Paleozoic stratigraphy of the Central and Northern part of the Catalonian Coastal Ranges (NE Spain)

The Paleozoic stratigraphic succession in the Catalonian Coastal Ranges spans the interval from Cambrian(?) to Carboniferous, with only one break, separating the pre-Carboniferous part of the sequence from the Carboniferous. The oldest rocks exposed form a sequence of schists, fine grained sandstones, gneisses (laminar pre-Hercynian intrusions), marbles, orto- and para-amphibolites and calcsilicate rocks. comparison with other localities iuggests an Early Cambrian age (or perhaps in part older). Upwards the sequence becomes more monotonous andconsists only of schists (or slates where themetamorphic grade is lower) and thin fine-grained sandstone layers (Cambrian-Ordovician). Still higher in the sequence, an altemation of greywackes and slates is found, with interlayered mud-supported conglomerates at its lower part and acid volcanic rocks which occur throughout the whole sequence. This part of the sequence has provided the oldest faunas known in the Catalonian Coastal Ranges, which indicate the Caradoc. Finally, in its uppermost part, the Ordovician sequence contains some thin limestone layers that contain Ashgill faunas. The Silurian, from Llandovery to Lower Ludlow, consists of black graptolitic shales with dolerite sills, whilst the upper Ludlow, Pridolian and Devonian consist of nodular limestones and marls withpelagic and hemipelagic faunas. The youngest Devonian faunas found correspond in general to the Emsian. The existence of a gap at this point of the sequence suggests the possibility that part of the Devonian could have been eroded. The Carboniferous is characterized by a thick culm sequence (Visean to Westphalian?), resting on thin chert and limestone layers (Tournaisian and Visean). A comparison with neighbouring areas shows a similarity regarding succession and facies with other Paleozoic massifs around the Western Mediterranean.

The Hercynian structure of the Catalonian Coastal Ranges (NE Spain)

In the Catalonian Coastal Ranges, Paleozoic sedimentary and meta-sedimentary rocks crop out in severa1 areas, intruded by late tectonic Hercynian granitoids and separated by Mesozoic and Tertiary cover sediments. Large structures are often difficult to recognize, although a general east-west trend can be observed on the geological map. Deformation was accompanied by the development of cleavages and regional metamorphism. Green-schist facies rocks are prominent throughout the Ranges, while amphibolite facies are restricted to small areas. In low-grade areas, the main deformation phase generated south-facing folds with an axial plane cleavage (slaty cleavage in metapelitic rocks). The intersection lineation (Ss/Sl) and the axes of minor folds trend cast-west, as do all mapable structures. Late deformations generated coarse crenulations, small chevrons and kink-bands, all intersecting the slaty cleavage at high angles. In medium- to high-grade areas no major folds have been observed. In these areas, the main foliation is a schistosity and is often folded, giving centimetric to decimetric, nearly isoclinal intrafolial folds. In schists, these folds aremuchmore common than inother lithologies, and can be associated with a crenulation cleavage. All these planar structures in high-grade rocks are roughly parallel. The late Hercynian deformational events, which gave rise to the crenulations and small chevrons, also produced large (often kilometric) open folds which fold the slaty cleavage and schistosity. As aconsequence, alternating belts with opposite dip (north and south) of the main foliation were formed. With respect to the Hercynian orogenic belt, the Paleozoic outcrops of the Catalonian Coastal Ranges are located within the northern branch of the Ibero-Armorican arc, and have a relatively frontal position within the belt. The Carboniferous of the Priorat-Prades area, together with other outcrops in the Castellón Province, the Montalbán massif (Iberian Chain) and the Cantabrian zone (specially the Pisuerga-Carrión Province) probably form part of a wide area of foreland Carboniferous deposition placed at the core of the arc.

Itsekkäät geenit sosiaalisissa yhteisöissä

Kirjoitus perustuu esitelmään Tieteen päivillä 9.1.2003. Kirjoittaja on Oulun yliopiston perinnöllisyystieteen professori.

Is leishmaniosis spreading to northern areas of the Iberian Peninsula? The examples of Lleida (NE Spain) and Andorra

The entomological and canine leishmaniosis surveyscarried out in the northwest of Catalonia and in Andorra in thecontext of the European project Emerging Diseases in a changing European eNvironment (EDEN) are summarized. The aim of the study was to obtain data on the presence of leishmaniosis in these areas and the spatial distribution of their vectors.

Gabbro, plagiogranite and associated dykes in the supra-subduction zone Evros Ophiolites, NE Greece

The incomplete Evros ophiolites in NE Greece form a NE-SW-oriented discontinuous belt in the Alpine orogen of the north Aegean. Field data, petrology and geochemistry are presented here for the intrusive section and associated mafic dykes of these ophiolites. Bodies of high-level isotropic gabbro and plagiogranite in the ophiolite suite are cross-cut by NE-SW-trending boninitic and tholeiitic-boninitic affinity dykes, respectively. The dykes fill tensile fractures or faults, which implies dyke emplacement in an extensional tectonic regime. The tholeiitic-transitional boninitic gabbro is REE- and HFS-depleted relative to N-MORB, indicating derivation from melting of a refractory mantle peridotite source. Associated boninitic dykes are slightly LREE-enriched, showing mineral and whole-rock geochemistry similar to the gabbro. The plagiogranite is a strongly REE-enriched high-silica trondhjemite, with textures and composition typical for an oceanic crust differentiate. Plagiogranite-hosted tholeiitic and transitional boninitic dykes are variably REE-enriched. Geochemical modelling indicates origin of the plagiogranite by up to 75% fractional crystallization of basaltic magma similar to that producing the associated tholeiitic dykes. All mafic rocks have high LILE/HFSE ratios and negative Ta-Nb-Ti and Ce anomalies, typical for subduction zone-related settings. The mafic rocks show a similar trace-element character to the mafic lavas of an extrusive section in Bulgaria, suggesting they both form genetically related intrusive and extrusive suites of the Evros ophiolites. The field occurrence, the structural context, the petrology and geochemical signature of the studied magmatic assemblage provide evidence for its origin in a proto-arc (fore-arc) tectonic setting, thus tracing the early stages of the tectono-magmatic evolution of Jurassic arc-marginal basin system that has generated the supra-subduction type Evros ophiolites.

Suomalaiset geenit hyötykäyttöön

Kirjoitus perustuu esitelmään valtakunnallisten tutkimuseettisten neuvottelukuntien järjestämässä seminaarissa "Bio- ja geenipankit" (20.9.2004)