Abstract:AbstractThis paper describes a buried, presumed pre-glacial, channel feature at Newcastle, 20km south-west of Dublin, which was discovered by drilling and geophysics in 1981. It is considered to be fluvial in origin with a possible karstic component. The eastern 2km of the buried channel contains a suite of varied channel sediments which may be of Cenozoic age. These sediment infills have been partly weathered under warm and humid conditions and also contain possibly reworked base metal mineralisation. It is envisaged that the channel may have discharged to the west into the Palæogene Portarlington Channel which drained the Thulean Dome situated to the north-east.
{"title":"The Buried Pre-Glacial Channel at Newcastle, Co. South Dublin","authors":"G. Jones, D. Drew","doi":"10.3318/IJES.2015.33.77","DOIUrl":"https://doi.org/10.3318/IJES.2015.33.77","url":null,"abstract":"Abstract:AbstractThis paper describes a buried, presumed pre-glacial, channel feature at Newcastle, 20km south-west of Dublin, which was discovered by drilling and geophysics in 1981. It is considered to be fluvial in origin with a possible karstic component. The eastern 2km of the buried channel contains a suite of varied channel sediments which may be of Cenozoic age. These sediment infills have been partly weathered under warm and humid conditions and also contain possibly reworked base metal mineralisation. It is envisaged that the channel may have discharged to the west into the Palæogene Portarlington Channel which drained the Thulean Dome situated to the north-east.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"33 1","pages":"4 - 77"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3318/IJES.2015.33.77","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45339773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:Articulation in erect bryozoans is known from the Ordovician to the Recent, and is developed in a number of Palaeozoic Orders. In the Order Cryptostomata, articulation is largely confined to some members of the Suborder Ptilodictyina and the Family Arthrostylidae of the Suborder Rhabdomesina, and was previous noted in the sole genus of the Family Bactroporidae. Articulation is reported herein in the Family Rhabdomesidae for the first time. The new genus Pharopora from the Mississippian of Ireland is characterised by zoaria composed of branches with regular internodes and conical-shaped articulating terminations.
{"title":"Articulation in the Family Rhabdomesidae (Cryptostomata: Bryozoa) from the Mississippian of Ireland","authors":"P. N. Wyse Jackson, A. Ernst, J. L. Suárez Andrés","doi":"10.3318/IJES.2017.35.35","DOIUrl":"https://doi.org/10.3318/IJES.2017.35.35","url":null,"abstract":"Abstract:Articulation in erect bryozoans is known from the Ordovician to the Recent, and is developed in a number of Palaeozoic Orders. In the Order Cryptostomata, articulation is largely confined to some members of the Suborder Ptilodictyina and the Family Arthrostylidae of the Suborder Rhabdomesina, and was previous noted in the sole genus of the Family Bactroporidae. Articulation is reported herein in the Family Rhabdomesidae for the first time. The new genus Pharopora from the Mississippian of Ireland is characterised by zoaria composed of branches with regular internodes and conical-shaped articulating terminations.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"35 1","pages":"35 - 44"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44797776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:A taxonomic illustrated review of the Late Cretaceous fossil birds known from the Argentine locality of El Brete (Salta Province, Patagonia, Argentina) is presented here for the first time. Although some of these specimens were first reported in the early 1980s, and then a handful more were presented in literature thoughout the 1990s, this important collection of fossil birds has largely remained undescribed since it was gathered 30 years ago. This is in spite of the fact that the El Brete collection provided the basis of C.A. Walker's insight that enantiornithine birds are anatomically—and phylogenetically—distinct from all other living and extinct avians. A catalogue of the known specimens from this site is also presented, and many elements are illustrated for the first time. We revise the anatomy of taxa from El Brete and provide complete lists of referred specimens, based on casts of the collection held in the Natural History Museum, London, and Walker's original manuscript. Six valid euenantiornithine birds are currently known from the El Brete locality—Enantiornis Walker 1981, Lectavis Chiappe 1993, Soroavisaurus Chiappe 1993, Yungavolucris Chiappe 1993, and Martinavis Walker et al. 2007—alongside a new taxon described and documented in this paper (Elbretornis). This new fossil euenantiornithine is remarkable because its humerus is highly pneumatised, more extensively than any other known Mesozoic fossil bird. The physiological and evolutionary implications of this bird and the other El Brete taxa are discussed.
{"title":"EUENANTIORNITHINE BIRDS FROM THE LATE CRETACEOUS OF EL BRETE (ARGENTINA)","authors":"C. A. Walker, G. Dyke","doi":"10.3318/IJES.2010.27.15","DOIUrl":"https://doi.org/10.3318/IJES.2010.27.15","url":null,"abstract":"Abstract:A taxonomic illustrated review of the Late Cretaceous fossil birds known from the Argentine locality of El Brete (Salta Province, Patagonia, Argentina) is presented here for the first time. Although some of these specimens were first reported in the early 1980s, and then a handful more were presented in literature thoughout the 1990s, this important collection of fossil birds has largely remained undescribed since it was gathered 30 years ago. This is in spite of the fact that the El Brete collection provided the basis of C.A. Walker's insight that enantiornithine birds are anatomically—and phylogenetically—distinct from all other living and extinct avians. A catalogue of the known specimens from this site is also presented, and many elements are illustrated for the first time. We revise the anatomy of taxa from El Brete and provide complete lists of referred specimens, based on casts of the collection held in the Natural History Museum, London, and Walker's original manuscript. Six valid euenantiornithine birds are currently known from the El Brete locality—Enantiornis Walker 1981, Lectavis Chiappe 1993, Soroavisaurus Chiappe 1993, Yungavolucris Chiappe 1993, and Martinavis Walker et al. 2007—alongside a new taxon described and documented in this paper (Elbretornis). This new fossil euenantiornithine is remarkable because its humerus is highly pneumatised, more extensively than any other known Mesozoic fossil bird. The physiological and evolutionary implications of this bird and the other El Brete taxa are discussed.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"27 1","pages":"15 - 62"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49560680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:New records of Solenodendron hibernicum are described from the Chadian of Counties Clare and Donegal, the oldest records of this genus in Ireland. (The term 'Chadian' is used herein rather than the 'Lower Viséan' preferred by some authors for this part of the Irish Visean succession.) Solenodendron is referred to the family Aulinidae Hill, 1981, which is elevated herein from subfamilial level. A continuous phylogeny of Solenodendron is proposed from the Courceyan to the Brigantian Substage.
{"title":"NEW RECORDS OF SOLENODENDRON (RUGOSA) IN IRELAND AND THEIR STRATIGRAPHIC AND PHYLOGENETIC SIGNIFICANCE","authors":"J. Nudds","doi":"10.3318/IJES.2013.31.2","DOIUrl":"https://doi.org/10.3318/IJES.2013.31.2","url":null,"abstract":"Abstract:New records of Solenodendron hibernicum are described from the Chadian of Counties Clare and Donegal, the oldest records of this genus in Ireland. (The term 'Chadian' is used herein rather than the 'Lower Viséan' preferred by some authors for this part of the Irish Visean succession.) Solenodendron is referred to the family Aulinidae Hill, 1981, which is elevated herein from subfamilial level. A continuous phylogeny of Solenodendron is proposed from the Courceyan to the Brigantian Substage.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"31 1","pages":"13 - 17"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47885148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:A mineral specimen was found in the National Museum of Ireland - Natural History (NMINH) that was catalogued as 'donegalite'. This is not a mineral name approved by the International Mineralogical Association's Commission on New Minerals, Nomenclature and Classification: it is an obsolete name. However, the name does not appear in the encyclopaedic Glossary of Obsolete Mineral Names (Bayliss 2000), a referenced list of about 30,000 discredited mineral names. Internet searches conducted up until 2017 on the mineral name ‘donegalite’ produced no substantive hits. The serendipitous find of an uncatalogued powder X-ray diffraction trace dating from 1983 in NMINH archives shows that ‘donegalite’ is the common mineral wollastonite. The name appears on a rare printed mineral label from Charles Robert Clarke Tichborne (~1838–1905), an English-born, Dublin-based analytical chemist. Tichborne appears to have coined the name for use in his private mineral collection, hence its extreme obscurity.
摘要：在爱尔兰国家自然历史博物馆（NMINH）发现了一个矿物标本，该标本被编目为“donegalite”。这不是国际矿物学协会新矿物、命名和分类委员会批准的矿物名称：这是一个过时的名称。然而，这个名字并没有出现在百科全书《废弃矿物名称词汇表》（Bayliss 2000）中，这是一个由大约30000个不可信的矿物名称组成的参考列表。直到2017年，对“donegalite”矿物名称进行的互联网搜索都没有产生实质性的点击。在NMINH档案中偶然发现了一个1983年的未编目粉末X射线衍射痕迹，表明“多奈加利特”是常见的硅灰石矿物。这个名字出现在查尔斯·罗伯特·克拉克·蒂奇伯恩（Charles Robert Clarke Tichborne，约1838–1905）罕见的印刷矿物标签上，他是一位出生于英国、都柏林的分析化学家。蒂奇伯恩似乎创造了这个名字，用于他的私人矿物收藏，因此它极为默默无闻。
{"title":"Donegalite: an exceptionally obscure synonym for wollastonite coined by Dublin-based chemist and mineral collector Charles R.C. Tichborne (~1838–1905)","authors":"P. Roycroft, Eileen J. Vard","doi":"10.3318/ijes.2019.37.3","DOIUrl":"https://doi.org/10.3318/ijes.2019.37.3","url":null,"abstract":"Abstract:A mineral specimen was found in the National Museum of Ireland - Natural History (NMINH) that was catalogued as 'donegalite'. This is not a mineral name approved by the International Mineralogical Association's Commission on New Minerals, Nomenclature and Classification: it is an obsolete name. However, the name does not appear in the encyclopaedic Glossary of Obsolete Mineral Names (Bayliss 2000), a referenced list of about 30,000 discredited mineral names. Internet searches conducted up until 2017 on the mineral name ‘donegalite’ produced no substantive hits. The serendipitous find of an uncatalogued powder X-ray diffraction trace dating from 1983 in NMINH archives shows that ‘donegalite’ is the common mineral wollastonite. The name appears on a rare printed mineral label from Charles Robert Clarke Tichborne (~1838–1905), an English-born, Dublin-based analytical chemist. Tichborne appears to have coined the name for use in his private mineral collection, hence its extreme obscurity.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"37 1","pages":"27 - 32"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45687709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Retirement of Professor Ian Sanders","authors":"M. Parkes","doi":"10.3318/ijes.2016.34.i","DOIUrl":"https://doi.org/10.3318/ijes.2016.34.i","url":null,"abstract":"","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"34 1","pages":"i - ii"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45808237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:AbstractThe Bulls Head Formation is the oldest lithostratigraphic formation in the 2.8km thick Dingle Group (Lower Old Red Sandstone) succession of the Dingle Peninsula. The formation mainly comprises thinly bedded, fine-grained purple-grey sandstones interlaminated with thin mudstone layers (Heterolithic Member) that were deposited in a very extensive shallow lake, here named ‘Lake Blasket’. The formation also includes two lake margin sheetflood systems (the Boat Cove and Trabane Members) that are only developed on the northern lake limit. The Bulls Head Formation has been previously assigned a late Silurian (late Ludlow-Pridoli) age. Two spore assemblages obtained from the Trabane Member are assigned to Z Interval Zone of the Breconisporites breconensis and Emphanisporites zavallatus BZ Oppel Zone, which indicates the upper part of the Bulls Head Formation is early Devonian (late Lockhovian) in age. In addition, a small disarticulated fish plate is recorded from the matrix of a mudclast conglomerate of the Trabane Member and this represents the first body fossil ever to be found in the Dingle Group. The plate is assignable to the Heterostraci group of jawless fish that were common in late Silurian and early Devonian times. A new palaeoenvironmental model for the Trabane Member proposes fluctuating lake levels and periodic fluvial sheetfloods with contemporaneous erosion.
{"title":"An early Devonian age for the Bulls Head Formation, Lower Old Red Sandstone, Dingle Peninsula","authors":"K. Higgs, J. Boyd, B. Williams","doi":"10.3318/IJES.2014.32.55","DOIUrl":"https://doi.org/10.3318/IJES.2014.32.55","url":null,"abstract":"Abstract:AbstractThe Bulls Head Formation is the oldest lithostratigraphic formation in the 2.8km thick Dingle Group (Lower Old Red Sandstone) succession of the Dingle Peninsula. The formation mainly comprises thinly bedded, fine-grained purple-grey sandstones interlaminated with thin mudstone layers (Heterolithic Member) that were deposited in a very extensive shallow lake, here named ‘Lake Blasket’. The formation also includes two lake margin sheetflood systems (the Boat Cove and Trabane Members) that are only developed on the northern lake limit. The Bulls Head Formation has been previously assigned a late Silurian (late Ludlow-Pridoli) age. Two spore assemblages obtained from the Trabane Member are assigned to Z Interval Zone of the Breconisporites breconensis and Emphanisporites zavallatus BZ Oppel Zone, which indicates the upper part of the Bulls Head Formation is early Devonian (late Lockhovian) in age. In addition, a small disarticulated fish plate is recorded from the matrix of a mudclast conglomerate of the Trabane Member and this represents the first body fossil ever to be found in the Dingle Group. The plate is assignable to the Heterostraci group of jawless fish that were common in late Silurian and early Devonian times. A new palaeoenvironmental model for the Trabane Member proposes fluctuating lake levels and periodic fluvial sheetfloods with contemporaneous erosion.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"32 1","pages":"50 - 70"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3318/IJES.2014.32.55","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42683421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:The Clifden district, illustrated with an accompanying new detailed 1:12,500 geological map and fold trace map, includes most of the stratigraphy of the Connemara Dalradian and is used to summarise present understanding of the older geological history of Connemara in the light of new structural work and recent age determinations. The Grampian metamorphism peaked with sillimanite formation during and after the late D2 syntectonic intrusions of metagabbros at 475–470Ma and the formation of the major D2 Derryclare fold which was then repeatedly folded by numerous major D3 folds synchronous with the injection in the south of the 467Ma Quartz diorite gneiss suite, maintaining the high-grade metamorphism. Late D3 saw the general initiation of cooling and uplift, the latter pronounced in eastern Connemara above and around the subterranean gathering of the Oughterard Granite magma, plus movement on the late D3 Renvyle-Bofin slide, generating an area of lower pressure metamorphism with cordierite and andalusite not found in the Clifden area.This was rapidly followed, or the ending was even partially overlapped, by D4 folding creating the Connemara Antiform and Synform and Joyces Antiform (and ‘the steep belt’) through which the later now exposed phases of the 462Ma Oughterard Granite intruded. Cooling continued up to and after the ~454 ± 4Ma Ordovician D5 Mannin Thrust brought the Dalradian rocks and their contained metagabbros and gneisses southwards onto the 474Ma metarhyolites of the Delaney Dome but the displacement on the thrust may have been small. The dome formed by a combination of the last D5 movements which folded the thrust producing the E-W D5 Mannin Antiform, which itself was later deformed by N-S D6 folds which passed into faults as the rocks became cooler and more brittle. The unusual N-S folding became possible because the Delaney Dome was not underlain by E-W striking Dalradian as everywhere else in Connemara. D6 complementary NE-SW sinistral and NW-SE dextral faults combined with reworked E-W D3 slides were late Ordovician to at least 438Ma, Telychian. D6 movements opened a basin in the eroded basement, which combined with the extraordinarily high sea-level after the late Ordovician (Hirnantian) glaciation ended, received Silurian sediments, sometimes during continued faulting. Sedimentation was abruptly terminated at the end of the Wenlock, by a short-lived but major~426Ma Scandian D7 folding of the Silurian rocks and the basement, tightening the Connemara and Joyces D4 folds (and possibly also the Mannin Antiform) which became composite structures. D7 finished before the long continued (from 425Ma) D8 sinistral transpression to sinistral transtension which accompanied the intrusions of the circular Omey (422–3Ma), Inish (423–4Ma) and Roundstone Granites (420 ± 4Ma) and the bulk of the following intrusions (~415–374Ma) of the Galway Granite batholith.
{"title":"The geology of the Clifden district, Connemara Co. Galway, Ireland and present understanding of Connemara geology","authors":"B. Leake","doi":"10.3318/ijes.2021.39.1","DOIUrl":"https://doi.org/10.3318/ijes.2021.39.1","url":null,"abstract":"Abstract:The Clifden district, illustrated with an accompanying new detailed 1:12,500 geological map and fold trace map, includes most of the stratigraphy of the Connemara Dalradian and is used to summarise present understanding of the older geological history of Connemara in the light of new structural work and recent age determinations. The Grampian metamorphism peaked with sillimanite formation during and after the late D2 syntectonic intrusions of metagabbros at 475–470Ma and the formation of the major D2 Derryclare fold which was then repeatedly folded by numerous major D3 folds synchronous with the injection in the south of the 467Ma Quartz diorite gneiss suite, maintaining the high-grade metamorphism. Late D3 saw the general initiation of cooling and uplift, the latter pronounced in eastern Connemara above and around the subterranean gathering of the Oughterard Granite magma, plus movement on the late D3 Renvyle-Bofin slide, generating an area of lower pressure metamorphism with cordierite and andalusite not found in the Clifden area.This was rapidly followed, or the ending was even partially overlapped, by D4 folding creating the Connemara Antiform and Synform and Joyces Antiform (and ‘the steep belt’) through which the later now exposed phases of the 462Ma Oughterard Granite intruded. Cooling continued up to and after the ~454 ± 4Ma Ordovician D5 Mannin Thrust brought the Dalradian rocks and their contained metagabbros and gneisses southwards onto the 474Ma metarhyolites of the Delaney Dome but the displacement on the thrust may have been small. The dome formed by a combination of the last D5 movements which folded the thrust producing the E-W D5 Mannin Antiform, which itself was later deformed by N-S D6 folds which passed into faults as the rocks became cooler and more brittle. The unusual N-S folding became possible because the Delaney Dome was not underlain by E-W striking Dalradian as everywhere else in Connemara. D6 complementary NE-SW sinistral and NW-SE dextral faults combined with reworked E-W D3 slides were late Ordovician to at least 438Ma, Telychian. D6 movements opened a basin in the eroded basement, which combined with the extraordinarily high sea-level after the late Ordovician (Hirnantian) glaciation ended, received Silurian sediments, sometimes during continued faulting. Sedimentation was abruptly terminated at the end of the Wenlock, by a short-lived but major~426Ma Scandian D7 folding of the Silurian rocks and the basement, tightening the Connemara and Joyces D4 folds (and possibly also the Mannin Antiform) which became composite structures. D7 finished before the long continued (from 425Ma) D8 sinistral transpression to sinistral transtension which accompanied the intrusions of the circular Omey (422–3Ma), Inish (423–4Ma) and Roundstone Granites (420 ± 4Ma) and the bulk of the following intrusions (~415–374Ma) of the Galway Granite batholith.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"39 1","pages":"1 - 28"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44028350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:The Louisburgh-Clare Island succession is a sequence of non-marine sedimentary rocks that forms one element of the complex geology along the Fair Head-Clew Bay Line in western Ireland. A first reliable age for the succession is provided by U-Pb dating of zircon from a tuff within the Strake Banded Formation by LA-ICP-MS, giving an age of 423 ± 4Ma (Silurian: Ludfordian or Pridoli). This age indicates that the Louisburgh-Clare Island succession is younger than the other Silurian successions in the west of Ireland. It also better places the succession in a geological history of terrane accretion and basin evolution along the southeast Laurentian margin. The Strake Banded Formation displays a post-Ludfordian cleavage whereas mainly brittle deformation is seen in early to mid-Devonian sedimentary basins along strike.
{"title":"A reliable age for the Louisburgh-Clare Island succession and its significance in the stabilisation of the Laurentian margin in Ireland","authors":"J. R. Graham, N. Riggs, B. McConnell","doi":"10.3318/ijes.2020.38.2","DOIUrl":"https://doi.org/10.3318/ijes.2020.38.2","url":null,"abstract":"Abstract:The Louisburgh-Clare Island succession is a sequence of non-marine sedimentary rocks that forms one element of the complex geology along the Fair Head-Clew Bay Line in western Ireland. A first reliable age for the succession is provided by U-Pb dating of zircon from a tuff within the Strake Banded Formation by LA-ICP-MS, giving an age of 423 ± 4Ma (Silurian: Ludfordian or Pridoli). This age indicates that the Louisburgh-Clare Island succession is younger than the other Silurian successions in the west of Ireland. It also better places the succession in a geological history of terrane accretion and basin evolution along the southeast Laurentian margin. The Strake Banded Formation displays a post-Ludfordian cleavage whereas mainly brittle deformation is seen in early to mid-Devonian sedimentary basins along strike.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"38 1","pages":"14 - 5"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46829006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract:Fossil marine reptile material is described from the restricted outcrops of Lower Jurassic strata exposed in Ireland. The remains consist of a single isolated fragment of rostrum from an ichthyosaur and two blocks of matrix that contain disarticulated and weathered plesiosaur vertebrae, rib fragments and a putative ilium. Although fragmentary and indeterminate, this material is a rare and significant occurrence of marine reptiles in Ireland and provides additional data on the distribution of ichthyosaurs and plesiosaurs in Europe during the Jurassic Period.
{"title":"RARE ICHTHYOSAUR AND PLESIOSAUR MATERIAL FROM THE LOWER JURASSIC OF IRELAND","authors":"Adam S. Smith","doi":"10.3318/IJES.2010.28.47","DOIUrl":"https://doi.org/10.3318/IJES.2010.28.47","url":null,"abstract":"Abstract:Fossil marine reptile material is described from the restricted outcrops of Lower Jurassic strata exposed in Ireland. The remains consist of a single isolated fragment of rostrum from an ichthyosaur and two blocks of matrix that contain disarticulated and weathered plesiosaur vertebrae, rib fragments and a putative ilium. Although fragmentary and indeterminate, this material is a rare and significant occurrence of marine reptiles in Ireland and provides additional data on the distribution of ichthyosaurs and plesiosaurs in Europe during the Jurassic Period.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"28 1","pages":"47 - 52"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45827756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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