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Marcel Huet 《Aquatic Sciences - Research Across Boundaries》1962,24(2):412-432
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One Million Years tephra record at IODP Sites U1436 and U1437: Insights into explosive volcanism from the Japan and Izu arcs 
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下载免费PDF全文 Julie Christin Schindlbeck Steffen Kutterolf Susanne M. Straub Graham D. M. Andrews Kuo‐Lung Wang Maryline J. Mleneck‐Vautravers 《Island Arc》2018,27(3)
The 1 Myr tephra records of IODP (International Ocean Discovery Program) Holes U1436A and U1437B in the Izu‐Bonin fore‐ and reararc were investigated in order to assess provenance and eruptive volumes, respectively. In total, 304 tephra samples were examined and 260 primary tephra layers were identified. Tephra provenance was determined by means of major and trace element compositions of glass shards and distinguished between Japan and Izu‐Bonin arc origin of the tephra layers. A total of 33 marine tephra compositions were correlated to the Japan arc and 227 to the Izu arc. Twenty marine tephra layers were correlated between the two drilling sites. Additionally, we defined eleven correlations of marine tephra deposits to major widespread Japanese eruptions; from the 1.05 Ma Shishimuta‐Pink Tephra to the 30 ka Aira‐Tn Tephra, both from Kyushu Island. These eruptions provide independent time markers within the sediment record and six correlations were used to date tephra layers from Japan in Hole U1436A to establish an alternative age model for this hole. Furthermore, the minimum distal tephra volumes of all detected events were calculated, which enabled the comparison of the tephra volumes that derived from the Japan and the Izu‐Bonin arcs. For some of the major Japanese eruptions these are the first volume estimations that also include distal deposits. All of the Japanese tephras derived from events with eruption magnitude Mv ≥ 5.6 and three of the investigated eruptions reach magnitudes Mv ≥ 7. Volcanic events of the Izu‐Bonin arc have mostly eruption magnitudes Mv ≤ 5. 相似文献
3.
High‐resolution evolution of terrigenous sediment yields in the Provence Basin during the last 6 Ma: relation with climate and tectonics 下载免费PDF全文
下载免费PDF全文 Estelle Leroux Marina Rabineau Daniel Aslanian Christian Gorini Stéphane Molliex Francois Bache Cécile Robin Laurence Droz Maryline Moulin Jeffrey Poort Jean‐Loup Rubino Jean‐Pierre Suc 《Basin Research》2017,29(3):305-339
Basin‐wide correlation of Messinian units and Plio‐Quaternary chronostratigraphic markers (5.3 Ma, 2.6 Ma, 0.9 Ma and 0.45 Ma), the mapping of total sediment thickness and the determination of overall sedimentary volumes enabled us to provide a high‐resolution quantitative history of sediment volumes for the last 6 Ma along the Gulf of Lions margin. The results point to (i) a dramatic increase in terrigenous sediment input during the Messinian Salinity Crisis. This increased sedimentation reflects enhanced regional fluvial erosion related to the dramatic fall of Mediterranean base‐level. Stronger weathering due to a regional wetter climate probably also increased erosional fluxes. (ii) A sediment input three times higher during the Plio‐Quaternary compared to the Miocene seems in agreement with published measurements from World's ocean. However, the timing of this increase being uncertain, it implies that the trigger(s) also remain(s) uncertain. (iii) A decrease in detrital volume around 2.6 Ma is attributed to a regional change in the drainage pattern of rivers in the northwestern Alps. (iv) This study also highlights the Mid‐Pleistocene Revolution around 0.9 Ma, which resulted in an almost doubling of sediment input in the Provencal Basin. 相似文献
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ABSTRACTEstimating groundwater recharge is crucial to ensuring the proper management of aquifers. In this study, net regional recharge and spatial potential recharge are estimated at four watersheds within the Charlevoix–Haute-Côte-Nord (CHCN) regions, Quebec Province, Canada. Four methods are applied based on available data. The first two approaches are regional water budget methods. These two methods differ in their estimation of vertical inflow (VI), which is estimated from two hydrological models: GR4J and HYDROTEL. The third method estimates potential recharge spatially over the study area. Finally, the streamflow data are analysed using the Eckhardt baseflow separation method to obtain an estimation of recharge, assuming that discharge is equal to recharge. According to the results of all investigated methods, the mean annual recharge for the CHCN region is approximately 183 mm, which is 18% of the total annual precipitation (P). The discussion section highlights uncertainties due to the assumptions of each method and the reliability of the data. 相似文献
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ReactMiCP, a new reactive transport simulator was developed based on the semismooth speciation solver SpecMiCP. Its main feature is a sequential iterative operator splitting algorithm where macroscopic model parameters are explicitly included in the formulation. Its correctness, robustness, and efficiency are tested against the MoMaS benchmark and two sets of cement paste lab experiments. We show that a robust speciation solver is a key requirement for good performance of the reactive transport simulator. We also demonstrate that a sequential iterative solver should be preferred over non-iterative solvers when using operator splitting. The flexibility and the speed of the simulator are used to test the influence of the database, the initial condition, and the diffusion coefficient model for the cement paste simulations. 相似文献
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Anna E. Nelson John L. Smellie Michael J. Hambrey Mark Williams Maryline Vautravers Ulrich Salzmann John M. McArthur Marcel Regelous 《Quaternary Science Reviews》2009,28(27-28):3138-3160
Detailed sedimentological and microtextural analyses of newly-discovered late Neogene diamictites and other coarse-grained facies, mostly sandwiched between hyaloclastite of the James Ross Island Volcanic Group and Cretaceous sandstone and mudstone, indicate deposition mainly by glacigenic debris flows. The deposits on James Ross Island (northern Antarctic Peninsula) constrain the depositional setting, ice–bed dynamics and regional palaeoclimate. The sequences on James Ross Island vary in age but are mainly late Miocene and Pliocene. Unlike Neogene sedimentary sequences elsewhere in Antarctica, those on James Ross Island are unusually well-dated by a combination of 40Ar/39Ar and 87Sr/86Sr analyses on fresh interbedded lavas and pristine bivalve molluscs, respectively. The Sr isotopic ages of the debris flows cluster around 4.74, 4.89, 5.44, 5.78, and 6.31 Ma and probably date relatively warm periods in the northern Antarctic Peninsula region, when the bivalves lived under ice-poor or seasonally ice-free conditions. The bivalves are often remarkably well-preserved, lack adhering lithified sediment and, in at least two locations, are large, mainly unfragmented and sometimes articulated, suggesting that they were alive immediately prior to their incorporation in subaqueous debris flows at the margins of an advancing glacier. These fossiliferous glacigenic debris flows signify episodes of ice expansion during relatively warm periods, or “interglacials”, of the late Miocene and Pliocene. The James Ross Island glacigenic sedimentary successions attain thicknesses of up to 150 m and extend over 4 km laterally. The high volume of glacigenic sediment delivery implicit in the James Ross Island successions indicates that a series of dynamic ice fronts crossed the region during the late Miocene and Pliocene epochs. Associated evidence, in the form of clast abrasion (including striations and faceting) and bedrock erosion, is indicative of basal sliding and subglacial sediment deformation active at the ice–bed interface and wet-based temperate or polythermal regimes, prior to remobilisation. The evidence further suggests two local ice caps on James Ross Island during the warm periods, as well as ice-overriding by the Antarctic Peninsula Ice Sheet from the west and northwest. 相似文献
7.
Laurent Jolivet Emmanuel Lecomte Benjamin Huet Yoann Denèle Olivier Lacombe Loïc Labrousse Laetitia Le Pourhiet Caroline Mehl 《Earth and Planetary Science Letters》2010,289(1-2):87-104
Low-angle normal faults accommodate a large part of continental post-orogenic extension. Besides the intrinsic rheological characteristics of the continental crust that may lead to the formation of shallow-dipping shear zones at the brittle–ductile transition, the role of pre-existing low-angle structures such as large thrusts has been proposed by several authors. We explore this question with the example of the North Cycladic Detachment System (NCDS) that is composed of a series of distinct detachments cropping out on the islands of Andros, Tinos and Mykonos, separating the Cycladic Blueschists in the footwall from the Upper Cycladic Nappe in the hanging wall. We show that these extensional structures are part of a single large-scale structure (more than 200 km along strike) that reactivates the Vardar suture zone. It extends eastward on Ikaria and westward offshore Evia and Thessalia where it probably connects to recent shallow-dipping normal faults evidenced on published seismic reflection profiles. The NCDS started its activity in the Oligocene concommitantly with the Aegean extension, and was still active in the Late Miocene. It has exhumed a series of metamorphic domes from southern Evia to Mykonos below low-angle detachment systems, made of low-angle normal faults and low-angle ductile shear zones. The ductile shear zones and the faults were created with a low dip and they kept the same attitude throughout their exhumation. We identify three main detachments that are part of a continuum of extension on the NCDS : Tinos detachment, Livada detachment and Mykonos detachment. A fourth detachment (Vari detachment) is the reactivation of an Eocene exhumation-related structure. Deformation in the footwall is characterized by intense stretching and flattening. Using the spatial evolution observed along strike from Andros to Mykonos we construct a history of formation of the NCDS starting with the reactivation of former thrusts leading to the exhumation of high-temperature metamorphic domes. The Aegean example shows that reactivation of earlier shallow-dipping discontinuities can play a fundamental role in continental post-orogenic extension. 相似文献
8.
Résumé Le contr?le de la population piscicole de la noue du Colébi a pu être effectué le 14 septembre 1959, à l'occasion de l'abaissement
du niveau de la Meuse. La noue est située en bordure du fleuve et est en communication permanente avec ce cours d'eau. Longue
de 184 m, large en moyenne de 14 à 24 m, elle couvre o ha 3270.
La population totale, ramenée à l'hectare, est de 820 kilos. Les poissons les plus abondants sont différents Cyprinides: Gardon
et Rotengle tout d'abord, Tanche et Brème ensuite. Les principaux voraces sont la Perche et le Brochet. Ils représentent 16,5%
du poids total de la population.
Les petits poissons (±5,0 à 15,0 cm de long) sont très abondants. En poids, ils représentent 61% de la population totale.
On compte 17,2 petits poissons par mètre carré. Le Gardon et le Rotengle sont les plus nombreux. 相似文献
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Amir Kalifi Philippe Sorrel Philippe-Hervé Leloup Vincenzo Spina Bastien Huet Albert Galy Jean-Loup Rubino Bernard Pittet 《Sedimentology》2020,67(5):2455-2501
A comprehensive sedimentological study was undertaken in the Miocene of the subalpine massifs and southern Jura (France) with the aim to constrain the evolution of process changes in third-order sequences of peripheral foreland basins during the overfilled phase (i.e. sediment supply higher than accommodation space). Fieldwork analyses based on 35 sedimentological sections allowed the identification of four depositional models: wave dominated, mixed wave-tide, river to tide and river dominated. The sections were dated using chemostratigraphy (i.e. marine strontium isotopic ratios), revealing three-third-order sequences between the Upper Aquitanian and the Langhian. Chronostratigraphical and sedimentological results document prominent and recurrent changes in depositional models along third-order sequences: (i) in the earliest stage of the transgression, mixed-energy coastal environments influenced by the local coastal morphology prevailed (in palaeo-highs or incised valleys); (ii) during the course of the transgression, Gilbert delta deposits suggest a prominent steepening linked to a tectonic uplift in the proximal depozone (between the tectonically active frontal part of the orogenic wedge and the proximal foredeep). Instead, in the distal depozone (between the proximal foredeep and the proximal border of the flexural uplifted forebulge), deposits were characterized either by wave-dominated or mixed wave-tide environments and are likely eustatically-driven; (iii) during the maximum flooding stage, water depth remained shallow below the storm-weather wave base; and (iv) during the regression, the proximal depozone is characterized by the progradation of gravel-rich fan deltas. In the distal depozone, mixed wave-tide systems preceded the development of river to tidal depositional environments. These results were integrated and compared with facies models from other basin analogues worldwide. A model tackling the evolution of process changes within third-order sequences (of the overfilled phase) of foreland basins is proposed, thereby improving sequence stratigraphic predictions in foreland basins. 相似文献