformities of the pluricolumnals, which are commonly swollen and more rarely grew a lip around the pit. Oichnus simplex is commonly centred on a columnal latus and adjacent sutures between columnals are deflected towards it. More rarely, pits are centred on the sutures between columnals. The O. simplex borings are interpreted as domiciles developed in live crinoids by an indeterminate, unmineralized invertebrate. The pluricolumnals are similar and are presumed to be derived from a single species, perhaps the poteriocrinine cladid Ureocrinus bockshii (Geinitz), the only nominal crinoid recorded from this site.
{"title":"Site selection of small round holes in crinoid pluricolumnals, Trearne Quarry SSSI (Mississippian, Lower Carboniferous), north Ayrshire, UK","authors":"S. Donovan, Gary Hoare","doi":"10.1144/sjg2018-010","DOIUrl":"https://doi.org/10.1144/sjg2018-010","url":null,"abstract":"Small round holes, Oichnus Bromley, are a locally common feature of crinoid pluricolumnals in the Mississippian of the British Isles. Numerous examples have been found from mudrocks in the Brigantian (Mississippian) Blackhall Limestone, Lower Limestone Formation, at Trearne Quarry, near Beith, north Ayrshire, all assigned to Oichnus simplex Bromley. These trace fossils are typically associated with growth deformities of the pluricolumnals, which are commonly swollen and more rarely grew a lip around the pit. Oichnus simplex is commonly centred on a columnal latus and adjacent sutures between columnals are deflected towards it. More rarely, pits are centred on the sutures between columnals. The O. simplex borings are interpreted as domiciles developed in live crinoids by an indeterminate, unmineralized invertebrate. The pluricolumnals are similar and are presumed to be derived from a single species, perhaps the poteriocrinine cladid Ureocrinus bockshii (Geinitz), the only nominal crinoid recorded from this site.","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2018-010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48093441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Ballantrae Complex, SW Scotland, is an ophiolitic assemblage of mostly Early and early Middle Ordovician age (Tremadoc–Arenig in terms of the British Ordovician Series). Its varied components were generated and assembled in the Iapetus Ocean, then obducted on to the Laurentian continental margin by the earliest Llanvirn. The timing of obduction is constrained by biostratigraphic and radiometric data. It was most probably a polyphase process initiated at about the beginning of the Arenig, at around 478 Ma. However, parts of the Complex are significantly younger, with some recent evidence taken to suggest an earliest Llanvirn age of about 464 Ma for the emplacement of some of the volcanic and pelagic sedimentary rocks. The oldest strata in the succession that now unconformably overlies the Ballantrae Complex were deposited at about 463 Ma. Hence there may have been as little as one million years available for the final stages of the Complex's tectonic assembly, obduction, uplift, erosion and downfaulting. Obduction of the Complex has been invoked as a factor in the initiation of the Grampian Orogeny and, whilst there is a broad correlation in timing, the detail from Ballantrae militates against a causal relationship.
{"title":"On the age of the Ballantrae Complex, SW Scotland","authors":"P. Stone, A. Rushton","doi":"10.1144/sjg2017-012","DOIUrl":"https://doi.org/10.1144/sjg2017-012","url":null,"abstract":"The Ballantrae Complex, SW Scotland, is an ophiolitic assemblage of mostly Early and early Middle Ordovician age (Tremadoc–Arenig in terms of the British Ordovician Series). Its varied components were generated and assembled in the Iapetus Ocean, then obducted on to the Laurentian continental margin by the earliest Llanvirn. The timing of obduction is constrained by biostratigraphic and radiometric data. It was most probably a polyphase process initiated at about the beginning of the Arenig, at around 478 Ma. However, parts of the Complex are significantly younger, with some recent evidence taken to suggest an earliest Llanvirn age of about 464 Ma for the emplacement of some of the volcanic and pelagic sedimentary rocks. The oldest strata in the succession that now unconformably overlies the Ballantrae Complex were deposited at about 463 Ma. Hence there may have been as little as one million years available for the final stages of the Complex's tectonic assembly, obduction, uplift, erosion and downfaulting. Obduction of the Complex has been invoked as a factor in the initiation of the Grampian Orogeny and, whilst there is a broad correlation in timing, the detail from Ballantrae militates against a causal relationship.","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2017-012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42598495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Over recent years the authors have been co-authors on a number of papers re-describing acanthodian species from classic localities in the Devonian strata of Scotland and Canada. In a number of works the noting of syntypes of particular species has been mentioned, but the authors have neglected to designate a lectotype for some of these species. In this article we remedy this oversight.
{"title":"Allocation of Devonian acanthodian lectotypes","authors":"M. Newman, C. Burrow","doi":"10.1144/sjg2018-008","DOIUrl":"https://doi.org/10.1144/sjg2018-008","url":null,"abstract":"Over recent years the authors have been co-authors on a number of papers re-describing acanthodian species from classic localities in the Devonian strata of Scotland and Canada. In a number of works the noting of syntypes of particular species has been mentioned, but the authors have neglected to designate a lectotype for some of these species. In this article we remedy this oversight.","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2018-008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64033645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Lonfearn Member, Lealt Shale Formation, is a distinctive unit within the Great Estuarine Group in the Middle Jurassic of the Inner Hebrides, Scotland. Its dominant lithology of fine-grained, partly laminated mudstone marks it out as a time of minimum input of coarse clastic material into the Hebridean Basin, when consistent facies extended over some 90 km between north Skye and the Isle of Eigg. Interbedded with the mudstones are thin (decimetre) shelly and partly ferruginous and oolitic limestones, the combination giving a unique facies association in the British Bathonian. The predominantly low-salinity biota is dominated by the bivalve Neomiodon, ostracods and spinicaudatans. Episodes of inferred higher salinity aid in correlating sections from the type locality in North Trotternish, Skye to other localities, principally Strathaird in south Skye and the Isle of Eigg. We describe the principal outcrops of the Lonfearn Member and the remarkable facies continuity within the Great Estuarine Group indicating tectonic quiescence within the basin and hinterland at this time. Supplementary material: The detailed measured stratigraphical logs discussed in this paper are available at https://doi.org/10.6084/m9.figshare.c.4093991
{"title":"The Lonfearn Member, Lealt Shale Formation, (Middle Jurassic) of the Inner Hebrides, Scotland","authors":"J. D. Hudson, M. Wakefield","doi":"10.1144/sjg2017-015","DOIUrl":"https://doi.org/10.1144/sjg2017-015","url":null,"abstract":"The Lonfearn Member, Lealt Shale Formation, is a distinctive unit within the Great Estuarine Group in the Middle Jurassic of the Inner Hebrides, Scotland. Its dominant lithology of fine-grained, partly laminated mudstone marks it out as a time of minimum input of coarse clastic material into the Hebridean Basin, when consistent facies extended over some 90 km between north Skye and the Isle of Eigg. Interbedded with the mudstones are thin (decimetre) shelly and partly ferruginous and oolitic limestones, the combination giving a unique facies association in the British Bathonian. The predominantly low-salinity biota is dominated by the bivalve Neomiodon, ostracods and spinicaudatans. Episodes of inferred higher salinity aid in correlating sections from the type locality in North Trotternish, Skye to other localities, principally Strathaird in south Skye and the Isle of Eigg. We describe the principal outcrops of the Lonfearn Member and the remarkable facies continuity within the Great Estuarine Group indicating tectonic quiescence within the basin and hinterland at this time. Supplementary material: The detailed measured stratigraphical logs discussed in this paper are available at https://doi.org/10.6084/m9.figshare.c.4093991","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41742688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Givetian (Middle Devonian) antiarch Asterolepis thule was first described in 1932 and its stratigraphical horizon was poorly understood as were all the Devonian deposits in the SE of Shetland (South East Shetland Group). Since that time a greater understanding of the age of these deposits has been made. This, coupled with the greater clarity of the biostratigraphy of the Devonian of Scotland and its correlation with the Baltic Devonian, has allowed the species to be placed in a biostratigraphical zonation. The species is confined to Sumburgh Head and so appears endemic. Other species are also endemic and there are some relict fauna in the South East Shetland Group. This suggests that the South East Shetland Group fauna originated mostly in isolation to the main depositional areas of the Givetian in Scotland and elsewhere, although some species are more cosmopolitan.
{"title":"A redescription of the endemic antiarch placoderm Asterolepis thule from the Middle Devonian (Givetian) of Shetland and its biostratigraphical horizon","authors":"M. Newman, J. D. Den Blaauwen","doi":"10.1144/sjg2018-005","DOIUrl":"https://doi.org/10.1144/sjg2018-005","url":null,"abstract":"The Givetian (Middle Devonian) antiarch Asterolepis thule was first described in 1932 and its stratigraphical horizon was poorly understood as were all the Devonian deposits in the SE of Shetland (South East Shetland Group). Since that time a greater understanding of the age of these deposits has been made. This, coupled with the greater clarity of the biostratigraphy of the Devonian of Scotland and its correlation with the Baltic Devonian, has allowed the species to be placed in a biostratigraphical zonation. The species is confined to Sumburgh Head and so appears endemic. Other species are also endemic and there are some relict fauna in the South East Shetland Group. This suggests that the South East Shetland Group fauna originated mostly in isolation to the main depositional areas of the Givetian in Scotland and elsewhere, although some species are more cosmopolitan.","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2018-005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47268831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shelf basins (‘glacial incisions’) can preserve a detailed record of palaeoclimatic changes due to their low-energy environment. The ‘Muck Deep’, a complex of glacially-overdeepened troughs on the Inner Hebrides shelf constitutes an example of such an environment. Five sediment cores from the Muck Deep have been analysed and related to geomorphological evidence and subsurface seismic facies. The cores show an integrated sequence of sedimentary and faunal variations from the retreat of ice (c. 17 ka) to the present day. Glacimarine sandy muds with ice-rafted debris are dated to about 11.9 cal ka BP, supporting glacial occupancy in western Scotland until the latest stages of GS-1. The transition from a paraglacial to a more stable landscape is indicated by an erosional boundary in one of the cores dated between 11.3 and 11.6 cal ka BP. Sandy sediments in a core from 200 m water depth show two upward-fining cycles and a mid-core erosional unconformity, interpreted as bottom-current deposits. Such structures do not occur in the western Muck Deep, indicating different bottom current velocities through time. A regional signal of increasing current energy at the end of the Holocene marine transgression is interpreted as the onset of modern oceanographic conditions. Supplementary material: Extra figures and table content is available at https://doi.org/10.6084/m9.figshare.c.4093997
陆架盆地（“冰川切口”）由于其低能量环境，可以保存古气候变化的详细记录。“Muck Deep”是内赫布里底群岛大陆架上一个由冰川覆盖过度的槽组成的综合体，就是这种环境的一个例子。对Muck Deep的五个沉积物岩心进行了分析，并将其与地貌证据和地下地震相联系起来。岩心显示了一个完整的沉积和动物群变化序列，这些变化源于冰的消退（约17 ka）直到今天。含冰椽碎屑的灰岩砂质泥岩的年代约为11.9年 cal ka BP，支持苏格兰西部冰川的占用，直到GS-1的最新阶段。从副冰川到更稳定景观的过渡由11.3年至11.6年期间的一个岩芯中的侵蚀边界指示 cal ka BP。200岩芯中的砂质沉积物 m水深显示两个向上变细旋回和一个中芯侵蚀不整合，解释为底流沉积。这种结构没有出现在西部Muck Deep，表明随着时间的推移，底部洋流速度不同。全新世海侵结束时洋流能量增加的区域信号被解释为现代海洋学条件的开始。补充材料：额外的数字和表格内容可在https://doi.org/10.6084/m9.figshare.c.4093997
{"title":"Lateglacial to Holocene palaeoenvironmental change in the Muck Deep, offshore western Scotland","authors":"R. Arosio, J. Howe","doi":"10.1144/sjg2017-014","DOIUrl":"https://doi.org/10.1144/sjg2017-014","url":null,"abstract":"Shelf basins (‘glacial incisions’) can preserve a detailed record of palaeoclimatic changes due to their low-energy environment. The ‘Muck Deep’, a complex of glacially-overdeepened troughs on the Inner Hebrides shelf constitutes an example of such an environment. Five sediment cores from the Muck Deep have been analysed and related to geomorphological evidence and subsurface seismic facies. The cores show an integrated sequence of sedimentary and faunal variations from the retreat of ice (c. 17 ka) to the present day. Glacimarine sandy muds with ice-rafted debris are dated to about 11.9 cal ka BP, supporting glacial occupancy in western Scotland until the latest stages of GS-1. The transition from a paraglacial to a more stable landscape is indicated by an erosional boundary in one of the cores dated between 11.3 and 11.6 cal ka BP. Sandy sediments in a core from 200 m water depth show two upward-fining cycles and a mid-core erosional unconformity, interpreted as bottom-current deposits. Such structures do not occur in the western Muck Deep, indicating different bottom current velocities through time. A regional signal of increasing current energy at the end of the Holocene marine transgression is interpreted as the onset of modern oceanographic conditions. Supplementary material: Extra figures and table content is available at https://doi.org/10.6084/m9.figshare.c.4093997","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2017-014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48440494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Upper Devonian strata occur in the Central and Northern North Sea and crop out in coastal exposures in northeastern Scotland. The strata comprise continental sandstones and intercalated conglomerates, siltstones and mudstones. The offshore Upper Devonian unit (Buchan Formation) has been proven as a locally important hydrocarbon reservoir; however, the limited core coverage in the North Sea means that the architecture of the Buchan Formation is poorly understood. This study looks at two localities in Caithness and Orkney with excellent Upper Devonian exposures, which are chronologically equivalent to the Buchan Formation. The main aims are to describe the facies present and to investigate the mineralogical compositions and porosity variations using petrographic analyses. The results indicate that the studied outcrops were formed by braided fluvial and aeolian dune deposition. The aeolian sandstones have higher compositional/textural maturity and porosity than the fluvial sandstones. The main control on porosity is facies variation that results in differences in sedimentary structures, grain size and abundance of rock fragments. With similar palaeoclimate, depositional environments, lithologies and petrographies, these outcrops can be considered excellent analogues for the Buchan Formation reservoirs in the North Sea.
{"title":"Facies and petrographic assessment of Upper Devonian outcrops, Dunnet Head and Orkney, northern Scotland","authors":"Longxun Tang, S. Jones, J. Gluyas","doi":"10.1144/sjg2017-017","DOIUrl":"https://doi.org/10.1144/sjg2017-017","url":null,"abstract":"Upper Devonian strata occur in the Central and Northern North Sea and crop out in coastal exposures in northeastern Scotland. The strata comprise continental sandstones and intercalated conglomerates, siltstones and mudstones. The offshore Upper Devonian unit (Buchan Formation) has been proven as a locally important hydrocarbon reservoir; however, the limited core coverage in the North Sea means that the architecture of the Buchan Formation is poorly understood. This study looks at two localities in Caithness and Orkney with excellent Upper Devonian exposures, which are chronologically equivalent to the Buchan Formation. The main aims are to describe the facies present and to investigate the mineralogical compositions and porosity variations using petrographic analyses. The results indicate that the studied outcrops were formed by braided fluvial and aeolian dune deposition. The aeolian sandstones have higher compositional/textural maturity and porosity than the fluvial sandstones. The main control on porosity is facies variation that results in differences in sedimentary structures, grain size and abundance of rock fragments. With similar palaeoclimate, depositional environments, lithologies and petrographies, these outcrops can be considered excellent analogues for the Buchan Formation reservoirs in the North Sea.","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2017-017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42059091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three closely associated arthropleurid trackways, Diplichnites cuithensis, from the Lower Carboniferous of Fife, Scotland, exhibit signs of interaction between track-makers. An extra file of footprints is found on the downslope side of two trackways (A and C), the upslope side of another (B). These additional files of footprints suggest that either: each trackway resulted from two arthropleurids of different sizes walking in tandem, matching their footprints exactly on one side for some distance; or that one arthropleurid was partially mounted on the back of another producing the three parallel files. It is here argued that the latter is correct and that this represents evidence of mating behaviour in arthropleurids.
{"title":"Mating trackways of a fossil giant millipede","authors":"M. Whyte","doi":"10.1144/sjg2017-013","DOIUrl":"https://doi.org/10.1144/sjg2017-013","url":null,"abstract":"Three closely associated arthropleurid trackways, Diplichnites cuithensis, from the Lower Carboniferous of Fife, Scotland, exhibit signs of interaction between track-makers. An extra file of footprints is found on the downslope side of two trackways (A and C), the upslope side of another (B). These additional files of footprints suggest that either: each trackway resulted from two arthropleurids of different sizes walking in tandem, matching their footprints exactly on one side for some distance; or that one arthropleurid was partially mounted on the back of another producing the three parallel files. It is here argued that the latter is correct and that this represents evidence of mating behaviour in arthropleurids.","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2017-013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44567327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paige E. dePolo, S. Brusatte, T. Challands, D. Foffa, D. Ross, Mark Wilkinson, Hong-yu Yi
Middle Jurassic dinosaur fossils are exceedingly rare, but new discoveries from the Isle of Skye, Scotland, are beginning to fill this gap. We here describe a new dinosaur tracksite found in the Lealt Shale Formation (Bathonian) of the Great Estuarine Group at Rubha nam Brathairean (Brothers' Point) on Skye. The site preserves an abundance of small sauropod manus and pes prints and several isolated and broken medium-to-large tridactyl footprints. The main site occurs on a single horizon of shaley limestone that formed in a lagoonal environment. The sauropod tracks are tentatively assigned to the ichnotaxon Breviparopus due to the narrow gauge of the trackways, the digital characteristics of the pes, and the ratio of heteropody observed between the manus and the pes. A theropod trackmaker is inferred for some of the tridactyl impressions with several indicative of the ichnotaxon Eubrontes. This new site strengthens the inference, originally based on a previously discovered locality near Duntulm Castle (Duntulm Formation) in northern Skye, that sauropods habitually spent time in lagoons during the Middle Jurassic. Supplementary material: The photogrammetric model of track BP2_40 and associated metadata and photographs are available at https://doi.org/10.6084/m9.figshare.c.4046390
中侏罗世恐龙化石极为罕见，但苏格兰斯凯岛的新发现正开始填补这一空白。我们在这里描述了在斯凯岛ruha nam Brathairean (Brothers’Point)的Great estuary Group的Lealt页岩组(Bathonian)中发现的一个新的恐龙足迹。该遗址保存了大量小型蜥脚类恐龙的手印和足印，以及一些孤立的、破碎的中型到大型三趾类恐龙脚印。主要场地位于单一水平的泥质石灰岩上，形成于泻湖环境中。根据足迹的狭窄范围、足趾的数字特征以及手足与足趾之间异足的比例，初步将这些蜥脚类动物的足迹归属于短爪目。在一些三趾动物的足迹中推断出兽脚亚目足迹的痕迹，其中有几个表明了鱼分类单元的特征。这个新的遗址加强了先前的推断，该推断最初是基于先前在斯凯北部Duntulm城堡(Duntulm组)附近发现的地点，即中侏罗纪时期蜥脚类动物习惯在泻湖中生活。补充资料:轨道BP2_40的摄影测量模型以及相关的元数据和照片可在https://doi.org/10.6084/m9.figshare.c.4046390上获得
{"title":"A sauropod-dominated tracksite from Rubha nam Brathairean (Brothers’ Point), Isle of Skye, Scotland","authors":"Paige E. dePolo, S. Brusatte, T. Challands, D. Foffa, D. Ross, Mark Wilkinson, Hong-yu Yi","doi":"10.1144/sjg2017-016","DOIUrl":"https://doi.org/10.1144/sjg2017-016","url":null,"abstract":"Middle Jurassic dinosaur fossils are exceedingly rare, but new discoveries from the Isle of Skye, Scotland, are beginning to fill this gap. We here describe a new dinosaur tracksite found in the Lealt Shale Formation (Bathonian) of the Great Estuarine Group at Rubha nam Brathairean (Brothers' Point) on Skye. The site preserves an abundance of small sauropod manus and pes prints and several isolated and broken medium-to-large tridactyl footprints. The main site occurs on a single horizon of shaley limestone that formed in a lagoonal environment. The sauropod tracks are tentatively assigned to the ichnotaxon Breviparopus due to the narrow gauge of the trackways, the digital characteristics of the pes, and the ratio of heteropody observed between the manus and the pes. A theropod trackmaker is inferred for some of the tridactyl impressions with several indicative of the ichnotaxon Eubrontes. This new site strengthens the inference, originally based on a previously discovered locality near Duntulm Castle (Duntulm Formation) in northern Skye, that sauropods habitually spent time in lagoons during the Middle Jurassic. Supplementary material: The photogrammetric model of track BP2_40 and associated metadata and photographs are available at https://doi.org/10.6084/m9.figshare.c.4046390","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2017-016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41576847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Bullock, J. Parnell, Magali Perez, A. Boyce, J. Feldmann, J. Armstrong
Carboniferous coals of the Ayrshire Coalfield are enriched in selenium (Se) relative to average UK and world compositions, substituting for sulphur in pyrite. Greenburn surface mine coals are characterized by syngenetic concretionary pyrite (c. 15% total area), occurring as bedding-parallel banding, and later-formed (epigenetic) cross-cutting pyrite in cleats (c. 9% total area). In these, sulphur isotope compositions for both syngenetic and epigenetic pyrite include isotopically light and heavy variants, suggesting diagenetic and hydrothermal fluid formation. Late/post-Visean cleat-filling pyrite is enriched in Se (up to 266 ppm) compared to the earlier-formed material (Se up to 181 ppm). Anomalous Se may have been sourced from near-by sulphidic Dalradian metamorphic rocks. Initial Se sequestration is associated with syngenetic pyrite mineralization, absorbed from seawater and pore waters, with additional Se introduced from fluids mobilized during epigenetic pyrite formation. Cleats from local brittle fracturing provided channels for fluid flow and a locus for precipitation of comparatively high-Se pyrite. Permian dolerite intrusions may have provided an enrichment source and/or fluid distribution mechanism. The Se concentrations of the Greenburn coals relate to multi-stage mineralization, with cleat-filling pyrite showing the highest Se content, and highlight the potential for high Se in similarly altered and fractured coal deposits worldwide. Supplementary material: LA-ICP-MS maps for Fe, Se, Ag, As, Cu, Hg, Pb and Te for Greenburn coal samples from seams 9300 Lime and 6900 Burnfoot Bridge are available at https://doi.org/10.6084/m9.figshare.c.3967860
艾尔郡煤田石炭系煤相对于英国和世界的平均成分富含硒(Se)，取代了硫铁矿中的硫。绿本露天矿煤的特征为同生块状黄铁矿(约占总面积的15%)，呈顺层平行带状分布，后期形成的(后生的)横切黄铁矿在理块中形成(约占总面积的9%)。其中，同生和表生黄铁矿的硫同位素组成均有轻同位素和重同位素变化，提示成岩和热液流体形成。与早期形成的材料(硒含量高达181ppm)相比，晚期/后visean清晰充填的黄铁矿富含硒(高达266ppm)。异常硒可能来源于附近的硫化物变质岩。初始的硒固存与同生黄铁矿矿化有关，从海水和孔隙水中吸收硒，并从表生黄铁矿形成过程中动员的流体中引入额外的硒。局部脆性压裂产生的裂隙为流体流动提供了通道，并为相对高硒黄铁矿的沉淀提供了场所。二叠系白云岩侵入可能提供了富集源和/或流体分布机制。Greenburn煤的硒含量与多阶段成矿作用有关，其中以填空型黄铁矿的硒含量最高，突出了世界范围内类似蚀变和破碎型煤层的高硒潜力。补充材料:从煤层9300 Lime和6900 Burnfoot Bridge获取的Greenburn煤样品的Fe, Se, Ag, As, Cu, Hg, Pb和Te的LA-ICP-MS图可在https://doi.org/10.6084/m9.figshare.c.3967860上获得
{"title":"Multi-stage pyrite genesis and epigenetic selenium enrichment of Greenburn coals (East Ayrshire)","authors":"L. Bullock, J. Parnell, Magali Perez, A. Boyce, J. Feldmann, J. Armstrong","doi":"10.1144/sjg2017-010","DOIUrl":"https://doi.org/10.1144/sjg2017-010","url":null,"abstract":"Carboniferous coals of the Ayrshire Coalfield are enriched in selenium (Se) relative to average UK and world compositions, substituting for sulphur in pyrite. Greenburn surface mine coals are characterized by syngenetic concretionary pyrite (c. 15% total area), occurring as bedding-parallel banding, and later-formed (epigenetic) cross-cutting pyrite in cleats (c. 9% total area). In these, sulphur isotope compositions for both syngenetic and epigenetic pyrite include isotopically light and heavy variants, suggesting diagenetic and hydrothermal fluid formation. Late/post-Visean cleat-filling pyrite is enriched in Se (up to 266 ppm) compared to the earlier-formed material (Se up to 181 ppm). Anomalous Se may have been sourced from near-by sulphidic Dalradian metamorphic rocks. Initial Se sequestration is associated with syngenetic pyrite mineralization, absorbed from seawater and pore waters, with additional Se introduced from fluids mobilized during epigenetic pyrite formation. Cleats from local brittle fracturing provided channels for fluid flow and a locus for precipitation of comparatively high-Se pyrite. Permian dolerite intrusions may have provided an enrichment source and/or fluid distribution mechanism. The Se concentrations of the Greenburn coals relate to multi-stage mineralization, with cleat-filling pyrite showing the highest Se content, and highlight the potential for high Se in similarly altered and fractured coal deposits worldwide. Supplementary material: LA-ICP-MS maps for Fe, Se, Ag, As, Cu, Hg, Pb and Te for Greenburn coal samples from seams 9300 Lime and 6900 Burnfoot Bridge are available at https://doi.org/10.6084/m9.figshare.c.3967860","PeriodicalId":49556,"journal":{"name":"Scottish Journal of Geology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1144/sjg2017-010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47250113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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