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Peer Reviewed Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.2 - Per a 2030, assolir la gestió sostenible i l’ús eficient dels recursos naturals

Distribution of convex slope breaks and fluvial knickpoints have been investigated in the Tenkawa district, northern Kii Mountains, southwest Japan. We found that paleosurface remnants are developed in higher elevations in the catchment of the Tennokawa River, which incises the paleosurfaces with a convex slope break, L1. The intersections of L1 and the tributaries of the Tennnokawa River coincide with knickpoints in 8 tributaries, suggesting that L1 was formed by knickpoint recession. 60% of landslides, or 75% of large landslides (>105 m2) in the study area involved L1 or occurred on slopes below L1, suggesting that they occurred on slopes destabilized by river incision. Paleosurfaces surrounded by slope breaks are widely developed in the Totsukawa catchment in the north and central Kii Mountains and we found that recent deep-seated catastrophic landslides have occurred on slopes with the slope breaks or newly incised slopes below the breaks.

National audience; Les cristallisations de calcite au sein des sables et des calcaires tertiaires du bassin de Paris datent des périodes de refroidissement des dernières glaciations. Leurs dispositions et habitus permettent de distinguer 3 principaux types de gisements : (1) des cristallarias (type Calcite de Fontainebleau) liées à des paléo-niveaux de nappe phréatique ; (2) des amas décamétriques de concrétions sphéroïdales correspondent à des accumulations au sein de paléo-taliks et thermokarsts (à notre connaissance décrits ici pour la première fois), (3) des cristaux limpides forment des géodes dans des formations carbonatées karstifiées. C’est le réchauffement en profondeur des eaux d’infiltration froides et riches en CO2 qui conduit à la précipitation des diverses variétés de calcite. Ces calcites sont des traceurs qui marquent l’extension des pergélisols et pointent la profondeur atteinte par le gel. Les agencements des cristallisations et leurs signatures isotopiques renseignent sur leur position par rapport à la surface et les paléo-nappes phréatiques. Ces calcites constituent un outil potentiel pour l’étude des paléo-morphologies pleistocènes et des vitesses d’érosion et d’enfoncement des réseaux hydrographiques durant cette période.

National audience; The siderolithic paleoweathering surfaces of the French Central Massif have been dated to the Late Jurassic/Early Cretaceous, contrasting with previously accepted Tertiary age and implying that the Massif has never hosted a thick sedimentary cover. This contradicts with former thermochronological results. Herein, we expose the arguments for and against the proposed geodynamic evolution of the French Massif Central constrained by paleomagnetic age determinations.

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Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:26:19Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:36:34Z : No. of bitstreams: 1 2-s2.0-82555173095.pdf: 4743737 bytes, checksum: d8a0006851a5085da227e8d2a237d848 (MD5) Made available in DSpace on 2014-05-27T11:26:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-06 This work has the objective of correlating altitude with the bauxite profiles in the Poços de Caldas Plateau in order to identify paleosurfaces. Then, bauxite profiles found in the Plateau have been classified and mapped through DEM. Three different types of bauxite profiles are highlighted in the area: (1) Rim Profiles which are well-developed and thick and are located in the areas of highest altitude in the Plateau; (2) Plateau Profiles which are not very thick and very clayey, normally appear in the lower portion of the landscape; (3) Reworked Profiles, characterized by bauxite reworked fragments composed by similar materials found in the tops of Rim and Plateau Profiles. After relating altitude to the constituting materials of the bauxite profiles, it is noticed that there are occurrences of Rim Bauxite Profiles located in altitudes of Plateau Profiles and Reworked Profiles located over Rim Profiles, above 1,400 meters of altitude. In the opposite direction, tops of the same elevation are found, where there should be Rim Profiles, there are rocky outcrops observed in field, without any evidence of laterite profiles. It is concluded, therefore, that the elevation rates by themselves, at least in this area, are not good enough references to determine the existence and distribution of paleosurfaces. Geography Department Geosciences Institute Universidade Estadual de Campinas/UNICAMP, João Pandiá Calógenas Street, 51, Barão Geraldo. 13083-870, Campinas, SP Geography Department Universidade Estadual Paulista, Ourinhos Campus. 1500 Vitalina Marcusso Ave, 19910-206 Ourinhos, SP Geography Department Universidade Estadual Paulista, Ourinhos Campus. 1500 Vitalina Marcusso Ave, 19910-206 Ourinhos, SP

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:25:23Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:47:04Z : No. of bitstreams: 1 2-s2.0-79955927222.pdf: 14806714 bytes, checksum: 88009a42c6a9cc2edc9b5d5a4c409e8d (MD5) Made available in DSpace on 2014-05-27T11:25:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-01 A few examples of supergene ore formation and their interaction with morphogenesis (palaeosurfaces) and weathering mineralogy are discussed. Geomorphological and mineralogical records to characterize palaeosurfaces associate the weathering of primary minerals and their relationship with concentrations of cooper and iron ore deposits in southeastern state of São Paulo, Brazil. We have distinguished two palaeosurfaces generated by several weathering phases and controlled by the geological framework. The first and oldest upper palaeosurfaces (900 - 1000 m a.s.l.), situated in Riberão Branco (Alto do Brancal), were developed on silico-limestones. It is formed by typical iron laterites enriched by secondary products of cooper. The second and younger level palaeosurfaces located in Itapeva (Santa Blandina and Bairro do Sambra). This palaeosurface is formed by copper percolating through the weathered rock (saprolite). Other features can be observed like neo-formed products in laterites. They are classified into two types: clay like silico- cupriferous products (with noticeable amounts of iron) and copper minerals (crysocolla, in their flat slopes). These features allowed the presence of copper ores and their morphogenesis control will help in the exploration and prospecting of supergene ore mineral. NUCLEARGEO-Tecnologia Nuclear em Sistemas Naturais Pesquisa Mineral Ltda Incubadora de Base Tecnológica da Unesp/INCUNESP.RC, Avenida 1-A, 915-Cidade Nova, CEP 13506-785. Rio Caro, SP Pós-Doutorado, Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista, UNESP, Avenida 24-A, 1515-Bela Vista, CEP 13506-900. Rio Claro, SP NUCLEARGEO-Tecnologia Nuclear em Sistemas Naturais Pesquisa Mineral Ltda Incubadora de Base Tecnológica da Unesp/INCUNESP.RC, Avenida 1-A, 915-Cidade Nova, CEP 13506-785. Rio Caro, SP Pós-Doutorado, Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista, UNESP, Avenida 24-A, 1515-Bela Vista, CEP 13506-900. Rio Claro, SP

Excursion géologique d'analyse des processus sédimentaires et des paysages. Support de cours.

THE MASSIF OF ARBAILLES (WEST PYRENEES). The Arbailles massif (200 -1 200 m) is located in the french north face of Pyrenees, Atlantic side. It forms a folded 165 square-kilometres unit of jurassic and cretaceous limestones under an oceanic climate of altitude (2000 mm/year). Observations jointly made on the surface and in the numerous underground galleries allow an occurate correlation of alternate surrective and karstic periods. The dismantled cavities and deposits pockets of the upper surface show two series of minerals, those from weathered marly-albian limestones and others supplied from the conglomerates pudding-stones of Mendibelza. During the Miocene, the Arbailles massif is a low area of tropical erosion on the side of the main mounts. Its surrection caused the scouring of the alterites cover, the formation of fields of karstic butts and a definitive drying of the fluviatile paleosystem. The different levels of dried valleys and the karstic hydrographie systems are successive stations of the karstic levels of origine. Paleomagnetic datations in Etxanko Zola and U/Th datations in Nébélé show that the surrection has been of about 500 m since lower Pleistocene. At the present time, water collection is made throught drainage systems without any connection to the fossil topography. Three aquifers can be distinguished : in lower cretaceous, in jurassic and in north and south limits. They are water-repellent because of more or less impermeable screens. Waters are agressive in summer and at equilibrium or lightly undersaturated the rest of the year. The modern human activities creates a recent destabilization of the environment with local erosions of grounds and an increasing turbidity of springs. An occurate study in the fail of Istaurdy allows a mesure of the effect of deforestation for the whole massif, Le massif des Arbailles (200 -1 200 m) est situé dans la zone nord-pyrénenne. Il forme une unité plissée de 165 km2, constituée de calcaires jurassiques et crétacés, soumise à un climat océanique montagnard (2000 mm/an). Les observations réalisées conjointement en surface et dans les réseaux souterrains permettent une étude précise des corrélations entre les phases de surrection et de karstification. Les poches d'altérites et les cavités démantelées de la haute surface présentent deux types de cortège minéral : l'un issu de l'altération des calcaires marneux albiens, l'autre provenant des poudingues de Mendibelza. Au Miocène, les Arbailles constituaient une surface d'altération tropicale de basse altitude raccordée à l'amont à la Haute-Chaîne. La surrection a permis le décapage de la couverture des altérites, l'individualisation d'un karst à buttes, l'assèchement définitif du système fluviatile. Les niveaux étagés des vallées sèches et des réseaux karstiques correspondent à des stationnements des niveaux de base karstique. Les datations par paléomagnétisme (réseau d'Etxanko Zola) et par U/Th (réseau du Nébélé) permettent de montrer que la composante de surrection depuis le Pléistocène inférieur est de l'ordre de 500 m environ. Actuellement l'essentiel du drainage s'effectue par des réseaux souterrains qui n'ont aucune liaison avec la topographie "fossile" de surface. On distingue trois aquifères (aquifères du Crétacé inférieur, du Jurassique, des bordures nord et sud) séparés par des écrans plus ou moins imperméables. L'étude de la minéralisation des émergences a permis de quantifier l'ablation karstique. La mise en valeur du massif par les hommes entraîne une déstabilisation récente du milieu qui se marque par une érosion des sols et une turbidité accrue des sources. L'étude de la coupe d'Istaurdy permet de mesurer l'impact de la déforestation sur l'environnement du massif., Vanara Nathalie. Le karst des Arbailles (Pyrénées-Atlantiques, France). In: Karstologia : revue de karstologie et de spéléologie physique, n°36, 2e semestre 2000. Le massif des Arbailles (Pyrénées-Atlantique) pp. 23-42.