Proceedings of the Geologists Association最新文献_第7页

New records of ammonites from the Lower Bajocian (Middle Jurassic) of England and Italy 英国和意大利下巴约西亚（中侏罗世）菊石的新记录

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-04-25 DOI: 10.1016/j.pgeola.2025.101117

Robert Chandler , Stefano Cresta

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First report of neosuchian remains in Aptian–Albian marine deposits of southeastern France 法国东南部Aptian-Albian海相沉积物中首次发现新苏世遗迹

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-07-23 DOI: 10.1016/j.pgeola.2025.101132

Jeremy E. Martin , Romain Jattiot

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Orogenic and fluvio-tectonic insights into the formation of the Middle Atlas Caves in the Jurassic dolomites (Morocco) 摩洛哥侏罗系白云岩中阿特拉斯溶洞形成的造山构造与河流构造研究

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-03-03 DOI: 10.1016/j.pgeola.2025.101097

Iliass Naouadir , Samira Adil , El Hassane Chellai , Abdallah Elaaraj , Abdennabi Alitane , Mohammed Ettaki , Márton Veress , Ismail Naouadir

{"title":"Orogenic and fluvio-tectonic insights into the formation of the Middle Atlas Caves in the Jurassic dolomites (Morocco)","authors":"Iliass Naouadir , Samira Adil , El Hassane Chellai , Abdallah Elaaraj , Abdennabi Alitane , Mohammed Ettaki , Márton Veress , Ismail Naouadir","doi":"10.1016/j.pgeola.2025.101097","DOIUrl":"10.1016/j.pgeola.2025.101097","url":null,"abstract":"<div><div>This article examines the caves of the Moroccan Middle Atlas using a multi-scale approach, both at the regional and outcrop levels. Our study employs a dual approach, combining numerical analysis and field observation, to investigate the formation of karst features. The results reveal a notable diversity in cave morphology, shaped by regional geological structures, tectonic activity, karstifiable carbonate substrate, pluvial climatic phases, and fluvial dynamics. Over 80 cave entrances have been identified and analysed in the El Menzel Causse, showing a correlation between their development and the main tectonic features of the region, including the North Middle Atlas Fault, the Median Middle Atlas Fault, and the fluvial network of the Sebou River. We suggest that the presence of these tectonic structures, along with allochthonous units linked to the uplift of the Middle Atlas, combined with Quaternary fluvial dynamics, played a central role in the karstogenesis of the El Menzel Causse caves. For the first time, a comparative study has been conducted between the karst processes of the Moroccan Atlas Mountains and those of the Dinaric Alps. This comparison highlights similarities between the karst phenomena of these two mountain ranges. Our comparative study deepens the understanding of karst processes in this specific region of Morocco, whilst providing valuable insights in comparison with other global karst systems, thereby contributing to the advancement of knowledge in karstology on an international scale.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 4","pages":"Article 101097"},"PeriodicalIF":1.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322756","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}

引用次数: 0

A ctenochasmatid pterosaur from the Portland Limestone Formation (Late Jurassic, Tithonian) of southern England 来自英格兰南部波特兰石灰石组（晚侏罗世，泰坦纪）的一条栉龙翼龙

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-03-11 DOI: 10.1016/j.pgeola.2025.101100

Roy E. Smith, David M. Martill

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Microvertebrates from a Rhaetian neptunian dyke at Holwell, Somerset: Dating the fissures 来自萨默塞特郡霍维尔的雷蒂亚海王星堤防的微型脊椎动物：裂缝的年代测定

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-03-29 DOI: 10.1016/j.pgeola.2025.101112

Oliver J. Weeks , Rebecca B. Cooper , David I. Whiteside , Christopher J. Duffin , Charles Copp , Claudia Hildebrandt , Deborah Hutchinson , Michael J. Benton

{"title":"Microvertebrates from a Rhaetian neptunian dyke at Holwell, Somerset: Dating the fissures","authors":"Oliver J. Weeks , Rebecca B. Cooper , David I. Whiteside , Christopher J. Duffin , Charles Copp , Claudia Hildebrandt , Deborah Hutchinson , Michael J. Benton","doi":"10.1016/j.pgeola.2025.101112","DOIUrl":"10.1016/j.pgeola.2025.101112","url":null,"abstract":"<div><div>Dating the Mesozoic-aged fissure deposits around Bristol and South Wales has been problematic, with ages of the older examples disputed as either Carnian or Rhaetian, a 30-million-year difference. The deposits filling fissures at Holwell, Somerset offer a chance to establish a date for at least one system of fissures because they are on the coast of the Mendip Palaeoisland, close to bedded Rhaetian marine deposits. The Holwell fissures have been known since the 1850s when they yielded some of the first ever reported Mesozoic mammals, and they are the type locality for several fossil shark species, <em>Duffinselache holwellensis</em>, <em>Pseudocetorhinus pickfordi</em> and <em>Palaeobates reticulatus</em>. Bone-rich fissure fills from a neptunian dyke at Holwell yielded over 3000 identifiable specimens, comprising mainly marine fishes but also coastal-dwelling placodonts and terrestrially derived lepidosaurs that lived on the palaeoisland. Over 95 % of the fauna comprises four fish taxa that are typical of the bedded Westbury Formation. The less common <em>Rhomphaiodon minor</em> associated with abundant <em>Synechodus rhaeticus</em> indicates that the deposits are likely not basal but are within the upper half of the Westbury Formation. We hereby confirm that these Holwell fissure fill faunas, including the mammals, are of Rhaetian age.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 4","pages":"Article 101112"},"PeriodicalIF":1.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322890","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}

引用次数: 0

Discovery of a phosphatic helical-looking microstructure in Sphenothallus (Cnidaria) from the Late Ordovician of Estonia: Implications for phosphatic biomineralization 在爱沙尼亚晚奥陶世Sphenothallus（刺胞属）中发现的一个磷化螺旋状微观结构：磷化生物矿化的意义

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-02-15 DOI: 10.1016/j.pgeola.2025.101096

Olev Vinn , Anna Madison

{"title":"Discovery of a phosphatic helical-looking microstructure in Sphenothallus (Cnidaria) from the Late Ordovician of Estonia: Implications for phosphatic biomineralization","authors":"Olev Vinn , Anna Madison","doi":"10.1016/j.pgeola.2025.101096","DOIUrl":"10.1016/j.pgeola.2025.101096","url":null,"abstract":"<div><div>The tube of <em>Sphenothallus</em> cf. <em>longissimus</em> from the Late Ordovician of Estonia features a phosphatic, broadly laminar structure. It consists of four to five major laminae; each of the laminae is homogenous exteriorly and shows remains of fibres at the bottom. The fibres in most external tube parts exhibit a plywood structure akin to that of Carboniferous <em>Sphenothallus</em> specimens from Russia, whilst the microstructure of a fibrous lamella in the internal part of the tube resembles the aragonitic helical structure found in molluscs. The reinterpretation of the plywood structure as an original biomineral structure of <em>Sphenothallus</em> and the discovery of a phosphatic structure resembling the aragonitic helical structure of molluscs suggest that the biomineralization capabilities of <em>Sphenothallus</em> may have been exceptional among Cnidaria. It now appears possible that phosphatic biomineralization was significantly more advanced than carbonate biomineralization within Cnidaria. This enhanced phosphatic biomineralization could have provided <em>Sphenothallus</em> with evolutionary advantages over similar encrusting tubicolous organisms with less developed biomineralization during the Paleozoic era.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 4","pages":"Article 101096"},"PeriodicalIF":1.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322755","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}

引用次数: 0

Late Cretaceous-Paleocene ostracods and foraminifera assemblages from the Fguira Salah section (Fahs region, northern Tunisia): Biostratigraphy and palaeogeography 突尼斯北部Fahs地区Fguira Salah剖面的晚白垩世-古新世介形类和有孔虫组合：生物地层学和古地理

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-02-14 DOI: 10.1016/j.pgeola.2025.01.003

Ahlem Amri, Nesrine Ouchir, Sofien Alyahyaoui

引用次数: 0

New insights into Neogene to Pleistocene tectono-sedimentary major events in northeastern Tunisia from surface and subsurface data 从地表和地下资料对突尼斯东北部新近系至更新世构造-沉积重大事件的新认识

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-03-06 DOI: 10.1016/j.pgeola.2025.101099

Sofien Alyahyaoui, Hedi Zouari

{"title":"New insights into Neogene to Pleistocene tectono-sedimentary major events in northeastern Tunisia from surface and subsurface data","authors":"Sofien Alyahyaoui, Hedi Zouari","doi":"10.1016/j.pgeola.2025.101099","DOIUrl":"10.1016/j.pgeola.2025.101099","url":null,"abstract":"<div><div>The main objective of this study is to analyse the structure of the Neogene to Recent rocks in the surface and subsurface of northeastern Tunisia, in order to identify unconformities in outcrops and detect these tectonic and sedimentary events in the subsurface data.</div><div>An integrated study of multi-data supported by the compilation of new outcrop data, seismic reflection profiles, and data from petroleum wells has been carried out in order to determine the structural evolution in the study area. This study has resulted in an improved understanding of the geological evolution of NE Tunisia during the Neogene to Pleistocene. Four major unconformities have been identified in this area, the Tortonian unconformity, the Messinian unconformity, the Pliocene unconformity and the mid-Pleistocene unconformity.</div><div>The mapping of unconformities indicates their association with a major inversion event that occurred from the Late Miocene to the present, resulting in the development of stratigraphy controlled by structural factors. The analysis of nineteen seismic sections has confirmed the existence of several features associated with compressive and transpressive tectonic events.</div><div>These include reverse faults, folds, and unconformities. The structural mapping of these unconformities reveals the presence of a dominant fault system bounding a large number of moderate sized basins.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 4","pages":"Article 101099"},"PeriodicalIF":1.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322888","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}

引用次数: 0

The Culham Brickworks, Oxfordshire, England: New insights from 1852 on a puzzling Jurassic–Cretaceous section 英国牛津郡的Culham砖厂：1852年对令人费解的侏罗纪-白垩纪剖面的新见解

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-03-04 DOI: 10.1016/j.pgeola.2025.101098

Nigel Banks

{"title":"The Culham Brickworks, Oxfordshire, England: New insights from 1852 on a puzzling Jurassic–Cretaceous section","authors":"Nigel Banks","doi":"10.1016/j.pgeola.2025.101098","DOIUrl":"10.1016/j.pgeola.2025.101098","url":null,"abstract":"<div><div>The Culham Brickworks was active from before 1850 for about 100 years and during its existence provided the only good exposure of the Early Cretaceous sub-Gault Formation unconformity in the Oxfordshire area of England. Six descriptions date from 1852 to 1926 detailing different sections as they were exposed in the <em>ca.</em> 350 m length of the excavations which moved gradually eastwards along the Thames riverbank. Over most of the excavated length the Gault Formation lies unconformably on the Late Jurassic Kimmeridge Clay Formation, but to the west the Aptian Lower Greensand Group intervenes and thickens to at least 4 m. A section described by John Phillips in 1860 has proved controversial, particularly for the claimed presence of 9 ft (2.7 m) of Kimmeridge Clay sands that were not seen by others. The earliest description is an unpublished manuscript from <em>ca.</em> 1852 by Daniel Sharpe containing previously unmentioned information, including a cross-section. This defines the Lower Greensand geometry more precisely and also throws additional doubt on Phillips' description. Using Sharpe's sections rather than Phillips', a cross-section has been drawn covering the entire length of the excavations. This illustrates significant relief at both the top of the Kimmeridge Clay Formation and the base of the Gault Formation. This reconstruction provides an essential starting point for any wider study of the Lower Greensand sandbody geometry and the nature of the sub-Gault Formation unconformity. The zonation of the Gault at the Brickworks continues to be reinterpreted, but the results are ambiguous.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 4","pages":"Article 101098"},"PeriodicalIF":1.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322757","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}

引用次数: 0

Do REEs in mudstones record bottom-water redox?: The Pliensbachian–Toarcian record (Lower Jurassic) and T-OAE in the Cleveland Basin, England 泥岩中稀土元素是否记录了底水氧化还原？克利夫兰盆地的Pliensbachian-Toarcian记录（下侏罗统）和T-OAE

IF 1.2 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-08-01 Epub Date: 2025-04-14 DOI: 10.1016/j.pgeola.2025.101114

Ian Jarvis , Elizabeth Atar , Darren R. Gröcke , João P. Trabucho-Alexandre

{"title":"Do REEs in mudstones record bottom-water redox?: The Pliensbachian–Toarcian record (Lower Jurassic) and T-OAE in the Cleveland Basin, England","authors":"Ian Jarvis , Elizabeth Atar , Darren R. Gröcke , João P. Trabucho-Alexandre","doi":"10.1016/j.pgeola.2025.101114","DOIUrl":"10.1016/j.pgeola.2025.101114","url":null,"abstract":"<div><div>The Pliensbachian–Toarcian of the Cleveland Basin provides a global reference for the interval incorporating the Toarcian Oceanic Anoxic Event (T-OAE ~183 Ma). Palaeoredox proxies show a progressive shift from oxic bottom waters in the late Pliensbachian through dysoxic–anoxic conditions in the earliest Toarcian to euxinia during the T-OAE. Anoxia–dysoxia persisted into the middle Toarcian. Laminated black shales with TOC contents >2.5 % characterise the anoxic–euxinic intervals. The rare-earth element (REE) geochemistry of the succession sampled in the Dove's Nest core is described and compared to data from nearby Yorkshire coastal outcrops. Interpretation is based on a review of REE behaviour in modern marine water columns, pore waters and sediments. Mud(stone) REE patterns are insensitive to bottom-water redox conditions. The REEs are principally located in the siliciclastic clay fraction of modern marine muds and ancient mudstones. Bulk mud(stone)s generally exhibit relatively flat REE patterns when normalised to average shale. Cerium anomalies are largely absent. Stratigraphical trends in the Yorkshire succession are related principally to sediment grain size. Authigenic and biogenic phosphates, principally carbonate fluorapatite, when present, dominate the whole-rock REE inventory leading to convex-upward patterns and large positive middle REE (MREE/MREE*) anomalies. These occur sporadically throughout the oxic–euxinic intervals, showing no correlation to bottom-water redox. The REE geochemistry of marine mudstones presents a combination of primary mineralogical and grain-size controls related to sediment provenance combined with the impact of authigenic mineral formation. Bulk mudstone REE patterns do not provide a viable bottom-water redox proxy.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 4","pages":"Article 101114"},"PeriodicalIF":1.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322891","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}

引用次数: 0