1. Introduction During the early Pliocene, the glauconite-bearing sands of the Kattendijk Formation were deposited in a shallow marine environment in the southern part of the North Sea Basin (Fig. 1). Its presence was established in the subsurface of the city of Antwerp and its harbor during excavation works (see Cogels, 1874; Gaemers, 1975; De Meuter et al., 1976; Louwye et al., 2004; De Schepper et al., 2009) and by means of boreholes in the Waasland (Laga, 1971) and Campine areas (Louwye & Laga, 1998; for location see Fig. 2). At these observation points, the Kattendijk Formation overlies units from different ages, ranging from the upper Miocene Diest Formation in the Campine area and northeast of the city of Antwerp (De Meuter et al., 1976; Louwye & Laga, 1998;) to the lower to middle Miocene Berchem Formation in the northern part of the city of Antwerp (Cogels, 1874; De Meuter et al., 1976) and even the lower Oligocene Boom Formation in the Waasland area (Laga, 1971; Gaemers, 1975; Fig. 2). The base of the Kattendijk Formation forms an important regional unconformity. Little detail is known about the geometry of the unconformity, only a few regional insights are known from schematic cross-sections (Laga, 1983) and the regional geological models (Jacobs et al., 2010; Matthijs et al., 2013; Deckers et al., 2019). This is mainly due to the poor distinction between the Kattendijk Formation and over- and underlying glauconite-bearing sands in low quality borehole descriptions
1. 上新世早期，Kattendijk组含海绿石砂沉积在北海盆地南部的浅海环境中(图1)。在挖掘工作中，它在安特卫普市及其港口的地下被证实存在(参见cogel, 1874;Gaemers, 1975;De Meuter et al.， 1976;Louwye et al.， 2004;De Schepper et al.， 2009)，并通过在Waasland (Laga, 1971)和Campine地区(Louwye & Laga, 1998;在这些观测点上，Kattendijk组覆盖着不同时代的单元，从Campine地区的上中新世Diest组到安特卫普市东北部(De Meuter et al.， 1976;Louwye & Laga, 1998;)至安特卫普市北部中新世下至中Berchem组(cogel, 1874;De Meuter et al.， 1976)，甚至Waasland地区下渐新统Boom组(Laga, 1971;Gaemers, 1975;图2)卡滕迪克组基底形成一个重要的区域不整合面。关于不整合面几何形状的细节知之甚少，仅从示意图截面(Laga, 1983)和区域地质模型(Jacobs et al.， 2010;Matthijs等人，2013;Deckers et al.， 2019)。这主要是由于在低质量的井眼描述中，很难区分Kattendijk组与上、下伏海绿石砂岩
{"title":"The architecture of the Kattendijk Formation and the implications on the early Pliocene depositional evolution of the southern margin of the North Sea Basin","authors":"J. Deckers, S. Louwye","doi":"10.20341/gb.2020.017","DOIUrl":"https://doi.org/10.20341/gb.2020.017","url":null,"abstract":"1. Introduction During the early Pliocene, the glauconite-bearing sands of the Kattendijk Formation were deposited in a shallow marine environment in the southern part of the North Sea Basin (Fig. 1). Its presence was established in the subsurface of the city of Antwerp and its harbor during excavation works (see Cogels, 1874; Gaemers, 1975; De Meuter et al., 1976; Louwye et al., 2004; De Schepper et al., 2009) and by means of boreholes in the Waasland (Laga, 1971) and Campine areas (Louwye & Laga, 1998; for location see Fig. 2). At these observation points, the Kattendijk Formation overlies units from different ages, ranging from the upper Miocene Diest Formation in the Campine area and northeast of the city of Antwerp (De Meuter et al., 1976; Louwye & Laga, 1998;) to the lower to middle Miocene Berchem Formation in the northern part of the city of Antwerp (Cogels, 1874; De Meuter et al., 1976) and even the lower Oligocene Boom Formation in the Waasland area (Laga, 1971; Gaemers, 1975; Fig. 2). The base of the Kattendijk Formation forms an important regional unconformity. Little detail is known about the geometry of the unconformity, only a few regional insights are known from schematic cross-sections (Laga, 1983) and the regional geological models (Jacobs et al., 2010; Matthijs et al., 2013; Deckers et al., 2019). This is mainly due to the poor distinction between the Kattendijk Formation and over- and underlying glauconite-bearing sands in low quality borehole descriptions","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87912495","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}
Pascal Mambwe, F. Delpomdor, S. Lavoie, Philippe Mukonki, J. Batumike, P. Muchez
1. Introduction In central Africa (Democratic Republic of the Congo, Zambia and eastern Angola), the Katanga Supergroup rocks record an up to 300 Ma complete Wilson cycle that was initiated at the >880 Ma intracontinental rifting between the Congo and Kalahari cratons, and ended at the ~573–530 Ma Lufilian orogeny. The resulting Lufilian Arc forms part of the Pan-African orogenic belts of Africa (Fig. 1; Batumike et al., 2006; Cailteux et al., 2007; Mambwe et al., 2019a). Continental break-up started with the eastward opening of the proto-Mozambique ocean, which propagated westwards into the area of the Zambezi Belt, forming the Zambian Roan Rift-Basin. Thereafter it evolved north-westwards into the area of the Lufilian Belt, forming the Congolese Roan Rift-Basin (Porada & Berhorst, 2000). Both basins widened allowing the development of Afar/Red Sea-type sedimentation in the Roan Rift-Basin, which was marked by a widespread deposition of continental (basal conglomerates, quartzites, feldspathic sandstones and shales) to marine (dominantly carbonates) rocks in the Musonoi Subgroup in the Democratic Republic of the Congo (DRC) (and the Mindola Subgroup, its stratigraphic equivalent in Zambia). These marine conditions continued in the Mines and Fungurume subgroups in DRC and in the Kitwe and Kirilabombwe subgroups in Zambia (Francois, 1987; Cailteux et al., 2005; Cailteux & De Putter, 2019). Figure 1. Geological map of the Central African Copperbelt (modified from Cailteux et
1. 在中非(刚果民主共和国、赞比亚和安哥拉东部)，Katanga超群岩石记录了长达300 Ma的完整Wilson旋回，该旋回开始于刚果和卡拉哈里克拉通之间的>880 Ma陆内裂谷运动，结束于~ 573-530 Ma鲁菲连造山运动。由此形成的陆菲连弧形成了非洲泛非造山带的一部分(图1;Batumike et al.， 2006;Cailteux et al.， 2007;Mambwe et al.， 2019a)。大陆分裂开始于原莫桑比克大洋向东打开，向西扩展到赞比西河带地区，形成了赞比亚罗安裂谷盆地。此后，它向西北发展进入卢非连带地区，形成刚果罗安裂谷盆地(Porada & Berhorst, 2000)。这两个盆地都扩大了，使得Roan裂谷盆地的阿法尔/红海型沉积得以发展，其标志是在刚果民主共和国(DRC)的Musonoi亚群(以及赞比亚的Mindola亚群)中广泛沉积陆相(基底砾岩、石英岩、长石砂岩和页岩)到海相(主要是碳酸盐岩)岩石。这些海洋条件在刚果民主共和国的Mines和Fungurume亚群以及赞比亚的Kitwe和Kirilabombwe亚群中继续存在(Francois, 1987;Cailteux et al.， 2005;Cailteux & De Putter, 2019)。图1所示。中非铜带地质图(修改自Cailteux et
{"title":"Sedimentary evolution and stratigraphy of the ~765–740 Ma Kansuki-Mwashya platform succession in the Tenke-Fungurume Mining District, Democratic Republic of the Congo","authors":"Pascal Mambwe, F. Delpomdor, S. Lavoie, Philippe Mukonki, J. Batumike, P. Muchez","doi":"10.20341/gb.2020.022","DOIUrl":"https://doi.org/10.20341/gb.2020.022","url":null,"abstract":"1. Introduction In central Africa (Democratic Republic of the Congo, Zambia and eastern Angola), the Katanga Supergroup rocks record an up to 300 Ma complete Wilson cycle that was initiated at the >880 Ma intracontinental rifting between the Congo and Kalahari cratons, and ended at the ~573–530 Ma Lufilian orogeny. The resulting Lufilian Arc forms part of the Pan-African orogenic belts of Africa (Fig. 1; Batumike et al., 2006; Cailteux et al., 2007; Mambwe et al., 2019a). Continental break-up started with the eastward opening of the proto-Mozambique ocean, which propagated westwards into the area of the Zambezi Belt, forming the Zambian Roan Rift-Basin. Thereafter it evolved north-westwards into the area of the Lufilian Belt, forming the Congolese Roan Rift-Basin (Porada & Berhorst, 2000). Both basins widened allowing the development of Afar/Red Sea-type sedimentation in the Roan Rift-Basin, which was marked by a widespread deposition of continental (basal conglomerates, quartzites, feldspathic sandstones and shales) to marine (dominantly carbonates) rocks in the Musonoi Subgroup in the Democratic Republic of the Congo (DRC) (and the Mindola Subgroup, its stratigraphic equivalent in Zambia). These marine conditions continued in the Mines and Fungurume subgroups in DRC and in the Kitwe and Kirilabombwe subgroups in Zambia (Francois, 1987; Cailteux et al., 2005; Cailteux & De Putter, 2019). Figure 1. Geological map of the Central African Copperbelt (modified from Cailteux et","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73071777","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 During the late Oligocene and Neogene, glauconitic sands were deposited in shallow marine conditions across the southern North Sea Basin (Fig. 1). The deposition of these glauconitic sands was not continuous, but interrupted by several hiatuses. One of the most important and widespread hiatuses in the southern North Sea Basin coincides with the Oligocene/Miocene boundary, in the Netherlands often referred to as Savian phase (in Wong et al., 2001; Verbeek et al., 2002; Munsterman & Brinkhuis, 2004). In the northern Campine Block, a structural entity along the southern margin of the North Sea Basin, this hiatus coincides with the boundary between the Voort and Berchem Formations (Figs 2 and 3). Here, age information on the late Oligocene Voort Formation was mainly based on biostratigraphic and radiometric studies on cored sections of the ON-Mol-1 (DOV ON-Mol-1) and Weelde boreholes (DOV kb8d8e-B161; cf. Van Simaeys, 2004; Van Simaeys et al. 2004; 2005; De Man & Van Simaeys, 2004; De Man et al., 2010). The age information on the early to middle Miocene Berchem Formation was then again based on biostratigraphic studies in its outcropping areas near and within the city of Antwerp and in several boreholes across the northern Campine Block (Louwye, 2005 and references therein), not including the ON-Mol-1 and Weelde boreholes. As the Voort and Berchem Formations were studied separately, the boundary between them or the Oligocene/Miocene hiatus was not yet biostratigra
1. 晚渐新世-新近纪期间，海绿石砂在整个北海盆地南部的浅海条件下沉积(图1)。海绿石砂的沉积不是连续的，而是被几次间断所中断。北海盆地南部最重要和最广泛的断裂之一与渐新世/中新世分界线重合，在荷兰常被称为萨维安期(Wong et al.， 2001;Verbeek et al.， 2002;Munsterman & Brinkhuis, 2004)。北Campine地块是北海盆地南缘的构造实体，该断陷期与Voort组和Berchem组的分界线重合(图2和图3)。在此，晚渐新世Voort组的年龄信息主要基于on - mol -1 (DOV on - mol -1)和Weelde钻孔(DOV kb8d8e-B161;参见Van simayys, 2004;Van simayys et al. 2004;2005;德曼和范西梅斯，2004;De Man et al.， 2010)。中新世早期至中期Berchem组的年龄信息再次基于其在安特卫普市附近和内部的露头区域以及Campine地块北部几个钻孔的生物地层学研究(Louwye, 2005和其中的参考文献)，不包括on - mol1和Weelde钻孔。由于Voort组和Berchem组是分开研究的，它们或渐新世/中新世裂孔之间的界线尚未形成生物地层
{"title":"The Oligocene/Miocene boundary in the ON-Mol-1 and Weelde boreholes along the southern margin of the North Sea Basin, Belgium","authors":"D. Munsterman, J. Deckers","doi":"10.20341/gb.2020.007","DOIUrl":"https://doi.org/10.20341/gb.2020.007","url":null,"abstract":"1. Introduction During the late Oligocene and Neogene, glauconitic sands were deposited in shallow marine conditions across the southern North Sea Basin (Fig. 1). The deposition of these glauconitic sands was not continuous, but interrupted by several hiatuses. One of the most important and widespread hiatuses in the southern North Sea Basin coincides with the Oligocene/Miocene boundary, in the Netherlands often referred to as Savian phase (in Wong et al., 2001; Verbeek et al., 2002; Munsterman & Brinkhuis, 2004). In the northern Campine Block, a structural entity along the southern margin of the North Sea Basin, this hiatus coincides with the boundary between the Voort and Berchem Formations (Figs 2 and 3). Here, age information on the late Oligocene Voort Formation was mainly based on biostratigraphic and radiometric studies on cored sections of the ON-Mol-1 (DOV ON-Mol-1) and Weelde boreholes (DOV kb8d8e-B161; cf. Van Simaeys, 2004; Van Simaeys et al. 2004; 2005; De Man & Van Simaeys, 2004; De Man et al., 2010). The age information on the early to middle Miocene Berchem Formation was then again based on biostratigraphic studies in its outcropping areas near and within the city of Antwerp and in several boreholes across the northern Campine Block (Louwye, 2005 and references therein), not including the ON-Mol-1 and Weelde boreholes. As the Voort and Berchem Formations were studied separately, the boundary between them or the Oligocene/Miocene hiatus was not yet biostratigra","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90896902","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}
Denis Turimumahoro, N. Hulsbosch, L. Nahimana, S. Dewaele, P. Muchez
La region de Kabarore-Mparamirundi renferme de nombreuses pegmatites liees aux leucogranites de 986 ± 10 Ma investigues dans la chaine Karagwe-Ankole. Elles sont intensement exploitees pour la columbite-tantalite et la cassiterite. Les elements alcalins presents dans la muscovite (370 a 7590 ppm de Rb, 8 a 1470 ppm de Cs) sont modelises par la cristallisation fractionnee de Rayleigh a partir d'une composition leucogranitique parentale (4,1 % de K, 321 ppm de Rb et 9 ppm de Cs). Le comportement decroissant du rapport K/Rb en fonction de Cs indique que la cristallisation fractionnee de Rayleigh est le principal processus de differenciation des divers facies de pegmatites. De plus, la trajectoire continue depuis le granite parental jusqu’aux pegmatites exploitees demontre un lien co-genetique entre eux. Les pegmatites non exploitees et celles des exploitations abandonnees correspondent a des pegmatites qui sont les moins fractionnees selon le modele (avec moins de 94 % de fractionnement) tandis que les pegmatites exploitees sont les plus fractionnees et constituent des produits de fractionnement de plus de 94 % de la composition initiale du leucogranite. Les elements Rb, Cs, Ta, Sn et Li contenus dans les muscovites peuvent servir d’outil precieux dans l’exploration des pegmatites.
{"title":"Géochimie des muscovites comme indicateur du fractionnement des pegmatites de la région de Kabarore-Mparamirundi (nord-ouest du Burundi, Afrique centrale) [Geochemical signature of muscovites as pathfinder for fractionation of pegmatites in the Kabarore-Mparamirundi area (northwestern Burundi, Centr","authors":"Denis Turimumahoro, N. Hulsbosch, L. Nahimana, S. Dewaele, P. Muchez","doi":"10.20341/gb.2020.005","DOIUrl":"https://doi.org/10.20341/gb.2020.005","url":null,"abstract":"La region de Kabarore-Mparamirundi renferme de nombreuses pegmatites liees aux leucogranites de 986 ± 10 Ma investigues dans la chaine Karagwe-Ankole. Elles sont intensement exploitees pour la columbite-tantalite et la cassiterite. Les elements alcalins presents dans la muscovite (370 a 7590 ppm de Rb, 8 a 1470 ppm de Cs) sont modelises par la cristallisation fractionnee de Rayleigh a partir d'une composition leucogranitique parentale (4,1 % de K, 321 ppm de Rb et 9 ppm de Cs). Le comportement decroissant du rapport K/Rb en fonction de Cs indique que la cristallisation fractionnee de Rayleigh est le principal processus de differenciation des divers facies de pegmatites. De plus, la trajectoire continue depuis le granite parental jusqu’aux pegmatites exploitees demontre un lien co-genetique entre eux. Les pegmatites non exploitees et celles des exploitations abandonnees correspondent a des pegmatites qui sont les moins fractionnees selon le modele (avec moins de 94 % de fractionnement) tandis que les pegmatites exploitees sont les plus fractionnees et constituent des produits de fractionnement de plus de 94 % de la composition initiale du leucogranite. Les elements Rb, Cs, Ta, Sn et Li contenus dans les muscovites peuvent servir d’outil precieux dans l’exploration des pegmatites.","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83928000","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}
L. Licour, P. Goderniaux, N. Dupont, M. Hennebert, R. Swennen, P. Steemans, F. Boulvain, E. Petitclerc, A. Rorive, J. Baele
1. Introduction and objectives Evaporitic formations have been observed in Givetian strata in Annappes, Tournai and Leuze deep boreholes, located on the northern border of the Brabant Parautochthon (Coen-Aubert et al., 1980) (Fig. 1). Delmer already formulated in 1972 the hypothesis that important volumes of evaporites, including halite, could be present in the deep basement of the Mons Basin. The dissolution of these evaporites could explain the peculiarities of the Upper Carboniferous and Meso-Cenozoic deposits in the Mons Basin. Figure 1 General geological map with location of Saint-Ghislain and other deep boreholes, and indication of the Givetian and Dinantian outcrops in the Brabant Parautochthon (modified after de Bethune, 1961). Note that the Conde, Douvrain and Ghlin boreholes have not reached the Devonian units. The Annappes (FR) borehole is located 16 km WNW from Tournai city. The main objective of the Saint-Ghislain borehole, drilled between 1972 and 1976, was to test this hypothesis. During the drilling, a total of several hundred metres of anhydrite (CaSO4) was recovered not from the Devonian, as expected, but from the Lower Carboniferous. Preserved anhydrite layers are located in Middle and Upper Visean limestones, between -1950 and -2750 m, representing about 50% of the series within this section (Dejonghe et al., 1976; Delmer, 1977; Groessens et al., 1979; de Magnee et al., 1986). This was the first direct evidence of the presence of evaporites in the French-
1. 在位于Brabant副岩浆岩北部边界的Annappes、Tournai和Leuze深钻孔的Givetian地层中观察到了蒸发地层(Coen-Aubert et al.， 1980)(图1)。Delmer在1972年已经提出了一个假设，即在Mons盆地的深层基底中可能存在大量的蒸发岩，包括岩浆岩。这些蒸发岩的溶蚀作用可以解释蒙斯盆地上石炭统和中新生代沉积的特点。图1总体地质图，包括Saint-Ghislain和其他深钻孔位置，以及布拉班特副岛礁的Givetian和Dinantian露头(de Bethune, 1961年修改后)。注意Conde、Douvrain和Ghlin钻孔没有到达泥盆纪单元。Annappes (FR)钻孔位于图尔奈市西北16公里处。Saint-Ghislain井眼于1972年至1976年间钻探，主要目的是验证这一假设。在钻探过程中，数百米厚的硬石膏(CaSO4)并非如预期的那样来自泥盆纪，而是来自下石炭世。保存完好的硬石膏层位于-1950和-2750 m之间的中上维西石灰岩中，约占该剖面内系列的50% (Dejonghe et al.， 1976;Delmer, 1977;Groessens等人，1979;de Magnee et al.， 1986)。这是第一个直接的证据，证明在法国-
{"title":"Stratigraphical reinterpretation of Devonian strata underlying the Mons Basin based on cuttings from the Saint-Ghislain borehole, Hainaut, Belgium","authors":"L. Licour, P. Goderniaux, N. Dupont, M. Hennebert, R. Swennen, P. Steemans, F. Boulvain, E. Petitclerc, A. Rorive, J. Baele","doi":"10.20341/gb.2020.002","DOIUrl":"https://doi.org/10.20341/gb.2020.002","url":null,"abstract":"1. Introduction and objectives Evaporitic formations have been observed in Givetian strata in Annappes, Tournai and Leuze deep boreholes, located on the northern border of the Brabant Parautochthon (Coen-Aubert et al., 1980) (Fig. 1). Delmer already formulated in 1972 the hypothesis that important volumes of evaporites, including halite, could be present in the deep basement of the Mons Basin. The dissolution of these evaporites could explain the peculiarities of the Upper Carboniferous and Meso-Cenozoic deposits in the Mons Basin. Figure 1 General geological map with location of Saint-Ghislain and other deep boreholes, and indication of the Givetian and Dinantian outcrops in the Brabant Parautochthon (modified after de Bethune, 1961). Note that the Conde, Douvrain and Ghlin boreholes have not reached the Devonian units. The Annappes (FR) borehole is located 16 km WNW from Tournai city. The main objective of the Saint-Ghislain borehole, drilled between 1972 and 1976, was to test this hypothesis. During the drilling, a total of several hundred metres of anhydrite (CaSO4) was recovered not from the Devonian, as expected, but from the Lower Carboniferous. Preserved anhydrite layers are located in Middle and Upper Visean limestones, between -1950 and -2750 m, representing about 50% of the series within this section (Dejonghe et al., 1976; Delmer, 1977; Groessens et al., 1979; de Magnee et al., 1986). This was the first direct evidence of the presence of evaporites in the French-","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90451656","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}
We address the role of the Congo River sediment dispersal in exporting and trapping organic carbon into deep offshore sediments. Of particular interest is the Congo submarine canyon, which constitutes a permanent link between the terrestrial sediment sources and the marine sink. The Congo River delivers an annual sediment load of ~40 Tg (including 2 Tg of C) that feed a mud-rich turbidite system. Previous estimates of carbon storage capacity in the Congo turbidite system suggest that the terminal lobe complex accounts for ~12% of the surface area of the active turbidite system and accumulates ~18% of the annual input of terrestrial particulate organic carbon exiting the Congo River. In this paper, we extend the approach to the whole active turbidite depositional system by calculating an average burial of terrestrial organic matter in the different environments: canyon, channel, and levees. We estimate that between 33 and 69% of terrestrial carbon exported by the Congo River is ultimately trapped in the different parts of turbidite system and we evaluate their relative efficiency using a source to sink approach. Our carbon budget approach, which consider annual river discharge versus offshore centennial accumulation rates, indicates that about half of the total particulate organic matter delivered yearly by the Congo River watershed escapes the study area or is not correctly estimated by our deep offshore dataset and calculations.
{"title":"Routing of terrestrial organic matter from the Congo River to the ultimate sink in the abyss: a mass balance approach (André Dumont medallist lecture 2017)","authors":"F. Baudin, C. Rabouille, B. Dennielou","doi":"10.20341/gb.2020.004","DOIUrl":"https://doi.org/10.20341/gb.2020.004","url":null,"abstract":"We address the role of the Congo River sediment dispersal in exporting and trapping organic carbon into deep offshore sediments. Of particular interest is the Congo submarine canyon, which constitutes a permanent link between the terrestrial sediment sources and the marine sink. The Congo River delivers an annual sediment load of ~40 Tg (including 2 Tg of C) that feed a mud-rich turbidite system. Previous estimates of carbon storage capacity in the Congo turbidite system suggest that the terminal lobe complex accounts for ~12% of the surface area of the active turbidite system and accumulates ~18% of the annual input of terrestrial particulate organic carbon exiting the Congo River. In this paper, we extend the approach to the whole active turbidite depositional system by calculating an average burial of terrestrial organic matter in the different environments: canyon, channel, and levees. We estimate that between 33 and 69% of terrestrial carbon exported by the Congo River is ultimately trapped in the different parts of turbidite system and we evaluate their relative efficiency using a source to sink approach. Our carbon budget approach, which consider annual river discharge versus offshore centennial accumulation rates, indicates that about half of the total particulate organic matter delivered yearly by the Congo River watershed escapes the study area or is not correctly estimated by our deep offshore dataset and calculations.","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79887730","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 Contrary to the situation in South Belgium where Devonian trilobites have been the focus of numerous contemporary studies, only few papers have dealt with taxa from East Belgium (Franke, 2006; Hellemond et al., 2019; van Viersen, 2013; van Viersen & Prescher, 2009). Nearly a century ago Asselberghs (1923) reported a poorly diversified, Early Devonian trilobite association from an outcrop near Breitfeld (Sankt Vith (Saint Vith in French) area, East Belgium). Although Asselberghs described and illustrated only one trilobite species, Homalonotus maillieuxi Asselberghs, 1923, he mentioned the occurrences of several others. The present paper aims to document the Breitfeld trilobite association fully, and to discuss its potential for biostratigraphic correlations of Emsian trilobites in the Ardenno-Rhenish Mountains as well as its palaeobiogeographic affinities. 2. Geological context Locality B-117 (“Pl. Saint-Vith 1” on the field maps of Maillieux that are kept by the Institut royal des Sciences naturelles de Belgique in Brussels (IRSNB)), southwest of the village centre of Breitfeld, East Belgium (Figs 1, 2); probably lower part of the Our Formation (lower Emsian). Figure 1. Geographic map of the studied area with the Breitfeld locality (B-117) indicated. The black dotted line indicates part of the former Vennbahn railway line. Figure 2. A. Overview geological map of southeast Belgium, northern France, Luxemburg and western Germany with key localities and Lochko
{"title":"A poorly diversified trilobite association from the lower Emsian (Lower Devonian) in the Sankt Vith area (East Belgium)","authors":"Allart P. VAN VIERSEN, Peter Taghon","doi":"10.20341/gb.2019.011","DOIUrl":"https://doi.org/10.20341/gb.2019.011","url":null,"abstract":"1. Introduction Contrary to the situation in South Belgium where Devonian trilobites have been the focus of numerous contemporary studies, only few papers have dealt with taxa from East Belgium (Franke, 2006; Hellemond et al., 2019; van Viersen, 2013; van Viersen & Prescher, 2009). Nearly a century ago Asselberghs (1923) reported a poorly diversified, Early Devonian trilobite association from an outcrop near Breitfeld (Sankt Vith (Saint Vith in French) area, East Belgium). Although Asselberghs described and illustrated only one trilobite species, Homalonotus maillieuxi Asselberghs, 1923, he mentioned the occurrences of several others. The present paper aims to document the Breitfeld trilobite association fully, and to discuss its potential for biostratigraphic correlations of Emsian trilobites in the Ardenno-Rhenish Mountains as well as its palaeobiogeographic affinities. 2. Geological context Locality B-117 (“Pl. Saint-Vith 1” on the field maps of Maillieux that are kept by the Institut royal des Sciences naturelles de Belgique in Brussels (IRSNB)), southwest of the village centre of Breitfeld, East Belgium (Figs 1, 2); probably lower part of the Our Formation (lower Emsian). Figure 1. Geographic map of the studied area with the Breitfeld locality (B-117) indicated. The black dotted line indicates part of the former Vennbahn railway line. Figure 2. A. Overview geological map of southeast Belgium, northern France, Luxemburg and western Germany with key localities and Lochko","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87528522","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}
F. Delpomdor, A. M. Ilambwetsi, F. Caxito, A. Pedrosa-Soares
1. Introduction For several decades, outcrops showing rudite deposits at the base of the lowermost carbonate-pelite unit of the Bambui Group, like those located at km-30 marker of the MG-424 roadway near Sao Jose de Lapa (Minas Gerais, eastern Brazil), firstly described by Costa & Branco (1961) as the type-section of the rudite-bearing Carrancas Formation, have been associated with Neoproterozoic glacial events (Martins-Neto et al., 2001; Sgarbi et al., 2001; Romano & Knauer, 2003; Uhlein et al., 2004, 2012, 2016; Romano, 2007; Ribeiro et al., 2008; Kuchenbecker et al., 2013, 2016; Babinski et al., 2012; Uhlein, 2014; Reis & Alkmim, 2015). More recently, this unit has been the subject of facies and stratigraphy analysis from type-sections in the Sete Lagoas High, southern Bambui basin, which have been newly interpreted as showing no evidence of glacial Cryogenian activity (Vieira et al., 2007; Rodrigues, 2008; Tuller et al., 2010). Caxito et al. (2012) interpreted the conglomeratic unit at these outcrops, as derived from local reworking of the basal platform of the lowermost unit of the Sete Lagoas Formation, along with its underlying basement. Other outcrops in adjacent areas commonly ascribed to the Carrancas Formation were recently re-interpreted as pre-glacial units deposited along fault margins (Uhlein et al., 2012, 2016). Recent chemostratigraphic studies on this stratigraphic interval supported general correlation with the lowermost part of the Sete Lagoas Formation (S
1. 几十年来，在Bambui群最底部的碳酸盐岩-泥岩单元底部的露头显示了粗砾岩矿床，例如位于Sao Jose de Lapa (Minas Gerais，巴西东部)附近MG-424公路km-30标记处的露头，Costa和Branco(1961)首次将其描述为含粗砾岩的Carrancas组的类型剖面，这与新元古代的冰川事件有关(Martins-Neto et al.， 2001;Sgarbi et al.， 2001;Romano & Knauer, 2003;Uhlein et al.， 2004, 2012, 2016;Romano, 2007;Ribeiro et al.， 2008;Kuchenbecker et al.， 2013, 2016;Babinski et al.， 2012;Uhlein, 2014;Reis & Alkmim, 2015)。最近，该单元已成为Bambui盆地南部Sete Lagoas High的类型剖面相和地层学分析的主题，这些剖面最近被解释为没有显示冰川低温期活动的证据(Vieira et al.， 2007;罗德里格斯,2008;Tuller et al.， 2010)。Caxito等人(2012)将这些露头处的砾岩单元解释为源自对Sete Lagoas组最下层单元的基台及其下伏基底的局部改造。邻近地区的其他露头通常被认为是Carrancas组，最近被重新解释为沿断层边缘沉积的前冰川单元(Uhlein et al.， 2012, 2016)。最近对该层段的化学地层学研究支持了该层段与Sete Lagoas组(S
{"title":"New interpretation of the basal Bambuí Group, Sete Lagoas High (Minas Gerais, E Brazil) by sedimentological studies and regional implications for the aftermath of the Marinoan glaciation: Correlations across Brazil and Central Africa","authors":"F. Delpomdor, A. M. Ilambwetsi, F. Caxito, A. Pedrosa-Soares","doi":"10.20341/gb.2019.010","DOIUrl":"https://doi.org/10.20341/gb.2019.010","url":null,"abstract":"1. Introduction For several decades, outcrops showing rudite deposits at the base of the lowermost carbonate-pelite unit of the Bambui Group, like those located at km-30 marker of the MG-424 roadway near Sao Jose de Lapa (Minas Gerais, eastern Brazil), firstly described by Costa & Branco (1961) as the type-section of the rudite-bearing Carrancas Formation, have been associated with Neoproterozoic glacial events (Martins-Neto et al., 2001; Sgarbi et al., 2001; Romano & Knauer, 2003; Uhlein et al., 2004, 2012, 2016; Romano, 2007; Ribeiro et al., 2008; Kuchenbecker et al., 2013, 2016; Babinski et al., 2012; Uhlein, 2014; Reis & Alkmim, 2015). More recently, this unit has been the subject of facies and stratigraphy analysis from type-sections in the Sete Lagoas High, southern Bambui basin, which have been newly interpreted as showing no evidence of glacial Cryogenian activity (Vieira et al., 2007; Rodrigues, 2008; Tuller et al., 2010). Caxito et al. (2012) interpreted the conglomeratic unit at these outcrops, as derived from local reworking of the basal platform of the lowermost unit of the Sete Lagoas Formation, along with its underlying basement. Other outcrops in adjacent areas commonly ascribed to the Carrancas Formation were recently re-interpreted as pre-glacial units deposited along fault margins (Uhlein et al., 2012, 2016). Recent chemostratigraphic studies on this stratigraphic interval supported general correlation with the lowermost part of the Sete Lagoas Formation (S","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2020-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91333145","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}
In the Chansin quarry (Belgium), a horizontal karstic gallery which seems to be totally filled has been discovered. The study of this filling shows that it is composed of a residual alterite from the bedrock. The ghost-rock karstification has stopped just after the first phase of this karstogenesis. The residual alterite is still present, without significant geometrical modification. The transition between the unaltered bedrock and the ghost-rock is very clear. We present the characteristics of this ghost-rock which is here regarded as a typical example of a pseudo-gallery and act as a reference for further definition.
{"title":"The ghost-rock of the Chansin quarry (Belgium) – A remarkable example of pseudogallery","authors":"C. Dubois, Y. Quinif","doi":"10.20341/gb.2019.004","DOIUrl":"https://doi.org/10.20341/gb.2019.004","url":null,"abstract":"In the Chansin quarry (Belgium), a horizontal karstic gallery which seems to be totally filled has been discovered. The study of this filling shows that it is composed of a residual alterite from the bedrock. The ghost-rock karstification has stopped just after the first phase of this karstogenesis. The residual alterite is still present, without significant geometrical modification. The transition between the unaltered bedrock and the ghost-rock is very clear. We present the characteristics of this ghost-rock which is here regarded as a typical example of a pseudo-gallery and act as a reference for further definition.","PeriodicalId":12812,"journal":{"name":"Geologica Belgica","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2019-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80747239","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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