Alpes De Haute Provence Research Articles

Erosion and sediment transport on steep marly hillslopes, Draix, Haute-Provence, France: an experimental field study

Despite a thin regolith layer, measured sediment yields indicate denudation rates of more than 10 to 20 mm yr −1 on strongly denuded slopes in black marl (terres noires), near Draix, Alpes de Haute-Provence. Overland-flow and rainfall-simulation experiments were conducted on three slopes in the Draix Erosional Research Basin to determine the nature and intensity of hillslope erosion processes. The experiments showed that during a single storm, sediment transport includes water–solid mixtures with a wide range of concentrations, from highly charged rill flow (up to 400 g l −1) to hyperconcentrated flow (up to 800 g l −1) to debris flows (up to 1400 g l −1). Miniature debris flows (MDFs), strongly controlled sediment transport as long as the sediment store was not depleted. Slope surfaces were completely reworked in the winter and the regolith layer was rebuilt. Temperature records from nine recent winter periods indicate that conditions are favourable for soil frost processes.

Occurrence of the belemnite Actinocamax plenus in the - Cenomanian of SE France and its significance

The Late Cenomanian belernniteActinocamaxplenus is recorded from the Tethyan Realm for the first time, from les Lattes in the Alpes de Haute-Provence, southeastem France. This exceptionally southerly occurrence of the species is coincident with a cold temperature event, the Plenus Cold Event, registered by oxygen isotope data from southeast England. The record of A. plenus from les Lattes enables a precise correlation to be made with the Plenus Marls of the Anglo-Paris Basin.

Rôle du climat sur les migrationset la composition des peuplements d'ammonites du Valanginien supérieur du bassin vocontien (S-E de la France)

This study concerns the ammonite succession of the Upper Valanginian of the La Charce (Drôme) and Angles (Alpes de Haute-Provence) sections in the Vocontian trough. We have tried to place the ammonite succession against lithological changes interpreted in terms of relative sea level changes after doing system tract analysis in the Vocontian trough and its surrounding platforms. The main result is the migration of mesogean ammonites during the third order lowstand systems tracts and the migration of boreal forms during the transgressive systems tracts. So, these migrations are not only due to easier communications between both realms, in the open sea environment of the Vocontian trough. We think the climate to be one of the most important factor controlling the migrations. According to these results, lowstands (increase of lime content) would be warmer than transgressive tracts (more marly). The climatic factor would also affect the recorded alternancy of ammonite associations between the limestone beds and marly interbeddings.

The Characterization of a Strain of Zucchini Yellow Fleck Virus Found in Southeastern France

AbstractA virus was isolated from squirting cucumber (Ecballium elaterium L.) collected in France (Alpes de Haute Provence). After mechanical inoculation, eight species belonging to the Cucurbitaceae were found susceptible to this virus with systemic symptoms of mosaic, chlorotic spots, and fruit deformations. The French ZYFV (ZYFV‐Fr) isolate differed from the type strain in its ability to infect some differential host plants. Elongated flexuous particles with a modal length of 752 nm were observed by electron microscopy in leaf extracts. Cytoplasmic inclusions similar to those associated with infections by members of the potyvirus group were observed by light microscopy. The virus was found by SDS‐immunodiffusion and DAS‐ELISA to be serologically related but distinct from the type strain of zucchini yellow fleck virus from Italy (ZYFV‐lt). ZYFV has not yet been found in cultivated cucurbit plants in France; this virus appears to be restricted to squirting cucumbers in a few localities. The distribution of ZYFV in France is discussed.

Transgression of an estuarine channel and tidal flat complex: the Lower Triassic of Barles, Alpes de Haute Provence, France

ABSTRACTThe Lower Triassic succession of Barles, Alpes de Haute Provence, France, comprises an unconformable quartz arenite sand body of 90m thickness. The succession may be informally divided into (i) lower channellized cross‐bedded member overlain by (ii) an upper fining upward member. The lower member comprises vertically stacked, subtidal channel units separated into five major sand bodies by thin developments of fine grained channel margin and shoal deposits. Subtidal channel fill deposits are dominated by varying scales of cross bedding. These scales vary systematically from the base to the top of the member, with large scale planar sets dominating the lowest channel sand body (sand body 1), medium scale planar and trough cross bedding characterizing sand bodies 2‐4, the largest scale planar sets in the highest sand body (sand body 5). This upward change in cross bedding scale is concomitant with a decrease in both the relief of major channel sand body erosion surfaces, and the proportion of preserved interchannel shoal deposits. The succeeding fining upward member comprises small scale tidal channel units overlain by channel shoal and tidal flat deposits. Tidal flat sequences are characterized by parallel laminated, wave and current rippled sandstones separated by bioturbated, fine grained siltstones and mudstones.The vertical variation in facies of the Lower Triassic succession suggests two main periods of deposition. The lower member is considered to preserve successively more seaward components of a transgressive estuarine complex. The overlying upper member records the seaward progradation of tidal channel, shoal and tidal flat environments.The unconformity bounded nature of the lower member, combined with its systematic variation in facies, suggests it may represent an incised valley‐estuarine fill developed in response to an early Triassic relative sea level fall and subsequent rise. Succeeding tidal channel and tidal flat deposits forming the upper fining upward member reflect a change in sediment supply and/or rate of relative sea level rise comparable with a progradational shoreline. It is unclear whether this final depositional episode represents a period of highstand progradation or a later lowstand shoreline system developed following a further period of relative sea level fall and rise.

Présence d'Hélicelles (Helicellinae) dansle Pliocène du midi de la France nouvelles données sur la dispersion du groupe au Pléistocène inférieur implications paléoclimatiques

Three Pliocene-Pleistocene sites of southern France recently yielded new elements concerned with the European0309 history of the Helicellids (Helicidae, Helicellinae) group. At Grenouillet (Alpes-de-Haute-Provence) the occurrence of Candidula unifasciata, in an upper Pliocene paleosoil, estimated at 3.2 Myr from the associated rodents, from the Valensole series, is the oldest known marker. This steppic species, which appears in moderate number at the bottom of the paleosoil, together with a traditional Neogene malacological assemblage, still of forest type, becomes abundant at the top. Such vertical distribution of the species is significant of the environment drying up and seems to correspond with a climatic aridification phase. This climatic occurrence at −3.2 Myr, already recognised by palynology, would combine with the general dynamics of xericity expanding towards the North of the Mediterranean Basin during late Neogene. The two lower Pleistocene malacological sites of La Viste (Bouches-du-Rhône) and Valensolette (Alpes de Haute-Provence) are separated by a long time gap. The former is referred to an early phase of lower Pleistocene; the latter, which also yielded a rodent fauna, is dated to about 0.7–1.0 Myr. Both malacofaunas are typically Quaternary; they no longer include any Neogene element, and however, at La Viste, one of the species (Trochoidea “trochoides”) shows archaic characteristics. These associations are related to clearly open environments and reveal conditions of climatic degradation, modulated on the two sites according to their location and age. They reflect two different episodes of the general cooling, which has occurred since −2,7 Myr with the succession of glacial-interglacial cycles.

Plants in the traditional medicine of the Ubaye Valley

The study of the traditional pharmacopoeia in the Ubaye Valley (in the Alpes de Haute Provence department) enabled us to draw up a table showing 136 medicinal plants, their vernacular names, their suitable parts, the instructions for use, the medical purposes and the principal pharmacological and therapeutical properties. This study points out the close connection between plants, pathology and the living conditions of an agro-sylvo-pastoral civilization.

Paleomagnetic correlation of the Mediterranean upper Neogene biochronology and Villafranchian vertebrate sites of the Massif Central, France

Magnetostratigraphic studies of Pliocene-Pleistocene continental deposits on the Plateau de Perrier and in the Le Puy-en-Velay basin (Massif Central), as well as in the Riez-Valensole basin (Alpes de Haute Provence, Mediterranean South), provide decisive reference dating of several well-known fossil-bearing Villafranchian sites. These are well distributed in the tephrostratigraphy on both sides of the Gauss/Matuyama geomagnetic boundary: the Roca-Neyra fauna falls within the Matuyama chron, while older sediments at Les Etouaires are situated just above the normal-reversed transition. The Vialette section lies below this reversal, within the Gauss chron. In the Riez-Valensole basin, the discovery of the Gauss/Matuyama boundary toward the top of the Puimoisson section leads to an excellent correlation with the Massif Central localities. Rodents of the Seynes zone occur below the reversal, while Equus appears just above. This calibration improves the Mediterranean upper Neogene biochronology and allows a direct correlation with Villafranchian vertebrate sites of the Massif Central.

Données nouvelles sur le Pléistocène supérieur des Alpes françaises du Sud. Le Würm récent du Bassin de la Bléone (Alpes de Haute Provence)

The sedimentological, pedological and stratigraphical study of the upper Pleistocene alluvial deposits in the Bleone Valley (Alpes de Haute Provence) throws a new light on the morphoclimatic evolution of the Southern French Alps during the last thirthy thousand years Radiocarbon dating of vegetable debris ans charcoal makes it possible to establish the chronology of this evolution with precision. Thus the main wurmian terrace of the Bleone is dated from 25 000 to 20 000 BP. An important stage of interstadial pedogenesis is shown to have taken place around 20 000 BP ("Bleone neo-wurmian interstadium"). The last wurmian glacial maximum of the Bleone Valley is immediately posterior to that period of pedogenesis.

Timberline Reconstruction in Alpes De Haute Provence and Alpes Maritimes, Southern French Alps

Timberline Reconstruction in Alpes De Haute Provence and Alpes Maritimes, Southern French Alps

Timberline Reconstruction in Alpes de Haute Provence and Alpes Maritimes, Southern French Alps

Owing to very extensive reafforestation ef- human conditions affecting timberline are forts in the middle of the last century, high- classed according to their relative imporaltitude forests have been reestablished and tance. The main controlling factor is temtimberline has been reconstructed in the perature of the growing season. Precipitation, southern French Alps. The altitudes of the re- soils, human activity, land ownership, and constructed timberline and of the natural legal conditions are important secondary factimberline (where it is still preserved) are tors that influence local variations in timberfound to be comparable. The physical and line.

“Smerdis” glangeaudi Priem (poisson téléostéen), espèce mythique du Stampien des environs de Corent (Puy-de-Dome)

The mythical character of the species «Smerdis glangeaudi Priem is demonstrated, using mainly lithological, anatomical, morphometrical and field arguments. In fact, this species has been described from a composite hypodigm which truly includes two specimens of Dapalis (=Smerdis) macrurus ( Ag.) from the neighbourhood of Céreste (Alpes de Haute-Provence) and another one of Dapalis (=Smerdis) minutus ( Bl.) from the ancient gypsum quarries of Aix-en-Provence.

Tethysia, nouveau genre d'Ostracode bathyal du jurassique supérieur-crétacé inférieur mésogéen

Here is described a new Ostracode genus, the species of which lived, from the Middle Tithonian to Upper Valanginian, in subbathyal-bathyal conditions of the Tethys ≪Sea≫. The type-species, with two subspecies, T. chabrensis chabrensis and T. chabrensis inflata, come from the vicinity of Angles and Barret-le-Bas (Alpes de Haute-Provence), where the future parastratotype of Valanginian will be located.