Pub Date : 2023-11-28DOI: 10.37570/bgsd-2023-72-08
W. Schwarzhans, Kent A. Nielsen
Few deepwater otolith associations from the Eocene have been found so far. The small assemblage of aragonitic-preserved otoliths from the Lillebælt Clay Formation described here therefore adds to the understanding of early Palaeogene deep-sea fish faunas. These otoliths were obtained from a level at about the Ypresian/Lutetian interface and may thus be older than the otoliths previously described from Trelde Næs from mold casts from carbonate concretions. Only 14 otoliths were recovered from about 6,000 kg processed bulk samples. The assemblage also differs in the composition and contains three new species and one new genus: Diaphus? duplex n. sp., Bregmaceros danicus n. sp. and the ophidiid Pronobythites schnetleri n. gen, n. sp. In addition, the new genus Treldeichthys n. gen. in Acanthomorpha incertae sedis is established for T. madseni (Schwarzhans, 2007). The small assemblage also differs in composition from comparable associations described from southwest France and northern Italy on the species level but shows some relationship on a higher systematic level. The mechanism and timing of the colonization of the deep sea by selected groups of fishes is discussed, particularly in respect to the depth migration of demersal fishes.
迄今为止，发现的始新世深水耳石很少。因此，本文描述的 Lillebælt Clay Formation（利勒贝尔粘土层）中保存的少量文石耳石组合有助于了解古新世早期的深海鱼类动物群。这些耳石取自约伊普雷期/卢塞梯期交界处的一个层位，因此可能比之前描述的从特雷尔德奈斯碳酸盐凝结物的铸模中提取的耳石更古老。从大约 6,000 千克处理过的散装样本中只发现了 14 块耳石。该集合体在成分上也有所不同，包含三个新种和一个新属：Diaphus? duplex n. sp.、Bregmaceros danicus n. sp.和 Ophidiid Pronobythites schnetleri n. gen, n. sp.。此外，为 T. madseni 建立了 Acanthomorpha incertae sedis 中的新属 Treldeichthys n. gen.（Schwarzhans，2007 年）。在物种层面上，该小型集合体的组成也不同于法国西南部和意大利北部描述的同类集合体，但在更高的系统层面上却显示出一定的关系。本文讨论了某些鱼类群体在深海定居的机制和时间，特别是底栖鱼类的深度洄游。
{"title":"Fish otoliths from the bathyal Eocene Lillebælt Clay Formation of Denmark","authors":"W. Schwarzhans, Kent A. Nielsen","doi":"10.37570/bgsd-2023-72-08","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-08","url":null,"abstract":"Few deepwater otolith associations from the Eocene have been found so far. The small assemblage of aragonitic-preserved otoliths from the Lillebælt Clay Formation described here therefore adds to the understanding of early Palaeogene deep-sea fish faunas. These otoliths were obtained from a level at about the Ypresian/Lutetian interface and may thus be older than the otoliths previously described from Trelde Næs from mold casts from carbonate concretions. Only 14 otoliths were recovered from about 6,000 kg processed bulk samples. The assemblage also differs in the composition and contains three new species and one new genus: Diaphus? duplex n. sp., Bregmaceros danicus n. sp. and the ophidiid Pronobythites schnetleri n. gen, n. sp. In addition, the new genus Treldeichthys n. gen. in Acanthomorpha incertae sedis is established for T. madseni (Schwarzhans, 2007). The small assemblage also differs in composition from comparable associations described from southwest France and northern Italy on the species level but shows some relationship on a higher systematic level. The mechanism and timing of the colonization of the deep sea by selected groups of fishes is discussed, particularly in respect to the depth migration of demersal fishes.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":"29 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139219888","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}
Pub Date : 2023-11-27DOI: 10.37570/bgsd-2023-72-07
A. T. Nielsen, K. Klitten
A detailed correlation of the lower Cambrian Læså Formation on southern Bornholm, Denmark, is based on gamma ray and formation resistivity wireline logs from 25 water supply wells and 5 scientific boreholes. The interpretation hinges on comparison with the wireline log suite obtained in the fully cored Borggård-1 borehole that penetrated the formation in its entirety. The Norretorp Member, 102.9 m thick in Borggård-1, consists predominantly of intensively bioturbated siltstone. Several levels are strongly glauconitic and usually also contain phosphorite nodules. Fine-grained sandstone beds, 0.5–20 cm thick and interpreted as tempestites, occur throughout the unit; a few thicker sandstone layers consist of stacked tempestites. However, many sandstone beds, primarily in the upper 2/3 of the member, have been partly or totally obliterated by the pervasive bioturbation. The overlying Rispebjerg Member, 3.5 m thick in Borggård-1, is dominated by well-cemented medium to coarse-grained quartz sandstone. The variable lithology of the Læså Formation is illustrated by photos of core samples from Borggård-1. The studied wells are located on different fault blocks with 18 km between the easternmost and westernmost well sites. The Norretorp Member is of almost similar thickness throughout the study area whereas the Rispebjerg Member is 2.2–5.6 m thick. The essentially unchanging thickness of the Læså Formation and the sheet like distribution of tempestites demonstrate that the intense faulting of southern Bornholm post-dates deposition. The Norretorp Member is divided into a lower log-unit (57 m thick in Borggård-1) characterized by a moderately variable gamma ray log pattern and an upper log-unit (46 m thick in Borggård-1) exhibiting a more uniform gamma radiation of overall lower intensity. The log-units reflect a more common occurrence of glauconite and phosphorite in the lower part of the member and a higher sand content in the upper part. These lithological differences are also reflected by a generally higher resistivity and P-wave velocity in the upper log-unit. Seven thicker sandstone horizons (15–80 cm thick), labelled S1 to S7, are laterally persistent within the Norretorp Member. Four additional horizons, referred to as MGL [multiple gamma low], MGH [multiple gamma high], MM [middle marker] and GH [gamma high], are also laterally widespread. A readily identifiable red-brown horizon is located at 4.4–5.9 m above the base of the Læså Formation in Borggård-1: it appears to be developed throughout the study area.
{"title":"Wireline log stratigraphy of the lower Cambrian Læså Formation, Bornholm, Denmark.","authors":"A. T. Nielsen, K. Klitten","doi":"10.37570/bgsd-2023-72-07","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-07","url":null,"abstract":"A detailed correlation of the lower Cambrian Læså Formation on southern Bornholm, Denmark, is based on gamma ray and formation resistivity wireline logs from 25 water supply wells and 5 scientific boreholes. The interpretation hinges on comparison with the wireline log suite obtained in the fully cored Borggård-1 borehole that penetrated the formation in its entirety. The Norretorp Member, 102.9 m thick in Borggård-1, consists predominantly of intensively bioturbated siltstone. Several levels are strongly glauconitic and usually also contain phosphorite nodules. Fine-grained sandstone beds, 0.5–20 cm thick and interpreted as tempestites, occur throughout the unit; a few thicker sandstone layers consist of stacked tempestites. However, many sandstone beds, primarily in the upper 2/3 of the member, have been partly or totally obliterated by the pervasive bioturbation. The overlying Rispebjerg Member, 3.5 m thick in Borggård-1, is dominated by well-cemented medium to coarse-grained quartz sandstone. The variable lithology of the Læså Formation is illustrated by photos of core samples from Borggård-1. The studied wells are located on different fault blocks with 18 km between the easternmost and westernmost well sites. The Norretorp Member is of almost similar thickness throughout the study area whereas the Rispebjerg Member is 2.2–5.6 m thick. The essentially unchanging thickness of the Læså Formation and the sheet like distribution of tempestites demonstrate that the intense faulting of southern Bornholm post-dates deposition. The Norretorp Member is divided into a lower log-unit (57 m thick in Borggård-1) characterized by a moderately variable gamma ray log pattern and an upper log-unit (46 m thick in Borggård-1) exhibiting a more uniform gamma radiation of overall lower intensity. The log-units reflect a more common occurrence of glauconite and phosphorite in the lower part of the member and a higher sand content in the upper part. These lithological differences are also reflected by a generally higher resistivity and P-wave velocity in the upper log-unit. Seven thicker sandstone horizons (15–80 cm thick), labelled S1 to S7, are laterally persistent within the Norretorp Member. Four additional horizons, referred to as MGL [multiple gamma low], MGH [multiple gamma high], MM [middle marker] and GH [gamma high], are also laterally widespread. A readily identifiable red-brown horizon is located at 4.4–5.9 m above the base of the Læså Formation in Borggård-1: it appears to be developed throughout the study area.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":"30 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139231614","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}
Pub Date : 2023-10-13DOI: 10.37570/bgsd-2023-71-06
Carlette N. Blok, Thierry Adatte, Jon R. Ineson, Emma Sheldon, Florian W.H. Smit, Bodil W. Lauridsen, Mads E. Jelby, Kresten Anderskouv, Stéphane Bodin
The alternating marlstone and chalk of the Lower Cretaceous succession in the Danish Central Graben (DCG) are important for the understanding of the evolution of the larger North Sea Basin. This study focusses on the clay mineral assemblages of the upper Hauterivian – lower Aptian in the DCG and Danish Basin (DB) and their implications. Clay mineral assemblages are predominantly used to assess palaeoclimate. In this study, however, they were additionally used in a source-to-sink context. Kaolinite was found to form a dominant component of the clay mineral assemblage in the sampled wells of the DCG and in the DB, suggesting that a feldspar- or kaolinite-rich source was present and actively eroded in the region during the Early Cretaceous. Moreover, a decreasing gradient west to east of average kaolinite content is observed in the three studied wells for the early Hauterivian to late Barremian (BC9-BC17), with the highest content observed in the North Jens-1 well (av. 74%), followed by the Boje-2C well (av. 49%) and lastly in the Vinding-1 well (av. 39%). Due to the relatively rapid settling of kaolinite in marine environments compared to other clay minerals, this gradient suggests that the main clay mineral source was located in the south-western part of the DCG. Isochore maps, a new palaeogeographic map of the DCG and the western part of the German sector of the North Sea illustrates where Lower Cretaceous rocks are absent in this region, due to either erosion or non-deposition. Potential subaerially exposed highs included the distant Baltic Shield to the north, the Ringkøbing–Fyn High to the east and the Heno Plateau within the DCG, with the latter being located closest to the North Jens-1 well and containing feldspar-rich sandstones of the Heno Formation (upper Kimmeridgian – lowermost Volgian/Tithonian). During the Early Cretaceous, part of the Heno Formation was potentially subaerially exposed or subject to wave reworking/erosion in parts of the Danish and German sectors. The sandstones could weather into kaolinite and this structural high is therefore suggested to have been the main source area for this part of the DCG, with minor sediment influxes from the Ringkøbing–Fyn High and Baltic Shield. In addition, the overall decrease in kaolinite in the DCG from the late Hauterivian to the late Barremian indicates a climatic change towards drier conditions, with some minor, slightly more humid periods.
{"title":"Clay mineral assemblages as a tool in source-to-sink studies: an example from the Lower Cretaceous of the North Sea Basin","authors":"Carlette N. Blok, Thierry Adatte, Jon R. Ineson, Emma Sheldon, Florian W.H. Smit, Bodil W. Lauridsen, Mads E. Jelby, Kresten Anderskouv, Stéphane Bodin","doi":"10.37570/bgsd-2023-71-06","DOIUrl":"https://doi.org/10.37570/bgsd-2023-71-06","url":null,"abstract":"The alternating marlstone and chalk of the Lower Cretaceous succession in the Danish Central Graben (DCG) are important for the understanding of the evolution of the larger North Sea Basin. This study focusses on the clay mineral assemblages of the upper Hauterivian – lower Aptian in the DCG and Danish Basin (DB) and their implications. Clay mineral assemblages are predominantly used to assess palaeoclimate. In this study, however, they were additionally used in a source-to-sink context. Kaolinite was found to form a dominant component of the clay mineral assemblage in the sampled wells of the DCG and in the DB, suggesting that a feldspar- or kaolinite-rich source was present and actively eroded in the region during the Early Cretaceous. Moreover, a decreasing gradient west to east of average kaolinite content is observed in the three studied wells for the early Hauterivian to late Barremian (BC9-BC17), with the highest content observed in the North Jens-1 well (av. 74%), followed by the Boje-2C well (av. 49%) and lastly in the Vinding-1 well (av. 39%). Due to the relatively rapid settling of kaolinite in marine environments compared to other clay minerals, this gradient suggests that the main clay mineral source was located in the south-western part of the DCG. Isochore maps, a new palaeogeographic map of the DCG and the western part of the German sector of the North Sea illustrates where Lower Cretaceous rocks are absent in this region, due to either erosion or non-deposition. Potential subaerially exposed highs included the distant Baltic Shield to the north, the Ringkøbing–Fyn High to the east and the Heno Plateau within the DCG, with the latter being located closest to the North Jens-1 well and containing feldspar-rich sandstones of the Heno Formation (upper Kimmeridgian – lowermost Volgian/Tithonian). During the Early Cretaceous, part of the Heno Formation was potentially subaerially exposed or subject to wave reworking/erosion in parts of the Danish and German sectors. The sandstones could weather into kaolinite and this structural high is therefore suggested to have been the main source area for this part of the DCG, with minor sediment influxes from the Ringkøbing–Fyn High and Baltic Shield. In addition, the overall decrease in kaolinite in the DCG from the late Hauterivian to the late Barremian indicates a climatic change towards drier conditions, with some minor, slightly more humid periods.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135856080","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}
Pub Date : 2023-08-12DOI: 10.37570/bgsd-2023-72-06
J. Pollerspöck, K. Nielsen, I. Feichtinger, N. Straube
This study describes for the first time a number of distinct fossil teeth documenting several deep-sea shark species from the Eocene, which were previously not recorded from the North Sea Basin, including Apristurus sp., Orthechinorhinus cf. pfeili, Deania cf. angoumeensis, Squaliolus sp., Etmopterus cf. cahuzaci and Paraetmopterus nolfi. Our findings significantly increase the deep-sea shark diversity documented from this area so far. Despite the fact that the North Sea Basin had already lost direct connections to the neighbouring marine areas in the Eocene, the fauna shows highest similarities with documented Eocene deep-sea faunas of France, Austria and northern Morocco using cluster analysis.
{"title":"New records of fossil deep-sea shark teeth from the Lillebælt Clay (Early–Middle Eocene) of Denmark","authors":"J. Pollerspöck, K. Nielsen, I. Feichtinger, N. Straube","doi":"10.37570/bgsd-2023-72-06","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-06","url":null,"abstract":"This study describes for the first time a number of distinct fossil teeth documenting several deep-sea shark species from the Eocene, which were previously not recorded from the North Sea Basin, including Apristurus sp., Orthechinorhinus cf. pfeili, Deania cf. angoumeensis, Squaliolus sp., Etmopterus cf. cahuzaci and Paraetmopterus nolfi. Our findings significantly increase the deep-sea shark diversity documented from this area so far. Despite the fact that the North Sea Basin had already lost direct connections to the neighbouring marine areas in the Eocene, the fauna shows highest similarities with documented Eocene deep-sea faunas of France, Austria and northern Morocco using cluster analysis.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49003032","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}
Pub Date : 2023-06-21DOI: 10.37570/bgsd-2023-72-05
T. Kočí, J. Milán, M. Jäger
Tubes of a new serpulid species, Neovermilia gundstrupensis sp. nov., from the lower part of the Kerteminde Marl Formation (Selandian, middle Paleocene) of Gundstrup gravel pit, Fyn, Denmark, represent the first serpulids of this group from the Selandian of Denmark. Within the long-ranging genus Neovermilia (Oxfordian to Recent), the new finds extend the last recorded occurrence of an informal sub-group of closely related serpulids from the upper Danian to the lower Selandian. Neovermilia gundstrupensis is characterized by a tube increasing only slowly in diameter reaching up to approximately 5 mm and possessing small, often densely spaced annular striae occasionally merging into weakly but never strongly developed annular peristomes. Almost all specimens found so far are attached to siliceous sponges of the genus Ventriculites. The tube morphology of the new species and the microstructure of the tube wall, as well as its palaeoecology are discussed.
来自丹麦Fyn Gundstrup砾石坑的Kerteminde Marl组（Selandian，古新世中期）下部的一种新的serpulid物种Neo朱虫属gundstrupensis sp.nov.的管，代表了丹麦Selandian的第一批serpulid。在新蠕虫属（Oxfordian to Recent）中，新发现将最后一次有记录的密切相关的非正规细尾蛇亚群的出现从上大丹阶扩展到下塞拉兰阶。新朱粉虫的特征是直径缓慢增加，达到约5毫米，并具有小的、通常密集分布的环状条纹，偶尔合并成弱但从未强烈发育的环状外变异体。到目前为止，几乎所有发现的标本都附着在Ventriculites属的硅质海绵上。对新种管的形态、管壁的微观结构及其古生态学进行了讨论。
{"title":"Neovermilia gundstrupensis sp. nov. (Polychaeta, Serpulidae) from the Selandian (middle Paleocene) of Fyn, Denmark","authors":"T. Kočí, J. Milán, M. Jäger","doi":"10.37570/bgsd-2023-72-05","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-05","url":null,"abstract":"Tubes of a new serpulid species, Neovermilia gundstrupensis sp. nov., from the lower part of the Kerteminde Marl Formation (Selandian, middle Paleocene) of Gundstrup gravel pit, Fyn, Denmark, represent the first serpulids of this group from the Selandian of Denmark. Within the long-ranging genus Neovermilia (Oxfordian to Recent), the new finds extend the last recorded occurrence of an informal sub-group of closely related serpulids from the upper Danian to the lower Selandian. Neovermilia gundstrupensis is characterized by a tube increasing only slowly in diameter reaching up to approximately 5 mm and possessing small, often densely spaced annular striae occasionally merging into weakly but never strongly developed annular peristomes. Almost all specimens found so far are attached to siliceous sponges of the genus Ventriculites. The tube morphology of the new species and the microstructure of the tube wall, as well as its palaeoecology are discussed.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43045128","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}
Pub Date : 2023-06-07DOI: 10.37570/bgsd-2023-72-03
J. S. Peel
The upper Henson Gletscher Formation (Cambrian, Miaolingian Series, Wuliuan Stage) of southern Lauge Koch Land and Løndal, south-western Peary Land, North Greenland (Laurentia) yields diverse assemblages of phosphatised Small Shelly Fossils after treatment with weak acetic acid. The occurrence merits description as a fossil Lagerstätte on account of the exceptional preservation of soft parts in some specimens, although the phosphatisation itself is generally rather coarse. Bradoriid and phosphatocopid arthropods are common and display substantial variation in their preservational history. Some specimens retain traces of internal morphology, although details are generally obscured by indifferent preservation. Rare specimens extend the range of stem-group pentastomid arthropods back by more than 10 million years. A unique hatching larva demonstrates the same early developmental stage of a stem-group priapulan worm to that described in some present-day priapulans. The preservation of an in place operculum has demonstrated that the widespread, supposed mollusc Protowenella is actually an unusual, strongly coiled hyolith. Abundant coprolites and cololites provide additional evidence of early phosphatisation. In terms of morphology, Cambrocoryne lagenamorpha gen. et sp. nov. superficially resembles wiwaxiid and some annelid sclerites, thelodont scales and the foraminiferan Lagena, but its true identity is obscure.
{"title":"A phosphatised fossil Lagerstätte from the middle Cambrian (Wuliuan Stage) of North Greenland (Laurentia)","authors":"J. S. Peel","doi":"10.37570/bgsd-2023-72-03","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-03","url":null,"abstract":"The upper Henson Gletscher Formation (Cambrian, Miaolingian Series, Wuliuan Stage) of southern Lauge Koch Land and Løndal, south-western Peary Land, North Greenland (Laurentia) yields diverse assemblages of phosphatised Small Shelly Fossils after treatment with weak acetic acid. The occurrence merits description as a fossil Lagerstätte on account of the exceptional preservation of soft parts in some specimens, although the phosphatisation itself is generally rather coarse. Bradoriid and phosphatocopid arthropods are common and display substantial variation in their preservational history. Some specimens retain traces of internal morphology, although details are generally obscured by indifferent preservation. Rare specimens extend the range of stem-group pentastomid arthropods back by more than 10 million years. A unique hatching larva demonstrates the same early developmental stage of a stem-group priapulan worm to that described in some present-day priapulans. The preservation of an in place operculum has demonstrated that the widespread, supposed mollusc Protowenella is actually an unusual, strongly coiled hyolith. Abundant coprolites and cololites provide additional evidence of early phosphatisation. In terms of morphology, Cambrocoryne lagenamorpha gen. et sp. nov. superficially resembles wiwaxiid and some annelid sclerites, thelodont scales and the foraminiferan Lagena, but its true identity is obscure.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49393524","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}
Pub Date : 2023-06-07DOI: 10.37570/bgsd-2023-72-04
O. Bennike, B. Nilsson
We retrieved a sediment core from Vasby Mose, a calcareous fen on eastern Sjælland, Denmark. The record spans the period from c. 14 700 to 6800 cal. years BP. During the Lateglacial, Vasby Mose was a lake where minerogenic sandy and clayey sediments accumulated. In the early Lateglacial, from c. 14 700 to 13 200 cal. years BP, a tundralike open, treeless vegetation with Betula nana and Dryas octopetala was found in the region. During the Younger Dryas, a rich flora of aquatic plants was found in the lake. In the Early to Mid-Holocene, Vasby Mose was a spring-fed calcareous fen, with deposition of peat and tufa. The flora included the sedges Carex rostrata and Carex paniculata, the aquatic plant Menyathes trifoliata, the calciphilous reed plant Cladium mariscus and the today nationally extinct bryophyte Meesia triquetra. The fauna included aquatic mollusc taxa such as Pisidium sp., Valvata spp. And Bithynia tentaculate and terrestrial or semi-terrestrial species such as Galba truncatula, Euconolus cf. alderi, Succinea/Oxyloma, Zonitoides nitidus and Vallonia pulchella. The Preboreal oscillation and other Early Holocene climate events are seen as short-lived, wet intervals.
{"title":"Lateglacial to Mid-Holocene history of Vasby Mose, eastern Sjælland, Denmark","authors":"O. Bennike, B. Nilsson","doi":"10.37570/bgsd-2023-72-04","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-04","url":null,"abstract":"We retrieved a sediment core from Vasby Mose, a calcareous fen on eastern Sjælland, Denmark. The record spans the period from c. 14 700 to 6800 cal. years BP. During the Lateglacial, Vasby Mose was a lake where minerogenic sandy and clayey sediments accumulated. In the early Lateglacial, from c. 14 700 to 13 200 cal. years BP, a tundralike open, treeless vegetation with Betula nana and Dryas octopetala was found in the region. During the Younger Dryas, a rich flora of aquatic plants was found in the lake. In the Early to Mid-Holocene, Vasby Mose was a spring-fed calcareous fen, with deposition of peat and tufa. The flora included the sedges Carex rostrata and Carex paniculata, the aquatic plant Menyathes trifoliata, the calciphilous reed plant Cladium mariscus and the today nationally extinct bryophyte Meesia triquetra. The fauna included aquatic mollusc taxa such as Pisidium sp., Valvata spp. And Bithynia tentaculate and terrestrial or semi-terrestrial species such as Galba truncatula, Euconolus cf. alderi, Succinea/Oxyloma, Zonitoides nitidus and Vallonia pulchella. The Preboreal oscillation and other Early Holocene climate events are seen as short-lived, wet intervals.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45881935","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}
Pub Date : 2023-02-23DOI: 10.37570/bgsd-2023-72-02
O. Humlum, Hanne H. Cristiansen, Lis E. Mortensen, F. Stuart, J. Stone
This paper presents a new complete field mapping of glacial landscapes, landforms and sediments in the Faroe Islands, supplemented by observations from bathymetric maps of the Faroe Shelf. In addition, previous investigations of Quaternary and espe-cially the Weichselian glaciation of the archipelago are reviewed. New cosmogenic nuclide exposure ages indicate that the last extensive glaciation of the Faroe Islands occurred during the Late Weichselian, most likely during the Last Glacial Maximum (LGM; c. 26.5–19.0 cal. ka BP), although a Younger Dryas (c. 12.9–11.7 cal. ka BP) age cannot be entirely excluded. Geomorphological mapping provides a background for reconstructing the extent and type of the glaciation of the Faroe Islands. The reconstructed Weichselian glaciation appears to have had the character of an exten-sive valley glaciation, with several marine glacier termini. The present glaciation of southern Spitsbergen, Svalbard, represents a modern analogue of the reconstructed Weichselian glaciation in the Faroe Islands. The lack of raised coastal features in the Faroe Islands, also at protected sites, suggests that postglacial isostatic uplift was smaller than post-LGM eustatic sea level rise. Numerical glacier reconstructions carried out for different extents of the last extensive Faroese glaciation suggest that such limited postglacial isostatic crustal uplift requires that the Faroe Shelf was not extensively glaciated during the Late Weichselian, but it doubtless was so during at least one of the previous Quaternary glaciations.
{"title":"Weichselian Glaciation of the Faroe Islands","authors":"O. Humlum, Hanne H. Cristiansen, Lis E. Mortensen, F. Stuart, J. Stone","doi":"10.37570/bgsd-2023-72-02","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-02","url":null,"abstract":"This paper presents a new complete field mapping of glacial landscapes, landforms and sediments in the Faroe Islands, supplemented by observations from bathymetric maps of the Faroe Shelf. In addition, previous investigations of Quaternary and espe-cially the Weichselian glaciation of the archipelago are reviewed. New cosmogenic nuclide exposure ages indicate that the last extensive glaciation of the Faroe Islands occurred during the Late Weichselian, most likely during the Last Glacial Maximum (LGM; c. 26.5–19.0 cal. ka BP), although a Younger Dryas (c. 12.9–11.7 cal. ka BP) age cannot be entirely excluded. Geomorphological mapping provides a background for reconstructing the extent and type of the glaciation of the Faroe Islands. The reconstructed Weichselian glaciation appears to have had the character of an exten-sive valley glaciation, with several marine glacier termini. The present glaciation of southern Spitsbergen, Svalbard, represents a modern analogue of the reconstructed Weichselian glaciation in the Faroe Islands. The lack of raised coastal features in the Faroe Islands, also at protected sites, suggests that postglacial isostatic uplift was smaller than post-LGM eustatic sea level rise. Numerical glacier reconstructions carried out for different extents of the last extensive Faroese glaciation suggest that such limited postglacial isostatic crustal uplift requires that the Faroe Shelf was not extensively glaciated during the Late Weichselian, but it doubtless was so during at least one of the previous Quaternary glaciations.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43066673","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}
Pub Date : 2023-02-01DOI: 10.37570/bgsd-2023-72-01
A. Schrøder, G. Carnevale
Bony fishes are among the best represented macrofossils from the earliest Eocene Fur Formation, northern Denmark. The most abundant fish of the formation has never been formally described, in spite of its abundance throughout the formation, and only referred to as an ‘argentinoid’. This work provides a taxonomic study of this argentinoid taxon, which is described herein as Surlykus longigracilis gen. et sp. nov. The caudal skeleton shows separated first preural and first ural centra, a unique condition within the Argentiniformes. In addition, it is characterised by having a large mouth and a single supramaxilla, which suggest that Surlykus gen. nov. occupies a basal position within the Argentiniformes, representing the sister-group to all the other lineages of this clade ([Argentinidae + Opisthoproctidae] + [Bathylagidae + Microstomatidae]), and, consequently, a stem-group Argentiniformes. Mass-mortality assemblages may indicate that Surlykus longigracilis gen. et sp. nov. formed large schools in the ancient North Sea Basin, where it probably represented the trophic nucleus of the fish communities.
硬骨鱼是丹麦北部始新世早期Fur组中最具代表性的大型化石之一。该地层中最丰富的鱼类从未被正式描述过，尽管它在整个地层中都很丰富，只被称为“阿根廷类”。本文对该阿根廷类分类群进行了分类研究，并将其命名为Surlykus longigracilis gen. et sp. 11 .尾骨显示出第一脊膜中央和第一脊膜中央的分离，这在阿根廷目中是独一无二的。此外，它的特点是有一个大嘴和一个上腋窝，这表明Surlykus gen. nov.在阿根廷亚纲中处于基部位置，代表了该分支的所有其他谱系([阿根廷亚纲科+ Opisthoproctidae] + [Bathylagidae + Microstomatidae])的姐妹群，因此，它是阿根廷亚纲的茎群。大量死亡组合可能表明，长形苏利库斯(Surlykus longigracilis gen. et sp. 11)在古北海盆地形成了大型鱼群，它可能代表了古北海盆地鱼类群落的营养核。
{"title":"The argentiniform Surlykus longigracilis gen. et sp. nov., the most abundant fish from the Eocene Fur Formation of Denmark.","authors":"A. Schrøder, G. Carnevale","doi":"10.37570/bgsd-2023-72-01","DOIUrl":"https://doi.org/10.37570/bgsd-2023-72-01","url":null,"abstract":"Bony fishes are among the best represented macrofossils from the earliest Eocene Fur Formation, northern Denmark. The most abundant fish of the formation has never been formally described, in spite of its abundance throughout the formation, and only referred to as an ‘argentinoid’. This work provides a taxonomic study of this argentinoid taxon, which is described herein as Surlykus longigracilis gen. et sp. nov. The caudal skeleton shows separated first preural and first ural centra, a unique condition within the Argentiniformes. In addition, it is characterised by having a large mouth and a single supramaxilla, which suggest that Surlykus gen. nov. occupies a basal position within the Argentiniformes, representing the sister-group to all the other lineages of this clade ([Argentinidae + Opisthoproctidae] + [Bathylagidae + Microstomatidae]), and, consequently, a stem-group Argentiniformes. Mass-mortality assemblages may indicate that Surlykus longigracilis gen. et sp. nov. formed large schools in the ancient North Sea Basin, where it probably represented the trophic nucleus of the fish communities.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45260197","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}
Pub Date : 2022-11-30DOI: 10.37570/bgsd-2022-70-10
C. Duffin, J. Milán
Oblidens bornholmensis, known from isolated upper posterior (palatine) and lower posterior (mandibular) tooth plates, was the first myriacanthid holocephalian to be described from the Hasle Formation (Pliensbachian, Early Jurassic) of Bornholm (Denmark). Further collecting in the Hasle Formation has yielded seven more specimens of myriacanthid tooth plates. Two mandibular tooth plates are assigned to Myriacanthus paradoxus, thereby extending both the geographical and stratigraphic range of the genus. In addition to new material of Oblidens bornholmensis, some distinctive myriacanthid palatine and mandibular tooth plates are described and left in open nomenclature. The Early Pliensbachian deposits of Bornholm preserve the most diverse myriacanthid fauna known to date.
{"title":"Further holocephalian remains from the Hasle Formation (Early Jurassic) of Denmark.","authors":"C. Duffin, J. Milán","doi":"10.37570/bgsd-2022-70-10","DOIUrl":"https://doi.org/10.37570/bgsd-2022-70-10","url":null,"abstract":"Oblidens bornholmensis, known from isolated upper posterior (palatine) and lower posterior (mandibular) tooth plates, was the first myriacanthid holocephalian to be described from the Hasle Formation (Pliensbachian, Early Jurassic) of Bornholm (Denmark). Further collecting in the Hasle Formation has yielded seven more specimens of myriacanthid tooth plates. Two mandibular tooth plates are assigned to Myriacanthus paradoxus, thereby extending both the geographical and stratigraphic range of the genus. In addition to new material of Oblidens bornholmensis, some distinctive myriacanthid palatine and mandibular tooth plates are described and left in open nomenclature. The Early Pliensbachian deposits of Bornholm preserve the most diverse myriacanthid fauna known to date.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41718761","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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