Proceedings of the Geologists Association最新文献_第6页

Dissolution as the origin of soft-sediment deformation structures in the Upper Cretaceous of the Noumerat area (Oued Mya Basin, Algerian Sahara) 阿尔及利亚撒哈拉Oued Mya盆地Noumerat地区上白垩统软沉积变形构造的溶蚀成因

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-08-05 DOI: 10.1016/j.pgeola.2025.101134

Mostapha Benzina , Abdelmalik Draoui , Małgorzata Pisarska-Jamroży , Hocine Guerradi , Hakim Hebib , Safa Maache

{"title":"Dissolution as the origin of soft-sediment deformation structures in the Upper Cretaceous of the Noumerat area (Oued Mya Basin, Algerian Sahara)","authors":"Mostapha Benzina , Abdelmalik Draoui , Małgorzata Pisarska-Jamroży , Hocine Guerradi , Hakim Hebib , Safa Maache","doi":"10.1016/j.pgeola.2025.101134","DOIUrl":"10.1016/j.pgeola.2025.101134","url":null,"abstract":"<div><div>This study presents the first evidence of soft-sediment deformation structures (SSDS) within Upper Cretaceous lagoonal deposits of the Noumerat area, formed as a result of dissolution processes. Sulphates, particularly anhydrite, are well known for their susceptibility to karstification, with dissolution commonly reported as the origin of collapse breccia. However, this research introduces not only as the origin of breccia but also as a trigger for a variety of SSDS. These deformation features are primarily associated with the dissolution of anhydrite in Noumerat sedimentary succession, located on the Mzab Plateau in the Northern Algerian Sahara. As the anhydrite dissolved, the overlying claystones subsided into collapse troughs, accompanied by lateral sliding, forming distorted structures such as dome-like folds, water-escape structures, and slump structures. Furthermore, the presence of faults and cracks within the anhydrite layers significantly accelerated dissolution, promoting the formation of breccia fragments within the karst system. This underscores the chemical instability and rapid dissolution of anhydrite. The presence of secondary gypsum-bearing claystones, along with evidence of unconformity, and unconformities further supports this interpretation.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 5","pages":"Article 101134"},"PeriodicalIF":1.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128157","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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Possible limpet home scars on a nautiloid from the Belemnite Stone (Lower Jurassic) near Lyme Regis, Dorset, UK 英国多塞特郡莱姆里吉斯附近Belemnite Stone（下侏罗纪）的鹦鹉螺上可能的帽贝家疤痕

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-04-15 DOI: 10.1016/j.pgeola.2025.101115

Paul G. Davis, Chris Paul, Heather Salmon

{"title":"Possible limpet home scars on a nautiloid from the Belemnite Stone (Lower Jurassic) near Lyme Regis, Dorset, UK","authors":"Paul G. Davis, Chris Paul, Heather Salmon","doi":"10.1016/j.pgeola.2025.101115","DOIUrl":"10.1016/j.pgeola.2025.101115","url":null,"abstract":"<div><div>A specimen of the nautiloid, <em>Cenoceras pertextum</em><span><span> (Dumortier), from the Lower Pliensbachian, </span>Belemnite<span> Stone (bed 121), Charmouth Mudstone<span> Formation, bears four small round or oval pits with a 4.0–7.5 mm maximum dimension that resemble similar structures on Cretaceous ammonites interpreted as limpet home scars. The pits are clustered near the periphery of the nautiloid shell, on the left side. This was the highest point on the nautiloid shell if orientated in the life position of modern </span></span></span><em>Nautilus macromphalus</em>. Long axes of the pits align with the growth direction of the nautiloid shell. Both features suggest that the nautiloid was alive when the limpet scars formed. To maintain aperture orientation during growth nautiloid shells rotate. Thus, forming deep limpet scars at the highest point can only be achieved on mature nautiloid shells. An ammonite, <em>Liparoceras pseudostriatum</em><span> Trueman, occurs in the body chamber, confirming the source rock, and sediment fill indicates that the shell lay on its right side post-mortem forming a benthic island. Attachment of the limpets after the death of the nautiloid does not explain the position and orientation of the scars and seems less likely. Fossil<span><span> limpet shells have been recorded from the Upper Sinemurian, Black Ven </span>Mudstone Member (beds 91 and 92), lower in the Charmouth Mudstone Formation.</span></span></div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 5","pages":"Article 101115"},"PeriodicalIF":1.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128502","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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On a coal specimen possibly associated with the classical Mio-Pleistocene São Jorge leaf bed site, Madeira Island, Portugal 葡萄牙马德拉岛，可能与经典的mio -更新世s<s:1> o Jorge叶床遗址有关的煤标本

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-04-10 DOI: 10.1016/j.pgeola.2025.101116

Carlos A. Góis-Marques , Pedro Correia , Miguel Menezes de Sequeira

{"title":"On a coal specimen possibly associated with the classical Mio-Pleistocene São Jorge leaf bed site, Madeira Island, Portugal","authors":"Carlos A. Góis-Marques , Pedro Correia , Miguel Menezes de Sequeira","doi":"10.1016/j.pgeola.2025.101116","DOIUrl":"10.1016/j.pgeola.2025.101116","url":null,"abstract":"<div><div>Due to the unusual presence of coal seams within a volcanic island, the São Jorge lignite, located in the north side of Madeira Island, was since the early 19th century a magnet for naturalists. In 1854 the site was visited by Sir Charles Lyell and Georg Hartung, where both discovered a leaf-bed associated with the lignite. This finding provided key proofs to Lyell's uniformitarian theory of the formation of volcanic islands and the long-term existence of laurel forests in Macaronesia. Despite its historical importance, lignite specimens from São Jorge remain unknown to date. Recently, the study of Funchal Natural History Museum (MMF, Madeira Island, Portugal) collections revealed a coal specimen associated with the classical site of São Jorge. Here we provide a critical analysis of this specimen using historical and palaeobotanical approaches. We show that this coal is not a lignite from São Jorge and that it was not collected in <em>ca.</em> 1905. Historically, the São Jorge site was covered by a landslide until 1917, making it inaccessible. Furthermore, the coal is either a bituminous coal or anthracite and contains typical rhizomorph fossils of extinct Lycophytes known as <em>Stigmaria ficoides</em> (Sternb.) Brongn., as already indicated in the old MMF record books. The coal is most likely a late Carboniferous (Pennsylvanian, 323.4–298.9 Ma) specimen from the early 20th century British coaling industry on Madeira Island, imported from the UK, which, at some point, was erroneously labelled as originating from the 7–1.8 Ma São Jorge outcrop in Madeira.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 5","pages":"Article 101116"},"PeriodicalIF":1.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128503","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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Tectono-sedimentary evolution of the Senhaja Basin (Western Meseta, Morocco) and its implication for understanding the late Variscan tectonic processes 摩洛哥西梅塞塔Senhaja盆地构造-沉积演化及其对认识晚瓦里斯坎构造过程的意义

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-08-12 DOI: 10.1016/j.pgeola.2025.101133

Amal Zouicha , Jamal El Kabouri , Roland Nádaskay , Tariq Zouheir , Hafid Saber , Ahmed El Attari , Khadra Zaid

{"title":"Tectono-sedimentary evolution of the Senhaja Basin (Western Meseta, Morocco) and its implication for understanding the late Variscan tectonic processes","authors":"Amal Zouicha , Jamal El Kabouri , Roland Nádaskay , Tariq Zouheir , Hafid Saber , Ahmed El Attari , Khadra Zaid","doi":"10.1016/j.pgeola.2025.101133","DOIUrl":"10.1016/j.pgeola.2025.101133","url":null,"abstract":"<div><div>During the final stage of the Variscan Orogeny, a series of intermontane basins developed along the present-day northwestern margin of Africa, predominantly within the Western (Moroccan) Meseta. Among them, the Senhaja Basin, located in the eastern Jebilet Massif, plays a key role in interpreting diachronous evolution of those basins. Whilst traditionally considered to have formed synchronously under similar geodynamic conditions, recent evidence suggests a more complex and diachronous development.</div><div>The depositional environment of the Senhaja Basin is dominated by a fluvial system, characterized by a diversity of facies ranging from the alluvial fans in its proximal part to lacustrine deposits in its distal part. The alluvial-fan gravels feature the coarsest material deposited within the Senhaja Basin.</div><div>Integration of sedimentological and structural data supports the interpretation of the Senhaja Basin as a pull-apart basin formed in response to NE–SW compression, accompanied by localized NW–SE extension. Comparative analysis with other Late Paleozoic basins in Morocco reveals the existence of two distinct generations of basins that evolved diachronously under varying tectonic regimes–ranging from compressional to extensional settings–whilst exhibiting similarities in sedimentary infill. These findings contribute to the broader discussion on the geodynamic evolution of late orogenic basins in the Moroccan Meseta and their implications for Late-Variscan tectonic reorganization.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 5","pages":"Article 101133"},"PeriodicalIF":1.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128156","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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Review of Oxfordian (Upper Jurassic) sequence stratigraphy of England (Yorkshire to Dorset) and a comparison with the North Sea Basin 英国（约克郡-多塞特）牛津（上侏罗统）层序地层学综述及与北海盆地的比较

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-06-02 DOI: 10.1016/j.pgeola.2025.101125

John K. Wright

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A new modern Hydrolithon-like coralline red alga from the Upper Ordovician of Estonia 来自爱沙尼亚上奥陶统的一种新的现代类水螅状珊瑚红藻

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-06-11 DOI: 10.1016/j.pgeola.2025.101127

Olev Vinn , Anna Madison , Mare Isakar , Magdy El Hedeny , Abdullah A. Alkahtane , Saleh Alfarraj

{"title":"A new modern Hydrolithon-like coralline red alga from the Upper Ordovician of Estonia","authors":"Olev Vinn , Anna Madison , Mare Isakar , Magdy El Hedeny , Abdullah A. Alkahtane , Saleh Alfarraj","doi":"10.1016/j.pgeola.2025.101127","DOIUrl":"10.1016/j.pgeola.2025.101127","url":null,"abstract":"<div><div><span><span><span>A new genus and species of encrusting fan-shaped calcareous coralline </span>red algae have been described from the lower Katian of Estonia. The </span>fossils occur on the shell of the brachiopod </span><em>Porambonites</em> as a crust consisting of radial rows that systematically bifurcate, forming secondary rows that further divide into two distinct structures. The exposed surface of the rows is nearly flat and uniformly perforated with single or double rows of large, circular pores. <em>Antiquifosliella tinnae</em><span> gen. et sp. nov. stands out among other Ordovician red algae due to its large pores, which may have had a dual function. These pores were most likely involved in both gas exchange and reproduction. </span><em>A. tinnae</em><span> gen. et sp. nov. most likely belongs to the stem group of Corallinaceae<span>, though it may also represent an early lineage within the </span></span><em>Hydrolithon</em> group. In the latter case, <em>Hydrolithon</em><span> is a classical “living fossil” showing only a little morphological evolution since the Late Ordovician. The discovery of true Corallinaceae from the Upper Ordovician proves the early Paleozoic origin of the group that was previously considered to be late Mesozoic.</span></div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 5","pages":"Article 101127"},"PeriodicalIF":1.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128507","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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A new multituberculate (Mammalia, Allotheria) from the Lulworth Formation (Cretaceous, Berriasian) of Dorset, England 英国多塞特的Lulworth组（白垩纪，Berriasian）一种新的多结核动物（哺乳目，异源兽目）

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-07-09 DOI: 10.1016/j.pgeola.2025.101128

Benjamin T. Weston , Steven C. Sweetman , Jake Kean , Charles Wood , David M. Martill , Roy E. Smith

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A night at the opera: the prestigious fate of green fluorite from the Voltennes mine, la Petite-Verrière, France 歌剧之夜：来自法国小verri<e:1> Voltennes矿的绿色萤石的命运

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-07-10 DOI: 10.1016/j.pgeola.2025.101130

Vincent Thiéry

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First record of serpulid aggregations and possible serpulid reefs from the Aptian (Cretaceous) of Algeria 阿尔及利亚阿普提亚（白垩纪）首次记录蛇形聚集体和可能的蛇形礁

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-06-06 DOI: 10.1016/j.pgeola.2025.101126

Olev Vinn , Imad Bouchemla , Madani Benyoucef , Magdy El Hedeny , Mansour I. Almansour , Saleh Alfarraj

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Aspects of the deglaciation of the Lochaber Glacial Lakes area, western Scottish Highlands 苏格兰高地西部Lochaber冰川湖区冰川消融的各个方面

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-10-01 Epub Date: 2025-07-28 DOI: 10.1016/j.pgeola.2025.101131

J. Douglas Peacock , James Rose

{"title":"Aspects of the deglaciation of the Lochaber Glacial Lakes area, western Scottish Highlands","authors":"J. Douglas Peacock , James Rose","doi":"10.1016/j.pgeola.2025.101131","DOIUrl":"10.1016/j.pgeola.2025.101131","url":null,"abstract":"<div><div>This paper examines the landforms and sediments in the area of the Lochaber Glacial Lakes in order to evaluate the process, pattern and timing of Late Devensian glaciation and ice wastage in that part of northwestern Scotland. Detailed evidence is provided for a number of critical areas including the Roy-Spey watershed region, the Allt Chonnal valley, the Glen Turret Fan and Moraine, the valley side fans of the upper and middle Roy valley and Glen Gloy. The work is based on field evidence and includes moraine ridges, fan landforms and sediments, along with the results of varve analyses from the Roy and Laggan valleys published elsewhere. The results suggest that, apart from some small corrie glaciers at the south side to the Roy-Spey watershed, much of the area was deglaciated following the Western Ross Readvance (<em>c.</em> 15.4–15.8 cal ka BP), prior to glaciers of the Loch Lomond Readvance (<em>c.</em> 12.9–11.7 cal ka BP) reaching the well-defined limits that held back the glacial lakes. The process of ice wastage within Glen Roy, from the Wester Ross Readvance, involved ice-marginal fluctuations, minor readvances and the formation of a pro-glacial lake related to the col at the Roy/Spey watershed. It is also proposed that many of the fans that occur along the sides of Glen Roy are of subaerial origin formed by paraglacial processes, rather than as subaquatic lake deltas.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 5","pages":"Article 101131"},"PeriodicalIF":1.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128154","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