Miracle-dz/UniFAR-FTUs huggingface dataset:
The igneous crystallization history of an ancient Martian meteorite from rare earth element microdistributions

Abstract— Rare earth element (REE) and other selected trace and minor element concentrations were measured in individual grains of orthopyroxene, feldspathic glass (of plagioclase composition) and merrillite of the ALH 84001 Martian meteorite. Unlike in other Martian meteorites, phosphate is not the main REE carrier in ALH 84001. The REE pattern of ALH 84001 bulk rock is dependent on the modal abundances of three REE‐bearing phases, namely, orthopyroxene, which contains most of the heavy rare earth elements (HREEs); feldspathic glass, which dominates the Eu abundances; and merrillite, which contains the majority of the light rare earth elements (LREEs). Variations in the REE abundances previously observed in different splits of ALH 84001 can easily be explained in terms of small variations in the modal abundances of these three minerals without the need to invoke extensive redistribution of LREEs. At least some orthopyroxenes (i.e., those away from contacts with feldspathic glass) in ALH 84001 appear to have preserved their original REE zonation from igneous fractionation. An estimate of the ALH 84001 parent magma composition from that of the unaltered orthopyroxene “core” (i.e., zoned orthopyroxene with the lowest REE abundances) indicates that it is LREE depleted. This implies that the Martian mantle was already partly depleted within ∼100 Ma of solar system formation, which is consistent with rapid accretion and differentiation of Mars. Although equilibration and exchange of REEs between phases (in particular, transport of LREEs into the interstitial phases, feldspathic glass and merrillite) cannot be ruled out, our data suggest that the LREE enrichment in melts “in equilibrium” with these interstitial phases is most likely the result of late‐stage infiltration of the cumulate pile by a LREE‐enriched melt.
An adaptive staggered grid finite difference method for modeling geodynamic Stokes flows with strongly variable viscosity

Here we describe a new staggered grid formulation for discretizing incompressible Stokes flow which has been specifically designed for use on adaptive quadtree‐type meshes. The key to our new adaptive staggered grid (ASG) stencil is in the form of the stress‐conservative finite difference constraints which are enforced at the “hanging” velocity nodes between resolution transitions within the mesh. The new ASG discretization maintains a compact stencil, thus preserving the sparsity within the matrix which both minimizes the computational cost and enables the discrete system to be efficiently solved via sparse direct factorizations or iterative methods. We demonstrate numerically that the ASG stencil (1) is stable and does not produce spurious pressure oscillations across regions of grid refinement, which intersect discontinuous viscosity structures, and (2) possesses the same order of accuracy as the classical nonadaptive staggered grid discretization. Several pragmatic error indicators that are used to drive adaptivity are introduced in order to demonstrate the superior performance of the ASG stencil over traditional nonadaptive grid approaches. Furthermore, to demonstrate the potential of this new methodology, we present geodynamic examples of both lithospheric and planetary scales models.
Vertical distributions and relationships of cloud occurrence frequency as observed by MISR, AIRS, MODIS, OMI, CALIPSO, and CloudSat

Multi‐sensor cloud height observations are investigated and compared in terms of vertical and latitudinal distributions of monthly mean cloud occurrence frequency (COF). Although this study emphasizes the standard Multiangle Imaging SpectroRadiometer (MISR) cloud top height (CTH) retrieval, the strengths and weakness among different passive and active remote sensing techniques with respect to cloud detection and height assessment are also discussed. The standard MISR CTH retrieval is less sensitive to high thin cirrus than the Atmospheric Infrared Sounder (AIRS) and Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), but MISR provides more accurate CTH retrievals in the middle and lower troposphere compared with other passive sensors, especially for clouds in the planetary boundary layer.
Precipitation interception in Australian tropical rainforests: II. Altitudinal gradients of cloud interception, stemflow, throughfall and interception

This article presents a comprehensive study of canopy interception in six rainforests in Australia's Wet Tropics for periods ranging between 2 and 3·5 years. Measurements of rainfall, throughfall, stemflow and cloud interception were made at sites characterized by different forest types, canopy structure, altitude, rainfall and exposure to prevailing winds. Throughfall at these sites ranged between 64 and 83% of total precipitation inputs, while stemflow ranged between 2 and 11%. At sites higher than 1000 m, cloud interception was found to contribute up to 66% of the monthly water input to the forest, more than twice the rainfall at these times. Over the entire study period, cloud interception accounted for between 4 and 30% of total precipitation inputs, and was related more to the exposure of sites to prevailing winds than to altitudinal differences alone.
Geophysical log responses and their correlation with bed‐to‐bed stress contrasts in Paleozoic rocks, Appalachian Plateau, New York

A 1-km profile of in situ stress and geophysical log data was acquired in the Wilkins well to study the relationship between rock properties and in situ stress contrasts. The Wilkins well penetrates Devonian clastic rocks on the Appalachian Plateau near the town of South Canisteo, New York. Open hole hydraulic fracture stress measurements were made in stratigraphic sequences where geophysical logs indicated significant bed-to-bed variations in elastic and lithologic properties. Analysis of stress magnitudes and interval-averaged geophysical data shows that principal horizontal stress magnitudes correlate directly with elastic stiffness and inversely with clay content. A similar relation is found for older Paleozoic strata penetrated by a well at Auburn, New York. Correlations between stress magnitude and geophysical properties observed in the Wilkins and Auburn wells provide strong evidence that bed to bed stress variations arise from a uniform ENE-WSW directed strain acting on beds of different Young's modulus rather than from variations in rock shear strength. Because of their high Young's modulus, sandstones, siltstones, and limestones in the northern Appalachian Basin are likely to be stronger barriers to hydraulic fracture propagation than shales. Porosity logs in the Wilkins well show that the large decrease in horizontal stress found at the base of the Rhine street Formation occurs where shales are less compacted. The correlation with undercompaction is consistent with a paleo-overpressure drainage mechanism as the cause for the stress decrease.
Magnetic decrease formation from <1 AU to ∼5 AU: Corotating interaction region reverse shocks

[1] Magnetic decreases (MDs) have been identified and studied throughout a Ulysses fast latitude scan that lasted from 29 February 1992 to 14 September 1993. Ulysses' distance was ∼5 AU from the Sun. MDs were unbiasedly selected by application of the Interplanetary Magnetic Decrease Automatic Detection code. MDs were found to occur in high-occurrence-frequency “clusters” with the top 10 peak events varying in magnitude from 116 MDs per day to 36 MDs per day. For comparative purposes, quiet, nonpeak intervals had an occurrence rate of 4.3 MDs per day. Each of the 10 MD clusters was analyzed in detail to determine their solar wind dependences. MD clusters were often found to occur within corotating interaction regions (CIRs), mainly localized in the trailing portions of CIRs between the interface (IF) and the reverse shock (RS). The MD clusters were divided into smaller subclusters. Within the limits of this study, MD subclusters were always found to occur in high-β (1 < β < 102) regions (HBRs). Small MD subclusters were detected in HBRs downstream of forward shocks (FSs) but less frequently than for the trailing portion of the CIR. The FS to IF region is generally a low-β region (LBR), where β ≤ 1.0. The 3920 MDs were identified in the study. The temporal thickness distribution of MDs is given by N = 2173 e−(t/17.3), where t is in seconds. The magnetic field angular changes were calculated across MDs. The angular dependence is %MDs = 2 + 48e−(ΔΘ°/18.8°). Only 13.5% of MDs were “linear” with angular changes <10° across the structures. Because MDs are found in abundance in the region spanning the CIR RS to close to the IF, it is argued that MDs must be formed continuously from close to the Sun (r < 0.5 AU) to ∼5 AU. The older MDs (those found close to the IF) are “fossils” that have been convected radially outward to ∼5 AU. A scenario is presented to explain the HBRs downstream of both CIR RSs and quasi-parallel FSs. The location of MD clusters in the trailing parts of CIRs and the paucity of linear MDs indicate that MD generation by mirror mode instability is unlikely. More promising candidates are shock compression of phase-steepened Alfven waves, shock–directional discontinuity interactions, and downstream turbulence. We emphasize the phase-steepened Alfven wave mechanism.
Observations of the vertical structure of the eddy field in the Kuroshio Extension

Normalized kinetic energy frequency distributions at a site in the Kuroshio Extension along 152°E are independent of depth as a good first approximation. The lowest frequencies are strongly vertically coherent from 350 to 6000 m depths (nominal). None of the other vertical sets of time series previously examined possess these characteristics to such a degree, coherence being typically much lower between the thermocline and abyssal depths, with spectral shape changing significantly as well. The vertical distributions of eddy kinetic energy at this Kuroshio Extension site and for the Gulf Stream along 55°W are very similar, if a depth independent contribution of approximately 100 cm2 s−2 be added to the former. The latter observation suggests the existence of a more energetic weakly depth-dependent component for the eddy field in the North Atlantic than for the North Pacific, at special locations in the vicinity of their mid-latitude jets, possibly a signature of distinct instability mechanisms.
Observational evidence of salt lens formation in the Iberian Basin

The quasi-synoptic picture of the mesoscale eddy field off Portugal is presented on the basis of recent hydrographic measurements. The dynamic topography and the salinity field at middepths (900–1300 m) is shown to be dominated by several isolated meddy structures superimposed on a general east-west gradient. Deduced from the actual dynamical situation, there is evidence for meddy generation in this region. Numerical process studies demonstrate the possibility of vortex formation by baroclinic instability of a northward middepth jet of Mediterranean Water and by fragmentation of larger-scale Mediterranean Water blobs.
Identification of Quaternary thrusts, folds and faults in a low seismicity area: examples in the Southern Alps (France)

In low seismicity areas, folds, faults and striated pebbles in recent alluvial deposits can demonstrate the Quaternary activity of tectonic structures and can reveal their kinematics. In the Digne nappe (Southern Alps), an out‐of‐sequence thrust occurred in the late Quaternary in response to WSW‐trending compression. The presence of late Quaternary compressional deformation in the Valavoire thrust could have resulted from the activity of the underlying Durance flexure with a maximum Pliocene–Quaternary uplift rate of about 0.1 mm yr−1. The Quaternary top surface of the Valensole basin, that truncates SW‐vergent thrust propagation folds, is folded above the Lambruissier anticline. Exceptional conditions resulted in the local preservation of this Quaternary fold morphology created with a minimum uplift‐rate of 0.05 mm yr−1 under a NE‐trending compression. At the front of the Digne nappe the deformation is characterized by WSW to WNW trends of compression and low strain rates during the Quaternary period.
Spatio‐temporal precipitation change assessments over Turkey

The availability of water, and its quality, are among the chief growing concerns that are expected to cause serious questions over the sustainability of the Mediterranean region especially under the present climate change impacts, in general, and over the water resources of Turkey, in particular, due to precipitation pattern variability and sensitivity at arid and semi‐arid regions within the country. In order to assess climate impacts concerning precipitation over Turkey, expected spatio‐temporal changes are examined by considering precipitation time series at 165 stations across the country covering the period from 1961 to 2008 for almost 5 decades. Methodologically, homogeneity and Mann‐Kendall rank correlation trend tests are applied at each station for the identification of statistically significant trends. Long‐term annual precipitation averages indicate a decreasing trend with some oscillations during the last 5 decades. However, in more refined periods, average precipitation decreased during 1968–1973 and 1998–2008, whereas it increased during 1973–1981 and 1989–1998. As a result, there is a significant decrease of about 12, 13, and 35% at all stations in annual, rainy period, and winter season total precipitations, respectively. On the other hand, increases occurred at 4, 3 and 19% of all stations in annual, rainy, and autumn season, respectively. Copyright © 2011 Royal Meteorological Society
Single Particle Characterization of Iron-induced Pore-forming

Aggregationof -synucleinisakeyeventinseveralneurode-generative diseases, including Parkinson disease. Recent find-ings suggest that oligomers represent the principal toxic aggre-gate species. Using confocal single-molecule fluorescencetechniques, such as scanning for intensely fluorescent targets(SIFT)andatomicforcemicroscopy,wemonitored peoplebeyond65yearsofage(2). Pathologically,PDischarac--synucleinoligomerformationatthesingleparticlelevel.Organicsolventswere used to trigger aggregation, which resulted in small oli-gomers (“intermediate I”). Under these conditions, Fe
Age, structural setting, and exhumation of the Liverpool Land eclogite terrane, East Greenland Caledonides

The close spatial relationship between Devonian high-pressure rocks (eclogites) and Ordovician–Silurian calc-alkaline plutonic rocks, as observed in Liverpool Land, NE Greenland, is not easily explained by existing tectonic models for the Caledonide orogen. New field studies and isotope dilution–thermal ionization mass spectrometry U-Pb geochronology demonstrate, however, that the association is just coincidental, because the two rock groups are located within distinct terranes separated by a composite structure. The major element is the Gubbedalen shear zone, a N-dipping shear zone dominated by a penetrative top-up-to-the-S ductile fabric. Superimposed brittle-ductile top-down-to-the-N shear zones are typical of the structurally uppermost part of the shear zone. The contact against the hanging wall is the N-dipping, brittle Gubbedalen extensional detachment fault. A zircon age of 399.5 ± 0.9 Ma for an eclogite body is interpreted to represent the time of high-pressure metamorphism of the footwall. The host gneiss was migmatized between ca. 388 Ma and ca. 385 Ma, as constrained by the ages of a pegmatite predating migmatization and crosscutting granites. Coeval synkinematic granites intrude along amphibolite-grade, top-to-the-S high-strain zones in the Gubbedalen shear zone. Juxtaposition of the Ordovician–Silurian plutonic terrane (hanging wall) against the Early to mid-Devonian eclogite terrane (footwall) is best explained by a tectonic model involving early mid-Devonian buoyancy-driven exhumation followed by late mid-Devonian syncontractional extension related to thrusting on the Gubbedalen shear zone in a dextral strike-slip zone. Subsequent exhumation through the brittle-ductile transition occurred by extension on early semiductile structures and the overprinting Gubbedalen extensional detachment fault, and erosion.
The petrogenesis of metamorphosed carbonatites in the Grenville Province, Ontario

Veins and dikes of calcite-rich rocks within the Central Metasedimentary Belt boundary zone (CMBbz) in the Grenville Province of Ontario have been interpreted to be true carbonatites or to be pseudocarbonatites derived from interaction of pegmatite melts and regional Grenville marble. The putative carbonatites have been metamorphosed and consist mainly of calcite, biotite, and apatite with lesser amounts of clinopyroxene, magnetite, allanite, zircon, titanite, cerite, celestite, and barite. The rocks have high P and rare earth element (REE) contents, and calcite in carbonatite has elevated Sr, Fe, and Mn contents relative to Grenville Supergroup marble and marble melange. Values of δ18OSMOW (9.9–13.3‰) and δ13CPDB (−4.8 to −1.9‰) for calcite are also distinct from those for marble and most marble melange. Titanites extracted from clinopyroxene–calcite–scapolite skarns formed by metasomatic interaction of carbonatites and silicate lithologies yield U–Pb ages of 1085 to 1035 Ma. Zircon from one carbonatite .
Paleomagnetism of spatter lavas from Stromboli volcano (Aeolian Islands, Italy): Implications for the age of paroxysmal eruptions

We report on 270 paleomagnetic directions retrieved from 17 different spatter deposits spread over the northern and western flanks of the Stromboli volcano (Aeolian Islands, Italy). The spatter were emplaced during previously undated high‐energy Strombolian eruptions occurring after the third‐seventh century AD. Our paleomagnetic directions were superimposed over the paleosecular variation curve of the geomagnetic field for the last two millennia, obtained by reducing to the coordinates of Stromboli the archeomagnetic and magnetic observatory data from France and Italy. This comparison suggests that most of the spatter exposed in the northern flank of the volcano were emplaced during several eruptions occurring between ca. 1400 and 1600 AD, while the western flank of Stromboli was diffusely spread by spatter during the powerful XX century eruptions. Conversely, there is no evidence for paroxysmal fire fountain activity occurring before 1400 AD, and between 1600 and 1907 AD.
Positioning of nuclei in Arabidopsis root hairs : an actin-regulated process of tip growth

The electric reflector lamp has a reflector body with a neck. A lamp vessel containing an electric element is secured in the reflector body, held by a mounting member which has a securing portion. A lamp base is secured around the neck. The mounting member has a circumferential wall which surrounds the neck and which has relief cooperating with relief of the neck so as to couple the circumferential wall to the neck. Elastic elements of the circumferential wall seize in the recesses in the ceramic lamp base so as to secure the base. The reflector lamp is readily assembled using a small number of components.
Spatiotemporal Pattern of Primary Succession in Relation to Meso-topographic Gradients on Recently Deglaciated Terrains in the Patagonian Andes

Abstract Vegetation in primary succession is influenced by multiple stochastic and environmental factors at different spatial and temporal scales. In this study we analyze the effect of meso-topographic heterogeneity on vegetation development following the retreat of Glaciar Seco in the southern Patagonian Andes. Composition and cover of algae, lichens, mosses, and vascular plants were recorded in 580 plots located in different topographic positions within a chronosequence of eight consecutive moraines. Sample plots were characterized by topographical and surface features. Spatiotemporal patterns in vegetation composition and their relationships to environmental factors were assessed by classification and ordination. We recognized eight communities that correspond to four major successional stages. The successional sequence is characterized by a physiognomic development from pioneer saxicolous lichens (first stage) to secondary colonizer lichens (second stage), followed by shrub colonization (third stage) and the development of Nothofagus spp. forests (fourth stage). Alternative successional trajectories on different topographic positions vary in the sequence of these four major successional stages, with the trajectories on the moraine ridge-top and base not going through some of the stages. A variance partition procedure shows that time since deglaciation and topographic position on the moraines account for comparable amounts of vegetation variance, emphasizing the importance of spatiotemporal analysis of vegetation development on heterogeneous landscapes. Broad trends in vegetation development follow environmental gradients. However, emergence and persistence of vegetation patterns can also be attributed to dynamic geomorphic processes such as moraine slope degradation affecting boulder distribution along the moraine foreslope. At the landscape scale, successional trajectories converge to a Nothofagus-dominated state, but significant variability remains in the understory due to the differential distribution of cryptogams along the moraine topographic gradient. Convergence is mostly related to the expansion of communities from more favorable sites towards the harsher moraine crest, but it is not a process of gradual deterministic changes along the different successional pathways.
Reply to Butterfield: Low-sulfate and early cements inhibit decay and promote Burgess Shale-type preservation

In his work, Butterfield (1) makes several claims about carbonate cements in the Walcott Quarry Member of the Burgess Shale, including the contention that they are not regularly associated with fossil-bearing beds. This claim is inaccurate. Each millimeter- to centimeter-scale bed within the interval is cemented by calcite (figures 2–5 in ref. 2), including the exceptionally fossiliferous Great Marella Layer referred to in the work (1), which contains cements dispersed throughout its thickness and a prominently-cemented top (Fig. 1). The work by Butterfield (1) also suggests that the carbonate cements in the Burgess Shale were derived from recrystallization of coarse-grained carbonates and bioclasts during metamorphism. However, well-preserved skeletal fossils, such as Scenella, occur with clear margins and petrographic characteristics that are sharply distinct from the fine-grained carbonates that surround them, excluding the possibility that bioclasts were the original source of carbonate. Importantly, the cements in the Burgess Shale are entirely consistent in growth habit and distribution with the six other deposits analyzed in our study (3), including a nearby but less metamorphosed locality in the Stephen Formation, all of which clearly display early-displacive growth of carbonate at the seafloor. The assertion in the work by Butterfield (1) that seafloor precipitates are uncommon in the Cambrian is at odds with a large body of evidence (4).