Pub Date : 2016-03-01DOI: 10.2113/GSSGFBULL.187.2.105
A. Brignon
En 1808 puis en 1824, Georges Cuvier signala dans la region du Mans la presence de restes de crocodiles fossiles a partir desquels fut creee l’espece Crocodilus maunyi GRAY, 1831. Il avait ete informe de ces decouvertes par le naturaliste manceau Louis Jean Charles Maulny (1758-1815) et par Jean Antoine Daudin (1749-1832), premier conservateur du Museum d’histoire naturelle du Mans. Faute de figures publiees, ce materiel est reste enigmatique durant deux siecles. Des aquarelles inedites conservees dans les archives de Georges Cuvier permettent de devoiler les specimens qu’il avait decrits sous le nom de « crocodiles fossiles des environs du Mans ». Ils comprennent des dents, des vertebres et des portions de mâchoires de crocodylomorphes marins et de plesiosauriens decouvertes dans le Mesozoique de la Sarthe (Bathonien, Callovien, Cenomanien ?). Un de ces dessins presente une dent de pliosaure du Bathonien de Ber- nay-en-Champagne qui serait la plus ancienne decouverte d’un representant de ce groupe. Deux autres aquarelles montrent une portion de mandibule d’un crocodylomorphe marin (Thalattosuchia, Metriorhynchidae indetermine) et une vertebre de plesiosaurien (Plesiosauria indetermine) du Callovien moyen de Chaufour-Notre-Dame, toujours conservees au Musee Vert, le museum d’histoire naturelle du Mans. Ces deux specimens furent decouverts en 1816 par un amateur local, le docteur Eusebe Marie Tendron (1778-1854). Crocodilus maunyi GRAY, 1831 reste neanmoins considere comme un nomen dubium au regard du manque de caracteres diagnostiques de l’ensemble de ses syntypes.
{"title":"Redécouverte des « crocodiles fossiles des environs du Mans » de Georges Cuvier après deux siècles d’oubli","authors":"A. Brignon","doi":"10.2113/GSSGFBULL.187.2.105","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.2.105","url":null,"abstract":"En 1808 puis en 1824, Georges Cuvier signala dans la region du Mans la presence de restes de crocodiles fossiles a partir desquels fut creee l’espece Crocodilus maunyi GRAY, 1831. Il avait ete informe de ces decouvertes par le naturaliste manceau Louis Jean Charles Maulny (1758-1815) et par Jean Antoine Daudin (1749-1832), premier conservateur du Museum d’histoire naturelle du Mans. Faute de figures publiees, ce materiel est reste enigmatique durant deux siecles. Des aquarelles inedites conservees dans les archives de Georges Cuvier permettent de devoiler les specimens qu’il avait decrits sous le nom de « crocodiles fossiles des environs du Mans ». Ils comprennent des dents, des vertebres et des portions de mâchoires de crocodylomorphes marins et de plesiosauriens decouvertes dans le Mesozoique de la Sarthe (Bathonien, Callovien, Cenomanien ?). Un de ces dessins presente une dent de pliosaure du Bathonien de Ber- nay-en-Champagne qui serait la plus ancienne decouverte d’un representant de ce groupe. Deux autres aquarelles montrent une portion de mandibule d’un crocodylomorphe marin (Thalattosuchia, Metriorhynchidae indetermine) et une vertebre de plesiosaurien (Plesiosauria indetermine) du Callovien moyen de Chaufour-Notre-Dame, toujours conservees au Musee Vert, le museum d’histoire naturelle du Mans. Ces deux specimens furent decouverts en 1816 par un amateur local, le docteur Eusebe Marie Tendron (1778-1854). Crocodilus maunyi GRAY, 1831 reste neanmoins considere comme un nomen dubium au regard du manque de caracteres diagnostiques de l’ensemble de ses syntypes.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"120 1","pages":"105-120"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77416219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-03-01DOI: 10.2113/GSSGFBULL.187.2.121
Jean‐David Moreau, Louis Baret, Gérard Lafaurie, C. Chateau-Smith
A new Late Jurassic flora was discovered in the fossiliferous lithographic limestone of the Causse Mejean, Lozere (southern France). It consists of the first Kimmeridgian/Tithonian plants from this area. Fossil plants are represented by megaremains preserved as impressions. This flora shows a co-occurrence of terrestrial plants and marine algae. The land plants include vegetative remains ascribed to bennettitaleans (Zamites Brongniart, 1828), conifers (Brachyphyllum Brongniart, 1828), and pteridosperms (Cycadopteris Zigno, 1853). Marine algae were ascribed to dasyclads (Goniolina D’Orbigny, 1850). Lithological and palaeontological features suggest preservation in a flat, homogeneous, protected environment, perhaps a brackish or marine lagoon, influenced by both continental and marine inputs. This discovery complements the few existing reports of European Late Jurassic floras, and indicates that coastal habitats were dominated by sub-arborescent vegetation, consisting of bennettitaleans and pteridosperms, and arborescent plants, such as conifers. Both the palaeoenvironmental context and certain xerophytic features suggest that these terrestrial plants from the Causse Mejean were well adapted to the hot, dry conditions of coastal areas.
{"title":"Terrestrial plants and marine algae from the Late Jurassic lithographic limestone of the Causse Méjean (Lozère, southern France)","authors":"Jean‐David Moreau, Louis Baret, Gérard Lafaurie, C. Chateau-Smith","doi":"10.2113/GSSGFBULL.187.2.121","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.2.121","url":null,"abstract":"A new Late Jurassic flora was discovered in the fossiliferous lithographic limestone of the Causse Mejean, Lozere (southern France). It consists of the first Kimmeridgian/Tithonian plants from this area. Fossil plants are represented by megaremains preserved as impressions. This flora shows a co-occurrence of terrestrial plants and marine algae. The land plants include vegetative remains ascribed to bennettitaleans (Zamites Brongniart, 1828), conifers (Brachyphyllum Brongniart, 1828), and pteridosperms (Cycadopteris Zigno, 1853). Marine algae were ascribed to dasyclads (Goniolina D’Orbigny, 1850). Lithological and palaeontological features suggest preservation in a flat, homogeneous, protected environment, perhaps a brackish or marine lagoon, influenced by both continental and marine inputs. This discovery complements the few existing reports of European Late Jurassic floras, and indicates that coastal habitats were dominated by sub-arborescent vegetation, consisting of bennettitaleans and pteridosperms, and arborescent plants, such as conifers. Both the palaeoenvironmental context and certain xerophytic features suggest that these terrestrial plants from the Causse Mejean were well adapted to the hot, dry conditions of coastal areas.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"32 1","pages":"121-127"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91278967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-03-01DOI: 10.2113/GSSGFBULL.187.2.73
Yacouba Ahmed, M. Konaté, M. Harouna
The Tefidet trough (eastern Niger) belongs to the Tenere megasystem set of Cretaceous rifts N130°E to N170°E oriented, corresponding to the direction of the Lake Chad-Hoggar tectonic axis. The study of the relationship between the structure of the trough and alkaline fissural volcanism that developed there from the Oligocene to Plio-Quaternary shows the uniqueness of the Tefidet trough compared to the neighboring contemporary volcanic areas of Hoggar, Cameroon, and southern Air. The tectono-magmatic reactivation of the Cretaceous Tefidet trough developed in two steps: – a period contemporaneous with the Tuareg shield bulging (Air, Hoggar, Iforas); – a subsequent extension period generally N060°E, which has persisted since the opening of the South Atlantic (upper Jurassic to Plio-Quaternary). The fissural volcanism, due to the reactivation of Pan African and Cretaceous faults evolved concomitantly with the N060°E extension (syn-magmatic micro-fractures with basaltic filling), in several steps, from Oligocene to Plio-Quaternary. This study highlights the existence of periods of quietness and recovery of volcanic activity, for which two assumptions can be made: – no enough absolute datings, – apolyphased extension of the rift. The latter hypothesis seems to be supported by three periods of volcanic quietness, 28–24 m.y., 20–14 m.y. and 8–5 m.y., observed in the northern and the southern Air, Greboun and Todgha, respectively.
{"title":"Tectono-magmatic reactivation of Téfidet Cretaceous trough during Cenozoic (Aïr, Niger)","authors":"Yacouba Ahmed, M. Konaté, M. Harouna","doi":"10.2113/GSSGFBULL.187.2.73","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.2.73","url":null,"abstract":"The Tefidet trough (eastern Niger) belongs to the Tenere megasystem set of Cretaceous rifts N130°E to N170°E oriented, corresponding to the direction of the Lake Chad-Hoggar tectonic axis. The study of the relationship between the structure of the trough and alkaline fissural volcanism that developed there from the Oligocene to Plio-Quaternary shows the uniqueness of the Tefidet trough compared to the neighboring contemporary volcanic areas of Hoggar, Cameroon, and southern Air. The tectono-magmatic reactivation of the Cretaceous Tefidet trough developed in two steps:\u0000 – a period contemporaneous with the Tuareg shield bulging (Air, Hoggar, Iforas); – a subsequent extension period generally N060°E, which has persisted since the opening of the South Atlantic (upper Jurassic to Plio-Quaternary). The fissural volcanism, due to the reactivation of Pan African and Cretaceous faults evolved concomitantly with the N060°E extension (syn-magmatic micro-fractures with basaltic filling), in several steps, from Oligocene to Plio-Quaternary. This study highlights the existence of periods of quietness and recovery of volcanic activity, for which two assumptions can be made:\u0000 – no enough absolute datings, – apolyphased extension of the rift. The latter hypothesis seems to be supported by three periods of volcanic quietness, 28–24 m.y., 20–14 m.y. and 8–5 m.y., observed in the northern and the southern Air, Greboun and Todgha, respectively.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"8 1","pages":"73-82"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73292813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-03-01DOI: 10.2113/GSSGFBULL.187.2.83
J. Berthelon, W. Sassi
Using the geologist’s interpretation of 6 published balanced cross-sections in the fold and thrust belts of the northwestern Mediterranean, a comparative analysis of the interpreted subsurface structural architecture is used to address the links between the structural style and the mechanics of fold and thrust emplacement. For each cross-section example, the geo-dataset and the methods used by the interpreters are different in quantity and quality. Here we have examined how useful is the content of information of each cross-section to constrain the structural evolution scenario. Each interpretation is examined according to considerations of the mechanics of sedimentary basin deformation and how uncertain is the extrapolation of fault trajectory at depth. It is shown that each case reveals a particular type of structural style: thin-skin or thick skin tectonics, fault-related folding, pre-existing fault pattern. The present structural analysis is used to determine for each cross-section the nature of the mechanical problem to address that will reduce uncertainty on the geologic scenario reconstruction. The proposed mechanical boundary conditions could serve to develop analog or numerical models that aim at testing the mechanical validity of the structural scenario of fold and thrust emplacement.
{"title":"A discussion on the validation of structural interpretations based on the mechanics of sedimentary basins in the northwestern Mediterranean fold-and-thrust belts","authors":"J. Berthelon, W. Sassi","doi":"10.2113/GSSGFBULL.187.2.83","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.2.83","url":null,"abstract":"Using the geologist’s interpretation of 6 published balanced cross-sections in the fold and thrust belts of the northwestern Mediterranean, a comparative analysis of the interpreted subsurface structural architecture is used to address the links between the structural style and the mechanics of fold and thrust emplacement. For each cross-section example, the geo-dataset and the methods used by the interpreters are different in quantity and quality. Here we have examined how useful is the content of information of each cross-section to constrain the structural evolution scenario. Each interpretation is examined according to considerations of the mechanics of sedimentary basin deformation and how uncertain is the extrapolation of fault trajectory at depth. It is shown that each case reveals a particular type of structural style: thin-skin or thick skin tectonics, fault-related folding, pre-existing fault pattern. The present structural analysis is used to determine for each cross-section the nature of the mechanical problem to address that will reduce uncertainty on the geologic scenario reconstruction. The proposed mechanical boundary conditions could serve to develop analog or numerical models that aim at testing the mechanical validity of the structural scenario of fold and thrust emplacement.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"50 1","pages":"83-104"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90671151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-01-01DOI: 10.2113/GSSGFBULL.187.1.55
Jean-Michel Pacaud
In 1826, Risso erected Niso eburnea, a gastropod species from Zanclean (Lower Pliocene) of La Trinite, Nice (Alpes-Maritimes, France), and designated it as type species of his new genus Niso. Considering the often inaccurate information on the type species of the genus Niso Risso, 1826 we give here a description and figures of this species. Moreover, the type material of Niso eburnea Risso, 1826, from Risso’s collection, considered as lost, have recently been discovered in the Collection de Paleontologie of the Museum national d’Histoire naturelle, Paris. A lectotype is herein designated to fix the status of this species.
{"title":"Découverte du matériel type de Niso eburnea Risso, 1826, espèce type du genre Niso Risso, 1826 (Mollusca, Gastropoda, Eulimidae) et implications taxonomiques","authors":"Jean-Michel Pacaud","doi":"10.2113/GSSGFBULL.187.1.55","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.1.55","url":null,"abstract":"In 1826, Risso erected Niso eburnea, a gastropod species from Zanclean (Lower Pliocene) of La Trinite, Nice (Alpes-Maritimes, France), and designated it as type species of his new genus Niso. Considering the often inaccurate information on the type species of the genus Niso Risso, 1826 we give here a description and figures of this species. Moreover, the type material of Niso eburnea Risso, 1826, from Risso’s collection, considered as lost, have recently been discovered in the Collection de Paleontologie of the Museum national d’Histoire naturelle, Paris. A lectotype is herein designated to fix the status of this species.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"44 1","pages":"55-62"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87450294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-01-01DOI: 10.2113/GSSGFBULL.187.1.11
G. Merzeraud, El Mabrouk Essid, Wissem Marzougui, H. Ammar, Sylvain Adnet, Laurent Marivaux, Rodolphe Tabuce, M. Vianey-liaud
The Kasserine area, in central Tunisia, is for a long time considered by many authors as an emerged island (or islets), since the upper Cretaceous until the middle Miocene. In the eighties, continental deposits were described and dated Eocene. At that time, no marine deposit older than middle Miocene were thus known in central Tunisia, and the only Eocene marine strata, were located in periphery of the emerged zone, in phosphatic basins. It is in the area of Djebel el Kebar, which is situated at the eastern edge of the Kasserine region that a detailed study of the Eocene-middle Miocene deposits was carried out. In the studied series, four major unconformities are observed and correlated on the whole of the site. Between these surfaces, three successive sedimentary units are observed from base to top and are composed of limestone, glauconite and clay deposits (unit I), shell beds limestone (unit II), conglomerate, sandstone and silty-clay (unit III). Paleontological and biostratigraphic results An important fossils locality was discovered in Djebel el Kebar, in glauconitic marine deposits of the first sedimentary unit. Fauna, very rich, contains many marine (shark, ray, sirenian, etc.) and continental forms (rodent, hyracoid and primate). The new dating clearly indicates that the deposits of the lower part of the series are Bartonian in age. Sedimentological results Thirteen facies were identified and the exceptional conditions of outcrop in Djebel el Kebar have allowed us to map the lateral facies evolution. The sedimentary environments were reconstituted and their succession shows a very shallow water-depth carbonate platform (wave dominated and influenced by storms and tide), passing upward into a sandy fluvial and estuarine environment. Tectono-sedimentary and sequential evolution A sequence stratigraphic framework was proposed, in which, on both sides of unconformities primarily of tectonic origin, three very partially preserved sequences (> 3 Ma) are compatible with the second order of [Vail et al. [1991]][1]. In these sequences, the major part of the studied series is set up in transgressive system tracts and highstand system tracts. The fossil locality then seems to be associated with several episodes with condensation, formed during the transgressive part of the second order cycle. Conclusions The first, new and important result of this work, is the characterization and dating of marine deposits older than middle-Miocene in Djebel el Kebar, in central Tunisia. The studied area is thus not in the emerged part of the zone of Kasserine during the Eocene. Between Bartonian and lower-Miocene, marine facies, evolve within an environment of very shallow marine carbonated platform. A major event (flexure coupled with eustatic fall in Miocene) would cause a change of depositional profile, the arrival of coarse terrigenous material and the installation of a continental fluvial and estuarine sedimentary environment. Finally the whole of the seri
突尼斯中部的Kasserine地区，从上白垩纪到中新世中期，长期以来一直被许多作者认为是一个新兴的岛屿(或小岛)。80年代，对始新世的陆相沉积进行了描述和定年。当时，突尼斯中部未发现超过中中新世的海相沉积，唯一的始新世海相地层位于出露带边缘的磷化盆地中。在位于Kasserine地区东部边缘的Djebel el Kebar地区，对始新世-中中新世沉积进行了详细的研究。在研究序列中，观察到四个主要的不整合面，并在整个遗址上进行了对比。在这些表面之间，从底部到顶部观察到三个连续的沉积单元，由灰岩、海绿石和粘土沉积(单元I)、壳层灰岩(单元II)、砾岩、砂岩和粉质粘土沉积(单元III)组成。古生物和生物地层学结果在第一个沉积单元海绿石海相沉积中，在Djebel el Kebar发现了重要的化石位置。动物群非常丰富，包括许多海洋动物(鲨鱼、鳐鱼、海龙等)和大陆动物(啮齿动物、水螅类动物和灵长类动物)。新的测年结果清楚地表明，该系列下部的沉积物年龄为巴顿期。确定了13种沉积相，并利用Djebel el Kebar的特殊露头条件绘制了横向相演化图。重建了沉积环境，其演替为极浅水深的碳酸盐岩台地(以波浪为主，受风暴和潮汐影响)，向上进入砂质河流和河口环境。构造-沉积与层序演化提出了一个层序地层格架，在以构造成因为主的不整合面两侧，有3个保存非常完好(> 3 Ma)的层序与2级相匹配[Vail等[1991]][1]。在这些层序中，研究的系列主要分布在海侵体系域和高地体系域。因此，化石位置似乎与二级旋回海侵阶段形成的几个凝结期有关。本工作的第一个重要新成果是对突尼斯中部Djebel el Kebar地区中中新世以上海相沉积物的表征和年代测定。因此，研究区不在始新世时期卡塞林带的出现部分。在巴尔东期和下中新世之间，海相，在极浅海相碳酸台地环境中演化。一个重大事件(中新世的挠曲与上升下降相结合)将导致沉积剖面的改变，粗大的陆源物质的到来，并形成陆相河流和河口沉积环境。最后，整个系列记录了大尺度的构造-隆起变化，由几个二级层序组成，部分保存完好。[1]: # ref - 69
{"title":"Stratigraphie et sédimentologie des dépôts marins et continentaux d’âge éocène moyen à miocène en Tunisie centrale (région du Djebel el Kébar)","authors":"G. Merzeraud, El Mabrouk Essid, Wissem Marzougui, H. Ammar, Sylvain Adnet, Laurent Marivaux, Rodolphe Tabuce, M. Vianey-liaud","doi":"10.2113/GSSGFBULL.187.1.11","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.1.11","url":null,"abstract":"The Kasserine area, in central Tunisia, is for a long time considered by many authors as an emerged island (or islets), since the upper Cretaceous until the middle Miocene. In the eighties, continental deposits were described and dated Eocene. At that time, no marine deposit older than middle Miocene were thus known in central Tunisia, and the only Eocene marine strata, were located in periphery of the emerged zone, in phosphatic basins. It is in the area of Djebel el Kebar, which is situated at the eastern edge of the Kasserine region that a detailed study of the Eocene-middle Miocene deposits was carried out. In the studied series, four major unconformities are observed and correlated on the whole of the site. Between these surfaces, three successive sedimentary units are observed from base to top and are composed of limestone, glauconite and clay deposits (unit I), shell beds limestone (unit II), conglomerate, sandstone and silty-clay (unit III). Paleontological and biostratigraphic results An important fossils locality was discovered in Djebel el Kebar, in glauconitic marine deposits of the first sedimentary unit. Fauna, very rich, contains many marine (shark, ray, sirenian, etc.) and continental forms (rodent, hyracoid and primate). The new dating clearly indicates that the deposits of the lower part of the series are Bartonian in age. Sedimentological results Thirteen facies were identified and the exceptional conditions of outcrop in Djebel el Kebar have allowed us to map the lateral facies evolution. The sedimentary environments were reconstituted and their succession shows a very shallow water-depth carbonate platform (wave dominated and influenced by storms and tide), passing upward into a sandy fluvial and estuarine environment. Tectono-sedimentary and sequential evolution A sequence stratigraphic framework was proposed, in which, on both sides of unconformities primarily of tectonic origin, three very partially preserved sequences (> 3 Ma) are compatible with the second order of [Vail et al. [1991]][1]. In these sequences, the major part of the studied series is set up in transgressive system tracts and highstand system tracts. The fossil locality then seems to be associated with several episodes with condensation, formed during the transgressive part of the second order cycle. Conclusions The first, new and important result of this work, is the characterization and dating of marine deposits older than middle-Miocene in Djebel el Kebar, in central Tunisia. The studied area is thus not in the emerged part of the zone of Kasserine during the Eocene. Between Bartonian and lower-Miocene, marine facies, evolve within an environment of very shallow marine carbonated platform. A major event (flexure coupled with eustatic fall in Miocene) would cause a change of depositional profile, the arrival of coarse terrigenous material and the installation of a continental fluvial and estuarine sedimentary environment. Finally the whole of the seri","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"39 1","pages":"11-25"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75116574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-01-01DOI: 10.2113/GSSGFBULL.187.1.41
E. Buffetaut
In 1860, the French geologist and palaeontologist Auguste Bravard (1803–1861) circulated a small number of copies of a hand-written and lithographed catalogue of the fossils he had collected in various parts of Argentina over a period of about eight years. Although the existence of this catalogue has been mentioned by various authors, it has never been really published in full. A facsimile reproduction is provided here. The contents of the catalogue and reactions to them are discussed, with special attention to comments in the correspondence between Charles Lyell and Charles Darwin. These comments were largely about Bravard’s identification among his fossils from Argentina of the genera Palaeotherium and Anoplotherium , well known components of the Late Eocene mammal fauna from the Montmartre gypsum, in the Paris Basin. This identification was later shown to be erroneous by Gervais, Burmeister and Ameghino. Bravard’s catalogue also includes what appears to be the first mention of fossil giant ground birds (Phorusrhacidae) in South America. # Note added in proof {#article-title-35}
{"title":"From Charles Darwin’s comments to the first mention of South American giant fossil birds: Auguste Bravard’s catalogue of fossil species from Argentina (1860) and its significance","authors":"E. Buffetaut","doi":"10.2113/GSSGFBULL.187.1.41","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.1.41","url":null,"abstract":"In 1860, the French geologist and palaeontologist Auguste Bravard (1803–1861) circulated a small number of copies of a hand-written and lithographed catalogue of the fossils he had collected in various parts of Argentina over a period of about eight years. Although the existence of this catalogue has been mentioned by various authors, it has never been really published in full. A facsimile reproduction is provided here. The contents of the catalogue and reactions to them are discussed, with special attention to comments in the correspondence between Charles Lyell and Charles Darwin. These comments were largely about Bravard’s identification among his fossils from Argentina of the genera Palaeotherium and Anoplotherium , well known components of the Late Eocene mammal fauna from the Montmartre gypsum, in the Paris Basin. This identification was later shown to be erroneous by Gervais, Burmeister and Ameghino. Bravard’s catalogue also includes what appears to be the first mention of fossil giant ground birds (Phorusrhacidae) in South America. # Note added in proof {#article-title-35}","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"21 1","pages":"41-53"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80036916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-01-01DOI: 10.2113/GSSGFBULL.187.1.3
Verati Chrystèle, Y. Mazabraud, J. Lardeaux, M. Corsini, D. Schneider, E. Voitus, F. Zami
In this paper, we provide the first structural map of Les Saintes archipelago (Guadeloupe, Lesser Antilles). The finite strain pattern displays four families of fault systems characterized by their statistical structural orientations: N000-N020, N050-N070, N090-N110 and N130-N140 trending fault systems. Our onshore results thus underline a fault network much more complex than the one depicted by the previous offshore geophysical investigations around Les Saintes archipelago, which show only N120-N150 trending system. According to the available K-Ar dating of the volcanic rocks and the relative chronology of the faults defined in the field, we determine the deformation history in Les Saintes islands since the last 3 Ma. The four highlighted trending fault systems are already active since the Pliocene and are consistent with the present-day extensional tectonics in the Guadeloupe archipelago compatible with the reactivation of inherited structures at the active arc scale. We interpret the tectonic evolution of Les Saintes islands as the result of interplay between subduction of aseismic ridges (Tiburon and Barracuda ridges) and oblique convergence. Furthermore, we recognized an exhumed geothermal paleo-system in Terre-de-Haut island which is a good analogue of the present-day active Bouillante geothermal system. Its duration is estimated at 400 k.y. during the Pliocene.
{"title":"Tectonic evolution of Les Saintes archipelago (Guadeloupe, French West Indies): relation with the Lesser Antilles arc system","authors":"Verati Chrystèle, Y. Mazabraud, J. Lardeaux, M. Corsini, D. Schneider, E. Voitus, F. Zami","doi":"10.2113/GSSGFBULL.187.1.3","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.1.3","url":null,"abstract":"In this paper, we provide the first structural map of Les Saintes archipelago (Guadeloupe, Lesser Antilles). The finite strain pattern displays four families of fault systems characterized by their statistical structural orientations: N000-N020, N050-N070, N090-N110 and N130-N140 trending fault systems. Our onshore results thus underline a fault network much more complex than the one depicted by the previous offshore geophysical investigations around Les Saintes archipelago, which show only N120-N150 trending system. According to the available K-Ar dating of the volcanic rocks and the relative chronology of the faults defined in the field, we determine the deformation history in Les Saintes islands since the last 3 Ma. The four highlighted trending fault systems are already active since the Pliocene and are consistent with the present-day extensional tectonics in the Guadeloupe archipelago compatible with the reactivation of inherited structures at the active arc scale. We interpret the tectonic evolution of Les Saintes islands as the result of interplay between subduction of aseismic ridges (Tiburon and Barracuda ridges) and oblique convergence. Furthermore, we recognized an exhumed geothermal paleo-system in Terre-de-Haut island which is a good analogue of the present-day active Bouillante geothermal system. Its duration is estimated at 400 k.y. during the Pliocene.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"15 1","pages":"3-10"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83649479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2016-01-01DOI: 10.2113/GSSGFBULL.187.1.27
M. Benabdellouahed, A. Baltzer, M. Rabineau, D. Aslanian, M. Sahabi, F. Germond, B. Loubrieu, Y. Biari
This study explores a portion of the West African margin at the junction between two well-known segments offshore Dakhla and offshore Mauritania with destructional architecture characterized by giant slides. In between these two segments, the Dakhla segment has historically been described as a constructional section. During an oceanographic Dakhla cruise (2002), high resolution seismic data, swath bathymetry and imagery were acquired around latitude 23°N, offshore Dakhla. This new data set reveals the existence of varied and complex morphologies on the continental slope, interpreted as a “shallot-shaped” canyon, seafloor depressions or pockmarks, ridges and scarps. These morphologies are interpreted as clues of sedimentary transfers and rupture processes. A scenario is proposed for the development of these different sedimentary morphologies.
{"title":"Slope morphologies offshore Dakhla (SW Moroccan margin)","authors":"M. Benabdellouahed, A. Baltzer, M. Rabineau, D. Aslanian, M. Sahabi, F. Germond, B. Loubrieu, Y. Biari","doi":"10.2113/GSSGFBULL.187.1.27","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.187.1.27","url":null,"abstract":"This study explores a portion of the West African margin at the junction between two well-known segments offshore Dakhla and offshore Mauritania with destructional architecture characterized by giant slides. In between these two segments, the Dakhla segment has historically been described as a constructional section. During an oceanographic Dakhla cruise (2002), high resolution seismic data, swath bathymetry and imagery were acquired around latitude 23°N, offshore Dakhla. This new data set reveals the existence of varied and complex morphologies on the continental slope, interpreted as a “shallot-shaped” canyon, seafloor depressions or pockmarks, ridges and scarps. These morphologies are interpreted as clues of sedimentary transfers and rupture processes. A scenario is proposed for the development of these different sedimentary morphologies.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"81 1","pages":"27-39"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72686091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2015-10-01DOI: 10.2113/GSSGFBULL.186.6.387
Hakim Moulouel, Luca Micarelli, I. Moretti, Djamel Machane
The Aigion active fault belongs to a system of north-dipping normal faults that affect the southern shore of the gulf of Corinth. Cores of AIG-10 well crossed the Aigion active fault show the usual presence of a damage zone and a gouge. This work presents a thin section analysis under optical and cathodoluminescence microscopy. It confirms the zonation in terms of fracturing next to the fault zone. Away from the fault zone, fracturing inherited from the Hellenic compressive phase is dominant, even though E-W fractures related to the current extension are observed. All these fractures are sealed and the filling is similar to the limestone host-rock in terms of luminescence. Close to the fault, the number of fault-related fractures increases. Under cathodoluminescence analysis, the fracture filling indicates the passage of several fluids that would be external, and the latest generation of fractures is still open. Beneath 5 m thick of cataclasite and ultracataclasite in limestone and radiolarite (fault core) and 13 m thick of gouge in radiolarite, in the footwall, observations are limited, because the presence of karst has restricted coring opportunities. Nevertheless we can see that the filling of the extension related fractures is different from what has been revealed in the hanging wall fault zone. This suggests that Aigion active fault plane acts as a local transverse seal and has always been. Analysis of cement sequences highlights longitudinal permeability; also, we discussed the role, in terms of fluid transfer, of fault propagation induced features.
{"title":"Fracturation des carbonates dans la zone de faille normale active d’Aigion (Grèce) à partir des carottes du puits: conséquences sur les propriétés de transfert de fluides","authors":"Hakim Moulouel, Luca Micarelli, I. Moretti, Djamel Machane","doi":"10.2113/GSSGFBULL.186.6.387","DOIUrl":"https://doi.org/10.2113/GSSGFBULL.186.6.387","url":null,"abstract":"The Aigion active fault belongs to a system of north-dipping normal faults that affect the southern shore of the gulf of Corinth. Cores of AIG-10 well crossed the Aigion active fault show the usual presence of a damage zone and a gouge. This work presents a thin section analysis under optical and cathodoluminescence microscopy. It confirms the zonation in terms of fracturing next to the fault zone. Away from the fault zone, fracturing inherited from the Hellenic compressive phase is dominant, even though E-W fractures related to the current extension are observed. All these fractures are sealed and the filling is similar to the limestone host-rock in terms of luminescence. Close to the fault, the number of fault-related fractures increases. Under cathodoluminescence analysis, the fracture filling indicates the passage of several fluids that would be external, and the latest generation of fractures is still open. Beneath 5 m thick of cataclasite and ultracataclasite in limestone and radiolarite (fault core) and 13 m thick of gouge in radiolarite, in the footwall, observations are limited, because the presence of karst has restricted coring opportunities. Nevertheless we can see that the filling of the extension related fractures is different from what has been revealed in the hanging wall fault zone. This suggests that Aigion active fault plane acts as a local transverse seal and has always been. Analysis of cement sequences highlights longitudinal permeability; also, we discussed the role, in terms of fluid transfer, of fault propagation induced features.","PeriodicalId":55978,"journal":{"name":"Bulletin de la Societe Geologique de France","volume":"53 1","pages":"387-397"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85077479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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