Miracle-dz/UniFAR-FTUs huggingface dataset:
Simultaneous in situ determination of U‐Pb and Sm‐Nd isotopes in monazite by laser ablation ICP‐MS

Results are presented for in situ simultaneous determination of U‐Pb and Sm‐Nd isotopes in monazite using the Laser Ablation Split‐Stream (LASS) method. This method uses a laser ablation system coupled to a magnetic‐sector inductively coupled plasma mass spectrometer (HR) (ICP‐MS) for measuring U‐Pb isotopes and a multicollector (MC) ICP‐MS for measuring Sm‐Nd isotopes. Ablated material is split using a Y‐connector and transported simultaneously to both mass spectrometers. In addition to Sm and Nd isotopes, the MC‐ICP‐MS is configured to also acquire Ce, Nd, Sm, Eu, and Gd elemental abundances. This approach provides age, tracer isotope, and trace element data in the same ablation volume, reducing sampling problems associated with fine‐scale zoning in accessory minerals and minimizing the material needed for ablation. Precision and accuracy of the U‐Pb method (and the precision of the Sm‐Nd method) is demonstrated with results from well‐characterized monazite reference materials. The LASS results agree within uncertainty with the isotope dilution thermal ionization mass spectrometry (ID‐TIMS) U‐Pb dates. The accuracy of the Sm‐Nd method is assessed by comparing the LA‐MC‐ICP‐MS results with ID‐TIMS determinations on a well‐characterized, in‐house monazite reference material. The LASS method is then applied to monazite from the Birch Creek Pluton in the White Mountains of California as a case study to illustrate the utility of this method for solving geologic problems. The U‐Pb ages and Sm‐Nd isotopic data from the LASS method support the conclusions drawn from previous results that monazite can record timing and information about the source region(s) of hydrothermal fluids.
Sedimentary fill of the Chile Trench (32–46°S): volumetric distribution and causal factors

The Chile Trench of the convergent continental margin of Central Chile is a sediment-filled basin that stretches over 1500 km in a north–south direction. The sediment fill reflects latitudinal variations in climate as well as in the morphology and geology of Chile, but also of sediment transport processes to the trench and within the trench. We try to untangle these signals by calculating the total volume and the latitudinal volume distribution of trench sediments and by relating this distribution to a number of factors that affect this pattern. The volume calculation is based on a model geometry of the top of the subducting oceanic plate that is buried beneath trench sediments and the sea floor as measured by swath bathymetry. We obtain the model geometry of the subducting plate by interpolating between depth-converted seismic reflection profiles that cross the trench. The total volume of the trench fill between 32 and 46°S is calculated to be 46000 ± 500 km3. The resulting latitudinal volume distribution is best explained by a sedimentation model that alternates between (1) glacial phases of high sediment flux from Southern Chile combined with active latitudinal sediment transport within the trench and (2) interglacial phases over which sediment input is dominated by local factors. Supplementary material: Top of the oceanic basement (TOB) grid is available as ascii raw data files (xyz) at www.geolsoc. org.uk/SUP18664.
Cyclonic Brine-Flow Pattern Recorded by Oriented Gypsum Crystals in the Badenian Evaporite Basin of the Northern Carpathian Foredeep

Abstract In the middle Miocene (Badenian), within sulfate evaporites formed in the northern Carpathian Foredeep basin of Poland, Ukraine, and the Czech Republic, the apices of the primary, bottom-grown gypsum crystals (selenites) are similarly aligned over broad areas and have a common azimuth. This crystal orientation is interpreted as the product of a consistent direction of a brine inflow during gypsum crystallization, and such a unique commonality is used as a tool for paleocurrent analysis in order to recognize both the local and the regional brine paleocurrents in the basin. Earlier sedimentologic and stratigraphic studies proved that these beds of oriented selenites were deposited at the same or nearly the same time, in a brine not more than a few meters deep. It is interpreted that the oriented selenites recorded only the mean flow within the basin, mainly from the periods of mixing (in the dry-season lowstands), when the whole brine column down to the bottom was Ca-sulfate oversaturated. The measured paleocurrent vectors showed that the brines flowed along the marginal zone of the Carpathian Foredeep basin predominantly in a counterclockwise direction. This longshore flow is interpreted as a typical cyclonic circulation analogous to those present in recent lakes and semi-closed basins in the northern hemisphere where counterclockwise mean water drift is directly or indirectly forced by Earth rotation (the Coriolis effect). The detected brine flow directions do not reflect downslope gravity flow of dense brines into the central basinal depths or subbasins that were filling with the halite facies.
Debris‐flood reconstruction in a pre‐alpine catchment in switzerland based on tree‐ring records of coniferous and broadleaved trees

Bollschweiler, M. , Stoffel, M. and Schläppy, R. , 2011. Debris‐flood reconstruction in a pre‐alpine catchment in Switzerland based on tree‐ring records of coniferous and broadleaved trees. Geografiska Annaler Series A, 93, 1–15. Abstract Past debris‐flood activity on the forested fan of Torrent de la Greffe located in the Swiss Prealps was assessed from growth disturbances in coniferous and broadleaved tree species. The study of 186 tree‐ring sequences sampled from 44 Norway spruce (Picea abies (L.) Karst. ) and 55 broadleaved trees from various species affected by past activity and the sampling of an additional 49 trees for the reference chronology allowed the reconstruction of 17 debris‐flood events since AD 1900. The spatial analysis of trees affected during particular events on the geomorphic map helped the identification of five breakout locations in the torrent and affected sectors on the fan. The coupling of tree‐ring analysis of coniferous and broadleaved tree species proved to be a valuable tool for the reconstruction of past events. Debris‐flood frequency in the investigated torrent (0.16 event yr‐1) is considerably lower than the frequencies reconstructed in most other catchments in the Swiss Alps. As material for the entrainment of debris floods is not always readily available, the torrent has to be seen as supply‐limited.
Delineation of Paleowind Direction from Dunes in Simcoe County, Ontario

Dune fields that developed along paleolake shorelines in Ontario are a product of paleoenvironmental conditions, which developed as a result of glacially influenced geological processes. In Simcoe County, Ontario, many dune fields were created between 3 and 12 ka, when this area was covered by a series of lakes, bordered by thick sandy beaches. Coastal sediments of the glacial Lake Algonquin and the Nipissing phase of the upper Great Lakes were reworked primarily by paleowind activity and intense periodic storms once lake levels had decreased. This formed dunes, which are now common along the south-eastern coast of Georgian Bay in Simcoe County. Dunes that developed earlier (8–10 ka) have a different average orientation than dunes that developed later (3–5 ka). Various geomorphometric techniques are tested to construct a replicable methodology for determining paleowind direction. Through identification of parabolic dunes, azimuth angles were determined and used to infer the dominant paleowind directions. Dunes on the paleolake Algonquin plain commonly have a north-east to south-west orientation, whereas dunes associated with Nipissing phase shorelines formed via north-westerly winds. These data may suggest changing prevailing winds in the Great Lakes region during deglaciation.Les champs de dunes qui se sont développés le long des rives du paléolac en Ontario sont le produit de conditions paléoenvironnementales nées en raison de processus géologiques d’influence glaciaire. Dans le comté de Simcoe, en Ontario, de nombreux champs de dunes ont été créés entre 3 et 12 ka, lorsque la région était couverte d’une série de lacs, bordés par d’épaisses plages sablonneuses. Les sédiments côtiers du lac Algonquin et de la phase Nipissing du haut des Grands Lacs ont été retravaillés surtout par l’activité du paléovent et d’intenses tempêtes périodiques lorsque les niveaux des lacs ont baissé. Il en a résulté la formation de dunes, qui sont désormais répandues le long de la côte sudest de la baie Georgienne dans le comté de Simcoe. Les dunes qui se sont formées antérieurement (8 à 10 ka) affichent une orientation moyenne différente de celles qui se sont développées ultérieurement (3 à 5 ka). Diverses techniques géomorphométriques sont mises à l’essai pour élaborer une méthodologie reproductible afin de déterminer la direction du paléovent. Par l’identification des dunes paraboliques, les angles azimutaux ont été déterminés et ont servi à établir par inférence les directions du paléovent dominant. Les dunes de la plaine du paléolac Algonquin offrent généralement une orientation nord-est à sud-ouest, tandis que les celles associées aux rives de la phase Nipissing se sont formées grâce aux vents nord-ouest. Ces données peuvent laisser conclure à un changement des vents dominants dans la région des Grands Lacs pendant la déglaciation.
Late Paleoproterozoic to Early Mesoproterozoic Tangdan Sedimentary Rock-Hosted Strata-bound Copper Deposit, Yunnan Province, Southwest China

Sedimentary rock-hosted strata-bound copper deposits are widespread in the Kangdian region of the Central Yunnan and southern Sichuan provinces, southwest China. The deposits occur within weakly metamorphosed rocks of the late Paleoproterozoic to early Mesoproterozoic Dongchuan Group and are spatially associated with discordant breccia bodies that are interpreted as having formed from salt diapirs. The Tangdan deposit, the largest in the region, consists of stratiform and discordant orebodies predominantly hosted in dolostones immediately above hematitic sandstones and siltstones and in black shales above the dolostones. Host rocks for the deposit display a complex paragenetic sequence of alteration and mineralization. Early sodic alteration resulted in the growth of both albite and ferroan dolomite. Later potassic alteration resulted in the precipitation of potassium feldspar and locally biotite in argillaceous layers. Sulfide mineralization was temporally and spatially associated with silicification that postdated both sodic and potassic alteration. Textures suggest that silicification may have preferentially affected evaporite minerals in the dolostones. Copper sulfides form bedding-parallel disseminations, veinlets and, to a lesser extent, stockworks. Copper sulfides are dominated by chalcopyrite with lesser bornite and chalcocite. Hypogene chalcopyrite and bornite from the Tangdan deposit have δ34S values that range from −12.7 to +9.3‰ and cluster between −3 to +5‰. The values suggest derivation from Mesoproterozoic marine sulfates. The dolostone host rocks have relatively homogeneous C and O isotope values ranging from 0.2 to 1.3‰ δ13CV-PDB and from 19.1 to 22.4‰ δ18OV-SNOW. Carbonate minerals in quartz sulfide veins display both a trend toward lighter oxygen isotope values and a trend to significantly lighter carbon isotope values. The light carbon isotope values suggest involvement of organic carbon in the mineralizing process. Alteration and mineralization at Tangdan probably occurred via interaction of oxidized saline brines derived from the underlying red-bed sequence with partially to wholly lithified dolostones. Sulfide precipitation was likely due to both redox reactions and mineralizing fluid pH changes resulting from dolomite and sulfate dissolution. The styles of alteration and mineralization at the Tangdan deposit are similar to those observed in the Central African Copperbelt, particularly the dolostone-hosted orebodies in the Mines Series of the Democratic Republic of Congo.
Acoustic impedance inversion and seismic reflection continuity analysis for delineating gas hydrate resources near the Mallik research sites, Mackenzie Delta, Northwest Territories, Canada

We combine acoustic impedance inversion of 3D seismic data, log-to-seismic correlation, and seismic attribute analyses to de- lineate gas-hydrate zones at the Mallik site, Mackenzie Delta, Northwest Territories, Canada. Well-log data define three dis- tinct hydrate zones over a depth range of 890–1100 m. Synthetic seismic modeling indicates the base of the two deeper hydrate zones are prominent reflectors. The uppermost gas-hydrate zone correlates to seismic data with a lower degree of confidence. The extent and geometry of the two lower hydrate zones suggest that local geology plays a significant role in the lateral and vertical distribution of gas hydrate at Mallik. The reliability of the hy- drate concentrations calculated from the inverted impedances is qualified by the match between original and synthetic seismic data to produce confidence maps for the two lower gas-hydrate- bearing intervals. A total in-place volume estimate of solid gas hydrate for an area of 1.44 km2 around well 5L-38 yields a value of approximately 45 equivalently, 6.6 of gas. We further qualify our mapping of gas hydrates by some amount of continuous resource, defined as lateral continuity measured by seismic attribute similarity and sand-dominated rock. Using these attributes, the continuous amount of hydrate at Mallik is about half the in-place volume. Else- where within the 3D seismic cube, the seismic impedance inver- sion yields evidence of potential gas-hydrate deposits near wells A-06 and P-59 at levels near the predicted base of the hydrate sta- bility zone.
Perspectives on panoramic photography

Digital imaging brings a new set of possibilities to photography. For example, little pictures can be assembled to form a large panorama, and digital cameras are trying to mimic the human visual system to produce better pictures. This manuscript aims at developing the algorithms required to stitch a set of pictures together to obtain a bigger and better image. This thesis explores three important topics of panoramic photography: The alignment of images, the matching of the colours, and the rendering of the resulting panorama. In addition, one chapter is devoted to 3D and constrained estimation. Aligning pictures can be difficult when the scene changes while taking the photographs. A method is proposed to model these changes —or outliers— that appear in image pairs, by computing the outlier distribution from the image histograms and handling the image-to-image correspondence problem as a mixture of inliers versus outliers. Compared to the standard methods, this approach uses the information contained in the image in a better way, and leads to a more reliable result. Digital cameras aim at reproducing the adaptation capabilities of the human eye in capturing the colours of a scene. As a consequence, there is often a large colour mismatch between two pictures. This work exposes a novel way of correcting for colour mismatches by modelling the transformation introduced by the camera, and reversing it to get consistent colours. Finally, this manuscript proposes a method to render high dynamic range images that contain very bright as well as very dark regions. To reproduce this kind of pictures the contrast has to be reduced in order to match the maximum contrast displayable on a screen or on paper. This last method, which is based on a complex model of the human visual system, reduces the contrast of the image while maintaining the little details visible the scene.
A 13C labelling study on carbon fluxes in Arctic plankton communities under elevated CO2 levels

The effect of CO2 on carbon fluxes in Arctic plankton communities was investigated during the 2010 EPOCA mesocosm study in Ny Alesund, Svalbard. Nine mesocosms were set up with initial pCO2 levels ranging from 185 to 1420 μatm for 5 weeks. 13C labelled bicarbonate was added at the start of the experiment to follow the transfer of carbon from dissolved inorganic carbon (DIC) into phytoplankton, bacteria, total particulate organic carbon (POC), zooplankton, and settling particles. Polar lipid derived fatty acids (PLFA) were used to trace carbon dynamics of phytoplankton and bacteria and allowed distinction of two groups of phytoplankton: phyto I (autotrophs) and phyto II (mixotrophs). Nutrients were added on day 13. A nutrient-phytoplankton-zooplankton-detritus model amended with 13C dynamics was constructed and fitted to the data to quantify uptake rates and carbon fluxes in the plankton community during the phase prior to nutrient addition (phase 1, days 0–12). During the first 12 days, a phytoplankton bloom developed that was characterized by high growth rates (0.87 days−1) for phyto I and lower growth rates (0.18 days−1) for phyto II. A large part of the carbon fixed by phytoplankton (~31%) was transferred to bacteria, while mesozooplankton grazed only ~6% of the production. After 6 days, the bloom collapsed and part of the organic matter subsequently settled into the sediment traps. The sedimentation losses of detritus in phase 1 were low (0.008 days−1) and overall export was only ~7% of production. Zooplankton grazing and detritus sinking losses prior to nutrient addition were sensitive to CO2: grazing decreased with increasing CO2, while sinking increased. Phytoplankton production increased again after nutrient addition on day 13. Although phyto II showed initially higher growth rates with increasing CO2 (days 14–22), the overall production of POC after nutrient addition (phase 2, days 14–29) decreased with increasing CO2. Significant sedimentation occurred towards the end of the experiment (after day 24) and much more material settled down in the sediment traps at low CO2.
Viscosity‐depth profile of the Earth's mantle: Effects of polymorphic phase transitions

We study the changes in rheological parameters and effective viscosity across mantle polymorphic phase transitions and the variations of these quantities with temperature and pressure throughout the earth's mantle. The intrinsic activation energy for oxygen ion diffusion in oxides E0* is shown to be systematically related to oxygen ion packing by E0*(kcal/mol) = (187±16) - (3.8±0.8) Vo=(A3), where Vo= is the volume per oxygen ion at zero pressure and 25°C. This relation allows the change in activation energy δE0* across a polymorphic phase transition to be estimated from the associated change in density. Under the assumptions that the activation volume V* remains constant or decreases across a phase transition and that the activation energy for subsolidus creep is equal to the activation energy for O= diffusion, we use δE0* in a general non-Newtonian flow law to estimate the increase in effective viscosity η and the decrease in activation volume V* across a phase transition. By modeling V* and the activation energy by using thermodynamical and mechanical relations for elastic continua and data from seismically derived earth models for relevant elastic parameters, we are able to estimate better the increases in viscosity across polymorphic phase transitions and throughout an adiabatic mantle. Our best models of mantle viscosity have (1) η increasing by less than an order of magnitude across any phase transition, (2) η essentially constant throughout the lower mantle, and (3) η in the lower mantle no more than 2 orders of magnitude greater than η in the upper mantle.
Job satisfaction of Spanish knowledge-based workers: Characterization and determinants

L’objectiu del document de treball es l’analisi de la caracteritzacio i els determinants de la satisfaccio dels treballadors del coneixement a Espanya. Per a realitzar aquesta analisi s’han utilitzat les microdades d’una enquesta representativa (Encuesta de Calidad de Vida en el Trabajo, ECVT) per a 8.061 ocupats el 2010. La satisfaccio en el treball s’ha aproximat a traves de les percepcions declarades pels treballadors, mesurades en una escala de 0 a 10, des d’una total insatisfaccio fins a una completa satisfaccio. S’ha observat que nomes una petita part dels treballadors espanyols estan explicitament insatisfets. Un 61,3% dels treballadors del coneixement reporten nivells de satisfaccio molt elevats (valors de 8 a 10). Un 41,4% dels treballadors menys intensius en coneixement reporten satisfaccio amb la seva feina (valors de 5 a 7). Per a l’analisi dels determinants de la satisfaccio en el treball s’ha utilitzat un model probit ordenat, que suposa una eleccio entre alternatives discretes. L’evidencia obtinguda suggereix que les dimensions financeres i no financeres (organitzacio i intensitat del treball) son les mes importants en la determinacio de la satisfaccio dels treballadors espanyols del coneixement. En concret, aquesta vindria explicada per la satisfaccio amb el salari, el nivell de motivacio, el desenvolupament de la carrera professional, l’avaluacio dels directius, les relacions entre directius i treballadors, i la satisfaccio amb les hores treballades i amb la seguretat de la feina. Finalment, l’estres i els riscos laborals tindrien efectes negatius sobre la satisfaccio dels treballadors del coneixement.
The Last Glaciation in Central Magellan Strait, Southernmost Chile

Abstract Glacial landforms and drift stratigraphy in central Magellan Strait, southernmost Chile, document repeated fluctuations during the last glacial cycle of outlet lobes from an ice cap centered over the southern Andes. The lobes developed comparatively low-gradient profiles because of low basal shear stresses over soft deformable beds and this made them sensitive to even small-scale changes in the mass balance. Such low profiles and rapid calving in deep proglacial lakes during deglaciation may have made the Magellan ice lobe particularly responsive to climatic fluctuations during the last glacial cycle, and to advance and retreat over considerable distances. Study of the glacial landforms and drift stratigraphy has led to the identification of at least five glacier advances to limits at and south of the Segunda Angostura. Fragments of mollusc shells contained in basal till indicate marine incursions between some advances, thus documenting extensive deglaciation. A partial chronology based on amino acid studies and radiocarbon dating suggests that five of these advances occurred during the last glacial cycle. The most extensive advances may have culminated during substages of marine isotope stage 5 (substage 5b or 5d) and/or during stage 4. Slightly less extensive advances occurred between ca. 28,000 and 14,000 yr B.P.
Characteristics and altitudinal distribution of periglacial decay phenomena in the massif of rondane, central norway

Abstract The orwegian massif of ondane is part of the candes ountains and is subject to polar, oceanic and continental influences. Because of its climatic context and its quartzitic structure, the massif has one of the thickest functional periglacial belts in urope (1200 m). This belt is not fixed considering its translation in altitude since the end of the ittle ce ge. This mobility is continuing and involves periglacial decay dynamics which are revealed by numerous and various periglacial forms in the field. Because of their frequency in the massif and also their sensitivity to climate fluctuations, earth patches and small non‐sorted circles have a diagnostic value for current periglacial climate fluctuations. The major aim of this study is to propose several indicators of this periglacial decay and to highlight its consequences on periglacial belt mobility because these landforms enable the delimitation of a critical belt of decay in the massif.