Estimating seismic-source rate parameters associated with incomplete catalogues and superimposed Poisson-renewal generating processes     

Jorge L. Alamilla  Rossana Vai  Luis Esteva 《Journal of Seismology》2015,19(1):55-68

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Assessment of the European Standard for the determination of resistance of marble to thermal and moisture cycles: recommendations for improvements     

Rossana Bellopede  Eleonora Castelletto  Bjorn Schouenborg  Paola Marini 《Environmental Earth Sciences》2016,75(11):946

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Coral- and oyster-microbialite patch reefs in the aftermath of the Triassic–Jurassic biotic crisis (Sinemurian,Southeast France)     

Simon Boivin  Mélanie Gretz  Bernard Lathuilière  Nicolas Olivier  Annachiara Bartolini  Rossana Martini 《Swiss Journal of Geoscience》2018,111(3):537-548

The end of the Triassic and the Early Jurassic are intervals characterised by profound biotic and environmental changes, accompanied by dramatic decreases in marine fauna diversity. Corals were strongly affected and assemblages underwent a severe reduction; compared with those of the Upper Triassic, the Early Jurassic is traditionally defined as holding a “reef gap”. A Sinemurian coral-microbialites patch reef, located in southern France in the Hérault department (Le Perthus locality), is here described. This bioconstruction developed in a shallow mixed siliciclastic-carbonate inner ramp setting. The reef volume is composed of up to 70% of an intercoral facies mostly microbialites, with subordinated sediments (approximately 20–30% of the intercoral facies). Therefore, the patch reef can be defined as a coral-microbialite bioconstruction, in which microbialites were the main framebuilders. The coral assemblage has low diversity and is dominated by massive to branching colonies of Chondrocoenia clavellata. This highlights the reef diversity after the T/J boundary crisis. The Le Perthus patch reef could have acted as an edge for the dominant currents and probably induced reductions in hydrodynamic energy and sedimentation on one of its sides. Consequently, it could have triggered the growth of small lateral bioconstructions, composed of oysters and microbialites, uniquely on one of its sides. The evolution of the facies shows that the Le Perthus patch reef grew in a shallowing-upward setting accompanied by an increase in siliciclastic inputs. The rate of bioerosion and the faunal assemblage suggest that the bioconstructions could have been developed in a mesotrophic environment.  相似文献   

Oxygen isotope fractionation between apatite-bound carbonate and water determined from controlled experiments with synthetic apatites precipitated at 10-37 °C     

Christophe Lécuyer  Vincent Balter  François Fourel  Romain Amiot  Olga Otero  Gérard Panczer  Rossana Martini 《Geochimica et cosmochimica acta》2010,74(7):2072-584

The oxygen isotope fractionation between the structural carbonate of inorganically precipitated hydroxyapatite (HAP) and water was determined in the range 10-37 °C. Values of 1000 ln α() are linearly correlated with inverse temperature (K) according to the following equation: 1000 ln α() = 25.19 (±0.53)·T⁻¹ − 56.47 (±1.81) (R² = 0.998). This fractionation equation has a slightly steeper slope than those already established between calcite and water ( [O’Neil et al., 1969] and [Kim and O’Neil, 1997]) even though measured fractionations are of comparable amplitude in the temperature range of these experimental studies. It is consequently observed that the oxygen isotope fractionation between apatite carbonate and phosphate increases from about 7.5‰ up to 9.1‰ with decreasing temperature from 37 °C to 10 °C. A compilation of δ¹⁸O values of both phosphate and carbonate from modern mammal teeth and bones confirms that both variables are linearly correlated, despite a significant scattering up to 3.5‰, with a slope close to 1 and an intercept corresponding to a 1000 ln α() value of 8.1‰. This apparent fractionation factor is slightly higher or close to the fractionation factor expected to be in the range 7-8‰ at the body temperature of mammals.  相似文献   

The caranto paleosol and its role in the early urbanization of Venice     

Sandra Donnici  Rossana Serandrei‐Barbero  Claudio Bini  Maurizio Bonardi  Alberto Lezziero 《Geoarchaeology》2011,26(4):514-543

As rising sea level threatens Venice, there is a need to construct a historical framework for interpreting modern environmental changes. Environmental conditions that would later help support Venice's urbanization were established during the Late Glacial period when calcic soils began to develop in the Venetian alluvial paleoplain. A calcic paleosol, buried by Middle to Late Holocene marine transgressive deposits, represents a subsurface layer long known in the Venice area as “caranto.” Referenced in the ancient chronicles of architects and builders, the caranto exhibits relatively high compressive and shear strength, making it an important substrate for supporting building foundations, some dating back to the Gothic era (12th–15th centuries A.D.). Hence, the caranto paleosol documents local post‐glacial environmental changes while playing an important role in Venetian building construction and human settlement. Here we provide geochemical, sedimentological, paleoecological, and chronological analyses of the caranto paleosol and related deposits based on recent coring of the Venetian Lagoon. © 2011 Wiley Periodicals, Inc.  相似文献   

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)     

Emmanuel Skourtsos  Daniel Vachard  Alexandra Zambetakis-Lekkas  Rossana Martini  Louisette Zaninetti 《Comptes Rendus Geoscience》2002,334(12):925-931

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.  相似文献   

Petrography and stable isotope aspects of cold-vent activity imprinted on Miocene-age “calcari aLucina” from Tuscan and Romagna Apennines,Italy     

Claudia Terzi  Franco Ricci Lucchi  Gian Battista Vai  Paul Aharon 《Geo-Marine Letters》1994,14(2-3):177-184

Over 20 occurrences of discontinuous limestone blocks, locally called calcari aLucina, were mapped in the Tuscan—Romagna region of the northern Italian Apennines. The limestones, consisting of a variable mixture of authigenic carbonates (calcite, dolomite, and aragonite), sulfides (primarily pyrite), and allogenic silicates, occur in association with turbidite and hemipelagite units that were deposited in foredeep basins during early to late Miocene times. The limestone blocks are interpreted to represent relicts of carbonate buildups formed around methane-rich fluid vents on the basis of their (1) striking petrographic similarities to carbonates from cold vents in the modern oceans; (2) unique chemosynthetic-like fauna, and (3) anomalously negative ¹³C values ( ¹³C = – 16 to – 58 PDB). The contemporaneous tectonism of the Apennine orogeny is likely to be the primary cause for the expulsion of the methane-rich fluids to the seabed in a manner analogous to the fluid-flow processes occurring at modern accretionary prisms.  相似文献   

Qualitative behaviour of the trajectories of test bodies in five-dimensional spherically-symmetric gravitational field     

L. Vaičiūnienė  I. Zhuk  K. Pyragas 《Astrophysics and Space Science》1990,163(2):255-263

Qualitative behaviour of the trajectories of test bodies is investigated in the five-dimensional gravitation theory for the spherically-symmetric solution. The Binnet formula is obtained for the trajectory. The region of the existence of circular trajectories as well as the regions of their stability are specially investigated using the method of numerical calculations. The values of the free parameters in the five-dimensional gravitation theory are estimated for the solar system.  相似文献   

Petrogenesis of the early Cretaceous Valle Chico igneous complex (SE Uruguay): Relationships with Paraná–Etendeka magmatism     

Michele Lustrino  Leone Melluso  Pietro Brotzu  Celso B. Gomes  Lucio Morbidelli  Rossana Muzio  Excelso Ruberti  Colombo C.G. Tassinari 《Lithos》2005,82(3-4):407-434

The early Cretaceous (130 Ma) igneous complex of Valle Chico (SE Uruguay) is made up of felsic plutonic and subordinate volcanic rocks and dykes cropping out over an area of about 250 km². This complex is strictly linked with the formation of the Paraná–Etendeka Igneous Province and the first stages of the South Atlantic Ocean rifting. The plutonic rocks range from quartz-monzonite to syenite, quartz-syenite and granite. The volcanic rocks and the dykes range from quartz-latite to trachyte and rhyolite; no substantial differences in term of chemical composition have been found between plutonic and volcanic rocks. Only a sample of basaltic composition (with tholeiitic affinity) has been sampled associated with the felsic rocks. The Agpaitic Index of the Valle Chico felsic rocks range from 0.72 to 1.34, with the peralkaline terms confined in the most evolved samples (SiO₂>65 wt.%). Initial ⁸⁷Sr/⁸⁶Sr₍₁₃₀₎ of the felsic rocks range from 0.7046 to 0.7201, but the range of ⁸⁷Sr/⁸⁶Sr of low-Rb/Sr samples cluster at 0.7083; ¹⁴³Nd/¹⁴⁴Nd₍₁₃₀₎ ratios range from 0.5121 (syenite) to 0.5117 (granite). The tholeiitic basalt show more depleted isotopic compositions (⁸⁷Sr/⁸⁶Sr₍₁₃₀₎=0.7061; ¹⁴³Nd/¹⁴⁴Nd₍₁₃₀₎=0.5122), and plots in the field of other early Cretaceous low-Ti basaltic rocks of SE Uruguay. The radiogenic Sr and unradiogenic Nd of the Valle Chico felsic rocks require involvement of lower crustal material in their genesis either as melt contaminant or as protolith (crustal anatexis). In particular, most of the Valle Chico (VC) felsic rocks define a near-vertical array in Sr–Nd isotopic spaces, pointing toward classical EMI-type composition; this feature is considered to reflect a lower crust involvement as observed for other mafic and felsic rocks of the Paraná–Etendeka Igneous Province. Decompression melting of the lower crust related to Gondwana continental rifting before the opening of the South Atlantic Ocean or the presence of thermal anomalies related to the Tristan plume may have induced the lower crust to partially melt. Alternative hypothesis considers contamination of upper mantle by a mafic/ultramafic keel composed of lower crust and uppermost mantle after delamination and detachment processes. This interaction may have occurred after the continent–continent collision during the last stages of the Panafrican Orogeny. This “lower crust” model does not exclude active involvement of upper crust as contaminant, necessary to explain the strongly radiogenic ⁸⁷Sr/⁸⁶Sr₍₁₃₀₎ isotopic composition of some VC SiO₂-rich rocks. Mineralogical (sporadic presence of pigeonite, Ca–Na and Na clinopyroxene, calcic- and calco-sodic amphibole) and geochemical evidences (major and trace element as well as Sr–Nd isotopic similarities with the felsic early Cretaceous volcanic rocks of the Arequita Formation in SE Uruguay) allow us to propose for the VC rocks a transitional rock series (the most abundant rock types are of syenitic/trachytic composition) preferentially evolving towards SiO₂-oversaturated compositions (granite/rhyolite) also with a strong upper crustal contribution as melt contaminant. This conclusion is in contrast with previous studies according which the VC complex had clear alkaline affinity. Many similarities between VC and the coeval Paresis granitoids (Etendeka, Namibia) are evidenced in this paper. The genetic similarities between VC and the rhyolites (s.l.) of SE Uruguay may find counterparts with the genetic link existing between the early Cretaceous tholeiitic-alkaline Messum complex and the quartz latites (s.l.) of the Awahab Formation (Etendeka region, Namibia).  相似文献   

Metazoan/microbial biostalactites from present‐day submarine caves in the Mediterranean Sea          下载免费PDF全文

Rossana Sanfilippo  Antonietta Rosso  Adriano Guido  Adelaide Mastandrea  Franco Russo  Robert Riding  Emma Taddei Ruggiero 《Marine Ecology》2015,36(4):1277-1293

Biostalactites formed by metazoan–microbialite associations from three submerged marine caves in the Plemmirio Peninsula (south of Syracuse, Ionian Sea) are randomly distributed and show different sizes and morphologies, as well as variations in surface roughness/smoothness. The biostalactites consist of crusts a few centimeters thick of small serpulids and other metazoans, associated with fine‐grained carbonate; the larger ones often include a nucleus of serpulid tubes (Protula). The metazoans include mainly serpuloideans, sponges, bryozoans and foraminifers but microbial carbonates are also significant components. The composition of both the living communities and thanatocoenoses on the outer surfaces, as well as the composition and fabric of the internal framework, were analysed and used to reconstruct the history of the caves. All of the identified sessile faunas mainly consist of cryptic and sciaphilic dwellers that reflect cave conditions and their variations through time. The distribution pattern, composition and abundance of the present‐day dwellers largely depend on the degree of roughness of the biostalactite surfaces and their positions within the caves. It has been suggested that the Protula specimens in the nuclei represent pioneer populations that formed aggregates during the early cave colonization phase, in response to relatively high food supply from seawater inflow and intruding continental waters. By contrast, the outer metazoan–microbialite carbonates reflect more confined conditions in the caves caused by Holocene sea‐level rises. Hypotheses are proposed for biostalactite growth, taking into account information about the growth rates of some constituents, and evidence of dissolution effects. Similarities and differences between these biostalactites and other Holocene deposits previously described from submarine caves in the Mediterranean Sea and in tropical reefs are discussed.  相似文献