Miracle-dz/UniFAR-FTUs huggingface dataset:
On the difficulty of assigning crustal residence, magmatic protolith and metamorphic ages to Lewisian granulites: constraints from combined in situ U–Pb and Lu–Hf isotopes

Abstract Zircons from two granulite facies gneisses from the central region of the Lewisian Complex have been investigated by high spatial resolution ion-microprobe U–Pb dating and laser ablation combined Pb–Hf isotope methods. The ion-microprobe data reveal a complex pattern of zircon ages distributed along the concordia curve between the time of granulite facies metamorphism at c. 2.5 Ga and the oldest zircon in each sample (respectively 2.89 Ga and 3.04 Ga). This Pb-loss pattern complicates assignment of an unambiguous magmatic protolith age to the zircon although cathodoluminescence (CL) imaging is used to suggest a preferred age of c. 2.85 Ga for both samples, with older grains being inherited. In situ Hf isotopes show a larger spread in the sample containing older grains which is also consistent with inheritance and further suggests that several crust extraction events are represented in the inherited population. Comparison of Hf isotope compositions with plausible model evolution curves suggests that crustal precursors to the Lewisian granulites were derived from their mantle source at c. 3.05–3.2 Ga. Supplementary material: Analytical methods and data tables are available at: http://www.geolsoc. org.uk/SUP18395
Remote sensing of net ecosystem productivity based on component spectrum and soil respiration observation in a boreal forest, interior Alaska

[1] We built a remote-sensing method for determining leaf area index (LAI) and ground cover mosses/lichens in boreal forests by field component spectral observation and radiative transfer modeling based on the spectrum. The method was applied to evaluate annual net ecosystem productivity (NEP) distribution in a boreal forest, interior Alaska, by accounting for net primary productivity (NPP) of the vegetation compositions and soil respiration observation synchronized to the spectral observation. Spectral reflectance and soil respiration were observed in two 30-m × 30-m plots in black spruce stands, central Alaska. Spectral characteristics of the forest floor and the needle leaves were used as input parameters of a radiative transfer model to evaluate nadir reflectances of spruce communities in relation to varying upper layer LAI, forest floor bryophyte types, and leaf spectral characteristics. Using the relationship, we obtained LAI and bryophyte area ratios for each pixel that corresponds to spruce forest on Landsat ETM+ imagery. The LAI-NPP relationship of spruce forest was estimated from Plonski's [1981] normal yield table data and specific leaf area, and NPP was calculated from LAI. Observations of daily respiration were extrapolated to annual timescales using soil temperature. On the basis of the annual soil respiration and NPP of the upper layer and forest floor, annual NEP geographical distribution in a recent normal year was estimated from remotely sensed LAI and forest floor bryophyte area ratios. The annually estimated NEP was 51 g C/m2/yr, which corresponds to the value (55 g C/m2/yr) for 150-year-old black spruce forest in the Boreal Ecosystem-Atmosphere Study (BOREAS) region, Canada.
Developing simple, operational, consistent NDVI-vegetation models by applying environmental and climatic information : Part I. Assessment of net primary production

Multiple linear regression techniques have been used to assess rangeland Net Primary Production (NPP) in Senegal. The biophysical principles of assessing NPP as a function of the Absorbed Photosynthetic Active Radiation (APAR) accumulated during the growing season, multiplied by the efficient coefficient (epsilon), have been used for the work. Accumulated APAR can be substituted with the seasonal integration of NDVI multiplied by the Photosynthetic Active Radiation (PAR). However, a linear regression showed that the NDVI alone was a better and more consistent estimator of rangeland NPP compared with the use of NDVI combined with the PAR data. A first characterization of environmental and climatic variability was attempted. Soil and vegetation information was used and GIS interpolation tools were exploited to create spatial surfaces of environmental and climatic variables from point observations. A multiple linear regression with the independent variables: integrated NDVI, percentage tree cover and mean su.
Impact of coating and weathering on the properties of chalk fracture surfaces

The surface topography of a natural fracture intersecting a chalk formation was mapped using a high-resolution laser-scanning device, and its roughness was evaluated using five different criteria. Two coated and two uncoated slices of the natural fracture surface were encased in flow cells and exposed to short (24 and 8 hours) interactions with percolating synthetic rainwater and industrial wastewater, followed by long drying periods (weeks). These flow experiments simulated the intermittent infiltration of surface runoff and industrial effluents typical of the study area and resulted in erosion of the fracture surfaces and modification of their roughness. The temporal variations in surface roughness were evaluated using three commonly used criteria (standard deviation from mean heights, differences between maximum and minimum heights, and the root-mean-square roughness) and two newly developed measures, namely, the slopes on the surfaces and a calculated roughness-related ratio (RRR). The mean slope maps and RRR calculations were found to be good criteria for evaluating surface topography and its uniformity across the fracture surface. The coated surfaces were significantly rougher, had greater relief, more heterogeneous topography, and a larger surface area than the uncoated surfaces. The results suggest that coating and fast weathering (caused by intermittent flow events) significantly change roughness, surface area, relief, and the heterogeneity of a fracture surface. These, in turn, may affect the spatial distribution of flow paths across that fracture surface. Consequently, when exploring the properties of fracture surfaces and fracture flow, the impact of surface skin and variations of the surface properties over short timescales should be taken into account.
Effects of Peclet number on pore‐scale mixing and channeling of a tracer and on directional advective porosity

Field tracer tests indicate that advective porosity, the quantity relating advective velocity to Darcy flux, may exhibit directional dependence. Theory (S. P. Neuman, 2005) suggests that directional variations in advective porosity could arise from incomplete mixing of an inert tracer between directional flow channels within a sampling volume of soil or rock that may be hydraulically isotropic or anisotropic, rendering advective porosity a function of Peclet number. Whereas Neuman was able to quantify the process for idealized intersecting fracture sets, his theory is too abstract to allow doing so for more complex systems of fractures or pores. We use Smoothed Particle Hydrodynamics (e.g., A. M. Tartakovsky and P. Meakin, 2005, 2006) to simulate advective‐diffusive transport of a passive tracer in the interior of an idealized pore space between impermeable circular or elliptical solid grains of random size, arranged randomly within a square domain. Our numerical experiments reveal a transition from complete mixing of tracer at small Peclet numbers to the gradual evolution of pore‐scale channels of tracer which allow less and less mixing as Peclet numbers grow. Advective porosity, computed as the ratio between total water flux across the domain boundaries and migration rate of the tracer center of mass, is found to diminish asymptotically from a value close to the total porosity at small Peclet numbers to a constant dominated entirely by advection at large Peclet numbers. When total porosity is kept constant, channeling is less pronounced and mixing more prominent when flow takes place parallel to the longer axes of elliptical grains as compared to when the grains are circular. On the other hand, channeling is more pronounced and mixing less so when flow takes place perpendicular to the longer elliptical grain axes. Correspondingly, the rate at which advective porosity diminishes with increasing Peclet number is slower and the asymptote is larger when flow takes place parallel to the longer axes of elliptical grains than when the grains are circular. However, the rate is faster and the asymptote smaller when flow takes place perpendicular to the longer elliptical grain axes.
Variability in Long Bone Growth Patterns and Limb Proportions within and Amongst Mesolithic and Neolithic Populations from Southeast Europe

1 Department of Archaeology, University College Cork, Cork, Ireland 2 Department of Archaeology, Faculty of Philosophy, University of Belgrade, Cika Ljubina 18-20, 11000 Belgrade, Serbia and Montenegro 3 Ephorate of Paleoanthropology and Speleology, Greek Ministry of Culture,11636 Athens, Greece 4 Leverhulme Centre for Human Evolutionary Studies, Department of Biological Anthropology, University of Cambridge, Cambridge CB2 1QH, UK
Ice Nucleating Properties of Meteoritic Material

Abstract A description is given of an attempt to duplicate the small particles formed by evaporation and recondensation during the flight of meteors in the atmosphere by heating meteors at a low pressure. A metallic meteorite produced entirely shiny spherules, almost all of which were in the size range 5 to 25 μ diameter, while a stony meteorite produced only irregular aggregates of tiny particles whose maximum dimensions were 0.1 to 0.2 μ. At water salutation and −10C, it is estimated that the iron meteorite creates about 105−106 ice nuclei per gram and the stony meteorite about 108−109. It is concluded that sufficient ice nuclei active at −15C are produced to explain observed concentrations in the troposphere.
Polyelectrolyte-Coated Gold Nanoparticles: The Effect of Salt and Polyelectrolyte Concentration on Colloidal Stability

Gold nanoparticles are widely used in biomedical applications. Their ease of surface modification, biocompatibility and the presence of surface plasmons makes them ideal tools for a variety of investigations. Polyelectrolyte-coated gold nanoparticles are employed in areas such as imaging, drug delivery and gene therapy; however, it is not well understood how different factors such as the polyelectrolyte and salt concentration affect the coating on the nanoparticles and hence their performance. Here, these parameters were systematically varied and their effect on the stability of the colloidal nanoparticle suspension was monitored. An increase in the polyelectrolyte concentration from 0 to 30 mg/mL led to a red shift of the surface plasmon peak and an increase in the zeta potential. Concentrations between 5 mg/mL and 30 mg/mL resulted in the most stable systems, with 1 mg/mL being the most unstable. Stable nanoparticle suspensions were formed in salt concentrations below 50 mM, while higher concentrations caused colloidal instability and irreversible aggregation.
Middle Cambrian echinoderm remains from the Henson Gletscher Formation of North Greenland

A Middle Cambrian (Series 3, Stage 5) echinoderm assemblage is described from the uppermost part of the Henson Gletscher Formation based on disarticulated material. This represents the first detailed echinoderm report from the Cambrian of North Greenland and one of the most diverse for that time. Recovered ossicles include a morphotype continuum between various biserial (brachiolar) and uniserial (“brachial”) plates from pelmatozoan feeding appendages along with thecal insertion plates, pelmatozoan holomeric and the oldest known polymeric stem elements and holdfasts. Ambulacral flooring plates from two different edrioasteroids are also described. This assemblage illustrates a high plasticity and disparity in early echinoderm stem and feeding appendages, thereby placing stress on the usual definitions of blastozoans and crinozoans, generally considered as two pelmatozoan subphyla. Along with previous studies, it also raises the question as to how early echinoderms responded to the Agronomic Revolution (Substrate Revolution). Echinoderm remains first appear during Cambrian Series 2, Stage 3, well after the Substrate Revolution had affected the first few centimetres of substrate used by this low-level tiering animals to stabilize themselves. Contrary to previous ideas, it is suggested that echinoderms evolved quickly and in a nonlinear way in response to the abrupt establishment of a mosaic of substrate types during the early Cambrian. Finally, this study highlights the primary importance of disarticulated elements in the elucidation of the early evolution, diversity and disparity of the earliest echinoderms. Such elements are much more common and always appear earlier in the geological record than the complete articulated specimens on which echinoderm studies generally focus despite the taphonomic biases which often characterize their preservation.
Vegetation and habitat of the salt marshes and beach plains in the south-western part of the Netherlands

Geographically the coasts of the Netherlands can be devided into three parts: (1) The coastal area (Wadden Area) of the Shallows and the Frisian Islands in the north, (2) the straight coast-line of beaches and dunes between Den Helder and Hook ofHolland, in which no salt marshes occur and (3) the south-westernpart of thecountry characterized by estuarine formations. The Wadden Area consists ofvast sand and mud flats, separated by creeks and channels of different dimensions. In the direction of the
Recent Trends in Melting Conditions on the Antarctic Peninsula and Their Implications for Ice-sheet Mass Balance and Sea Level

Abstract Long-term records from meteorological stations on the Antarctic Peninsula show strong rising trends in the annual duration of melting conditions. In each case, the trend is statistically significant and represents a major increase in the potential for melting; for example, between 1950 and 2000 the record from Faraday/Vernadsky Station showed a 74% increase in the number of positive degree-days (PDDs). A simple parameterization of the likely effects of the warming on the rate of snow melt suggests an increase across the Antarctic Peninsula ice sheet from 28 ± 12 Gt a−1 in 1950, to 54 ± 26 Gt a−1 by 2000. Given a similar rate of warming over the next 50 years this may reach 100 ± 46 Gt a−1. The majority of this increased meltwater does not drain into the sea but is refrozen in the ice sheet, and it is difficult to predict the fraction of ablation that will become runoff; however, a calculation based on an established criterion for runoff indicates that the contribution from the Antarctic Peninsula, as a direct and immediate response to climate warming is significant, equivalent to (0.008–0.055) mm a−1 of global sea level rise. Given future warming this could easily treble in the coming 50 years. This contribution due to increased runoff could be augmented by any dynamic imbalance in the glaciers draining the ice sheet. This finding appears to contradict the conclusions of previous assessments, including the Intergovernmental Panel on Climate Change, which considered the contribution of runoff from Antarctica to sea level rise would be insignificant.
Limited Pliocene/Pleistocene glaciation in Deep Freeze Range, northern Victoria Land, Antarctica, derived from in situ cosmogenic nuclides

The question of how stable the climate in Antarctica has been during the last few million years compared to the rest of the planet is still controversial. This study attempts to add new information to the discussion by reconstructing the timing and spatial extent of glacial advances in northern Victoria Land over tens of thousands to millions of years. In Terra Nova Bay region, surface exposure ages and erosion rates of glacially rounded bedrock and glacial erratics have been determined using the cosmogenic nuclides 3He, 10Be and 21Ne. Three morphological units have been analysed. They yield minimum ages of 11 to 34 ka, 309 ka, and 2.6 Ma, respectively. Erosion rates were as low as 20 cm Ma−1 since middle Pliocene time. Taking erosion into account, the oldest surface is 5.3 Ma old. Pleistocene glacier advances had considerable extent, reaching up to 780 m above modern ice levels, but have been restricted to the valleys since at least mid-Pliocene. The existence of landscapes of mid-Pliocene age in northern Victoria Land implies that the climatic stability of the McMurdo Dry Valleys is not unique within the Transantarctic Mountains, but rather the expression of a constantly cold and hyperarid climate regime in entire Victoria Land.
Heritage Tourism and Nation-State Political Power: Interpretive Trails of the Gyalrong People, Sichuan, China

Abstract In China, conservation of minority heritage has been closely related to tourism development. Ecomuseums have also become a new model which serves to satisfy two major tasks: minority heritage protection and tourism development. In this paper, I explore how trails are planned in Gyalrong people's villages under the mode of ecomuseum. Through interviews and field survey in several villages, including review of three major tourism plans and proposals from local officials, I compared trails that were constructed by local ethnic groups with trails that are currently planned predominantly by the government. Through this comparison, I found that there are conflicts and an unbalanced relationship between the ethnic groups and the government. Furthermore, I emphasize the ways in which the philosophy of the ecomuseum is displaced and modified in the context of Chinese society. In conclusion, I point out problems faced by local ethnic communities as they find their way to achieving sustainable development under the framework of heritage tourism and nation-state political power. Ecomuseums and heritage tourism have been discussed a great deal in China and internationally; this study points out key problems and critical issues in current ways of developing heritage tourism in the landscape of minorities in China.
Three-dimensional finite element nonlinear dynamic analysis of pile groups for lateral transient and seismic excitations

The effects of material nonlinearity of soil and separation at the soilpile interface on the dynamic behaviour of a single pile and pile groups are investigated. An advanced plasticity-based soil model, hierarchical single surface (HiSS), is incorporated in the finite element formulation. To simulate radiation effects, proper boundary conditions are used. The model and algorithm are verified with analytical results that are available for elastic and elastoplastic soil models. Analyses are performed for seismic excitation and for the load applied on the pile cap. For seismic analysis, both harmonic and transient excitations are considered. For loading on the pile cap, dynamic stiffness of the soilpile system is derived and the effect of nonlinearity is investigated. The effects of spacing between piles are investigated, and it was found that the effect of soil nonlinearity on the seismic response is very much dependent on the frequency of excitation. For the loading on a pile cap, the nonlinearity increa.
Geochemistry of the Permian sandstones from the Malužiná Formation in the Malé Karpaty Mts (Hronic Unit, Western Carpathians, Slovakia): implications for source-area weathering, provenance and tectonic setting

Abstract The Permian sandstones of the Malužiná Formation in the northern part of the Malé Karpaty Mts are dominantly quartzofeldspathic and quartzolithic in composition with abundant feldspars and volcanic, plutonic igneous and less metasedimentary lithic fragments, indicating the sand grains were derived from a basement uplift and recycled orogen. The Malužiná Formation sandstones have moderate to high SiO2 contents (68-85 wt. %; on average 76 wt. %), TiO2 concentrations averaging 0.3 wt. %, Al2O3 contents of about 12 wt. %, and Fe2O3 (total Fe as Fe2O3) + MgO contents of around 2.9 wt. %. The Chemical Index of Alteration (CIA) values for the Permian Malužiná Formation sandstones vary from 45 to 68 with an average of 55, indicating low to moderate weathering of the source area. The bulk chemical composition and selected trace elements preserve the signatures of a felsic and intermediate igneous provenance, and suggest mostly an active continental margin tectonic setting of the source area for the Malužiná Formation sandstones. The Eu/Eu* (~0.78), La/Sc (~7.28), Th/Sc (~2.10), La/Co (~6.67), Th/Co (~1.85), and Cr/Th (~6.57) ratios as well as the chondrite-normalized REE patterns with flat HREE, LREE enrichment, and negative Eu anomalies indicate derivation of the Malužiná Formation sandstones from felsic rock sources. The deposition of the Malužiná Formation sandstones took place in a rifted continental margin environment supplied from collision orogen on a thick continental crust composed of rocks of older fold belts.
Calculating exchange times in a Scottish fjord using a two-dimensional, laterally-integrated numerical model

In order to assess the potential impact of pollutants, particularly soluble wastes discharged by the mariculture industry, on the fjordic sea loch environment in Scotland, simple management models have been developed which estimate steady-state concentrations based on the quantities of effluent released and the residence time of such material within a loch. These models make various simplifications about the hydrodynamic characteristics of Scottish sea lochs, the most important of which is the concept of an exchange time which parametrizes the rate at which pollutants are removed from the system. Exchange times for individual lochs are calculated using the tidal prism method, which has some well-known shortcomings. In this paper, a two-dimensional laterally-integrated circulation model is used to investigate the exchange characteristics of Loch Fyne and its sub-basins. By simulating the transport of a passive, conservative tracer, the turnover times for the loch, two sub-basins and various depth layers are calculated. By varying the starting time of the tracer simulations, the variability in the exchange times is examined. The results from the circulation model are compared with the estimates given by the tidal prism method. The results show that the tidal prism method consistently underestimates the exchange times, although the predicted times tend to lie within the range of the simulated times. Including a simple return flow factor into the tidal prism estimate leads to significant improvements in the comparison.
Sedimentary models for extensional tilt-block/half-graben basins

Summary Extensional tectonism produces characteristic half-graben/tilt-block systems whose facies mosaics are influenced by tectonically induced slopes resulting from hanging wall downtilting and footwall uplift. The characteristic asymmetrical subsidence vectors that therefore develop across the graben also exert a fundamental control upon facies distributions. A number of predictive tectono-sedimentary facies models are presented in which these various influences are explored. Alluvial fans and cones react to tilting by becoming segmented, those in the hanging wall showing down-dip hanging wall off-lap and those sourced in the footwall showing progradation from the apex. Lake and coastal waters react instantly to tilting, causing transgression and seiche-induced erosion. Axial through-flowing river channels and delta lobes tend to migrate or avulse towards the axis of maximum subsidence but may be constrained by the toes of footwall-sourced fans. Peat accumulation or soil development are accentuated up the hanging wall dip slope away from the locus of maximum deposition. In coastal areas, fan deltas sourced in the footwall pass offshore into small submarine fans whilst axial fans issue from delta fronts where individual fan lobes may migrate under fault control. In carbonate provinces the footwall scarp may become a bypass margin whilst the hanging wall dip slope may undergo a ramp-to-rimmed shelf evolution with time.