Proceedings of the Geologists Association最新文献

New information on the Dyrham Formation (Lower Jurassic, Pliensbachian) of the East Midlands Shelf, UK 英国东米德兰兹大陆架 Dyrham 地层（下侏罗统，普利恩巴赫统）的新信息

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.08.004

Robin I. Knight

Previously unpublished Lower Jurassic sections of the East Midlands Shelf, along with reassessment of museum collections and previously published successions, indicate that seafloor sedimentation was dominated by complex erosional and depositional processes driven by dynamic and complex shelfal seafloor energy regimes during the Davoei and Margaritatus Zones of the Pliensbachian. The possible influence of tectonically driven relative sea level fluctuations is uncertain. Distinct condensation events, marked by authigenic mineralisation and clast reworking, can be identified at the Davoei–Margaritatus zonal boundary at the base of the Stokesi Subzone (‘Lower Authigenic Mineral Bed’), and at the boundary between the Stokesi and Subnodosus Subzones (‘Upper Authigenic Mineral Bed’). These correspond to a recognised candidate sequence boundary and candidate maximum flooding surface respectively. The Stokesi Subzone is well defined in all the studied sections by the ammonites between the two marker beds, whilst the Subnodosus Subzone can only be proven at Middleton Cheney. Nutrient supply for mineralisation observed in the ‘Authigenic Mineral Beds’ was derived from the erosion of uppermost Davoei Zone and lowermost Stokesi Subzone sediments. The high concentrations of authigenic mineralisation ions in the Davoei sediments were generated by large amounts of organic material derived from continental run-off.

之前未发表的东米德兰兹大陆架下侏罗世剖面图，以及对博物馆藏品和之前发表的连续岩层的重新评估表明，在普利恩巴赫期的达沃伊区和玛格丽塔图斯区，海底沉积主要是由复杂的侵蚀和沉积过程驱动的，这些过程受到动态和复杂的大陆架海底能量机制的影响。构造驱动的相对海平面波动可能产生的影响尚不确定。在Stokesi亚区底部的Davoei-Margaritatus带边界（"下自成矿床"）以及Stokesi亚区和Subnodosus亚区的边界（"上自成矿床"），可以发现以自成矿化和碎屑再加工为标志的明显凝结事件。这些地方分别与公认的候选层序边界和候选最大淹没面相对应。在所有研究的剖面中，斯托克斯亚区都被两个标志性矿床之间的褐铁矿明确界定，而亚诺多苏斯亚区只能在米德尔顿切尼得到证实。在 "自生矿物床 "中观察到的矿化所需的养分来自最上层达沃伊区和最下层斯托克斯亚区沉积物的侵蚀。达沃伊沉积物中高浓度的自生矿化离子是由来自大陆径流的大量有机物质产生的。

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引用次数: 0

A new Early Cretaceous ommatine beetle (Insecta: Coleoptera: Archostemata) from Inner Mongolia, China 中国内蒙古新发现的早白垩世母甲虫（昆虫纲：鞘翅目：始祖鸟科

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.08.002

Yingshun Tang , Ming Li , Zhengyu Song , Honghe Xu , Hui Wang , Edmund A. Jarzembowski , Bo Wang

A new archostematan beetle, Brochocoleus sonidensis sp. nov. (Insecta: Coleoptera: Archostemata) is described based on a specimen preserved in the dorsal aspect from the Lower Cretaceous Damoguaihe Formation of Inner Mongolia, China. The new species is the first body species of the genus disinterred in China and can be distinguished from the other congeners based on its largest known size, not strong forward convergence of the lateral edges of the prothorax, and the unique combination of the aspect ratios of the pronotum and head.

根据中国内蒙古下白垩统达木盖河组保存的背侧标本，描述了一种新的弓背甲虫Brochocoleus sonidensis sp.该新种是该属在中国发现的第一个体部物种，其最大的已知体型、前胸侧缘不向前收敛以及前胸和头部长宽比的独特组合使其有别于其他同属物种。

引用次数: 0

Stratigraphy and sedimentology of the upper Cenomanian–lower Coniacian in the Northern Aures Range (Algeria) 北奥勒斯山脉（阿尔及利亚）上震旦纪-下震旦纪的地层学和沉积学

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.03.003

The stratigraphical features and palaeoenvironmental conditions of the upper Cenomanian–lower Coniacian carbonates from the northern part of the Aures Range are described for the first time. Four formations have been recognised, namely the Arris, Adahri, Yabous, and Bou Ouali, respectively. Planktonic foraminifera enable us to assign the upper part of the Arris Formation and the lower part of the Adahri Formation to the Middle–Upper Cenomanian (Rotalipora sp. cf. R. cushmani Total Range Zone), the upper part of the Adahri Formation to the Cenomanian–Turonian Transition to the lower Turonian (Whiteinella archaeocretacea Partial Range Zone and Helvetoglobotruncana helvetica Total-Range Zone, respectively), the lower member of the Yabous Formation to the middle Turonian (Marginotruncana sigali Partial Range Zone), and the upper member of the Yabous Formation to the upper Turonian (Marginotruncana schneegansi Partial Range Zone). The Turonian–Coniancian boundary was dated approximately. This biozonation enables a correlation with several upper Cenomanian–lower Coniacian sections outside Algeria, mainly within the Tethyan and Boreal domains. Based on the field data, and microfacies studies, the strata of these formations are arranged into eleven microfacies types (MT 1 to MT 11) that are described in terms of depositional environments, and grouped into three main facies associations (FA 1, FA 2, and FA 3): (i) a deep shelf-basin facies zone; (ii) marginal sand shoals, an open-marine/restricted platform facies zone; and (iii) an outer platform and toe-of-slope/distal slope facies zone. Analysis of the sequence stratigraphy has allowed the recognition of three third-order depositional sequences grouped into two megasequences and correlated to a regional scale.

该报告首次描述了奥雷斯山脉北部上元古-下元古碳酸盐岩的地层特征和古环境条件。共确认了四个地层，分别为 Arris、Adahri、Yabous 和 Bou Ouali。浮游有孔虫使我们能够将 Arris 地层的上部和 Adahri 地层的下部归入中-上震旦纪（Rotalipora sp.cushmani Total Range Zone），将 Adahri Formation 的上部归入仙人漫纪-都龙纪过渡到下都龙纪（Whiteinella archaeocretacea Partial Range Zone 和 Helvetoglobotruncana helvetica Total-Range Zone、分别），雅布斯地层下统至都龙纪中统（Marginotruncana sigali 部分范围区），雅布斯地层上统至都龙纪上统（Marginotruncana schneegansi 部分范围区）。都元古代-康熙元年界线的年代大致确定。这种生物区系可与阿尔及利亚境外的几个上震旦纪-下震旦纪地段相关联，主要是在泰西和北方地区。根据野外数据和微成因研究，这些地层被划分为 11 个微成因类型（MT 1 至 MT 11），这些微成因类型根据沉积环境进行了描述，并分为三个主要成因组合（FA 1、FA 2 和 FA 3）：(i) 深陆架-盆地面带；(ii) 边缘沙滩、开放-海洋/限制平台面带；(iii) 外部平台和坡脚/斜坡面带。通过对地层序列的分析，可以确认三个三阶沉积序列，分为两个巨序列，并与区域尺度相关联。

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引用次数: 0

Lateglacial Interstadial to mid-Holocene stratigraphy and palynology at Pepper Arden Bottoms, North Yorkshire, UK 英国北约克郡 Pepper Arden Bottoms 的冰期间层至全新世中期地层学和古植物学

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.08.005

James B. Innes , Mairead M. Rutherford , David R. Bridgland , Ben R. Gearey , Malcolm C. Lillie , Wishart A. Mitchell , Charlotte E. O'Brien , Richard T. Jones , Gareth J. Thompson

Investigations at Pepper Arden Bottoms, a lake basin site on the interfluve between the rivers Tees and Swale in northeast England, have recovered lithostratigraphical, pollen and plant macrofossil sequences which have allowed the reconstruction of sedimentary and vegetation history from the Lateglacial Interstadial to the post-Ulmus Decline mid-Holocene. Although the calcareous nature of the sediment and lack of terrestrial plant macrofossils precluded radiocarbon dating of sediments pre-dating the Ulmus Decline, pollen analyses showed sediment accumulation from the middle of the Lateglacial Interstadial, with the lake catchment remaining poorly vegetated until the Holocene, with low values for woody taxa, and grasses and sedges dominant. The late Interstadial cold phase GI-1b is present in the pollen stratigraphy, with a major reduction in Betula frequencies, replaced by Juniperus, and an increase in cold-tolerant herbs, mainly grasses and sedges. Microcharcoal frequencies are consistently substantial throughout the Lateglacial levels, probably indicating a natural fire regime, but are absent from the Holocene, suggesting little Mesolithic or Neolithic activity nearby, which is confirmed by a lack of pollen indicators of disturbance. The Lateglacial (Loch Lomond) Stadial is entirely dominated by Cyperaceae and Poaceae pollen, with very few trees and shrubs. The successive migration of postglacial thermophilous trees is recorded in the Holocene and possible effects of the Preboreal Oscillation and the 8.2 ka BP cold events are recognised. An Ulmus Decline occurs near the top of the profile, after which the assemblage is dominated by Alnus as the lake became terrestrialised and was occupied by fen and then alder carr. The very open Lateglacial vegetation adds this site to a northern group in northeast England with poor Lateglacial woodland development, in contrast to sites to the south, in North Yorkshire, where Lateglacial Betula woodland was much better established.

在英格兰东北部蒂斯河和斯威尔河交汇处的一个湖盆遗址 Pepper Arden Bottoms 进行的调查发现了岩石地层、花粉和植物大化石序列，从而可以重建从大冰期间冰期到全新世中期乌尔姆斯衰退后的沉积和植被历史。虽然沉积物的钙质性质和陆生植物大化石的缺乏排除了对榆树衰退之前沉积物进行放射性碳测年的可能性，但花粉分析显示沉积物从腊肠冰期间冰期中期开始积累，湖泊流域直到全新世之前一直植被稀少，木本类群含量较低，禾本科植物和莎草占主导地位。花粉地层中出现了间冰期晚期的寒冷阶段 GI-1b，桦树的频率大幅下降，被杜松取代，耐寒草本植物（主要是禾本科和莎草）的频率上升。在整个拉特格拉冰期地层中，微炭的频率一直很高，这可能表明这里有自然的火灾机制，但全新世则没有微炭，这表明附近几乎没有中石器时代或新石器时代的活动，这一点也从缺乏扰动迹象的花粉中得到了证实。拉特格拉冰期（洛蒙湖）的花粉完全以桧柏科和禾本科花粉为主，很少有乔木和灌木。全新世记录了冰期后嗜热树木的陆续迁移，并确认了前生物涛动和 8.2 ka BP 寒冷事件可能造成的影响。在剖面顶部附近出现了榆树衰退现象，之后随着湖泊陆地化，湖泊被沼泽和桤木林所占据，桤木树群开始占据主导地位。非常开阔的腊特拉冰期植被使该地点跻身英格兰东北部腊特拉冰期林地发展较差的北部地区，与之形成鲜明对比的是，在北约克郡南部的地点，腊特拉冰期的桦树林地发展得要好得多。

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引用次数: 0

The structural setting and geometry of the Faringdon Trough defined by subsurface mapping 通过地下测绘确定法林顿海槽的结构环境和几何形状

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.09.001

Nigel Banks

Data from over 80 boreholes have been used together with the surface geology to interpret the subsurface structure and stratigraphy of the Corallian to Gault (Upper Jurassic to Lower Cretaceous) sediments in the Vale of the White Horse, between Faringdon and Wantage in West Oxfordshire. The gentle regional dip to the SSE of the sediments in this area is interrupted by two major features. The first is the Faringdon Fault, first defined at outcrop just east of Faringdon. This has been traced SE from the outcrop extent for at least 8 km in the subsurface towards Wantage. It has an estimated maximum downthrow to the SW of ca 40 m. Contrary to previous interpretations, this fault was probably active during Kimmeridge Clay deposition.

The second feature is the Faringdon Trough, an erosional palaeovalley filled with at least 50 m of marine Lower Greensand sediments. The Trough trends SSE from Faringdon and cuts deeply through the Kimmeridge Clay to reach the underlying Corallian. A subtle structural feature, here named the Baulking Fault, has a throw of < 10 m and its movement was probably pre-Cretaceous, but it seems to have influenced the path and geometry of the Faringdon Trough, dividing it into two segments. Contrary to previous interpretations, subsurface mapping suggests that the main Trough has a broad U-shape in cross-section with a planar base where it rests on resistive Corallian limestone. Along its margins depositional dips of up to 9° have been widely recorded in the Lower Greensand sediments.

我们利用 80 多个钻孔的数据和地表地质信息，对位于西牛津郡法林顿和旺塔吉之间的白马谷科拉伦至高尔特（上侏罗世至下白垩世）沉积物的地下结构和地层进行了解释。该地区沉积物向东南方向的平缓区域倾角被两个主要地貌打断。第一条是法林顿断层，最初是在法林顿以东的露头处确定的。该断层从露头处开始向东南方向延伸，在地下至少延伸了 8 公里，一直延伸到旺塔吉。据估计，该断层向西南方向的最大下倾角约为 40 米。与之前的解释相反，该断层很可能在金默里奇粘土沉积期间就已开始活动。第二个地貌是法林顿槽，这是一个侵蚀性古山谷，其中充满了至少 50 米深的下绿砂岩海洋沉积物。海槽从法林顿向东南方向延伸，深深地穿过基姆里奇粘土，到达下层的科拉利亚岩。一个微妙的结构特征在此被命名为鲍尔金断层（Baulking Fault），其倾角为 10 米，其运动可能发生在白垩纪之前，但它似乎影响了法林顿海槽的走向和几何形状，将其分为两段。与之前的解释相反，地下测绘表明，主海槽的横截面呈宽阔的 U 形，底部为平面，位于具有阻力的科拉利亚石灰岩上。在下绿砂岩沉积物中广泛记录了其边缘高达 9° 的沉积倾角。

{"title":"The structural setting and geometry of the Faringdon Trough defined by subsurface mapping","authors":"Nigel Banks","doi":"10.1016/j.pgeola.2024.09.001","DOIUrl":"10.1016/j.pgeola.2024.09.001","url":null,"abstract":"<div><div>Data from over 80 boreholes have been used together with the surface geology to interpret the subsurface structure and stratigraphy of the Corallian to Gault (Upper Jurassic to Lower Cretaceous) sediments in the Vale of the White Horse, between Faringdon and Wantage in West Oxfordshire. The gentle regional dip to the SSE of the sediments in this area is interrupted by two major features. The first is the Faringdon Fault, first defined at outcrop just east of Faringdon. This has been traced SE from the outcrop extent for at least 8 km in the subsurface towards Wantage. It has an estimated maximum downthrow to the SW of <em>ca</em> 40 m. Contrary to previous interpretations, this fault was probably active during Kimmeridge Clay deposition.</div><div>The second feature is the Faringdon Trough, an erosional palaeovalley filled with at least 50 m of marine Lower Greensand sediments. The Trough trends SSE from Faringdon and cuts deeply through the Kimmeridge Clay to reach the underlying Corallian. A subtle structural feature, here named the Baulking Fault, has a throw of <10 m and its movement was probably pre-Cretaceous, but it seems to have influenced the path and geometry of the Faringdon Trough, dividing it into two segments. Contrary to previous interpretations, subsurface mapping suggests that the main Trough has a broad U-shape in cross-section with a planar base where it rests on resistive Corallian limestone. Along its margins depositional dips of up to 9° have been widely recorded in the Lower Greensand sediments.</div></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"135 5","pages":"Pages 596-612"},"PeriodicalIF":1.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540326","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

Early Miocene lacustrine deposits from the Oued Tilatou Formation (Aurès Massif, Eastern Algeria): Sedimentology, micropalaeontology, and palaeoenvironmental implications 来自 Oued Tilatou 地层（阿尔及利亚东部 Aurès 山丘）的早中新世湖相沉积：沉积学、微古生物学和古环境影响

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.08.003

Somia Khanfer , Fouad Djaiz , Josep Sanjuan , Lucas Silveira Antonietto , Bachir Lamouri , Amine Cherif , Hicham El Asmi , Cameron Manche

Lacustrine depositional systems provide a valuable record of palaeoenvironmental conditions since they rely on a delicate balance between accommodation space and water-sediment supply controlled by tectonic activity and climatic conditions. This study presents new sedimentological and micropalaeontological information from the early Miocene lacustrine Oued Tilatou Formation, northeastern Algeria. Based on sedimentary facies and microfossil assemblages, the Oued Tilatou Formation (OTF) is divided into two discrete units, the Lower OTF and the Upper OTF. The Lower OTF is characterised by reddish clay-rich carbonate mudstone containing reworked foraminifera and ostracods interspersed by polymodal clast-supported conglomerates attributed to alluvial deposition. The Lower OTF was deposited under fluvial–palustrine conditions, marked by a notable terrigenous sediment influx. In contrast, the Upper OTF encompasses greenish charophyte-dominated (Sphaerochara sp.) carbonate mudstone interbedded with silty carbonate mudstone, and dolomitic wackestone containing charophyte thalli, several ostracod species, and stromatolites. The dominant ostracod taxa within this interval are Mediocypris sp. cf. M. candonaeformis, indicating freshwater–brackish water conditions. The transition in depositional facies from the Lower OTF to the Upper OTF is interpreted as reflecting changes in the environment from fluvial–palustrine to shallow water lacustrine with fluctuation in freshwater input during the Burdigalian (Early Miocene). This study provides new insights on the interplay between early Miocene climate conditions and the tectonic uplift of the Aurès Massif, and their implications for lacustrine palaeoenvironmental conditions.

湖沼沉积系统提供了古环境条件的宝贵记录，因为它们依赖于受构造活动和气候条件控制的容纳空间和水-沉积物供应之间的微妙平衡。本研究介绍了阿尔及利亚东北部早中新世湖相 Oued Tilatou 地层的新沉积学和微观古生物学信息。根据沉积面貌和微化石组合，Oued Tilatou 地层（OTF）被划分为两个独立单元，即 OTF 下层和 OTF 上层。下OTF层的特征是富含红色粘土的碳酸盐泥岩，其中含有有孔虫和浮游动物的再加工体，并夹杂着多模式的碎屑支撑砾岩，这些砾岩被认为是冲积沉积物。下OTF沉积于河流-河口沉积条件下，以显著的土著沉积物流入为特征。与此相反，上OTF包含以绿色叶绿藻为主（Sphaerochara sp.）的碳酸盐泥岩，夹有淤泥质碳酸盐泥岩和白云质瓦基岩，其中含有叶绿藻菌丝、多种梭形纲动物和叠层石。该区间的主要梭形纲类群为 Mediocypris sp.沉积面貌从下OTF向上部OTF的过渡被解释为反映了布迪加里（早中新世）期间淡水输入波动所导致的环境从河流-河口区向浅水湖泊区的变化。这项研究为中新世早期气候条件与奥勒斯丘陵构造隆升之间的相互作用及其对湖泊古环境条件的影响提供了新的见解。

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引用次数: 0

A Tithonian (Upper Jurassic) lake shoreline in Buckinghamshire, UK: Evidence from stromatolite distribution in the Purbeck Formation 英国白金汉郡的提托尼（上侏罗统）湖岸线：普贝克地层叠层石分布的证据

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.08.001

Jonathan D. Radley , Robert A. Coram

Stromatolites in the essentially non-marine Purbeck Formation (Tithonian, Upper Jurassic) west of Aylesbury (Buckinghamshire, UK) cap an erosion surface truncating lacustrine–palustrine carbonates, previously documented from an exposure close to the site of the former Bugle Pit, Hartwell. The stromatolite occurrences in this area follow a regional northwest–southeast structural grain, evidenced by local normal faults, some demonstrably active during Late Jurassic–Early Cretaceous time. Observations from associated lithofacies and biota suggest a littoral lacustrine setting for the stromatolite ‘belt’. We hypothesise that the present-day stromatolite distribution reflects a fault-controlled palaeo-shoreline, and that growth of the stromatolites was linked to lacustrine transgression driven by syn-sedimentary movement on these faults. Littoral sand associated with the stromatolites was possibly reworked from older marine sediments undergoing erosion on a nearby fault footwall, or distally, on the western margin of the Anglo-Brabant Massif.

艾尔斯伯里（英国白金汉郡）以西基本上不属于海洋的普贝克地层（Tithonian，上侏罗统）中的叠层石覆盖了一个侵蚀面，该侵蚀面截断了湖泊-咸水层碳酸盐岩，之前在哈特威尔的 Bugle Pit 旧址附近的一处出露地层中也有记录。该地区的叠层石分布在西北-东南走向的区域构造纹理上，由当地的正断层证明，其中一些断层明显活跃于晚侏罗世-早白垩世时期。根据对相关岩性和生物群的观察，叠层石 "带 "的环境为沿岸湖沼。我们假设，叠层石现今的分布反映了受断层控制的古海岸线，叠层石的生长与这些断层上的合沉积运动所驱动的湖沼变迁有关。与叠层石有关的沿岸砂可能是从附近断层脚壁或远处盎格鲁-布拉班特山丘西缘遭受侵蚀的较古老海洋沉积物中重新加工而成的。

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引用次数: 0

Microvertebrates from the Lower Greensand Group (Lower Cretaceous) of Clophill, Bedfordshire, UK, and Nutfield, Surrey, UK 英国贝德福德郡 Clophill 和萨里郡 Nutfield 下绿砂岩组（下白垩统）的微脊椎动物

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.07.002

Lila Blake , Max Fursman , Christopher J. Duffin , Trevor Batchelor , Claudia Hildebrandt , Michael J. Benton

The Lower Greensand of southern England (early Aptian–early Albian; c., 120–110 Ma) has yielded diverse faunas of vertebrates, but these have not been reported in detail. Here, we present rich faunas, mainly comprising sharks, bony fishes, and crocodyliforms, from two localities to the north and south of the London–Brabant Massif. The first, Clophill Quarry, near Leighton Buzzard in Bedfordshire, has yielded fossils from the Brown Sands Formation, representing an inshore, tidally influenced environment, such as an estuary mouth. The second, Patteson Court Quarry, Nutfield, Surrey, has produced fossils from the Sandgate Formation (Redhill Sands Member). The faunas of both locations are similar, and they share a remarkable assemblage of at least 23 chondrichthyan taxa, one Edaphodon-like chimaeroid, ten hybodontiform sharks, and 12 neoselachian sharks. The hybodontiform sharks comprise two morphological groups, those with high-cusped piercing teeth, sometimes with lateral cusplets and a coronal ornament of vertical ridges, and those with low-crowned crushing teeth. The 12 species of neoselachian sharks include one representative of the extinct Synechodontiformes, as well as examples of the modern orders Hexanchiformes, Lamniformes, Carchariniformes, Squatiniformes, Heterodontiformes, and Orectolobiformes. Bony fishes are represented mostly by crushing teeth of Pycnodontiformes, Aspidorhynchiformes, Amiiformes, Lepisosteiformes, and Semionotiformes. Crocodyliforms are identified from seven morphotypes of elongate, goniopholid-like teeth. Based on these fossil teeth, the fauna is 53 % chondrichthyan and 21 % osteichthyan; neoselachians represent 32–45 % of the chondrichthyans, lower than figures from the underlying Wealden.

英格兰南部的下绿砂岩（早安普世-早阿尔比世；约，120-110Ma）产生了多种多样的脊椎动物群，但尚未有详细的报道。在此，我们介绍了来自伦敦-布拉班特山丘北部和南部两个地点的丰富动物群，主要包括鲨鱼、硬骨鱼类和鳄形目动物。第一个地点是贝德福德郡莱顿巴扎德附近的克洛菲尔采石场，这里出产的化石来自布朗沙层，代表了一种近岸、受潮汐影响的环境，如河口。第二个地点位于萨里州纳特菲尔德的帕特森宫采石场，出土的化石来自桑盖特地层（红山沙层）。这两个地点的动物群很相似，它们都有一个引人注目的组合，其中包括至少 23 个软骨鱼类类群、1 个类似埃达弗顿的类群、10 个双齿鲨类群和 12 个新齿鲨类群。双齿鲨包括两个形态类群，一类具有高尖的穿刺齿，有时具有侧尖齿和由垂直脊组成的冠状装饰，另一类具有低冠的破碎齿。新石器时代的 12 种鲨鱼包括已灭绝的新齿形目（Synechodontiformes）的一个代表，以及现代的六齿形目（Hexanchiformes）、蓝齿形目（Lamniformes）、胭脂鱼形目（Carchariniformes）、鱿鱼形目（Squatiniformes）、异齿形目（Heterodontiformes）和直齿形目（Orectolobiformes）的代表。硬骨鱼类的代表主要是侏儒鱼形目、蛛形目、黍形目、鳞鱼形目和半齿鱼形目中的破碎齿。鳄形目是通过七种形态的拉长、类似钩齿的牙齿确定的。根据这些牙齿化石，该动物群中软骨鱼类占 53%，骨鱼类占 21%；新石首鱼类占软骨鱼类的 32-45%，低于下伏魏尔登（Wealden）的数字。

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引用次数: 0

Re-assessing the age of the type locality of Nythosaurus larvatus (Therapsida, Cynodontia) and implications on the evolutionary dynamics of cynodonts 重新评估秧鸡龙（Therapsida, Cynodontia）模式产地的年龄及其对秧鸡龙进化动态的影响

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-10-01 DOI: 10.1016/j.pgeola.2024.08.007

J. Benoit, S. Jirah, E.S. Lund, T. Lafferty, V. Buffa, L.A. Norton

Nythosaurus larvatus was one of the first cynodonts named and, for a long time, the only therapsid for which the endocranial cast was described. The holotype and only skull of this species is thus a landmark in the history of therapsid palaeontology. It is believed to have come from Commissie Drift 303 (Free State Province, South Africa), a locality that has been traditionally dated to the Lystrosaurus declivis Assemblage Zone. However, this age was mostly based on the synonymy between Nythosaurus larvatus and Thrinaxodon liorhinus, the former being the only fossil indisputably reported from this locality and the latter being an index taxon for the Lystrosaurus declivis Assemblage Zone. A recent revision of Nythosaurus larvatus also questioned the age of Commissie Drift. Here, we report the result of our fieldwork to re-assess the age of this locality. We find that the stratigraphy conforms to the lower Burgersdorp Formation and that the fossil tetrapod fauna does not match the Lystrosaurus declivis Assemblage Zone. The overall scarcity of fossil bones, absence of plants and dicynodonts, and relative dominance of amphibian remains all point to an assignation to the Langbergia–Garjainia Subzone of the Cynognathus Assemblage Zone, which is consistent with the stratigraphy. The discovery of new material attributable to cf. Nythosaurus bolsters the notion that this taxon is from the late Olenekian. Nythosaurus larvatus can safely be considered a valid taxon, and may in fact occur elsewhere in this subzone.

幼龙是最早被命名的犬齿龙之一，而且在很长一段时间里，它是唯一一个被描述了颅内铸模的兽脚类。因此，该物种的主模式和唯一的头骨是兽脚类古生物学史上的一个里程碑。据信，它来自Commissie漂流区303号（南非自由州省），该地点历来被定为Lystrosaurus declivis集合区。然而，这一年代主要是基于幼龙（Nythosaurus larvatus）和栗鼻龙（Thrinaxodon liorhinus）之间的同义关系，前者是该地点无可争议地报告的唯一化石，而后者则是Lystrosaurus declivis Assemblage Zone的索引类群。最近对幼龙（Nythosaurus larvatus）的修订也对康米西河漂流的年代提出了质疑。在此，我们报告了重新评估该地点年龄的实地考察结果。我们发现，这里的地层与下伯格斯多普层（Burgersdorp Formation）一致，而且四足动物化石与Lystrosaurus declivis集合带不一致。骨骼化石的总体稀缺性、植物和双齿兽的缺失以及两栖动物化石的相对优势都表明，该化石区应归属于Cynognathus集合带的Langbergia-Garjainia亚区，这与地层学是一致的。发现了可归属于尼特龙的新材料，这进一步证实了该类群来自奥利尼克晚期的观点。可以有把握地将幼龙（Nythosaurus larvatus）视为一个有效的类群，事实上它可能出现在该子区的其他地方。

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引用次数: 0

The aberrant crinoid Cyathidium (Echinodermata, Crinoidea, Cyrtocrinida) from lower Campanian phosphatic chalk in West Sussex (UK) and Picardie (France) 英国西萨塞克斯郡和法国皮卡迪省下坎帕尼亚期磷化白垩中的异常棘皮动物Cyathidium（棘皮动物门，Crinoidea，Cyrtocrinida

IF 1.2 4区地球科学 Q2 Earth and Planetary Sciences

Proceedings of the Geologists Association

Pub Date : 2024-08-02 DOI: 10.1016/j.pgeola.2024.07.001

Andy S. Gale, John W.M. Jagt

A new species of the “living fossil” crinoid , , is described from lower Campanian phosphatic chalks in southern England and northern France. The squat, robust stalkless crinoid lived in high-energy conditions in phosphate chalk basins, attached to the surface of the basal hardground. Other Cretaceous and lower Paleogene occurrences of the genus, from France, the Czech Republic and Denmark are briefly reviewed.

该研究描述了英格兰南部和法国北部下坎帕尼亚磷质白垩纪的一种新的 "活化石 "棘皮动物Ⅳ。这种扁平、粗壮的无柄棘皮动物生活在磷酸盐白垩盆地的高能环境中，附着在基底硬地的表面。本文简要回顾了该属在法国、捷克共和国和丹麦的其他白垩纪和下古新世的分布情况。

引用次数: 0