Irish Journal of Earth Sciences最新文献

New Data on the Ben Levy Anticline, With Reverse Reactivation on the Coolin Fault Giving Up-Side-Down Silurian Rocks in Joyces Country, Connemara 关于本-利维起伏线的新数据，Coolin 断层的反向重新激活，在康尼马拉的乔伊斯地区产生了上下颠倒的志留纪岩石

Irish Journal of Earth Sciences Pub Date : 2023-12-01 DOI: 10.1353/ijes.0.a916010

B. Leake

引用次数: 0

New Light on the Oughterard Granite: Connemara’s S-Type Granite, Ireland 奥特拉德花岗岩的新发现：爱尔兰康尼马拉的 S 型花岗岩

Irish Journal of Earth Sciences Pub Date : 2023-12-01 DOI: 10.1353/ijes.0.a916009

B. Leake

{"title":"New Light on the Oughterard Granite: Connemara’s S-Type Granite, Ireland","authors":"B. Leake","doi":"10.1353/ijes.0.a916009","DOIUrl":"https://doi.org/10.1353/ijes.0.a916009","url":null,"abstract":"Most of the Connemara granites, including the Galway Granite batholith, have a clearly defined circular or ellipsoidal outcrop shape and are I-Type granites often with K-feldspar phenocrysts, whereas the Oughterard Granite (OG) forms numerous small intrusions scattered east-west over 40km with two larger linked bodies near Oughterard and is S-Type and aphyric. The only comprehensive mapping, mineralogical and chemical study of the OG was published over 50 years ago before the important 1974 recognition of the distinction of I- and S-Type granites was first made. New mapping of the southern Oughterard area with small OG intrusions is presented and many scattered published chemical and Rb, Sr, S and Pb isotopic studies integrated to confirm overall their individual conclusions that the peraluminous OG is of S-Type, being formed from melted Dalradian rocks as are the fluid-carried associated uneconomic mineral deposits. The OG is confined to the high sillimanite zone, mostly south of, and mainly later than, the 465-464Ma D4 Connemara Antiform, where a wide (>15km N-S) >70km E-W band of 469Ma gabbros and 467Ma quartz diorite gneisses intruded into already hot Dalradian rocks undergoing regional metamorphism. This generated the OG magmas by partial melting of pelites and semi-pelites. The upward intrusion of the OG magma was significantly delayed, as has been shown by precise dating in other granites elsewhere, to ~464-461Ma during the late stages and mostly after D4 but before the country rocks had completely cooled. The OG intrusions as a whole probably form the second largest area of S-Type granite in Ireland, after the Leinster Granite.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"5 3","pages":"-"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139016725","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}

引用次数: 0

Structural Control of the Deposition and Subsequent Deformation of the Killary Habour-Joyce Country Silurian Succession Killary Habour-Joyce Country志留纪演替沉积及其后变形的结构控制

Irish Journal of Earth Sciences Pub Date : 2023-12-01 DOI: 10.1353/ijes.0.a916339

Michael Badley, John Graham, B. Leake

{"title":"Structural Control of the Deposition and Subsequent Deformation of the Killary Habour-Joyce Country Silurian Succession","authors":"Michael Badley, John Graham, B. Leake","doi":"10.1353/ijes.0.a916339","DOIUrl":"https://doi.org/10.1353/ijes.0.a916339","url":null,"abstract":"The Killary Harbour–Joyce Country succession of Silurian rocks forms the remnant of one of three successor basins that developed after the Grampian Orogeny and which are preserved in western Ireland. Its outcrop everywhere obscures the contact between the Dalradian rocks of Connemara and the Ordovician rocks of the South Mayo Trough. The outcrop is bisected by the prominent north-west trending Maam Valley Fault Zone that is shown to have a component of synsedimentary movement down-throwing to the southwest. The original basin margins lay well outside the current outcrop area. North-south shortening and inversion of the basin was accomplished by reactivation and inversion of earlier fault structures and was exclusively in the brittle zone. Folding of the Silurian rocks with weak to moderate cleavage and deformation of the basement rocks of Connemara was accomplished by largely vertical movements along numerous strike parallel and oblique fractures. Break-back inversion structures were developed along the southern margin of the South Mayo Trough, which include thrusting associated with footwall shortcut faults and clockwise rotation. Although the timing of deformation overlaps that of diorite sill emplacement, it remains poorly constrained in absolute terms.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"15 12","pages":"-"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139024877","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}

引用次数: 0

The Impact of Topography and Rotation in Shaping the Basin-Scale Circulation in Lough Corrib, Ireland, Under Homogenous Conditions 同质条件下地形和旋转对塑造爱尔兰科里布湖流域尺度环流的影响

Irish Journal of Earth Sciences Pub Date : 2023-12-01 DOI: 10.1353/ijes.0.a916338

Heather Cannaby, Martin White

{"title":"The Impact of Topography and Rotation in Shaping the Basin-Scale Circulation in Lough Corrib, Ireland, Under Homogenous Conditions","authors":"Heather Cannaby, Martin White","doi":"10.1353/ijes.0.a916338","DOIUrl":"https://doi.org/10.1353/ijes.0.a916338","url":null,"abstract":"The impact of the Earth’s rotation on circulation patterns in homogenous basins has been well studied using numerical models. This contribution addresses the need for supporting observational studies. Bottom mounted acoustic doppler current (ADCP) velocity profiles are analysed alongside drifter tracks and numerical solutions in order to demonstrate how rotation modifies circulation patterns and horizontal velocity profiles in Lough Corrib, Ireland. The wind driven circulation in Lough Corrib forms a system of topographic gyres, shaped by the complex bathymetry of the basin. Surface and benthic frictional boundary layers are demonstrated to be closely described by classical Ekman theory, despite the system being constrained by shallow water depths (mean depth = 8.4m) and small horizontal dimensions (~10km). Observed velocity profiles can be derived theoretically by summing the two driving forces of the flow (the barotropic pressure gradient force and the surface wind stress force) and their opposing forces (internal friction and Coriolis acceleration). Rotation introduces a significant cross-wind component to the flow, which is thus described as being quasi-geostrophic. The barotropic pressure gradient force is empirically quantified as a function of wind stress by relating surface set-up to the surface water shear velocity. The vertical eddy viscosity profile, derived from ADCP data, increases approximately linearly with increasing depth and is largest at the upper interface of the benthic boundary layer.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"189 ","pages":"-"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139012476","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}

引用次数: 0

Deposition in the Northwest Porcupine Basin During the Cretaceous 白垩纪期间西北豪猪盆地的沉积作用

Irish Journal of Earth Sciences Pub Date : 2023-12-01 DOI: 10.1353/ijes.0.a915717

Tareq Shath, David Naylor

{"title":"Deposition in the Northwest Porcupine Basin During the Cretaceous","authors":"Tareq Shath, David Naylor","doi":"10.1353/ijes.0.a915717","DOIUrl":"https://doi.org/10.1353/ijes.0.a915717","url":null,"abstract":"The paper details the sedimentary infill of the northwest part of the Porcupine Basin, offshore west Ireland, during the Cretaceous. This is a critical area for understanding the sediment input and incremental infilling of the basin, particularly during the early Cretaceous. Late Jurassic rifting and early Berriasian erosion produced a northward narrowing valley on the Base Cretaceous unconformity surface, which provided an entry point for sediment into the basin and also constrained the lateral extent of initial sedimentation. Following Berriasian marine transgression, the first deposits in the Porcupine Basin were turbidites located in localised depressions on the unconformity surface (named here informally as Basal Deposits 1–4). As the unconformity surface became smoother, the succeeding layers were more widespread (Sequences 1–3, the top being of probable Barremian age). Several features, interpreted as mounded fans sourced from the basin flanks, are developed in the Valanginian-Barremian section. Where drilled, the Berriasian to Barremian section is predominantly fine-grained. The rifted marginal horsts were covered in late Barremian time, and Aptian and later sediments onlapped the flanks of the Porcupine High to the west. The ‘Near Base Aptian’ is a well-defined prograding surface and the ‘Near Top Aptian’ horizon is a marked unconformity. The Aptian section is comprised predominantly of deep-water mudrocks and siltstones, although a distinctive, possibly shallower, erosive Intra-Aptian event was also mapped. A renewed sediment influx, comprising of sand prone deltaics, occurred at the northern margin of the basin during the Albian. Sand content decreases southwards into the basin. Sedimentation in the late Cretaceous was dominated by the basinwide deposition of the Chalk Group (Cenomanian-Selandian) deposited in a stable thermal subsidence setting. At the northern basin margin Upper Cretaceous deposits are thin and lithologically variable. The well-defined ‘Top Chalk’ reflector, which shows mounded features, is overlain unconformably by Paleocene clastics.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"270 ","pages":"-"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139013962","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}

引用次数: 0

The Distribution and Engineering Properties of Interglacial Deposits in Cork City and Harbour 科克市和海港冰期沉积物的分布和工程特性

Irish Journal of Earth Sciences Pub Date : 2023-12-01 DOI: 10.1353/ijes.0.a915719

Stephen Curtis, Michael Long

{"title":"The Distribution and Engineering Properties of Interglacial Deposits in Cork City and Harbour","authors":"Stephen Curtis, Michael Long","doi":"10.1353/ijes.0.a915719","DOIUrl":"https://doi.org/10.1353/ijes.0.a915719","url":null,"abstract":"A reassessment of existing data and additional testing on sediment core samples from one site was used to study the extent, nature, composition and engineering properties of the Quaternary interglacial deposits in an area of Cork city and harbour where many future developments are planned. A clear link is apparent between rockhead elevation and the presence of the interglacial deposits. Well-defined pockets of the deposit were proven. These are found mostly on the southern side of the Cork buried valley axis and increase in thickness to the north. The base of the interglacial deposits appears to mirror that of the rockhead and the western extent of the former coincides with a steep drop off in the latter. Much of the deposit encountered in commercial investigations is a thick relatively uniform silt/clay consistent with that described in previous studies. The sediment is predominantly silt sized, but its behaviour and engineering properties are consistent with those of a stiff clay. Sample disturbance effects were found to be significant and these likely result in an underestimation of the preconsolidation stress and the undrained shear strength of the material. Future work would benefit from the use of in-situ site investigation and geophysical techniques.","PeriodicalId":35911,"journal":{"name":"Irish Journal of Earth Sciences","volume":"58 1","pages":"-"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138993878","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}

引用次数: 0

A Vertically Embedded Orthoconic Nautiloid From the Pennsylvanian of County Clare, Ireland – An Unusual Case of ‘Distraction Sinking’? 来自爱尔兰克莱尔郡宾夕法尼亚的垂直嵌入的正立方体鹦鹉螺——一个不寻常的“分心下沉”案例?

Irish Journal of Earth Sciences Pub Date : 2023-10-01 DOI: 10.1353/ijes.0.a909326

Eamon Doyle

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Is Bitumen the Key to the Quality of the Monasterboice Stone Crosses? 沥青是修道院石十字架质量的关键吗?

Irish Journal of Earth Sciences Pub Date : 2023-09-01 DOI: 10.1353/ijes.0.a907888

George Sevastopulo, Roger Stalley, Ian Sanders

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Palaeoecology of Small Round Holes in Mississippian Crinoids: Salthill Quarry, Clitheroe, UK 密西西比海绵体小圆孔的古生态学：英国克利塞罗Salthill采石场

Irish Journal of Earth Sciences Pub Date : 2023-08-01 DOI: 10.1353/ijes.0.a904063

S. Donovan

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Diverse Gyracanthus Spine Morphologies From the Jarrow Assemblage (Pennsylvanian), County Kilkenny, Ireland 爱尔兰基尔肯尼郡Jarrow组合(宾夕法尼亚)中Gyracanthus脊柱形态的多样性

Irish Journal of Earth Sciences Pub Date : 2022-12-10 DOI: 10.1353/ijes.0.0007

Aodhán Ó Gogáin

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