Estratigrafía y sedimentología del Paleógeno de la Sierra de Tramuntana (Mallorca)

El Palegeóno aflorante en la Sierra de Tramuntana muestra la existencia de dos unidades litoestratigráficas principales: la inferior (Fm. Calizas de Peguera) está constituida predominantemente por materiales carbonatados lacustres, con depósitos carbonosos en su base, un nivel intermedio de sedimentos detríticos fluviales y una intercalación marina a techo, mientras que la unidad superior (Fm. Detritica de Cala Blanca) registra la evolución lateral de un sistema detrítico fluvio-aluvial con paleocorrientes hacia el SE, progradante sobre una unidad basal de calcarenitas marinas.

Estratigrafia del Cretacico inferior continental de la Cordillera Iberica Central

El Cretácico inferior continental de la Cordillera Ibérica Central está representado en dos subcuencas de sedimentación: las Cubetas de Aguilón y Oliete. Los estudios realizados sobre estos materiales han permitido definir nuevas unidades litoestratigráficas, cuya caracterización bioestratigráfica se realiza a partir de su contenido en carofitas. La identificación de discontinuidades significativas permiten definir tres secuencias de depósito que abarca en el intervalo temporal Valanguniense y/o Hauteriviense-Barremiense inferior y que son correlacionables con las S.D.K1.2 y/o K1.3, K1.4 YK1.5 y/o K1.6 definidas en Salas et al. (1991) y Salas y Casas (1993) para la Cuenca del Maestrazgo. Estos resultados ponen de manifiesto que el registro estratigráfico de la zona central de la Cordillera Ibérica tiene una entidad similar al de los márgenes de las Cuencas del Maestrazgo, Aliaga- Peñagolosa y Cameros.

The geologic and geomorphologic maps of Santa Coloma de Farners (Girona, Spain)

Notice about the geologic and geomorphologic maps of Santa Coloma de Farners, at scale 1:10,000 published by Unitat de Geologia of the Universitat de Girona

Geologic maps published by university de Girona's unity of geodynamics

In 1978 University de Girona's Unity of Geodynamics started publishing geological maps, in several themes and scales, of various areas of the Province of Girona (fig. 1). So far, up to 38 maps, gathered in several collections, have been published

Aportación al estudio de arcillas expansivas asociadas a las facies garumnienses de la Conca de Tremp (Prepirineo de Lleida)

Some clay levels of the garumnian facies, which surface in the southern sector of the Tremp Basin present a principal mineralogy of expansive type. The oedometer essays show that such materials present a very high grade of potencial expansivity. The swelling pressure presents values higher than 390 KN/m2. In the majority of the areas wherw this kind of clays surface the hydric erosion phenomena and the mass movements often appear to be very common and intense. The geomorphological role of the expansive clays is discussed as the triggering factor, associated to the development of these denudative processes

Evolution of an Archean greenstone belt in the Stormy Lake - Kawashegamuk Lake area (stratigraphy, structure and geochemistry) - Western Wabigoon Subprovince, Northwest Ontario /

330 km 2 of the easter-n part of the Archean Manitou Lakes - Stormy Lake metavolcanic - metasedimentary belt have been mapped and sampled. A large number of rocks ~.vere analyzed for the major and trace constituents including the rare-earth elements (REE). The Stormy Lake - Kawashegamuk Lake area may be subdivided into four major lithological groups of supracrustal rocks 1) A north-facing mafic assemblage, consisting of pillowed tholeiitic basalts and gabbro sills characterized by flat REE profiles, is exposed in the south part of the map area and belongs to a 8000 m thick homoclinal assemblage outside the map area. Felsic pyroclastic rocks believed to have been issued from a large central vent conformably overlie the tholeiites. 2) A dominantly epiclastic group facing to the north consists of terrestrial deposits interpreted to be an alluvial fan deposit ; a submarine facies is represented by turbiditic sediments. 3) The northeastern part of the study area consists of volcanic rocks belonging to two mafic - felsic cycles facing to the southuest ; andesitic flows with fractionated REE patterns make up a large part of the upper cycle, whereas the lower cycle has a stronger chemical polarity being represented by tholeiitic flows, with flat REE, which a r e succeeded by dacitic and rhyolitic pyroclasti cs. iii 4) A thick monotonous succession of tholeiitic pillmled basalt f lows and gabbro sills with flat REE represent the youngest supracrustal rocks. TIle entire belt underwent folding, faulting and granitic plutonism during a tectono-thermal event around 2700 Ma ago. Rocks exposed in the map area were subjected to regional greenschist facies metamorphism, but higher metamorphic grades are present near late granitic intrusions. Geochemical studies have been useful in 1) distinguishing the various rock units ; 2) relating volcanic and intrusive rocks 3) studying the significance of chemical changes due to post magmatic processes 4) determining the petrogenesis of the major volcanic rock types. In doing so, two major volcanic suites have been recognized : a) a tholeiitic suite, mostly represented by mafic rocks, was derived from partial melting of upper mantle material depleted in Ti, K and the light REE ; b) a calc-alkalic suite which evolved from partial melting of amphibolite in the lower crust. The more differentiated magma types have been produced by a multistage process involving partial melting and fractional crystallization to yield a continuum of compos i t i ons ranging from basaltic andesite to rhyolite. A model for the development of the eastern part of the Manitou Lakes - Stormy Lake belt has been proposed.

Petrography, geochemistry and structure of the Timmins area, Ontario

Regional structural analysis of the Timmins area indicates four major periods of tectonic deformation. The DI deformation is characterized by a series of isoclinal FI folds which are outlined in the study area by bedding, pillow tops and variolitic flows. The D2 deformation developed the Porcupine Syncline and refolded the Fl folds about a NE. axis. A pervasive S2 foliation developed during low grade (greenschist) regional metamorphism associated with the D2 deformation. The S2 foliation developed south of the Destor-Porcupine Break. The third phase of tectonic D3 deformation is recognized by the development of a S3 sub-horizontal crenulation cleavage which developed on the plane of the S2 foliation. No meso scopic folds are associated with this deformation. The 8 3 crenulation cleavage is observed south of the Destor-Porcupine Break. The D4 tectonic deformation is recorded as a subvertical S4 crenulation cleavage which developed on the plane of the S2 foliation and also offsets the S3 crenulation cleavage. Macroscopic F4 folds have refolded the F2 axial plane. No metamorphic recrystallization is associated with this deformation. The S4 crenulation cleavage is observed south of the Destor-Porcupine Break. Petrographic evidence indicates that the Timmins area has been subjected to pervasive regional low grade (greenschist) metamorphism which has recrystallized the original mineralogy. South of the study are~ the Donut Lake ultramafic lavas have been subjected to contact medium grade (amphibolite facies) metamorphism associated with the intrusion of the Peterlong Lake Complex. The Archean volcanic rocks of the Timmins area have been subdivided into komatiitic, tholeiitic and calcalkaline suites based on Zr, Ti0 2 and Ni. The three elements were used because of their r e lative immobility during subsequent metamorphic events. Geochemical observations in the Timmins area indicates that the composition of the Goose Lake and Donut Lake Formations are a series of peridotitic, pyroxenitic and basaltic komatiites. The Lower Schumacher Formation is a sequence of basaltic komatiites while the upper part of the Lower Schumacher Formation is an intercalated sequence of basaltic komatiites and low Ti0 2 tholeiites. The variolitic flows are felsic tholeiites in composition and geochemical evidenc e sugg ests that they developed as a n immiscible splitting of a tholeiitic magma. The Upper Schumacher Formation is a sequence of tholeiitic rocks dis p laying a mild iron enrichment. The Krist and Boomerang Formations are the felsic calc-alkaline rocks of the study area which are characteristically pyroclastic. The Redstone Fo rmation is dominantly a calc-alkali ne sequence of volcani c rocks whose minor mafic end me mbers exposed in 1t.he study hav e basaltic komatiitic compositions. Geochemical evidence sugges ts that the Keewatin-type se dimentary rocks have a composition similar to a quartz diorite or a granodiorite. Fi e l d obs ervations and petrographic evidence suggests that they were derived fr om a distal source and now repr esent i n part a turbidite sequence. The Timiskaming-type sedimentary rocks approach the c omp osi t ion of the felsic calc-alkaline rocks of the study area . The basal conglomerate in the study are a sugge s ts that th e uni t was derived fr om a proximal source. Petrographic and ge ochemical evidence suggests that the peridotitic and pyroxenitic komatiites originated as a 35-55% partial melt within the mantle, in excess of 100 Km. depth. The melt ros e as a diapir with the subsequent effusion of the ultramafic lavas, The basaltic komatiites and tholeiitic rocks originated in the mantle from lesser degrees of partial melting and fractionated in low pressure chambers. Geochemical evidence suggests a "genetic link" between the basaltic komatiites and tholeiites, The calc-alkaline rocks developed as a result of the increa.se In PO in the magma chamber. The felsic calcalkaline rocks are a late stage effusion possibly the last major volcanic eruptions in the area.

Algunes precisions sobre l’estratigrafia de la Cova de l’Arbreda (Serinyà, Girona)

Estudi de l’estratigrafia de la Cova de l’Arbreda, situada a Serinyà, a la comarca del Pla de l’Estany (Girona). Se centre en el reompliment que hi va haver al llarg del Paleolític Superior, en què s’observa un canvi a cop d’ull què, situat sobre els nivells solutrians, s’havia atribuït al pas vers el postglacial

Pla de gestió dels senders ecoturístics del la zona d’interès etnològic de les Gavarres

El massís de les Gavarres és un espai que forma part del Pla d’Espais Naturals d’Interès Natural de Catalunya i es caracteritza per ser un espai molt ric en patrimoni cultural, sobretot etnològic. És per això que des de l’entitat del Consorci de les Gavarres sorgeix la proposta d’elaborar un conjunt de senders ecoturístics sobra la Zona d’Interès Etnològic de la Gavarres. L’objectiu principal és impulsar la posta en valor i crear instruments de gestió dels principals elements del patrimoni cultural que es troben presents arreu del massís de les Gavarres, a partir del disseny d’un conjunt de senders ecoturístics que, de manera respectuosa amb el medi ambient, serveixin d’instruments de dinamització i de gestió per a la conservació de l’espai i els seu elements patrimonials.

Evolução termocronológica do sudoeste de Angola e correlação com o sudoeste brasileiro: termocronologia por traços de fissão em apatita

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização estrutural da porção sul do greenstone belt de Guarinos, GO

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização do arcabouço estrutural da Bacia de Pelotas e da área emersa adjacente

Pós-graduação em Geologia Regional - IGCE

Estudo da porção offshore da bacia do Benin e o seu potencial no armazenamento de hidrocarbonetos, margem equatorial africana

Pós-graduação em Geologia Regional - IGCE

As formações ferríferas bandadas de Piumhi: geologia, petrografia e caracterização tecnológica

Pós-graduação em Geologia Regional - IGCE

Neotectônica do baixo vale do rio Jaguaribe - Ceará

Pós-graduação em Geologia Regional - IGCE