Search results for "Rift"
showing 10 items of 526 documents
Isotope geochemistry of Pantelleria volcanic fluids, Sicily Channel rift: a mantle volatile end-member for volcanism in southern Europe
2000
Chemical and isotopic ratio (He, C, H and O) analysis of hydrothermal manifestations on Pantelleria island, the southernmost active volcano in Italy, provides us with the first data upon mantle degassing through the Sicily Channel rift zone, south of the African–European collision plate boundary. We find that Pantelleria fluids contain a CO2–He-rich gas component of mantle magmatic derivation which, at shallow depth, variably interacts with a main thermal (∼100°C) aquifer of mixed marine–meteoric water. The measured 3He/4He ratios and δ13C of both the free gases (4.5–7.3 Ra and −5.8 to −4.2‰, respectively) and dissolved helium and carbon in waters (1.0–6.3 Ra and −7.1 to −0.9‰), together wi…
Early Jurassic normal faulting in a carbonate extensional basin: characterization of tectonically driven platform drowning (High Atlas rift, Morocco).
2009
18 pages; International audience; This paper describes a tectonostratigraphic model of the synrift evolution of the Early Jurassic High Atlas rift of Morocco. The model is constrained by mapping of a set of inverted extensional blocks, by facies analysis of carbonate platform and turbiditic to hemipelagic synrift deposits, and by high-resolution (n 3 100 ka) biostratigraphy of the Early Jurassic succession. The chronostratigraphic packages of the High Atlas of Rich vary significantly in thickness, facies and architecture from one tectonic block to another. Our study shows how synrift strain varied in space and time over a long time interval (14 Ma) around the High Atlas rift. Initially, in …
Marqueurs de tectonique synsédimentaire dans les séries syn- et post-rift du bassin intérieur du Gabon.
2006
9 pages; International audience
Dynamique sédimentaire des dépôts post-rift du bassin intérieur du Gabon.
2006
14 pages; International audience
Permian-Triassic Rifting Stage
2019
International audience; The Permian-Triassic rifting represents the first of the two Mesozoic rifting stages recorded in the Iberian Peninsula. Its first phases of development started during the Early Permian, and were linked to the beginning of the break-up of Pangea, the large, unique and rheologically unstable supercontinent that mainly resulted from the collision of Gondwana and Laurussia. This chapter analyzes this first rifting stage in Iberia in two separate phases, an initial or tectonic phase, and a later mature phase. This analysis focuses on the main Permian-Triassic basins of the Iberian Peninsula: the Pyrenean, Iberian, Catalan, Ebro and Betic basins, as well as the basins loca…
Calculating the long-term displacement rates of a normal fault from the high-resolution stratigraphic record (early Tethyan rifting, French Alps)
2003
Displacement rates of normal faults deduced from stratigraphic data are often unreliable. Here we calculate the velocity of motion on a normal fault from the variations in accommodation potential on both sides of the fault within a highresolution time-frame established by biostratigraphy and physical stratigraphy. Our example is the Ornon normal fault bounding the Early Jurassic Bourg-d’Oisans Basin formed during Tethyan rifting. We show that motion on the fault was discontinuous when examined at high resolution and over a long time interval. During a first interval (Hettangian to Sinemurian Arietites bucklandi zone) a low rate of displacement (= 202–423 m Myr -1 ) coeval with diffused exte…
La présence de l’Etat dans l’Est du diocèse des Gaules au IVe s. : au miroir des sources matérielles et écrites
2021
Der vorliegende Artikel schlägt eine Synthese der Präsenz des Staates in Ostgallien vor. Er beschränkt sich auf das 4. Jh. von der Tetrarchie bis in die theodosianische Zeit. Er stützt sich auf eine kritische und fachübergreifende Betrachtung der materiellen und schriftlichen Dokumentation, die insbesondere bemüht ist, die Daten in Form von Karten zu präsentieren.
Skriftliga språkkunskaper i A-svenska hos finska abiturienter på basis av processbarhetsteori
2016
Tämän tutkimuksen tarkoituksena oli tutkia suomenkielisten, ruotsin kielen pitkää oppimäärää opiskelevien abiturienttien kirjallista kielitaitoa lukio-opintojen loppuvaiheessa. Tutkimushenkilöt (n=12) olivat aloittaneet ruotsin kielen opiskelun alakoulun 3.–5. vuosiluokalla ja valmistautuivat tutkimushetkellä ruotsin kielen pitkän oppimäärän ylioppilaskirjoituksiin. Tutkimuksen pohjana käytettiin Pienemannin prosessoitavuusteoriaa (1998). Tutkittavat kieliopilliset rakenteet olivat inversio väitelauseessa, jälkilauseen sanajärjestys, kieltosanan paikka sivulauseessa, epäsuora kysymys sekä adjektiivi attributiivisena ja predikatiivisena lauseenjäsenenä. Tutkimuksen tulokset osoittavat, että …
Sinemurian to lowermost Toarcian ammonites of the Brescian Prealps (Southern Alps, Italy): preliminary biostratigraphical framework and correlations.
2009
10 pages; International audience; A set of 28 ammonite biohorizons or faunal assemblages is proposed for the Sinemurian, the Pliensbachian and the lowermost Toarcian of the Brescian Prealps, in part based on the published data of the authors of this contribution and partly on new results, derived both from recent field investigations and from the study of the historical collection of Lower Jurassic ammonites preserved in the Museum of Natural Sciences of Brescia (Northern Italy). The biohorizons are present in the Liassic carbonate succession of the Brescian Prealps, cropping out between the eastern surroundings of Brescia (Botticino), to the east, and Lake Iseo, to the west. Since the Hett…