Spirifer disjunctus (Sowerby, J. de C. in Sedgwick & Murchison, 1840) et S. verneuili Murchison, 1840 (Brachiopoda, Spiriferida): 175 annees de confusion. ‘Spirifera disjuncta’ Sowerby, J. de C. in Sedgwick & Murchison, 1840 et ‘Spirifer Verneuili’ Murchison, 1840 ont ete declares synonymes en 1840. ‘Spirifera disjuncta’ est base sur une serie type comprenant les moules de trois specimens du Devonien superieur d’Angleterre : un specimen provient du Strunien de Barnstaple dans le nord du Devon, les deux autres du Famennien superieur de Petherwin dans le nord des Cornouailles. La serie type de ‘Spirifer Verneuili’ comprend trois specimens du Frasnien du Boulonnais en France. Des lectotypes sont designes dans ce travail. La synonymie acceptee des deux especes prevaut encore a l’heure actuelle; elle est consideree injustifiee.
Spirifer disjunctus (Sowerby, J. de C. in Sedgwick & Murchison, 1840)和S. verneuili Murchison, 1840 (Brachiopoda, Spiriferida): 175年的混淆。“Spirifera disjunta”Sowerby, J. de C. in Sedgwick & Murchison, 1840和“Spirifer verneuli”Murchison, 1840在1840年被宣布为同义词。“Spirifera disjunta”是基于一个典型的系列，包括来自英格兰上泥盆纪的三个标本的模具:一个来自北德文郡Barnstaple的strunian标本，另外两个来自北康沃尔郡Petherwin的famennian标本。“Spirifer verneuli”的标准系列包括三个来自法国布洛涅的弗拉斯尼安标本。在这项工作中指定了选择型。这两种物种的同义词仍然普遍存在;这被认为是不合理的。
{"title":"Spirifer disjunctus (Sowerby, J. de C. in Sedgwick & Murchison, 1840) and S. verneuili Murchison, 1840 (Brachiopoda, Spiriferida): 175 years of confusion","authors":"P. Sartenaer","doi":"10.20341/gb.2017.010","DOIUrl":"https://doi.org/10.20341/gb.2017.010","url":null,"abstract":"Spirifer disjunctus (Sowerby, J. de C. in Sedgwick & Murchison, 1840) et S. verneuili Murchison, 1840 (Brachiopoda, Spiriferida): 175 annees de confusion. ‘Spirifera disjuncta’ Sowerby, J. de C. in Sedgwick & Murchison, 1840 et ‘Spirifer Verneuili’ Murchison, 1840 ont ete declares synonymes en 1840. ‘Spirifera disjuncta’ est base sur une serie type comprenant les moules de trois specimens du Devonien superieur d’Angleterre : un specimen provient du Strunien de Barnstaple dans le nord du Devon, les deux autres du Famennien superieur de Petherwin dans le nord des Cornouailles. La serie type de ‘Spirifer Verneuili’ comprend trois specimens du Frasnien du Boulonnais en France. Des lectotypes sont designes dans ce travail. La synonymie acceptee des deux especes prevaut encore a l’heure actuelle; elle est consideree injustifiee.","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"10 1","pages":"181-188"},"PeriodicalIF":1.8,"publicationDate":"2017-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77971208","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}
K. Beerten, Vanessa M. A. Heyvaert, D. Vandenberghe, J. V. Nieuland, F. Bogemans
1. IntroductionThe Gent Formation was introduced by Paepe & Vanhoorne (1976) to include “all coversands deposited during the Weichselian”. Gullentops et al. (2001) extended the chronostratigraphical position of the Gent Formation to all sandy aeolian coversand deposits dating from the Middle and Late Pleistocene (Tables 1 & 2) and subdivided the formation in three members: the Dilsen Member (pre-Weichselian), the Sint-Lenaarts Member and the Wildert Member (both Weichselian). The Dilsen Member was initially introduced by Paulissen (1973) to include the coversand deposits in which an interglacial (Eemian) soil had developed. The Sint-Lenaarts Member was originally defined by De Ploey (1961) as reworked aeolian sand, with silt and peat layers, occurring underneath the Wildert Member. The latter included all coversand deposits that covered the pre-existing landscape as a blanket. In the scheme proposed by Gullentops et al. (2001), aeolian sands that constitute a dune landform where grouped into the Hechtel Formation. This formation included Late Glacial dune sands covering the Usselo Soil (Gullentops, 1957), as well as drift sands originating from aeolian reworking of older dune sands and Podzols during the Holocene (grouped in the Kalmthout Member; De Ploey, 1961). Table 1. Quaternary lithostratigraphy of marine, fluvial and aeolian deposits of Belgium, as defined in Gullentops et al. (2001).Table 2. Correlation between the latest version of the Dutch lithostratigraphy (TNO, 20
1. Paepe和vanhohorne(1976)介绍了根特组，包括“魏希塞尔期沉积的所有覆盖层”。Gullentops et al.(2001)将根特组的年代地层位置扩展到中晚更新世以来的所有砂质风成覆盖层和沉积物(表1和表2)，并将该组细分为三个段:Dilsen段(前Weichselian)、Sint-Lenaarts段和Wildert段(均为Weichselian)。Dilsen成员最初是由Paulissen(1973)提出的，包括间冰期(Eemian)土壤发育的覆盖层和沉积物。Sint-Lenaarts段最初由De Ploey(1961)定义为在Wildert段下方发生的带有淤泥和泥炭层的风沙改造层。后者包括所有覆盖原有景观的覆盖物和沉积物。在Gullentops等人(2001)提出的方案中，构成沙丘地貌的风成沙被归类为Hechtel组。这一地层包括覆盖在乌塞洛土壤上的晚冰期沙丘砂(Gullentops, 1957)，以及全新世时期由旧沙丘砂和灰堆形成的风成改造形成的流沙(属于Kalmthout段;De Ploey, 1961)。表1。比利时海相、河流和风成沉积的第四纪岩石地层学，如Gullentops等人(2001)所定义。表2。荷兰最新版岩石地层对比(TNO, 2009)
{"title":"Revising the Gent Formation : a new lithostratigraphy for Quaternary wind-dominated sand deposits in Belgium","authors":"K. Beerten, Vanessa M. A. Heyvaert, D. Vandenberghe, J. V. Nieuland, F. Bogemans","doi":"10.20341/GB.2017.006","DOIUrl":"https://doi.org/10.20341/GB.2017.006","url":null,"abstract":"1. IntroductionThe Gent Formation was introduced by Paepe & Vanhoorne (1976) to include “all coversands deposited during the Weichselian”. Gullentops et al. (2001) extended the chronostratigraphical position of the Gent Formation to all sandy aeolian coversand deposits dating from the Middle and Late Pleistocene (Tables 1 & 2) and subdivided the formation in three members: the Dilsen Member (pre-Weichselian), the Sint-Lenaarts Member and the Wildert Member (both Weichselian). The Dilsen Member was initially introduced by Paulissen (1973) to include the coversand deposits in which an interglacial (Eemian) soil had developed. The Sint-Lenaarts Member was originally defined by De Ploey (1961) as reworked aeolian sand, with silt and peat layers, occurring underneath the Wildert Member. The latter included all coversand deposits that covered the pre-existing landscape as a blanket. In the scheme proposed by Gullentops et al. (2001), aeolian sands that constitute a dune landform where grouped into the Hechtel Formation. This formation included Late Glacial dune sands covering the Usselo Soil (Gullentops, 1957), as well as drift sands originating from aeolian reworking of older dune sands and Podzols during the Holocene (grouped in the Kalmthout Member; De Ploey, 1961). Table 1. Quaternary lithostratigraphy of marine, fluvial and aeolian deposits of Belgium, as defined in Gullentops et al. (2001).Table 2. Correlation between the latest version of the Dutch lithostratigraphy (TNO, 20","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"73 1","pages":"95-102"},"PeriodicalIF":1.8,"publicationDate":"2017-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82172893","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}
1. IntroductionThe lower Toarcian strata of southeast Belgium and the Grand Duchy of Luxembourg, known as the Grandcourt Marls or the Grandcourt Formation, yield a rich and diverse ichthyofauna, comprising the saurichthyid Acidorhynchus Stensio, 1925, the amiiform Caturus Agassiz, 1834, the semionotid Lepidotes Agassiz, 1832, the dapediids Dapedium Leach, 1822 and Tetragonolepis Bronn, 1830, the pachycormids Sauropsis Agassiz, 1832, Pachycormus Agassiz, 1833, Saurostomus Agassiz, 1833, Euthynotus Wagner 1860 and Haasichthys Delsate, 1999, the pholidophorid Pholidophorus Agassiz, 1832 (represented by two species) and the primitive cycloid teleost Leptolepis Agassiz, 1832 (Delsate, 1999a, b).Delsate (1999c) described the new species Pholidophorus friedeni on the basis of specimens found in different Toarcian localities of the Grand Duchy of Luxembourg. He stated that this taxon was also recorded in Germany and attributed this new species to the genus Pholidophorus, although without giving any reason for his choice. Moreover, he expressed some doubts about this generic attribution. Fragmentary samples of the same species, collected in the lower Toarcian strata of Athus (southeast Belgium), are housed in the collection of the Royal Belgian Institute of Natural Sciences (Brussels), but were not studied until now. The aim of this paper is to study the osteology of “Pholidophorus” friedeni in a more detailed way than had been previously done, to discuss its generic attribution and t
{"title":"Osteology and relationships of Luxembourgichthys (“Pholidophorus”) friedeni gen. nov. (Teleostei, “Pholidophoriformes”) from the Lower Jurassic of Belgium and the Grand Duchy of Luxembourg","authors":"L. Taverne, É. Steurbaut","doi":"10.20341/GB.2017.003","DOIUrl":"https://doi.org/10.20341/GB.2017.003","url":null,"abstract":"1. IntroductionThe lower Toarcian strata of southeast Belgium and the Grand Duchy of Luxembourg, known as the Grandcourt Marls or the Grandcourt Formation, yield a rich and diverse ichthyofauna, comprising the saurichthyid Acidorhynchus Stensio, 1925, the amiiform Caturus Agassiz, 1834, the semionotid Lepidotes Agassiz, 1832, the dapediids Dapedium Leach, 1822 and Tetragonolepis Bronn, 1830, the pachycormids Sauropsis Agassiz, 1832, Pachycormus Agassiz, 1833, Saurostomus Agassiz, 1833, Euthynotus Wagner 1860 and Haasichthys Delsate, 1999, the pholidophorid Pholidophorus Agassiz, 1832 (represented by two species) and the primitive cycloid teleost Leptolepis Agassiz, 1832 (Delsate, 1999a, b).Delsate (1999c) described the new species Pholidophorus friedeni on the basis of specimens found in different Toarcian localities of the Grand Duchy of Luxembourg. He stated that this taxon was also recorded in Germany and attributed this new species to the genus Pholidophorus, although without giving any reason for his choice. Moreover, he expressed some doubts about this generic attribution. Fragmentary samples of the same species, collected in the lower Toarcian strata of Athus (southeast Belgium), are housed in the collection of the Royal Belgian Institute of Natural Sciences (Brussels), but were not studied until now. The aim of this paper is to study the osteology of “Pholidophorus” friedeni in a more detailed way than had been previously done, to discuss its generic attribution and t","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"274 1","pages":"53-67"},"PeriodicalIF":1.8,"publicationDate":"2017-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75093293","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}
R. Adriaens, B. Ronchi, G. Mertens, Sofie Hollanders, J. Elsen, M. Dusar, N. Vandenberghe
1. Introduction Halloysite is a dioctahedral 1:1 clay mineral of the kaolinite group frequently discussed in literature because of its potential for nanotechnological applications (Keeling, 2015; Yuan et al., 2015; Yuan et al., 2016). Its geological occurrence has been primarily linked to soil and weathering environments, by the weathering and alteration of volcanic rocks (Vaughan et al., 2002; Velde & Meunier, 2008), the alteration of clay minerals like montmorillonite or biotite (Hill, 2000; Papoulis et al., 2009) or weathering of feldspars (Sheets & Tettenhorst, 1997; Adamo et al., 2001). Halloysite is also a common mineral constituent in karst and paleokarst environments as a result of acid weathering (Polyak & Guven, 2000; Joussein et al., 2005). In Belgium, halloysite was reported in over 30 localities, almost all with a very similar geological setting, i.e. karstified carbonate substrates filled up by Cenozoic sand deposits (Buurman & Van der Plas, 1968; Dupuis & Ertus, 1995; Goemaere & Hanson, 1997; Nicaise, 1998; Kloprogge & Frost, 1999; De Putter et al. 2002; Bruyere, 2004). A similar geological setting is found inside the underground quarries of Hinnisdael, locally known as “mergelgrotten” (“marl caves”), located in Vechmaal, Limburg province, Belgium (Fig. 1). In two of the Hinnisdael underground quarries, dolines filled with marine sand were intersected and an irregular white clay layer occurs at the contact between the karstified top of the Cretaceous calcareni
1. 高岭土是一种双八面体1:1的高岭石粘土矿物，由于其在纳米技术上的应用潜力，在文献中经常被讨论(Keeling, 2015;Yuan等，2015;袁等人，2016)。它的地质发生主要与土壤和风化环境有关，通过火山岩的风化和蚀变(Vaughan et al.， 2002;Velde & Meunier, 2008)，粘土矿物如蒙脱石或黑云母的蚀变(Hill, 2000;Papoulis et al.， 2009)或长石风化(Sheets & Tettenhorst, 1997;Adamo et al.， 2001)。由于酸性风化作用，高岭土也是喀斯特和古岩溶环境中常见的矿物成分(Polyak & Guven, 2000;Joussein et al.， 2005)。在比利时，据报道在30多个地方发现了高岭土，几乎所有地方都具有非常相似的地质环境，即由新生代砂沉积充填的岩溶碳酸盐基底(Buurman & Van der Plas, 1968;Dupuis & Ertus, 1995;Goemaere & Hanson, 1997;他,1998;kloproge & Frost, 1999;De Putter et al. 2002;Bruyere, 2004)。在Hinnisdael的地下采石场中也发现了类似的地质环境，当地称为“mergelgrotten”(“泥灰岩洞”)，位于比利时林堡省的veechmaal(图1)。在Hinnisdael的两个地下采石场中，填满海砂的石灰石被相交，在白垩纪石灰砾岩的岩溶顶部之间的接触处出现了不规则的白色粘土层
{"title":"Halloysite occurrence at the karstified contact of Oligocene sands and Cretaceous calcarenites in Hinnisdael quarries, Vechmaal (NE of Belgium)","authors":"R. Adriaens, B. Ronchi, G. Mertens, Sofie Hollanders, J. Elsen, M. Dusar, N. Vandenberghe","doi":"10.20341/gb.2017.002","DOIUrl":"https://doi.org/10.20341/gb.2017.002","url":null,"abstract":"1. Introduction Halloysite is a dioctahedral 1:1 clay mineral of the kaolinite group frequently discussed in literature because of its potential for nanotechnological applications (Keeling, 2015; Yuan et al., 2015; Yuan et al., 2016). Its geological occurrence has been primarily linked to soil and weathering environments, by the weathering and alteration of volcanic rocks (Vaughan et al., 2002; Velde & Meunier, 2008), the alteration of clay minerals like montmorillonite or biotite (Hill, 2000; Papoulis et al., 2009) or weathering of feldspars (Sheets & Tettenhorst, 1997; Adamo et al., 2001). Halloysite is also a common mineral constituent in karst and paleokarst environments as a result of acid weathering (Polyak & Guven, 2000; Joussein et al., 2005). In Belgium, halloysite was reported in over 30 localities, almost all with a very similar geological setting, i.e. karstified carbonate substrates filled up by Cenozoic sand deposits (Buurman & Van der Plas, 1968; Dupuis & Ertus, 1995; Goemaere & Hanson, 1997; Nicaise, 1998; Kloprogge & Frost, 1999; De Putter et al. 2002; Bruyere, 2004). A similar geological setting is found inside the underground quarries of Hinnisdael, locally known as “mergelgrotten” (“marl caves”), located in Vechmaal, Limburg province, Belgium (Fig. 1). In two of the Hinnisdael underground quarries, dolines filled with marine sand were intersected and an irregular white clay layer occurs at the contact between the karstified top of the Cretaceous calcareni","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"29 1","pages":"43-52"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76465258","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}
1. Introduction The platinum group elements (PGE: Ru, Rh, Pd, Os, Ir & Pt) are considered as critical metals (European Commission, 2014) and are highly valued for their high-tech applications. They are being recycled and intensely mined, but still deficits are experienced and expected in the coming years (European Commission, 2014). Since the large PGE deposits, such as the Bushveld Complex in South Africa and the Noril’sk-Talnakh deposits in Russia, will become depleted with time, new deposits need to be explored for their PGE potential, to sustain future demand. The mafic-ultramafic intrusions in Burundi, which are part of the Kabanga-Musongati alignment, are such potential deposits. They intruded the Mesoproterozoic rocks of the Karagwe-Ankole belt around 1375 Ma and form a SW-NE alignment of nine intrusions in Burundi, with further continuation towards Tanzania (Fig. 1; Fernandez-Alonso et al., 2012). Several drilling campaigns have been executed between 1970 and 1990 to explore the nickel and PGE potential of these intrusions (PNUD-UNDP, 1977; Exploration und Bergbau Gmbh, 1985;Deblond, 1994; Deblond & Tack, 1999). Although some limited data on the concentration of PGE in the boreholes of these campaigns is available (e.g. Klerkx, 1975, 1976), not much is known about the PGE distribution. In addition, the petrogenesis of the intrusions needs further elaboration, expanding on the work of e.g. Bandyayera (1997) and Duchesne et al. (2004). Figure 1. (A) Regional geology o
1. 铂族元素(PGE: Ru, Rh, Pd, Os, Ir和Pt)被认为是关键金属(欧盟委员会，2014年)，并因其高科技应用而受到高度重视。它们正在被回收和密集开采，但未来几年仍将出现赤字(欧盟委员会，2014年)。由于大型PGE矿床，如南非的Bushveld Complex和俄罗斯的Noril 'sk-Talnakh矿床，将随着时间的推移而枯竭，因此需要勘探新的矿床，以获得其PGE潜力，以维持未来的需求。布隆迪的镁铁质-超镁铁质侵入体是Kabanga-Musongati矿线的一部分，就是这样的潜在矿床。它们在1375 Ma左右侵入Karagwe-Ankole带的中元古代岩石，并在布隆迪形成了一个由9个侵入体组成的SW-NE走向，进一步向坦桑尼亚延伸(图1;Fernandez-Alonso et al.， 2012)。1970年至1990年期间进行了几次钻探活动，以探索这些侵入体的镍和PGE潜力(开发计划署-开发计划署，1977年;Exploration und Bergbau Gmbh, 1985;Deblond, 1994;Deblond & Tack, 1999)。虽然在这些运动的钻孔中有一些有限的PGE浓度数据(例如Klerkx, 1975年，1976年)，但对PGE的分布所知不多。此外，在Bandyayera(1997)和Duchesne et al.(2004)等人的工作基础上，对侵入岩的成因需要进一步阐述。图1所示。(A)区域地质
{"title":"Platinum group element mineralization at Musongati (Burundi): concentration and Pd-Rh distribution in pentlandite","authors":"Bram Paredis, P. Muchez, S. Dewaele","doi":"10.20341/GB.2016.018","DOIUrl":"https://doi.org/10.20341/GB.2016.018","url":null,"abstract":"1. Introduction The platinum group elements (PGE: Ru, Rh, Pd, Os, Ir & Pt) are considered as critical metals (European Commission, 2014) and are highly valued for their high-tech applications. They are being recycled and intensely mined, but still deficits are experienced and expected in the coming years (European Commission, 2014). Since the large PGE deposits, such as the Bushveld Complex in South Africa and the Noril’sk-Talnakh deposits in Russia, will become depleted with time, new deposits need to be explored for their PGE potential, to sustain future demand. The mafic-ultramafic intrusions in Burundi, which are part of the Kabanga-Musongati alignment, are such potential deposits. They intruded the Mesoproterozoic rocks of the Karagwe-Ankole belt around 1375 Ma and form a SW-NE alignment of nine intrusions in Burundi, with further continuation towards Tanzania (Fig. 1; Fernandez-Alonso et al., 2012). Several drilling campaigns have been executed between 1970 and 1990 to explore the nickel and PGE potential of these intrusions (PNUD-UNDP, 1977; Exploration und Bergbau Gmbh, 1985;Deblond, 1994; Deblond & Tack, 1999). Although some limited data on the concentration of PGE in the boreholes of these campaigns is available (e.g. Klerkx, 1975, 1976), not much is known about the PGE distribution. In addition, the petrogenesis of the intrusions needs further elaboration, expanding on the work of e.g. Bandyayera (1997) and Duchesne et al. (2004). Figure 1. (A) Regional geology o","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"20 1","pages":"15-32"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88044292","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}
1. Introduction The Givetian of the Zemmour is well exposed to the north of Bir Moghreim (formerly Fort Trinquet), in the northern part of Mauritania (Fig. 1). It was investigated in great detail, from a lithologic and biostratigraphic point of view, by Sougy (1964) who gathered among others a large collection of rugose corals in the early Sixties. Part of these specimens was sent to Professor Marius Lecompte of the Catholic University of Louvain in Belgium and is now stored in the Collection of Palaeontology of the Institut royal des Sciences naturelles de Belgique at Brussels. Three Givetian species of massive rugose corals have been identified in the Zemmour by Coen-Aubert (2013); these are Phillipsastrea torreana (Milne-Edwards & Haime, 1851), P. kergarvanensis Coen-Aubert & Plusquellec, 2007 and P. sobolewi (Rozkowska, 1956). Besides two massive colonies belonging to Argutastrea Crickmay, 1960 and Iowaphyllum Stumm, 1949, a diverse fauna of mostly solitary rugose corals is described in this paper. Unfortunately, the Givetian of the Zemmour is not dated or subdivided with much precision as there are nearly no recent studies on other groups of fossils and as there are no block samples available for the extraction of microfossils such as conodonts. Figure 1. General setting in Northwestern Africa. 2. Geological setting and material The Givetian of the Zemmour has been summarized with some detail by Coen-Aubert (2013), on the basis of the three main sections investigated by
{"title":"Givetian rugose corals from the Zemmour in Mauritania","authors":"M. Coen-Aubert","doi":"10.20341/GB.2017.009","DOIUrl":"https://doi.org/10.20341/GB.2017.009","url":null,"abstract":"1. Introduction The Givetian of the Zemmour is well exposed to the north of Bir Moghreim (formerly Fort Trinquet), in the northern part of Mauritania (Fig. 1). It was investigated in great detail, from a lithologic and biostratigraphic point of view, by Sougy (1964) who gathered among others a large collection of rugose corals in the early Sixties. Part of these specimens was sent to Professor Marius Lecompte of the Catholic University of Louvain in Belgium and is now stored in the Collection of Palaeontology of the Institut royal des Sciences naturelles de Belgique at Brussels. Three Givetian species of massive rugose corals have been identified in the Zemmour by Coen-Aubert (2013); these are Phillipsastrea torreana (Milne-Edwards & Haime, 1851), P. kergarvanensis Coen-Aubert & Plusquellec, 2007 and P. sobolewi (Rozkowska, 1956). Besides two massive colonies belonging to Argutastrea Crickmay, 1960 and Iowaphyllum Stumm, 1949, a diverse fauna of mostly solitary rugose corals is described in this paper. Unfortunately, the Givetian of the Zemmour is not dated or subdivided with much precision as there are nearly no recent studies on other groups of fossils and as there are no block samples available for the extraction of microfossils such as conodonts. Figure 1. General setting in Northwestern Africa. 2. Geological setting and material The Givetian of the Zemmour has been summarized with some detail by Coen-Aubert (2013), on the basis of the three main sections investigated by","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"6 1","pages":"161-180"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80086994","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}
1. IntroductionSince over a decade, numerous studies have postulated that extremely low global temperatures (-50 °C) existed during successive separate glaciations in the Cryogenian period (770–580 Ma). This would explain not only the presence of ice at sea level near the equator, but also an icy cover on all oceans (Snowball Earth Hypothesis; Kirschvink, 1992; Hoffman et al., 1998; Hoffman & Schrag, 2002). The original suggestion of a “global” glaciation in the Neoproterozoic by Harland (1964) was partly based on paleomagnetic data (Harland & Bidgood, 1959) pointing to low paleolatitudes for these glacial deposits. The latter, widely distributed on all continents, are sharply overlain by a cap carbonate unit, interpreted as the result of a sudden switch back to a greenhouse climate related to the increase of atmospheric carbon dioxide due to volcanic degassing (Hoffman & Schrag, 2002). Despite the absence of many typical “glacial” features (e.g., faceted and striated clasts, dropstones, etc.), most Neoproterozoic diamictites were considered as glacial or periglacial deposits. However, not all reported Neoproterozoic diamictites were interpreted in this way, but also as the result ofsyntectonic sedimentgravityflows (Eyles & Januszczak, 2004, 2007) associated with widespread rifting of the Rodinia Supercontinent.In this paper, we present a new macro- and microscale structural analysis of the Upper Diamictite Formation (UDF) in the West Congo Supergroup (WCS) of the Democratic
{"title":"Facies and micromorphology of the Neoproterozoic Upper Diamictite Formation in the Democratic Republic of Congo: New evidence of sediment gravity flow","authors":"F. Delpomdor, L. Tack, A. Préat","doi":"10.20341/GB.2017.004","DOIUrl":"https://doi.org/10.20341/GB.2017.004","url":null,"abstract":"1. IntroductionSince over a decade, numerous studies have postulated that extremely low global temperatures (-50 °C) existed during successive separate glaciations in the Cryogenian period (770–580 Ma). This would explain not only the presence of ice at sea level near the equator, but also an icy cover on all oceans (Snowball Earth Hypothesis; Kirschvink, 1992; Hoffman et al., 1998; Hoffman & Schrag, 2002). The original suggestion of a “global” glaciation in the Neoproterozoic by Harland (1964) was partly based on paleomagnetic data (Harland & Bidgood, 1959) pointing to low paleolatitudes for these glacial deposits. The latter, widely distributed on all continents, are sharply overlain by a cap carbonate unit, interpreted as the result of a sudden switch back to a greenhouse climate related to the increase of atmospheric carbon dioxide due to volcanic degassing (Hoffman & Schrag, 2002). Despite the absence of many typical “glacial” features (e.g., faceted and striated clasts, dropstones, etc.), most Neoproterozoic diamictites were considered as glacial or periglacial deposits. However, not all reported Neoproterozoic diamictites were interpreted in this way, but also as the result ofsyntectonic sedimentgravityflows (Eyles & Januszczak, 2004, 2007) associated with widespread rifting of the Rodinia Supercontinent.In this paper, we present a new macro- and microscale structural analysis of the Upper Diamictite Formation (UDF) in the West Congo Supergroup (WCS) of the Democratic","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"80 1","pages":"69-79"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73672676","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}
The Oligocene sediments formed between the Pyrenean and Savian tectonic pulses. The earliest Oligocene was characterized by a widespread shallow water transgression. Global cooling coincided with the subsequent retreat of the sea which is also the time of the Grande Coupure faunal turnover. Renewed stepwise transgression resulted in the deposition of the Boom Clay during the Rupelian. High-frequency cyclic changes in water depth of the Boom Clay are driven by waxing and waning of ice masses while lower-frequency cycles can be tectonic signals. By the end of the Rupelian, differential vertical tectonics resulted in considerable erosion west of the Campine subsidence area and in shallower water depth in the eastern part of the southern coastal area. Subsidence of the Lower-Rhine graben resumed at the start of the Chattian. The sea could only briefly transgress over the area outside the graben but in the graben thick Chattian sediments are preserved. Outside the graben, erosion continued to dominate during the Chattian and the Aquitanian. This long period above sea level is due to a combination of the Savian tectonic uplift pulse and a global low sea level.
{"title":"Tectonic and climatic signals in the Oligocene sediments of the Southern North-Sea Basin (Ernest Van den Broeck medallist lecture 2016)","authors":"N. Vandenberghe","doi":"10.20341/gb.2017.007","DOIUrl":"https://doi.org/10.20341/gb.2017.007","url":null,"abstract":"The Oligocene sediments formed between the Pyrenean and Savian tectonic pulses. The earliest Oligocene was characterized by a widespread shallow water transgression. Global cooling coincided with the subsequent retreat of the sea which is also the time of the Grande Coupure faunal turnover. Renewed stepwise transgression resulted in the deposition of the Boom Clay during the Rupelian. High-frequency cyclic changes in water depth of the Boom Clay are driven by waxing and waning of ice masses while lower-frequency cycles can be tectonic signals. By the end of the Rupelian, differential vertical tectonics resulted in considerable erosion west of the Campine subsidence area and in shallower water depth in the eastern part of the southern coastal area. Subsidence of the Lower-Rhine graben resumed at the start of the Chattian. The sea could only briefly transgress over the area outside the graben but in the graben thick Chattian sediments are preserved. Outside the graben, erosion continued to dominate during the Chattian and the Aquitanian. This long period above sea level is due to a combination of the Savian tectonic uplift pulse and a global low sea level.","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"25 1","pages":"105-123"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81923608","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}
1. IntroductionDuring the systematic lithostratigraphic description of the Palaeozoic deposits from the subsurface of the Campine Basin in northern Belgium (Lagrou, 2012), it appeared that certain stratigraphic intervals in deep boreholes, already identified and investigated as separated units by different authors (Langenaeker, 2000; Laenen, 2003), were not yet formally named. As one of the goals of the detailed stratigraphic study of Lagrou (2012) was to put all data in the Flemish web-based ‘Databank Ondergrond Vlaanderen’ (DOV), codes for the different lithostratigraphic units were needed. To be in accordance with DOV as well as with the Belgian official stratigraphy, the newly proposed lithostratigraphic units were submitted to the Belgian National Commission on Stratigraphy.This was the case for the Devonian Booischot Formation which is defined at the base of the Booischot borehole, above the Caledonian basement of the Brabant Massif. The Booischot borehole (Fig. 1A) has been drilled in 1963 for the Geological Survey of Belgium where the collection of cores is still stored and easily available. More generally, we present in this paper a complete stratigraphic overview of the Devonian from the Campine Basin, which has also been intersected by the Heibaart borehole (Fig. 1A). The study of the Heibaart borehole is mainly based on the unpublished report of Cornet (1976) illustrated by two photographic volumes of discontinuous cores with comments, which are stored in the Arch
{"title":"Update of the Devonian lithostratigraphic subdivision in the subsurface of the Campine Basin (northern Belgium)","authors":"D. Lagrou, M. Coen-Aubert","doi":"10.20341/gb.2016.017","DOIUrl":"https://doi.org/10.20341/gb.2016.017","url":null,"abstract":"1. IntroductionDuring the systematic lithostratigraphic description of the Palaeozoic deposits from the subsurface of the Campine Basin in northern Belgium (Lagrou, 2012), it appeared that certain stratigraphic intervals in deep boreholes, already identified and investigated as separated units by different authors (Langenaeker, 2000; Laenen, 2003), were not yet formally named. As one of the goals of the detailed stratigraphic study of Lagrou (2012) was to put all data in the Flemish web-based ‘Databank Ondergrond Vlaanderen’ (DOV), codes for the different lithostratigraphic units were needed. To be in accordance with DOV as well as with the Belgian official stratigraphy, the newly proposed lithostratigraphic units were submitted to the Belgian National Commission on Stratigraphy.This was the case for the Devonian Booischot Formation which is defined at the base of the Booischot borehole, above the Caledonian basement of the Brabant Massif. The Booischot borehole (Fig. 1A) has been drilled in 1963 for the Geological Survey of Belgium where the collection of cores is still stored and easily available. More generally, we present in this paper a complete stratigraphic overview of the Devonian from the Campine Basin, which has also been intersected by the Heibaart borehole (Fig. 1A). The study of the Heibaart borehole is mainly based on the unpublished report of Cornet (1976) illustrated by two photographic volumes of discontinuous cores with comments, which are stored in the Arch","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"4 1","pages":"1-13"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82447814","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}
1. IntroductionThe Grand-Duchy of Luxembourg is divided into two main geographical regions, the Eisleck (Oesling in German) to the north (32% of the area) and the Guttland to the south (68% of the area). They correspond to two main geological provinces of the country (Fig. 1).Figure 1. Location map of the studied area.In the Eisleck region, lithostratigraphic units are of lower Devonian (Pragian and Emsian) age; they were folded during the Variscan orogeny) and belong to the SE part of the Ardenne Anticlinorium. From NNW to SSE, the main tectonic structures are: the Houffalize Synclinorium, the Bastogne-Stubach (Stupbach) Anticlinorium, the Neufchâteau-Wiltz-Eifel Synclinorium and the Givonne Anticlinorium. In detail, these large scale structures are complicated by numerous secondary synclines and anticlines.In the Guttland region, lithostratigraphic units belong to the Mesozoic era (Triassic and Jurassic); they are relatively flat-lying and form the northeastern tip of the Paris Basin, the so-called “Gulf of Trier-Luxembourg”.The oldest contribution to geology of the Eisleck region dates back to 1828 and is due to Steininger. The works of Wies (1867) and Wies & Siegen (1877) do not provide a lot of substantial additional information, except on the mineral wealth contained in the grounds of the Eisleck region. The first important contribution concerning the geological subdivisions of the Eisleck region is due to Gosselet (1885). Up to recently, the Luxembourg Devonian stratig
{"title":"The lithostratigraphy of the lower Devonian formations of the Eisleck region (northern Luxembourg). Comparison with their Belgian lateral equivalents","authors":"L. Dejonghe, R. Colbach, E. Goemaere","doi":"10.20341/gb.2017.001","DOIUrl":"https://doi.org/10.20341/gb.2017.001","url":null,"abstract":"1. IntroductionThe Grand-Duchy of Luxembourg is divided into two main geographical regions, the Eisleck (Oesling in German) to the north (32% of the area) and the Guttland to the south (68% of the area). They correspond to two main geological provinces of the country (Fig. 1).Figure 1. Location map of the studied area.In the Eisleck region, lithostratigraphic units are of lower Devonian (Pragian and Emsian) age; they were folded during the Variscan orogeny) and belong to the SE part of the Ardenne Anticlinorium. From NNW to SSE, the main tectonic structures are: the Houffalize Synclinorium, the Bastogne-Stubach (Stupbach) Anticlinorium, the Neufchâteau-Wiltz-Eifel Synclinorium and the Givonne Anticlinorium. In detail, these large scale structures are complicated by numerous secondary synclines and anticlines.In the Guttland region, lithostratigraphic units belong to the Mesozoic era (Triassic and Jurassic); they are relatively flat-lying and form the northeastern tip of the Paris Basin, the so-called “Gulf of Trier-Luxembourg”.The oldest contribution to geology of the Eisleck region dates back to 1828 and is due to Steininger. The works of Wies (1867) and Wies & Siegen (1877) do not provide a lot of substantial additional information, except on the mineral wealth contained in the grounds of the Eisleck region. The first important contribution concerning the geological subdivisions of the Eisleck region is due to Gosselet (1885). Up to recently, the Luxembourg Devonian stratig","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":"34 1","pages":"33-42"},"PeriodicalIF":1.8,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79447447","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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