bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics and age of formation of the Seram-Ambon ophiolites (Central Indonesia)
Authors: Monnier Christophe , Girardeau Jacques , Permana Hariady , Rehault Jean-Pierre , Bellon Hervé , Cotten Jo
Published: June 2005

The Seram-Ambon ophiolitic series comprise peridotites, websterites, gabbros and lavas. Petro-geochemical data show that the peridotites are weakly depleted rocks, except for the rare Cpx-free harzburgites. They underwent a sub-solidus metamorphic re-equilibration in the plagioclase field. The associated websterites and gabbros display various chemical features, allowing to define 3 types of websterites and 2 groups of gabbros. They have mostly BAB characteristics (presence of negative anomalies in Nb, Zr, Ti and Y), except the group 2 gabbros which have N-MORB features and the type 3 websterites which bear adakitic affinities. Lavas also display a variety of compositions, including high-Mg IAT and Mg-rich BABB with sub-alkaline affinities. Both IAT and BABB display high Th/Nb ratios which support an origin close to a continental crust environment.

Our 20 to 15 Ma 40K/40Ar ages calculated for the BABB and 15-9 Ma for the IAT show that the basin and arc formed in a very short span of time, before their obduction 9–7 Ma ago [Linthout et al., 1997]. Considering the paleogeographic situation in the Miocene [Haile, 1979 ; Haile, 1981] and our data, we propose that the Seram-Ambon ophiolites formed during the early Miocene in a small, short-lived (10 Ma), transtensive basin bordered on its east by an active margin and on its western part by a passive continental margin over which it was later obducted towards the SW direction.
U-Pb zircon age of 548 Ma for the leptynites (high-grade felsic rocks) of the central part of the Maures Massif. Geodynamic significance of the so-called leptyno-amphibolitic complexes of the Variscan belt of western Europe
Authors: Innocent Christophe , Michard Annie , Guerrot Catherine , Hamelin Bruno
Published: June 2005

U-Pb zircon and Rb-Sr geochronological, and Sm-Nd isotopic studies have been carried out on the so-called leptyno-amphibolitic complex of the central part of the Maures Massif. The emplacement of the protolith of the felsic end-member (« leptynites ») has been dated at 548 Ma, an age much older than those (lower Ordovician) previously obtained on other leptyno-amphibolitic complexes. Rb-Sr data obtained on whole rocks and on mineral separates give an age of 348 Ma for the amphibolite-facies metamorphism. Nd isotopes indicate that the amphibolites display clear-cut mantle-derived signatures, whereas a significant crustal contribution is recorded in the three analyzed felsic facies. One of these acidic terms can be interpreted in terms of a simple mixing between two components, respectively similar to the amphibolites and to the two other felsic samples. These latter involve another mantle source, distinct from that of the amphibolites, and comparable to that of continental alkali basalts. These data indicate that the central part of the Maures Massif and the southern Massif Central were possibly part of the same pre-Variscan structural unit. The lack of evidence for a clear genetic relationship between the respective protoliths of the two end-members of the leptyno-amphibolitic complex raises once again the problem of the geodynamic significance of these formations.
Chronostratigraphy of the key Upper Miocene (Lower Turolian) sequence of la Montagne d’Andance (Ardèche, France). Implications of new 40Ar/39Ar laser fusion and unspiked K-Ar dating of trachytic tephra and basalts
Authors: Pastre Jean-François , Singer Brad S. , Guillou Hervé , Pupin Jean-Pierre , Riou Bernard
Published: June 2005

A trachytic tephra layer deposited in the lower part of the Upper Miocene (Turolian) diatomite sequence at la Montagne d’Andance (Coiron basaltic province, France) contains glass shards (73 % SiO2), plus crystals of sanidine, ilmenite, biotite, amphibole, clinopyroxene, zircon, sphene and apatite. This composition and other volcanological data suggest a correlation to the Cantal stratovolcano, 150 km distant, better than to the nearer (50 km) Mézenc area. The 7.54 ± 0.06 Ma (± 2 σ) isochron defined by eight 40Ar/39Ar laser fusion analyses of sanidine gives a precise age for the beginning of the fossiliferous sequence, known for its rich flora and fauna. Moreover, unspiked K-Ar ages determined from three basaltic lava flows that pre- and post-date the lacustrine sedimentation are 7.37 ± 0.06, 7.17 ± 0.06 and 7.13 ± 0.06 Ma (± 2σ), thereby bracketing the sequence to a 400 kyr period between ca. 7.5 and 7.1 Ma. These are the first radioisotopic constraints for the lower part of the Turolian continental stage. They imply an age about 20 % younger for the fauna than proposed by previous biostratigraphic correlation. This new chronology is consistent with correlation of the lower limit of the Turolian to the Tortonian-Messinian boundary (7.30 ± 0.15 Ma) of the global marine stages.
65 m.y.-long magmatic activity in Sumatra (Indonesia), from Paleocene to Present
Authors: Bellon Hervé , Maury René C. , Sutanto  , Soeria-Atmadja Rubini , Cotten Joseph , Polvé Mireille
Published: June 2005

Sumatra is the largest volcanic island of the Indonesian archipelago. The oblique subduction of the Indian Ocean lithosphere below the Sundaland margin is responsible for the development of a NW-SE trending volcanic arc, the location of which coincides approximately with the Great Sumatran Fault Zone (GSFZ). We present in this paper ca. 80 new 40K-40Ar ages measured on Cenozoic calc-alkaline to shoshonitic magmatic rocks sampled all along this arc from Aceh to Lampung. The results show that magmatic activity started during the Paleocene (ca. 63 Ma) all along the arc, and was more or less permanent until Present. However, its spatial distribution increased at ca. 20 Ma, a feature possibly connected to the development of the Great Sumatran Fault. The position of Plio-Quaternary magmatic rocks is shifted away from the trench by a few tens of kilometres with respect to that of Paleocene to Miocene ones, a feature consistent with a significant tectonic erosion of the Sundaland margin during the Cenozoic.

The studied samples display typical subduction-related geochemical signatures. However, we have been unable to identify clear geochemical trends, either spatial or temporal. We suggest that the lack of such regular variations reflects a complex igneous petrogenesis during which the contribution of the Sundaland continental crust overprinted those of the mantle wedge and the subducted slab.
A sequence analyzed from the basin to the platform : the Middle Oxfordian calcareous succession in southeastern France
Authors: Gaillard Christian , Emmanuel Laurent , Hanzo Micheline , Lathuiliere Bernard , Atrops François , Bodeur Yves , Bouhamdi Abdelkader , Marchand Didier , Enay Raymond , Ruget Christiane , Werner Winfried
Published: June 2005

Middle Oxfordian sedimentation is very homogeneous in southeastern France. It is characterized by a specific alternation of marls and fine-grained limestones (G. transversarium Zone). This work shows that sets of calcareous beds allow accurate stratigraphic correlations in various paleogeographic areas, from the shallow Jura platform to the deep Dauphinois basin. Following a rifting period, this sedimentation illustrates a doming period with decreasing subsidence and water depth. This corresponds to the establishment of a wide marine area more favourable to carbonate sedimentation. Considering sequence stratigraphy, some slight variations occur in the sediment record and lead to interesting comparisons between the platform and the basin. The geochemical evolution, mainly the manganese content, seems to be dependant of the activity of the Ligurian Tethys oceanic ridge. This fact shows that sedimentation in southeastern France could be significantly controlled by tectono-eustasy.
Radiolarian Cretaceous age of Soulabest radiolarites in ophiolite suite of eastern Iran
Authors: Babazadeh Seyed Ahmad , De Wever Patrick
Published: June 2005

The ophiolite-flysch range (accretionary prism) of the Sistan suture zone from eastern Iran includes several intensely deformed tectonic units, some of which consist of volcaniclastic rocks, volcanic rocks, siliceous pelagic sediments (cherts and radiolarites) and calcareous rocks (deep marine, platform), whereas others are represented by terrigenous turbidites. The Soulabest radiolarites are located in the Ratuk complex of the Tirrul’s subdivision [Tirrul et al. , 1983], or in the ophiolite suite of the Gazik province.

The local biostratigraphy of this region is based on two faunal assemblages. Faunal assemblage I is dated early Aptian, faunal assemblage II is attributed to middle-late Albian. The most abundant fauna is found in the middle-late Albian. The timing of the oceanic opening in eastern Iran remained questionable until now. The study of the radiolarites of the Soulabest area provides new data for dating the primary opening between two microcontinents : the Lut and Afghan blocks. It is proposed that the oceanic opening of the two blocks occurred prior to the early Aptian. In previous reports, the age of opening was attributed to Upper Cretaceous.

All reported Radiolaria are found in red radiolarites and green-red argillaceous cherts. This formation is unconformably overlain by Maastrichtian conglomerates. It indicates that the closure of the basin occurred in Maastrichtian age.
Late Hercynian leucogranites modelling as deduced from new gravity data : the example of the Millevaches massif (Massif Central, France)
Authors: Gebelin Aude , Martelet Guillaume , Brunel Maurice , Faure Michel , Rossi Philippe
Published: June 2005

The Millevaches granitic complex, located in the northern part of the French Massif Central, is elongated in a N-S direction, perpendicular to the main E-W trend of the Hercynian belt. It is affected on its limits and in its core by several ductile shear zones that have necessarily played a great role in the emplacement and exhumation of the massif. Based on gravity modelling and recent field observations, this study intends to highlight the massif structure at depth and discuss its mode of emplacement and relations with the surrounding terrains.

The new gravity and density measurements on the north-east part of the Millevaches massif improve the gravity coverage of the northern Limousin. Using these new data we model the deep structure of the Millevaches plateau. The density measurements made on the different types of granites of the massif, and on the surrounding terrains improve the interpretation of the Bouguer anomaly. Analysis and inversion of the residual Bouguer anomaly in the area show that the Millevaches massif is 2 to 4 km-thick, from north to south and from west to east, locally rooting down to about 6 km deep in its eastern and southern terminations. These two zones coincide with porphyritic plutons and, because of the complex composite structure of the massif, cannot be definitively interpreted as feeding zones. In the field, the N-S-oriented Pradines vertical fault affects the core of the massif on 4 to 5 km width. Microstructural observations evidence that the faulting is contemporaneous of the granites emplacement. We suggest that this tectonic lineament could have triggered the migration of the magma, although it is not related to a clear gravity anomaly. AMS measurements in the north-central part of the Millevaches massif suggest that the magnetic foliation and lineation display a general sub-horizontal pattern. Moreover, on the western border of the Millevaches massif, the Argentat deep seismic profile shows sub-horizontal layering of gneisses and micaschists and evidences normal faulting offset of this layering along Argentat fault. This agrees fairly well with the gravity results, suggesting that (i) the Millevaches massif would be at a high structural level in the crust, (ii) the exhumation of the massif would have been favoured along the Argentat normal fault. As a whole, the massif can be described as a laccolith, 2 to 4 km-thick, emplaced as a “magmatic lens” into the sub-horizontally foliated gneisses and micaschists.
Eustatic and palaeogeographic control of the western Aurès Upper Cretaceous sedimentation (Algeria)
Authors: Herkat Missoum
Published: June 2005

The Upper Cretaceous sedimentation in the Aurès Mountains occurred in a subsident basin delimited to the south by the Saharan platform and by the Preatlasic high zone to the north. In these series 4 transgressive-regressive megasequences are distinguished, the first one (I) in the late Albian-Cenomanian, the second one (II) in the Turonian, the third one (III) in the Coniacian - Santonian and the fourth one (IV) in the Campanian - Maastrichtian. Each megasequence is made up of three or four sequences, which correspond to third order cycles identified in the eustatic chart of Haq et al. [1987]. In late Albian and lower Turonian periods, during the deposition of basal sequences of the megasequences I and II, the reactivation of basement faults in the Aurès basin occurs consecutively to distension phases, resulting in the formation of rotated blocks. At the same time high eustatic levels are reached according to the global eustatic curve. These processes control the drowning of the carbonate platforms pre-existing to these sequences, and deep ramps progressively form on the tilted block tops. This sedimentary setting generates in the late Albian and lower Turonian series anoxic sequences made up of calcareous and shaly transgressive pelagic intervals. The succeeding sequences lack pelagic facies and are composed of alternate marls / carbonate beds deposited on a homoclinal ramp, indicating a gradual development of shallow open marine conditions, which became progressively restricted upwards. Toward the top of these megasequences, lagunal muds and isolated rudists mounds, surrounded by bioclastic and ooid / pellet banks occur. The Coniacian-Santonian and Campanian-Maastrichtian megasequences are characterized by a shallow ramp sedimentation, essentially marly during the Coniacian, Santonian and Campanian periods, interlayered with some bioclastic / ooid carbonate banks and upwards by sequences mostly homogeneous. The Maastrichtian platform carbonates are composed of bioclastic / ooid sands and were deposited in a ramp-barrier-bank system. Some sequences in the Campanian-Maastrichtian megasequence are condensed or absent due to the accommodation reduction related to a weak subsidence rate period.
Geologic evolution and geodynamic controls of the Tertiary intramontane piggyback Meso-Hellenic basin, Greece
Authors: Ferrière Jacky , Reynaud Jean-Yves , Pavlopoulos Andreas , Bonneau Michel , Migiros Georges , Chanier Frank , Proust Jean-Noël , Gardin Silvia
Published: June 2005

The Meso-Hellenic Basin (MHB) is a large, narrow and elongated basin containing up to c. 5 km of Cenozoic sediments, which partially covers the tectonic boundary between the external, western zones (Pindos) and the internal, eastern zones (Pelagonian) of the Hellenide fold-and-thrust belt. New results, based on micropaleontologic, sedimentologic and tectonic field data from the southern half of the MHB, suggest that the MHB originated as a forearc basin during the first stages of a subduction (Pindos basin), and evolved into a true piggyback basin as a result of the collision of thicker crustal units (Gavrovo-Tripolitsa). The late Eocene forearc stage is marked by sharply transgressive, deep sea turbiditic deposition on the subsiding active margin. At this stage, large scale structures of the Pelagonian basement (i.e. the newly defined “Pelagonian Indentor”) control deposition and location of two main subsiding sub-basins located on both sides of the MHB. The Eocene-Oligocene boundary corresponds to a brief tectonic inversion of the basin, at the onset of collision (main compressive event). The true piggyback stage (Oligo-Miocene) is recorded by slope deposition and dominated by gravity processes (from slumped, fine grained turbidites to conglomeratic fan- or Gilbert-deltas). The new elongated geometry of the MHB is controlled by the underthrusted, NNW-SSE trending, thick external zones. During this stage, the locus of subsidence migrates in the same direction (eastward) as underthrusting. This subsidence, favoured by thick dense ophiolitic basement, is attributed to basal tectonic erosion of the upper Pelagonian unit while the tectonic structures of this upper unit control the stepped migration of subsidence. Growing duplexes in the Gavrovo underthrusted unit, which formed local uplifts, were mainly situated on the eastern side of the subsiding areas and associated with normal faulting (late Oligocene–early Miocene). They constituted new loads that could also have been responsible for minor but widespread lithospheric subsidence. The development of the local and regional uplifts explains the basin evolution toward shallow, dominantly conglomeratic deposits and its final emergence at the end of the middle Miocene. This trend toward emersion is emphasized by the late Miocene global sea-level fall. The MHB was subsequently overprinted by neotectonic deformation associated with the development of a continental basin (Ptolemais) and uplift attributed to the evolution of the Olympos structure that developed further east as the underthrusting moved in this direction. These results demonstrate that the Meso-Hellenic Basin evolves as a large scale piggyback Basin and that its sedimentary infill is largely controled by tectonic activity rather than only eustatic sea-level variations.
Bathymetric map of the NE Atlantic Ocean and Bay of Biscay: kinematic implications
Authors: Sibuet Jean-Claude , Monti Serge , Loubrieu Benoît , Mazé Jean-Pierre , Srivastava Shiri
Published: June 2005

The new bathymetric map of the Bay of Biscay and Northeast Atlantic Ocean is based on available conventional and swath bathymetric data. It extends from the European coast to the mid-Atlantic ridge in longitude and from the Azores-Gibraltar fracture zone to 50°N in latitude. Grid spacing is 1 km. The map is in Mercator projection at a 1/2,400,000 scale (41°N latitude). With respect to previously published maps, the detailed morphology of the Eurasian and Iberian continental margins is now well established. In addition, we have mapped the two fossil trajectories of the Bay of Biscay triple junction, which limit the western extension of the Bay of Biscay sensu stricto.

The Bay of Biscay and Northeast Atlantic Ocean opened simultaneously, between chrons M0 (118 Ma) and 33o (80 Ma). A triple junction existed during that period. Fossil triple junctions trajectories on each of the three Eurasia (EU), Iberia (IB) and North America (NA) plates separate oceanic domains which were formed between the three plate pairs : IB/EU for the Bay of Biscay, EU/NA and IB/NA for the northern and southern portions of the Northeast Atlantic respectively. On each side of the fossil trajectories, rift directions formed between different plate pairs display different azimuths. The three triple junction branches have been identified on the basis of magnetic, seismic and bathymetric data. They are generally associated with a basement ridge which generally appears in the youngest parts of triple junction branches. The intersections of fossil trajectories with the base of the continental margins correspond to conjugate points before the opening of the Bay of Biscay, giving an additional independent constraint for plate reconstructions at M0 time. In addition, rotations of Iberia as deduced from plate kinematic reconstructions at chrons A33o (80 Ma), M0 (118 Ma) and M25 (156.5 Ma), fit with those derived from paleomagnetic declination data of the stable Iberia with respect to EU. The identification of chrons M0 and M3 (125 Ma) in the Bay of Biscay implies that the northern Bay of Biscay margin rifting episode ended in lowermost Cretaceous instead of late Aptian as currently admitted in the litterature. The duration of the rifting episode is reduced to about 20 Ma, as it has been already suggested for the Iberian Abyssal Plain margin [Wilson et al., 2001].
Quaternary calc-alkaline and alkaline volcanism in an hyper-oblique convergence setting, central Myanmar and western Yunnan
Authors: Maury René C. , Pubellier Manuel , Rangin Claude , Wulput Laurence , Cotten Joseph , Socquet Anne , Bellon Hervé , Guillaud Jean-Philippe , Htun Hla Myo
Published: June 2005

Quaternary to recent volcanic centres located in Central Myanmar basin and in western Yunnan (Tengchong rift) display contrasted geochemical signatures. Mt. Popa lavas range in composition from calc-alkaline to potassic calc-alkaline and derive from partial melting of a subduction-modified mantle. The Monywa Holocene maars are made up of absarokites thought to result from low degrees of melting of a similar source. The Tengchong rift potassic calc-alkaline andesites and dacites also display typical subduction-related imprints. On the contrary, the geochemical signature of the Singu alkaline mafic basaltic trachyandesites which are offset by the Sagaing Fault suggests that they derive from the melting of deep enriched intraplate-type mantle, similar to the source of common Plio-Quaternary alkali basalts and related rocks from the Sundaland.

The origin of this uncommon spatial and temporal magmatic association is connected to an unusual tectonic setting of hyper-oblique convergence. The collision between India and the Sundaland is marked by shear partitioning within Myanmar, a significant part of the right lateral motion being accommodated by the Sagaing Fault. Rapid uprise of high temperature alkaline magmas derived from the melting of enriched Sundaland-type mantle and channelled by Neogene fault planes parallel to the Sagaing Fault led to the emplacement of the Singu lavas. Active subduction of the Gulf of Bengal oceanic lithosphere resulted in the development of a Wadati-Benioff plane located 100 to 140 km beneath Mt. Popa and Monywa. The dehydration of this slab led to metasomatism and subsequent melting of the Central Myanmar mantle wedge, and finally to the emplacement of calc-alkaline and shoshonitic magmas in those volcanoes. The origin of the subduction-related signature of the Tengchong lavas has to be related to an older subduction event.
Use of close-range photogrammetry to characterize fracture surfaces
Authors: Filipe Frédéric , Sausse Judith
Published: June 2005

Natural fractures are characterized by rough surfaces and complex fluid flows. A large distribution of apertures (residual voids) within their walls and the presence of contact points produce heterogeneous flows (channelling). The resulting permeabilities, porosities or fluid-rock exchange surfaces cannot be realistically modelled by parallel and smooth plate models. It is therefore very important to better constrain models of the fracture planes : asperity heights and aperture distribution to be able to fix specific models of permeability in specific fracture void geometry. In this approach, a precise description of the fracture surface planes is given by providing some new quantitative data of surface roughness in the case of natural fractures. Studied fractures are sampled in a granite and a sandstone in the deep basement of the Hot Dry Rock site of Soultzsous-Forêts (Bas-Rhin, France). An original use of close-range photogrammetry is performed to quantify XYZ data on fracture walls. This methodology is presented as a non destructive, precise and accurate technology to quantify some digital terrain models (DTM) of the fracture plane topography. XYZ results are statistically treated in terms of surface roughness and tortuosity and are compared for different rocks to previous data obtained by mechanical profilometry. The results shows that the photogrammetric approach gives same order of asperity heights magnitudes as profilometry despite a shift towards more important values of roughness when close range photogrammetry uses relative autocorrelation models. The advantage of photogrammetry is that this technique gives very quick results and is non destructive when thin alteration or pulverulent deposits are present within fracture walls or in the rock matrix. The disadvantage is that a slight smoothing of data is inherent to an absolute model calibration. Finally only relative 300*300 DTM are finally chosen to match profilometry data because of their higher precision in terms of micro roughness description to compare natural fracture surfaces. In the objective of a classification of fracture roughness in specific geological contexts, the photogrammetric approach gives a good estimation of different classes of roughness in function of rock alteration and type.
A giant pterosaur from the Lower Cretaceous of the eastern Paris Basin
Authors: Buffetaut Eric
Published: June 2005

A large pterosaur bone, preserved as a natural cast of the interior cavity, was found in an old collection kept at the Natural History Museum of Troyes (France). Although no precise geographical data are available, the lithology of the matrix indicates that it comes from the Hauterivian Toxaster Limestone of the eastern Paris Basin. Despite its unusual preservation, the specimen shows various morphological details, and is identified as an ornithocheiroid pterosaur humerus. This specimen is among the largest known pterosaur humeri (length as preserved: 345 mm), indicating a wing span of more than 7 metres. It shows that giant pterosaurs had already appeared at a very early stage in the Cretaceous.
Statistical analysis of the volcanic eruption frequency in the azores islands : a contribution to risk assessment
Authors: Caniaux Guy
Published: June 2005

The datations of the last eruptive events which have occurred on 13 active volcanic complexes of the Azores are presented. By supposing that these events follow a statistical Poisson distribution, we estimate the occurrence period of these events, as well as the eruption probabilities for the next 300 years. Pico Mountain, Região dos Picos (São Miguel Island), the stratovolcano of Sete Cidades (São Miguel Island), the linear volcanic complexes of São Roque – Piedade (Pico Island) and of Capelo (Faial Island) must be considered as the most active volcanoes of the archipelago. The eruption styles of next eruptions are also specified.
The ammonite fauna renewal at the boundary middle–late Toarcian: new data and consequences
Authors: Becaud Marc , Rulleau Louis , Elmi Serge
Published: June 2005

Several proposals have been made concerning the Toarcian informal substages. A three part division, here adopted, includes a Middle Toarcian encompassing the Bifrons and Variabilis ammonite zones, according to the definition well established by Monestier [1921]. Other authors, following Buckman [1888], admit a binary definition but with different meanings. The boundary is placed either below the Variabilis (Lower / Upper Toarcian limit), or below the Thouarsense zones (“Whitbian”–“Yeovilian” limit) [Howarth, 1992]. These differences are largely due to a strong sedimentary instability: condensations, gaps and faunal mixings were widespread during the Variabilis zone in NW Europe and eurocaucasian domain and its Tethyan equivalent, the Gradata zone. Contemporarily, a major renewal occurred in the ammonite faunas. This provoked a near general segregation that is the reason of the use of different zone standards.

In NW Europe, the faunal renewal occurred during the Variabilis zone as it as been established in the stratotype localities of Poitou and Vendée (Poitou – Vendée) [Gabilly, 1973, 1976a]. This is also well known in the Causses [Guex, 1972, 1975]. These two areas give good reference sections for the ammonite succession at the top of the Middle Toarcian. These data have been supplemented by recent works concerning NW Europe as well as the Tethyan margins (Portugal, Betics, Morocco, Algeria, Apennines). New observations have also been realized in France (Poitou-Vendée, Causses, Lyon area). They allow to have a better knowledge of the development of the faunal renewal and of the appearance of new taxa (genus, sub and superfamilies). Special attention is given to the Phymatoceratids, Grammoceratids and Hammatoceratoids.

In consequence, the main renewal did not happened at the end of the Middle Toarcian (end of the Variabilis zone) but sooner at the beginning of the Illustris subzone. New ammonite morphologies appeared that will dominate the assemblages at the beginning of the late Toarcian (Grammoceratinids) and that will be at the origin of the main Middle Jurassic assemblages (Hammatoceratids). Among the species from the Illustris subzone, some are good markers for the correlations between the faunal domains and provinces (“Pseudogrammoceras” aratum Buck., “Pseudogrammoceras” subregale Pinna, “Geczyceras” costatum (Gab.), Osperleioceras (Pseudopolyplectus) bicarinatum (Ziet.)).

It appears that the difficulties to place the Middle–Upper Toarcian limit result closely of the sedimentary perturbations that happened in Europe from the west to the eurocaucasian domains and in the whole western Tethys. The substage problem is secondary as stated by Gabilly but it is convenient for long range comparisons. The main units to establish the correlations are the biostratigraphic zones (biozones). In such a matter, the Variabilis zone is of particular importance, according to the coeval sedimentary and palaeontologic events.
Late Maastrichtian and K/T paleoenvironment of the eastern Tethys (Israel): mineralogy, trace and platinum group elements, biostratigraphy and faunal turnovers
Authors: Adatte Thierry , Keller Gerta , Stüben Doris , Harting Markus , Kramar Utz , Stinnesbeck Wolfgang , Abramovich Sigal , Benjamini Chaim
Published: June 2005

The late Maastrichtian to early Danian at Mishor Rotem, Israel, was examined based on geochemistry, bulk rock and clay mineralogies, biostratigraphy and lithology. This section contains four red clay layers of suspect impact or volcanic origin interbedded in chalk and marly chalks. PGE anomalies indicate that only the K/T boundary red layer has an Ir dominated PGE anomaly indicative of an impact source. The late Maastrichtian red clays have Pd dominated PGE anomalies which coincide with increased trace elements of terrigenous and volcanogenic origins. Deccan or Syrian-Turkey arc volcanism is the likely source of volcanism in these clay layers. Glauconite, goethite and translucent amber spherules are present in the clay layers, but the Si-rich spherules reported by Rosenfeld et al. [l989] could not be confirmed. The absence of Cheto smectite indicates that no altered impact glass has been present. The red layers represent condensed sedimentation on topographic highs during sea level highstands. In the Negev area, during the late Maastrichtian, the climate ranged from seasonally wet to more arid conditions during zones CF3 and CF2, with more humid wet conditions in the latest Maastrichtian zone CF1 and in the early Danian, probably linked to greenhouse conditions. Planktic foraminifera experienced relatively high stress conditions during this time as indicated by the low species richness and low abundance of globotruncanids. Times of intensified stress are indicated by the disaster opportunist Guembelitria blooms, which can be correlated to central Egypt and also to Indian Ocean localities associated with mantle plume volcanism. Marine plankton thus support the mineralogical and geochemical observations of volcanic influx and reveal the detrimental biotic effects of intense volcanism.
A New Way to Use Solid‐State Carbon‐13 Nuclear Magnetic Resonance Spectroscopy to Study the Sorption of Organic Compounds to Soil Organic Matter
Authors: Smernik Ronald J.
Published: June 2005

Several solid‐state 13C nuclear magnetic resonance (NMR) techniques were used to characterize soil organic matter spiked with 13C‐labeled organic compounds spanning a range of hydrophobicities (benzoic acid, benzophenone, naphthalene, phenanthrene, and palmitic acid). The chemical shifts of NMR resonances of the sorbed species were shifted by up to 3 ppm relative to those of the neat compounds. Sorption also resulted in increased resonance linewidth for the compounds containing a single 13C label, indicating the presence of a range of different chemical environments at the sites of sorption. On the other hand, sorption decreased the linewidth of the resonance of naphthalene, which was uniformly 13C‐labeled. This was attributed to the removal of intermolecular 13C–13C dipolar coupling. Heterogeneity of the organic matter was demonstrated using the spectral editing technique proton spin relaxation editing (PSRE), which enabled the identification and quantification of charcoal‐rich domains characterized by rapid rates of proton spin–lattice relaxation in the static frame (T1H), and humic domains characterized by slow rates of T1H relaxation. Furthermore it was demonstrated that the sorbed 13C‐labeled molecules “inherit” the T1H “signature” of the organic matrix in their immediate vicinity. Thus PSRE on the spiked soils enabled evaluation of the relative affinity of the two domain types for the sorbate molecules. The charcoal‐rich domains were shown to have a twofold to tenfold greater affinity for the organic compounds, with greater differences found for the more hydrophobic compounds.
Accelerated Soil Dissipation of Tebuconazole following Multiple Applications to Peanut
Authors: Potter Thomas L. , Strickland Timothy C. , Joo Hyun , Culbreath Albert K.
Published: June 2005

Repeated application may increase rates of pesticide dissipation in soil and reduce persistence. The potential for this to occur was investigated for the fungicide, tebuconazole (α‐[2‐(4‐chlorophenyl)ethyl]‐α‐(1,1‐dimethylethyl)‐1H‐1,2,4‐triazole‐1‐ethanol), when used for peanut (Arachis hypogaea L.) production. Soil samples were collected from peanut plots after each of four tebuconazole applications at 2‐wk intervals. Soil moisture was adjusted to field capacity as necessary and samples were incubated in the laboratory for 63 d at 30°C. Untreated plot samples spiked with the compound served as controls. Results indicated accelerated dissipation in field‐treated samples with the time to fifty percent dissipation (DT50) decreasing from 43 to 5 d after three tebuconazole applications. Corresponding increases in rates of accumulation and decay of degradates were also indicated. Best‐fit equations (r2 = 0.84–0.98) to dissipation kinetic data combined with estimates of canopy interception rates were used to predict tebuconazole and degradates concentration in soil after each successive application. Predicted concentrations compared with values measured in surface soil samples were from twofold less to twofold greater. Use of kinetic data will likely enhance assessments of treatment efficacy and human and ecological risks from normal agronomic use of tebuconazole on peanut. However, the study indicated that varying soil conditions (in particular, soil temperature and water content) may have an equal or greater impact on field dissipation rate than development of accelerated dissipation. Results emphasize that extension of laboratory‐derived kinetic data to field settings should be done with caution.
Vadose Zone Clays and Water Content beneath Wet and Dry Canyons of the Pajarito Plateau, New Mexico
Authors: Vaniman D. , Broxton D. , Chipera S.
Published: June 2005

Clay mineralogy in the vadose zone at Los Alamos National Laboratory (LANL), situated on the Pajarito Plateau of northern New Mexico, differs significantly beneath wet and dry canyons. Drainage across LANL is generally from west to east and feeds into the Rio Grande along the eastern margin of the plateau. Canyons with headwaters in the Sierra de los Valles west of the plateau support more flow and are wetter than canyons with headwaters on the plateau. Los Alamos Canyon, one of the wetter canyons, has extensive clay alteration to depths >30 m in the subcanyon vadose zone. Mortandad Canyon, one of the drier canyons, has less clay alteration. Hydraulic property data for the Otowi Member of the Bandelier Tuff, one of the most widespread lithologies of the plateau, indicate that zones of high clay abundance have hydraulic transmissivities (Ksat) one to two orders of magnitude lower than less altered tuff (∼10−4 vs. 10−2 to 10−3 cm/s). Occurrences of halloysite, and perhaps kaolinite, indicate zones where the water/rock ratio is or has been high within the vadose zone. Gravimetric water content data collected at 110°C from vadose zone rocks with low to moderate clay content provide water abundance data for matrix flow calculations. These data may be in error by up to ∼5 to 16% because some of the water measured is actually held in clay interlayers rather than in pore spaces; such errors are minor but should be considered in the use of gravimetric moisture data. The use of electrical methods to explore for vadose wet zones is valid on the Pajarito Plateau as long as the results are treated broadly, with the understanding that some intervals of high conductivity are not entirely related to either movable water content or clay abundance.
The multispecies microbial cluster of Fusobacterium, Parvimonas, Bacteroides and Faecalibacterium as a precision biomarker for colorectal cancer diagnosis
Authors: Conde‐Pérez Kelly , Aja‐Macaya Pablo , Buetas Elena , Trigo‐Tasende Noelia , Nasser‐Ali Mohammed , Rumbo‐Feal Soraya , Nión Paula , Arribas Elsa Martín‐De , Estévez Lara S. , Otero‐Alén Begoña , Noguera José F. , Concha Ángel , Pardiñas‐López Simón , Carda‐Diéguez Miguel , Gómez‐Randulfe Igor , Martínez‐Lago Nieves , Ladra Susana , Aparicio Luis M. A. , Bou Germán , Mira Álex , Vallejo Juan A. , Poza Margarita
Published: February 2024

The incidence of colorectal cancer (CRC) has increased worldwide, and early diagnosis is crucial to reduce mortality rates. Therefore, new noninvasive biomarkers for CRC are required. Recent studies have revealed an imbalance in the oral and gut microbiomes of patients with CRC, as well as impaired gut vascular barrier function. In the present study, the microbiomes of saliva, crevicular fluid, feces, and non‐neoplastic and tumor intestinal tissue samples of 93 CRC patients and 30 healthy individuals without digestive disorders (non‐CRC) were analyzed by 16S rRNA metabarcoding procedures. The data revealed that Parvimonas, Fusobacterium, and Bacteroides fragilis were significantly over‐represented in stool samples of CRC patients, whereas Faecalibacterium and Blautia were significantly over‐abundant in the non‐CRC group. Moreover, the tumor samples were enriched in well‐known periodontal anaerobes, including Fusobacterium, Parvimonas, Peptostreptococcus, Porphyromonas, and Prevotella. Co‐occurrence patterns of these oral microorganisms were observed in the subgingival pocket and in the tumor tissues of CRC patients, where they also correlated with other gut microbes, such as Hungatella. This study provides new evidence that oral pathobionts, normally located in subgingival pockets, can migrate to the colon and probably aggregate with aerobic bacteria, forming synergistic consortia. Furthermore, we suggest that the group composed of Fusobacterium, Parvimonas, Bacteroides, and Faecalibacterium could be used to design an excellent noninvasive fecal test for the early diagnosis of CRC. The combination of these four genera would significantly improve the reliability of a discriminatory test with respect to others that use a single species as a unique CRC biomarker.
Oleanolic acid alleviates obesity‐induced skeletal muscle atrophy via the PI3K/Akt signaling pathway
Authors: Sun Yaqin , Wei Xiaofang , Zhao Tong , Shi Hongwei , Hao Xiaojing , Wang Yue , Zhang Huiling , Yao Zhichao , Zheng Minxing , Ma Tianyun , Fu Tingting , Lu Jiayin , Luo Xiaomao , Yan Yi , Wang Haidong
Published: February 2024

Oleanolic acid (OA) is a pentacyclic triterpene with reported protective effects against various diseases, including diabetes, hepatitis, and different cancers. However, the effects of OA on obesity‐induced muscle atrophy remain largely unknown. This study investigated the effects of OA on skeletal muscle production and proliferation of C2C12 cells. We report that OA significantly increased skeletal muscle mass and improved glucose intolerance and insulin resistance. OA inhibited dexamethasone (Dex)‐induced muscle atrophy in C2C12 myoblasts by regulating the PI3K/Akt signaling pathway. In addition, it also inhibited expression of MuRF1 and Atrogin1 genes in skeletal muscle of obese mice suffering from muscle atrophy, and increased the activation of PI3K and Akt, thereby promoting protein synthesis, and eventually alleviating muscle atrophy. Taken together, these findings suggest OA may have potential for the prevention and treatment of muscle atrophy.
Institute for Artificial Intelligence and Fundamental Interactions (IAIFI): Infusing physics intelligence into artificial intelligence
Authors: Thaler Jesse , Williams Mike , LaFleur Marisa
Published: February 2024

The NSF AI Institute for Artificial Intelligence and Fundamental Interactions (IAIFI, pronounced /aI‐faI/) is one of the inaugural NSF AI research institutes (https://iaifi.org). The IAIFI is enabling physics discoveries and advancing foundational AI through the development of novel AI approaches that incorporate first principles from fundamental physics. By combining state‐of‐the‐art research with early career talent and a growing AI + physics community in the Boston area and beyond, the IAIFI is enabling researchers to develop AI technologies to tackle some of the most challenging problems in physics, and transfer these technologies to the broader AI community. Since trustworthy AI is as important for physics discovery as it is for other applications of AI in society, IAIFI researchers are applying physics principles to develop more robust AI tools and to illuminate existing AI technologies. To cultivate human intelligence, the IAIFI promotes training, education, and public engagement at the intersection of physics and AI. In these ways, the IAIFI is fusing deep learning with deep thinking to gain a deeper understanding of our universe and AI.
Molecule Maker Lab Institute: Accelerating, advancing, and democratizing molecular innovation
Authors: Burke Martin D. , Denmark Scott E. , Diao Ying , Han Jiawei , Switzky Rachel , Zhao Huimin
Published: February 2024

Many of the greatest challenges facing society today likely have molecular solutions that await discovery. However, the process of identifying and manufacturing such molecules has remained slow and highly specialist dependent. Interfacing the fields of artificial intelligence (AI) and synthetic organic chemistry has the potential to powerfully address both limitations. The Molecule Maker Lab Institute (MMLI) brings together a team of chemists, engineers, and AI‐experts from the University of Illinois Urbana‐Champaign (UIUC), Pennsylvania State University, and the Rochester Institute of Technology, with the goal of accelerating the discovery, synthesis and manufacture of complex organic molecules. Advanced AI and machine learning (ML) methods are deployed in four key thrusts: (1) AI‐enabled synthesis planning, (2) AI‐enabled catalyst development, (3) AI‐enabled molecule manufacturing, and (4) AI‐enabled molecule discovery. The MMLI's new AI‐enabled synthesis platform integrates chemical and enzymatic catalysis with literature mining and ML to predict the best way to make new molecules with desirable biological and material properties. The MMLI is transforming chemical synthesis and generating use‐inspired AI advances. Simultaneously, the MMLI is also acting as a training ground for the next generation of scientists with combined expertise in chemistry and AI. Outreach efforts aimed toward high school students and the public are being used to show how AI‐enabled tools can help to make chemical synthesis accessible to nonexperts.
Generative AI: An AI paradigm shift in the making?
Authors: Miikkulainen Risto
Published: February 2024

It is sometimes difficult to evaluate progress in Generative AI, that is, image generation and large language models. This may be because they represent a paradigm shift in AI, and the traditional ways of developing, evaluating, understanding, and deploying AI systems no longer apply. Instead, we need to develop new such approaches, possibly by extending those currently in use in cognitive neuroscience and psychology. In this manner, a new AI paradigm can be created, providing a significant leap in AI research and practice.
Minimally conscious state plus versus minus: Likelihood of emergence and long‐term functional independence
Authors: Llorens Roberto , Ippoliti Camilla , Navarro María Dolores , Colomer Carolina , Maza Anny , Goizueta Sandra , Olaya José , Moliner Belén , Ferri Joan , Noé Enrique
Published: February 2024

Objective

Severe brain injuries can result in disorders of consciousness, such as the Minimally Conscious State (MCS), where individuals display intermittent yet discernible signs of conscious awareness. The varied levels of responsiveness and awareness observed in this state have spurred the progressive delineation of two subgroups within MCS, termed “plus” (MCS+) and “minus” (MCS‐). However, the clinical validity of these classifications remains uncertain. This study aimed to investigate and compare the likelihood of emergence from MCS, as well as the functional independence after emergence, in individuals categorized as in MCS+ and MCS‐.

Methods

Demographic and behavioral data of 80 participants, admitted as either in MCS+ (n = 30) or MCS‐ (n = 50) to a long‐term neurorehabilitation unit, were retrospectively analyzed. The neurobehavioral condition of each participant was evaluated weekly until discharge, demise, or emergence from MCS. The functional independence of those participants who emerged from MCS was assessed 6 months after emergence.

Results

While only about half of the individuals classified as in MCS‐ (n = 24) emerged from the MCS, all those admitted as in MCS+ did, and in a shorter postinjury period. Despite these differences, all individuals who emerged from the MCS demonstrated similar high disability and low functional independence 6 months after emergence, regardless of their state at admission.

Interpretation

Individuals classified as MCS+ exhibited a higher likelihood of emergence and a shorter time to emergence compared to those in MCS‐. However, the level of functional independence 6 months after emergence was found to be unrelated to the initial state at admission.
Tunable Electromagnetic Performance of Pt–Si–O Films in Mid‐Infrared and Microwave Spectrums
Authors: Luo Haojie , Fan Xiaomeng , Li Xin , Ye Fang , Xue Jimei
Published: February 2024

Electromagnetic performance regulation in mid‐infrared (MIR) and microwave (MW) spectrums is crucially significant, which can be achieved by heterophase introduction and structural manufacturing. In this work, Si‐O amorphous phase is introduced into Pt film by magnetron co‐sputtering technique, the film thickness is optimized by adjusting deposition time. After annealing treatment, a double‐layered structure is constructed with the migration and growth of Pt crystals, in which the lower layer is composed of Pt coarse grains while the upper layer is Si‐O amorphous phase with embedded Pt fine grains. Furthermore, due to the thickness difference, diverse kinds of structural patterns (arrays or mesh) can be obtained with the solid‐state dewetting of the lower layer. According to the increasing thickness, the infrared emissivity can decrease from 0.67 to 0.25 (8–14 μm), demonstrating a great decline of apparent temperature of 162.9 °C when the background is 300 °C. And the microwave transmissivity also exhibits tremendous variation over 90% (from 96% to 5%), realizing the transformation from transmitting to shielding.