Proceedings of the Geologists Association最新文献_第5页

An assessment of sediment noise modelling on the Upper Jurassic Kimmeridge Clay: Implications for aquifer-eustasy 上侏罗统Kimmeridge粘土沉积物噪声模拟的评估：对含水层-游动的影响

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-08-18 DOI: 10.1016/j.pgeola.2025.101136

Andrew Davies, Michael D. Simmons

{"title":"An assessment of sediment noise modelling on the Upper Jurassic Kimmeridge Clay: Implications for aquifer-eustasy","authors":"Andrew Davies, Michael D. Simmons","doi":"10.1016/j.pgeola.2025.101136","DOIUrl":"10.1016/j.pgeola.2025.101136","url":null,"abstract":"<div><div>Relative sea-level curves obtained from analysis of the stratigraphic record provide crucial insights into various aspects of the Earth system. In recent years, several studies have employed sediment noise modelling (DYNOT and lag-1 autocorrelation coefficient) of astronomically tuned records to obtain information on changes in water depth and relative sea-level. Many of these studies provide support for aquifer-eustasy by demonstrating an out of phase relationship between relative lake level (from sediment noise modelling) and published eustatic curves. However, few studies have validated the sea/lake level curves derived from sediment noise modelling with independent water depth indicators. Here sediment noise modelling is critically evaluated using data from the Upper Jurassic Kimmeridge Clay Formation of the southern UK, where astronomical forcing has previously been demonstrated. Sediment noise modelling-derived water depth records are compared to detrital quartz-silt concentrations, previously shown to be an excellent proxy for relative sea-level changes through correlation with contemporaneous proximal successions. There is minimal correlation between the sediment noise modelling results and the independent quartz-silt record. Consequently, more research is required to demonstrate the validity of sediment noise modelling as a proxy for water depth change in sedimentary successions. This work implies that support for aquifer-eustasy as a primary driver of short-term, moderate magnitude sea-level change from sediment noise modelling studies should be re-evaluated.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101136"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718869","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

Stratigraphical and sedimentological insights into the Bajocian (Middle Jurassic) Teniet El Klakh Formation, Western Saharan Atlas, Algeria 阿尔及利亚西撒哈拉地图集地区Bajocian（中侏罗世）Teniet El Klakh组地层与沉积学研究

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-10-03 DOI: 10.1016/j.pgeola.2025.101143

Madani Benyoucef , Marcin Krajewski , Sixto Rafael Fernández-López , Imad Bouchemla , Fayçal Mekki , Mariusz A. Salamon , Mohammed Adaci , Mohamed Amine Zaidi , Djamel Belloumou

{"title":"Stratigraphical and sedimentological insights into the Bajocian (Middle Jurassic) Teniet El Klakh Formation, Western Saharan Atlas, Algeria","authors":"Madani Benyoucef , Marcin Krajewski , Sixto Rafael Fernández-López , Imad Bouchemla , Fayçal Mekki , Mariusz A. Salamon , Mohammed Adaci , Mohamed Amine Zaidi , Djamel Belloumou","doi":"10.1016/j.pgeola.2025.101143","DOIUrl":"10.1016/j.pgeola.2025.101143","url":null,"abstract":"<div><div>This study, based on lithostratigraphical and biostratigraphical analyses, focuses on ammonites, trace fossils, and sedimentary facies of the Bajocian Teniet El Klakh Formation in the Ain Sefra area of the Western Saharan Atlas, Algeria. This formation represents a key Middle Jurassic succession within the Maghrebian Tethys realm, marking the transition from the Liassic carbonate platform and the Upper Jurassic coastal–continental clastic deposits. Field observations, combined with microscopic analyses allowed the recognition of thirteen siliciclastic and carbonate facies types (FT1–FT13), each interpreted in terms of its depositional environment. These facies types are grouped into three main facies associations (FA1–FA3), corresponding to distinct palaeoenvironmental settings: (i) lower shoreface to offshore transition, (ii) storm-dominated upper shoreface, and (iii) shoal. The trace fossils <em>Palaeophycus heberti</em>, <em>Paleodictyon strozzii</em>, <em>Protopaleodictyon</em> cf. <em>submontanum</em>, <em>Zoophycos brianteus</em>, <em>Zoophycos cauda-galli</em>, and <em>Zoophycos villae</em> are reported here for the first time from the Bajocian of the Saharan Atlas. Contrary to earlier interpretations, the newly identified ammonite assemblages indicate a Lower to Upper Bajocian age (Humphriesianum and Niortense zones) for the Teniet El Klakh Formation.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101143"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145719055","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 Quaternary evolution of a large rock slope deformation (Robinson, English Lake District) – a first such exploration by cosmogenic exposure dating in the British mountains 大型岩石斜坡变形（Robinson, English Lake District）的晚第四纪演化——首次在英国山区进行宇宙成因暴露测年

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-10-28 DOI: 10.1016/j.pgeola.2025.101152

Peter Wilson , David Jarman , Maria Miguens-Rodriguez , Derek Fabel

{"title":"Late Quaternary evolution of a large rock slope deformation (Robinson, English Lake District) – a first such exploration by cosmogenic exposure dating in the British mountains","authors":"Peter Wilson , David Jarman , Maria Miguens-Rodriguez , Derek Fabel","doi":"10.1016/j.pgeola.2025.101152","DOIUrl":"10.1016/j.pgeola.2025.101152","url":null,"abstract":"<div><div>The temporal dynamics of the Robinson rock slope failure (RSF), the largest such feature in the Lake District of northwest England, have been assessed through cosmogenic (<sup>10</sup>Be) surface-exposure dating of quartz veins on the headscarp/rupture surface and an upper-mid-slope antiscarp. Movement along the headscarp/rupture surface began during the Lateglacial ~15.4–14.3 ka, and movement could have continued, incrementally or episodically, until the mid-Holocene ~4.6 ka. Displacement rates for the headscarp/rupture surface averaged over that time are in the range 3–4.5 mm/a. These are the first rates to be reported for an RSF in Britain and Ireland. Ages from the upper-mid-slope antiscarp (~8–6.5 ka) indicate early-mid-Holocene movement, although <sup>10</sup>Be inheritance may have aged these samples somewhat. Reasons for RSF activity at Robinson at those times are complex, but probably involved paraglacial stress release augmented by the concentrated erosion of bedrock in a trough below a glacial breach, along with the structural characteristics of the local bedrock. The cosmogenic ages suggest that other RSFs in this area may have a longer history of instability than hitherto thought.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101152"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145719060","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

Lacrimichnus in a cromyocrinid crinoid from the Upper Carboniferous of Ohio, USA, and its bearing on parasitism of Palaeozoic crinoids 美国俄亥俄州石炭统上石炭统蛇形海百合的寄生特征及其与古生代海百合寄生的关系

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-08-18 DOI: 10.1016/j.pgeola.2025.101140

James R. Thomka

引用次数: 0

Vertebrate tracks in Pliocene aeolianite deposits of the Wankoe Formation, Western Cape Province, South Africa 南非西开普省Wankoe组上新世风成岩沉积物中的脊椎动物足迹

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-10-02 DOI: 10.1016/j.pgeola.2025.101149

Charles W. Helm , Given Banda , Hayley C. Cawthra , Richard M. Cowling , Jan C. De Vynck , Mark G. Dixon , Pieter-Jan Gräbe , Jean A. Malan , Willo M. Stear , Guy H.H. Thesen

{"title":"Vertebrate tracks in Pliocene aeolianite deposits of the Wankoe Formation, Western Cape Province, South Africa","authors":"Charles W. Helm , Given Banda , Hayley C. Cawthra , Richard M. Cowling , Jan C. De Vynck , Mark G. Dixon , Pieter-Jan Gräbe , Jean A. Malan , Willo M. Stear , Guy H.H. Thesen","doi":"10.1016/j.pgeola.2025.101149","DOIUrl":"10.1016/j.pgeola.2025.101149","url":null,"abstract":"<div><div>Aeolianites of the Wankoe Formation, of Pliocene age, are encountered in the southern Cape of South Africa. Until now, and in contrast with the prevalence of vertebrate tracksites in the coastal Pleistocene Waenhuiskrans Formation, no vertebrate tracks have been identified in the Wankoe Formation. However, our studies indicate that the formation is richly fossiliferous and that vertebrate tracks are commonly encountered in suitable areas, although non-karstified outcrops are in general sparsely distributed. Whilst many of the tracks are only evident in profile, a vertebrate trackway in the Grootbos Private Nature Reserve, for example, comprises five tracks preserved in plan view. Although identification to trackmaker species is not possible, several plausible trackmaker taxa can be postulated. In combination, these tracksites appear to contain the first recorded Pliocene vertebrate tracks described from southern Africa. Pedestalling of tracks has been noted at two sites, suggesting that this unusual form of track preservation could be sought elsewhere in Wankoe Formation deposits. A dedicated search, focusing on areas with substantial cliff exposures, should yield further discoveries.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101149"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145719057","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

New species of Stellularis (Hemiptera: Cicadomorpha: Procercopidae) from the Lower Cretaceous Jiufotang Formation in northeastern China 标题中国东北下白垩统九佛塘组星蛾新种（半翅目：蝉形目：原蝎科）

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-08-13 DOI: 10.1016/j.pgeola.2025.101138

Yannan Lü, Xiaoxue Du, Leidan Ning, Qianqi Zhang

引用次数: 0

Petrogenesis of lava from Saka (Guercif, Morocco): Source characterization and magma evolution 摩洛哥Saka （Guercif）熔岩成因：来源特征及岩浆演化

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-10-21 DOI: 10.1016/j.pgeola.2025.101151

Abdallah Elaaraj , Maham Eboubekrine Sedigh , Ali Lhachmi , Hassan Tabyaoui , Abdennabi Alitane , Massimo Tiepolo , Iliass Naouadir

{"title":"Petrogenesis of lava from Saka (Guercif, Morocco): Source characterization and magma evolution","authors":"Abdallah Elaaraj , Maham Eboubekrine Sedigh , Ali Lhachmi , Hassan Tabyaoui , Abdennabi Alitane , Massimo Tiepolo , Iliass Naouadir","doi":"10.1016/j.pgeola.2025.101151","DOIUrl":"10.1016/j.pgeola.2025.101151","url":null,"abstract":"<div><div>The Plio-Quaternary volcanism of Saka, located in the Guercif region in northeastern Morocco, holds significant geological interest in the study of mantle-derived magma and magmatic differentiation processes. Its historical activity has been mainly effusive, producing a variety of volcanic rocks ranging from ultrabasic to acidic compositions. In this study, around forty samples were collected, prepared as polished thin sections, and analyzed under a petrographic microscope. Twelve representative samples were selected for major and trace element analyses, carried out by inductively coupled plasma-mass spectrometry (ICP-MS) with laser ablation. The volcanic rocks of Saka are primarily composed of basanite, basalt, trachy-andesite, and trachyte, forming a strongly differentiated alkaline series evolving from alkaline basalts to trachytes. Geochemical analyses reveal enrichment in SiO<sub>2</sub>, Al₂O₃, Na₂O, and K₂O, and depletion in MgO and CaO, indicating a process of assimilation and fractional crystallization. A good correlation is observed between certain trace elements (U, Nb, Ta, La, Zr, Hf, Yb, Rb, Y) and the differentiation index. The Saka lavas are mantle-derived and exhibit characteristics like ocean island basalts (OIBs) with HIMU (high <em>μ</em>, μ = <sup>238</sup>U/<sup>204</sup>Pb) signatures. Geotectonically, Saka volcanism developed in an intraplate extensional setting, classified as Within-Plate Basalt (WPB) and Within-Plate Volcanic Zone (WPVZ), likely related to lithospheric thinning and subduction rollback in the Alboran region, favouring mantle decompression and magma ascent along pre-existing faults.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101151"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145719059","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

Analysis of karst factors and paleoenvironmental significance of endo- and exokarst landforms in the Middle Atlas of Morocco 摩洛哥中地图集内、外岩溶地貌岩溶因子及古环境意义分析

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-08-13 DOI: 10.1016/j.pgeola.2025.101137

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

{"title":"Analysis of karst factors and paleoenvironmental significance of endo- and exokarst landforms in the Middle Atlas of Morocco","authors":"Iliass Naouadir , Samira Adil , El Hassane Chellai , Mohammed Ettaki , Abdallah Elaaraj , Abdennabi Alitane , Mario Parise , Márton Veress","doi":"10.1016/j.pgeola.2025.101137","DOIUrl":"10.1016/j.pgeola.2025.101137","url":null,"abstract":"<div><div>The El Menzel Causse, located in the northern Middle Atlas, showcases a remarkable yet largely underexplored karstic geodiversity. The richness and uniqueness of this region, particularly its exokarstic and endokarstic features, as well as its position at the boundary between the Tabular and Folded Middle Atlas, motivated our study. This research marks the first comprehensive analysis of the genesis and evolution of both endokarstic and exokarstic forms within the Middle Atlas. The observed karstic features, such as lapies, poljes, uvalas, caves, dry valleys, and karst springs, illustrate a wide morphological diversity. By combining field surveys, petrographic analysis, and advanced techniques such as satellite data, we conducted a detailed study of karstic processes and the factors influencing karstogenesis. Our results in the Middle Atlas highlight the complexity and interdependence of the factors involved, including climatic, pedological, lithological, stratigraphic, petrographic, morphostructural, hydrological, paleogeographic, and geodynamic elements. The convergence of these factors has led to a diverse array of karstic forms, shaping the distinct landscape of the Middle Atlas. In conclusion, this multidisciplinary study offers new insights into the mechanisms of karstic geodiversity in the region. Our findings provide valuable perspectives not only for understanding the karsts of the Moroccan Atlas but also for other similar orogenic belts, such as the Alps, underscoring the importance of continued research in this field.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101137"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718870","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 geometry of the Lower Greensand sand body near Nuneham Courtney, Oxfordshire, England 英国牛津郡Nuneham Courtney附近的Lower Greensand砂体的几何形状

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 Epub Date: 2025-10-17 DOI: 10.1016/j.pgeola.2025.101150

Nigel Banks

{"title":"The geometry of the Lower Greensand sand body near Nuneham Courtney, Oxfordshire, England","authors":"Nigel Banks","doi":"10.1016/j.pgeola.2025.101150","DOIUrl":"10.1016/j.pgeola.2025.101150","url":null,"abstract":"<div><div>The Lower Greensand Group sand outcropping near Nuneham Courtney, Oxfordshire is one of several lenticular marine sandstone deposits that formed in the Early Cretaceous along the northern margin of the Weald and Wessex Basins. In the study area the interval between the top of the Upper Jurassic Corallian Group and the base of the Cretaceous Gault Formation comprises Upper Jurassic and Lower Greensand sediments varying in combined thickness from 30 m to 55 m across the six kilometre Lower Greensand outcrop. The Top Corallian surface forms a gently dipping, un-faulted, planar base to the Upper Jurassic interval, which is overlain by the Lower Greensand Group with erosive unconformity. The Upper Jurassic varies in thickness from 25 to 55 m. The Lower Greensand is 0–20 m. The name Nuneham Sand Formation is proposed for this isolated Lower Greensand sand body. It has been little studied, but subsurface mapping, together with historical outcrop descriptions, provides new insights into its geometry. Across the outcrop the maximum Upper Jurassic and Lower Greensand thicknesses are found in the east. In the west, the Upper Jurassic sediments are more eroded, but the Lower Greensand is thin or absent. Given poor biostratigraphical control, multiple erosional and depositional models could explain this geometry. However, the most likely scenario is that a limited supply of coarse Lower Greensand sediments did not fully fill the marked topographical relief that had been created, at least in part, by strong tidal currents: this relict topography was passively onlapped by marine Gault clays.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"136 6","pages":"Article 101150"},"PeriodicalIF":1.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145719058","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

IF 1.3 4区地球科学

Proceedings of the Geologists Association Pub Date : 2025-12-01 DOI: 10.1016/j.pgeola.2025.101139

Malcolm B. Hart

引用次数: 0