Palaeomagnetic chronology of the evaporitic sedimentation in the Neogene Fortuna Basin (SE Spain): early restriction preceding the 'Messinian Salinity Crisis'

The magnetostratigraphic study of the evaporitic Río Chicamo section (240 m) in the Neogene Fortuna Basin (Murcia, southeast Spain) has identified the record of five magnetozones. The most probable correlations with the standard geomagnetic polarity time scale (GPTS) imply that the marine evaporitic sedimentation of this basin was not coeval with the Messinian evaporites of the Sorbas Basin (Almeria, southeast Spain) and the Caltanissetta Basin (central Sicily) (assigned to the reverse Chron C3r, late Messinian by Gautier et al., 1994). The marine evaporites and diatomites from the Fortuna Basin are older (late Tortonian to early Messinian) than the evaporites of those basins. The chronological framework for the sedimentation in the Fortuna Basin together with the isotopic data from the sulphates in these evaporitic units indicate the following. (1) Restriction and confinement in the basin initiated as early as uppermost Tortonian, leading to deposition of evaporites under mixed (marine-continental) conditions. (2) The subsequent sedimentation of marine evaporites and diatomites in this basin occurred in a period between the Tortonian and Messinian transition and the early Messinian: the onset of this sedimentation pre-dates similar sediments of restricted marine environments in the eastern Betics basins, and possibly of the western Mediterranean region also. (3) Episodes of restriction and reflooding in the basin would have occurred in response to periodic fluctuations of the oceanic level under local tectonic controls. In the Fortuna Basin, the global base level drop associated with the late Messinian Salinity Crisis was recorded by the progradation of alluvial fans leading to thick clastic deposits overlying the youngest evaporites. These observations hint to: (a) the peculiar characteristics and sensitiveness of some of the marginal intramontane basins in the eastern Betics to reflect structural controls framed in the late Neogene global climatic changes; and (b) the diachronism of the beginning of the marine evaporitic deposition in the Mediterranean region linked to the salinity crisis during the Messinian

Creació d'una Eina de suport per a la docència en Geoquímica. Una eina d'aprenentatge autònom i d'avaluació

La proposta presentada s'emmarca en un projecte d'innovació docent de la Universitat de Barcelona. L'objectiu és desenvolupar una nova eina interactiva que d'una banda ajudi els alumnes a reforçar i/o ampliar els coneixements de geoquímica de manera autònoma i, de l'altra, sigui un nou recurs d'avaluació per al professorat. Amb el desenvolupament d'aquest eina, l'alumnat disposarà d'un recurs didàctic que li permetrà madurar i ampliar el seus coneixements en el camp de la geoquímica

Improving transversal comptetences by using wikis in collaborative work

Work on transversal competences in university degrees is a teaching line entirely established since the implementation of the European Credit Transfer System (ECTS). Nevertheless, undergraduate students present shortcomings in the development of some of these competences, especially on collaborative work, time management, oral and writing expression, and on the use of information resources. This paper presents a virtual tool and associated guidelines to enhance the information management during the development of collaborative works, and to facilitate the information availability among the students. Moreover, this tool and the guideline improve the individual monitoring and evaluation of the contributions of the students to the work. The proposal presented in this work belongs to a teaching innovation project carried out in the Earth Sciences Faculty of the Universitat de Barcelona, and implemented in the subjects General Geology (first-year in the Engineering Geology degree, 6 ECTS) and Geochemistry (third-year course in the Geology degree, 9 ECTS)

Millora de competències transversals mitjançant el treball col·laboratiu amb wikis

L'aplicació de wikis en el desenvolupament de treballs col·laboratius és una eina virtual que millora la gestió de la informació científica que es recull i en facilitat la disponibilitat a tots els membres del grup. Aquesta eina, a més, millora el seguiment i avaluació del treball i de les contribucions de cada membre del grup per part del professorat. En aquest treball es presenten els resultats d'aquesta l'experiència docent en dues assignatures molt diferenciades

Depositional models of lacustrine evaporites in the SE margin of the Ebro Basin (Paleogene, NE Spain)

An important evaporitic sedimentation occurred during the Paleogene (Eocene to lower Oligocene) in the Barberà sector of the southeastern margin of the Tertiary Ebro Basin. This sedimentation took place in shallow lacustrine environments and was controlled by a number of factors: 1) the tectonic structuration of the margin; 2) the high calcium sulphate content in the meteoric waters coming from the marginal reliefs; 3) the semiarid climate; and 4) the development of large alluvial fans along the basin margin, which also conditioned the location of the saline lakes. The evaporites are currently composed of secondary gypsum in surface and anhydrite at depth. There are, however, vestiges of the local presence of sodium sulphates. The evaporite units, with individual thicknesses ranging between 50 and 100 m, are intercalated within various lithostratigraphic formations and exhibit a paleogeographical pattern. The units located closer to the basin margin are characterized by a massive gypsum lithofacies (originally, bioturbated gypsum) bearing chert, and also by meganodular gypsum locally (originally, meganodules of anhydrite) in association with red lutites and clastic intercalations (gypsarenites, sandstones and conglomerates). Chert, which is only linked to the thickest gypsum layers, seems to be an early diagenetic, lacustrine product. Cyclicity in these proximal units indicates the progressive development of low-salinity, lacustrine bodies on red mud flats. At the top of some cycles, exposure episodes commonly resulted in dissolution, erosion, and the formation of edaphic features. In contrast, the units located in a more distal position with regard to the basin margin are formed by an alternation of banded-nodular gypsum and laminated gypsum layers in association with grey lutites and few clastic intercalations. These distal units formed in saline lakes with a higher ionic concentration. Exposure episodes in these lakes resulted in the formation of synsedimentary anhydrite and sabkha cycles. In some of these units, however, outer rims characterized by a lithofacies association similar to that of the proximal units occur (nodular gypsum, massive gypsum and chert nodules)

Comunicació intraespecífica en insectes

Pràctiques d’Etologia i Evolució de la ConductaAquest document conté el guió de pràctiques " Comunicació intraespecífica en insectes", un manual d'ús del programari a utilitzar en les pràctiques i guia del professor

Conducta agonista en Betta splendens

Pràctiques d’Etologia i Evolució de la ConductaAquest document conté el guió de pràctiques " Conducta agonista en Betta splendens" i la guia del professor

Middle Triassic evaporite sedimentation in the Catalan basin: implications for the paleogeographic evolution in the NE Iberian platform

The eastern sector of the epicontinental Iberian platform underwent restriction after the sedimentation of the lower Muschelkalk carbonates (Middle Triassic) under extensional regime. This resulted in the accumulation of the marine evaporites and the alluvial siliciclastics of the middle Muschelkalk facies in the Triassic Catalan basin, which varied between 100 and 120 m in thickness. This facies consists of three lithostratigraphic units sedimented at basin scale (Lower, Middle and Upper), each of which includes a distinct evaporite unit. In the Lower Unit, the evaporitic sedimentation started as a transgressive sulfate lagoon (Paüls Gypsum unit). During the Middle Unit time, a regressive evaporitic mudflat, made up of a mosaic of shallow gypsum salinas surrounded by anhydrite sabkhas (Arbolí Gypsum unit) developed; in the northeastern half of the basin, an alluvial plain was formed by siliciclastics (Guanta Sandstone unit) of a west and northwest provenance (Lleida High). During the Upper Unit time, a new transgressive sulfate lagoon occupied the southern half of the basin (Camposines Gypsum), whereas an evaporitic mudflat of red-to-variegated mudstones, marls, and lacustrine carbonates developed in the northern half. Cyclic sedimentation was mainly recorded in the evaporitic mudflat-alluvial plain complex of the Middle Unit. The sulfur isotopic values of gypsum in the three evaporite units show a decrease in d34S with time and also a clear distinction from the values of the Keuper facies in the basin. A division of the lithostratigraphic succession into two third-order depositional sequences is proposed. The middle Muschelkalk succession in the Catalan basin is compared with the equivalent one in the subsurface of the adjacent Triassic Maestrat basin, which was filled with >600 m of marine evaporites.Peer ReviewedPostprint (author's final draft