Proceedings of the Geologists Association最新文献

The cliff and foreshore sections at Lavernock, South Wales form the type section of the Penarth Group, representing the Rhaetian stage in the UK, the latest Triassic. The Rhaetian bonebeds here have been famous for over 150 years for their vertebrate fossils. Here, we show that, unusually, the Lavernock basal Westbury Formation bonebed is dominated by osteichthyan teeth, with sharks such as Lissodus relatively rare. The rounded teeth of the durophagous bony fish Sargodon are abundant, with teeth of Severnichthys next in abundance, and Gyrolepis the rarest, quite unlike most other Rhaetian bone beds. Also, small elements such as shark denticles have not been found, whilst larger bones of marine reptiles (ichthyosaurs, plesiosaurs) and dinosaurs do occur. The dinosaur bones are unusual, and Lavernock may have yielded more such bones than any other British Rhaetian bone bed. These terrestrial elements suggest that the lower bone bed accumulated close to shore, but underwent considerable transport, with clasts perhaps moving back and forwards, to explain the abrasion of specimens, the larger elements and absence of smaller specimens. Dinosaurs are more widely documented in the Late Triassic of the Penarth area, around Lavernock, than anywhere else in the UK.

A series of historical documents by the 19th-century amateur naturalist and palaeontologist Alfred Brown report the earliest discovery of bone-bearing cave breccia in the former Transvaal (South Africa). The oldest of these reports dates from 1890 and predates the first mention of the existence of bone-bearing breccia at the famous Sterkfontein-Kromdraai caves by five years. The breccia fragment was kept by Brown in his collection, where it was noted to come from the Monte Christo gold mine near Ventersdorp (North-West Province). Brown's specimen is lost, but we could relocate the mine and confirm the presence of breccia deposits. Alfred Brown's notes are the earliest scientific report about the bone-bearing nature of Plio-Pleistocene South African caves and the first to acknowledge them as a potential source of hominin fossils, some 30 years before the discovery of the Taung Child, Australopithecus africanus. The finding strengthens the chronology of the discovery of the South African fossil hominin sites. It also significantly shortens the gap between the gold rush and the first discovery of bone-bearing breccia in the Witwatersrand.

A great range and number of journals exist to promote and disseminate local knowledge in the areas of natural history, geology, geography and ecology. Many are still active; others are lost. The journals act as mouthpieces for local societies and are a repository of local knowledge. Some are hard to locate but the websites of local societies provide information on topics covered and the regularity of publication of the journals. The loss of journals seems to be the result of the pressure on academics to publish in international outlets and the growth of highly informative websites.

In order to better constrain the structural evolution of the North–South Axis (NOSA) running through central Tunisia, a multidisciplinary approach based on geological mapping, field observations and paleostress analysis was used. The geological study of the middle part of the NOSA including the Gadoum, Akrouta, Sidi Khalif, Khechem El Kaleb and Faïd structures, showed the predominance of N–S and E–W fault sets. Movement on the faults of this fault network caused the formation of depositional areas and the collapsed and tilting of fault bounded blocks located in the Southern part of the Gadoum–Akrouta sector. The Gadoum and Akrouta Jebels formed as a result of slip and rotation on a single N–S trending listric fault in the Cenomanian during which time reactivation of both the N–S and E–W fault sets occurred. During Coniacian–Santonian times, when the Aleg Formation was being deposited, the study area was affected by a transtensive regime. This regime led to the division of the area into blocks (e.g., the Gadoum–Akrouta block and the Wadi El Abiod Syncline) and this resulted in the Aleg Formation being deposited with variable thicknesses. During the Campanian–Early Maastrichtian, a N–S transpressive regime was established, and this regime, coupled with the salt tectonics, resulted in the formation of an angular unconformity, subsidence inversion and lateral thickness variations of the Abiod Formation. During the Early Eocene, an E–W fault network affected the sedimentary basin. These faults, arranged in steps, generated accommodation spaces for sediments which increase in thickness along the North–South Axis.

Morocco hosts a wealth of geological heritage, alongside a rich and varied palaeontological heritage that dates back 1.7 billion years, and archaeological assets that chronicle the biological evolution of the human species and their cultural activities. Research into Morocco's geoheritage has pinpointed several sites and monuments, both nationally and internationally recognised, noted for their unique geological formations and aesthetic appeal. This study aims to offer a comprehensive review of the geoheritage research conducted in Morocco over the last 14 years (2008–2022). This research is sourced from databases including Scopus, Science Direct, and Google Scholar. The documents retrieved have been meticulously reviewed after isolating publications that primarily focus on Moroccan geoheritage sites. The findings indicate a growing trend in the number of studies conducted in this realm over the years. Initially, most research concentrated on the identification and characterisation of Morocco's geoheritage localities. However, with the burgeoning interest in this field, geoscientists have broadened their scope to explore diverse facets of geoheritage site evaluation, encompassing aspects such as geoparks, geotourism, geoeducation, and geoconservation.

Rhaetian seas in the latest Triassic transgressed from west to east over the southwest of the UK, reaching parts of South Wales and the North Somerset coast first. Evidence comes from marine conditions in the pre-Rhaetian Williton Member, a unit not seen further east. Here, we confirm this hypothesis with reports of diverse, Rhaetian-style fish faunas in the Williton Member, as well as evidence that the Westbury Formation bonebeds are from deeper waters than most others in the region. Our study focuses on the classic coastal section at Lilstock, which shows the entire Penarth Group and the Triassic-Jurassic boundary. The Williton Member fossil beds yield Rhaetian-type chondrichthyans (Lissodus, denticles), osteichthyan teeth (Gyrolepis, Sargodon, Saurichthys), and bivalves. The basal and higher bone beds of the Westbury Formation are dominated by osteichthyans (86.8 %, 84.7 %), with chondrichthyans relatively rare (13.2 %, 15.3 %), the opposite of what is seen at other locations in the southwest of the UK (16–59 % osteichthyans; 41–84 % chondrichthyans). The similarity of the faunal composition in the basal and higher Rhaetian bone beds is also unusual, and the dominance by bony fishes can be interpreted as evidence for deeper water than further to the east.

Well-defined manus and pes print couple, likely from a trackway attributable to a sauropod dinosaur are revealed on a fallen block of Ravenscar Group sandstones in a cliff fall at Whitby, Yorkshire, England. The pes print displays four, possibly five toes and thus closely resembles that of the ichnogenera Brontopodus and Parabrontopodus. They are here referred to Brontopodus cf. pentadactylus Kim and Lockley, 2012. Impressions of a scaled integument are present around parts of the pes. The prints were likely made by a sauropod with a hip height of between 1.92 m and 2.83 m.

Three new fossil wings of dragonflies are described from the Upper Eocene of the Isle of Wight (UK), which add to our knowledge of the Odonata fauna of the Bembridge Insect Bed. They consist of a male hind wing attributed to the Gomphaeschnidae Anglogomphaeschna eocenica, a forewing attributed to the Aeshnidae Aeschnophlebia andreasi, and the first Libellulidae discovered in this outcrop. The two former fossils provide more complete diagnoses of these Aeshnoidea. Although the latter is too incomplete for formal description, it belongs to the subfamily Pantalinae, and is among the oldest known fossils that can be attributed to the crown group of the Libellulidae.

Three ichnospecies of Lophoctenium (L. comosum, L. richteri and L. cf. haudimmineri) are reported from the Upper Devonian Argiles de Marhouma Formation (southwestern Algeria) for the first time. This formation contains a diverse assemblage of trace fossils belonging to the Nereites ichnofacies. We describe three ichnospecies of Lophoctenium that correspond to three different feeding strategies among the diverse ichnofauna of the Argiles de Marhouma Formation. The strategy of L. comosum evidences food-rich sediments as it maximises the amount of collected food per foraged distance. The strategy of L. richteri is probably most efficient for feeding in slightly less nutrient rich sediment, but gives the opportunity to discover more prolific feeding sites by moving on longer distances. The strategy with a straight central burrow and probes on both sides of the main burrow with long interspaces (L. cf. haudimmineri) was presumably used in the least food rich sediment. It seems that the Lophoctenium was widespread in the Devonian, but restricted to seas surrounding Gondwana.

An association between round or oval features and linear features has been noted in South African Pleistocene coastal deposits, in apparent association with elephant tracks. The round or oval features sometimes exhibit concentric rings, and the latter often comprise near-parallel grooves and ridges. In one case the concentric rings and parallel grooves are closely connected. Such an association requires interpretation, even if this remains hypothetical until further sites are identified. Elephants are the heaviest extant land mammals, and their capacity to impart substantial forces onto the substrates on which they tread is well documented. Such forces include a seismic component, and seismic communication between elephants has received considerable attention in recent decades. Comparisons with dinosaur tracks are instructive in interpreting the available ichnological evidence. In the absence of plausible alternatives, the possibility that the noted features represent an ichnological signature of elephant seismicity or seismic communication needs to be considered. The rock art record in southern Africa suggests that ancestral humans were aware of elephant seismic communication. A comprehensive approach to elephant seismicity can involve not just research into the habits of extant elephants, but also the rock art record and the trace fossil record. To illustrate these concepts, findings from South African trace fossil sites and rock art sites are presented.