Miracle-dz/UniFAR-FTUs huggingface dataset:
Dating the Glen Garry tephra: a widespread late-Holocene marker horizon in the peatlands of northern Britain

The distal Icelandic tephra known as the Glen Garry layer has been dated by AMS 14C at eight ombrotrophic peat bogs from northern England and Scotland. The geochemistry of all the tephra layers is consistent with there being only one Glen Garry tephra, rather than two or more from eruptions of the same volcanic source. At seven of the sites, all in Scotland, the tephra layer was bracketed by 1 cm contiguous samples below, at and above the horizon. At the one English site, Walton Moss, Cumbria, a suite of 16 AMS dates was applied to a 116 cm section of a peat core containing the tephra. The resulting dates were calibrated and wiggle-matched using the BCal and Bpeat programmes to give an estimated age for the Glen Garry tephra of 2176 cal. BP, with a 2σ range of 2210—1966 cal. BP. This 244 year range is an improvement on the 410 years calibrated date range for the date without the wiggle-match. This age estimate will allow future work on peat profiles and other sediments containing the tephra to use the date as a pinning-point in age/depth models and obviate the need for radiocarbon dating at this period.
Distribution of Phytolacca americana in a coastal sand dune

This study examined the main factors affecting the distribution of Phytolacca americana, an exotic plant species in Korea, in coastal sand dunes. The areas examined from June 2004 to February 2006 were in Sindusagu where was located on Sindu-ri, Wonbuk-myen, Taean-gun, Chungcheongnam-do. The vegetation, sediment properties, sizes and ages of Robinia pseudoacacia, P. americana and Pinus thnunbergii and spatial distribution of P. americana were assessed. Firstly, correlation coefficients (CC) between P. americana’s root biomass and sediment properties were not significant. Secondly, of the four community types, P. americana was not in the mixed herbaceous community and its density was the highest in the P. thunbergii−R. pseudoacacia and R. pseudoacacia community The Poisson distribution analysis revealed the distribution of P. americana to be severely clumped. The root biomass of P. americana and the basal area of R. pseudoacacia were significantly correlated, but the CCs between P. thunbergii and other two species were not significant. The ages of P. americana and R. pseudoacacia in a quadrat were significantly correlated. Thirdly, P. americana’s ages in a quadrat were mostly similar to each other. Therefore, the spatial distribution of P. americana was largely influenced by R. pseudoacacia but not by the sediment properties, and plants in a narrow area were concurrently germinated.
Proterozoic collisional tectonism in the Trans-Hudson orogen, Saskatchewan

Isotopic and structural data from the juvenile Reindeer zone of the Trans-Hudson orogen, northern Saskatchewan, indicate a pre-1.85 Ga thermotectonic event, possibly reflecting arc-continent collision, followed by a more extensive, nappe-forming, ca. 1.83-1.80 Ga thermotectonism during terminal continent-continent collision. Preliminary data from the adjacent, ensialic Cree Lake zone suggest high-grade reworking of Archean crust by the pre-1.85 Ga event. In the Rae province to the west, high-grade metamorphism and reworking of Archean crust occurred about 2.0 Ga and may be related to the formation of the coeval Taltson magmatic zone.
Stratigraphic Framework and Petroleum Potential of Northeastern Baltimore Canyon Trough, Mid-Atlantic Outer Continental Shelf

Geologic data from 29 wells in the Baltimore Canyon Trough were released to the public as of 1982, and provide sufficient information for establishing Upper Jurassic through Cenozoic rock-stratigraphic units. Most of the units are lithologically similar to formations on the Scotian Shelf and are, therefore, considered in this study to be the Scotian Shelf homotaxial equivalents. The oldest rocks penetrated by exploratory wells in the Baltimore Canyon Trough are of Late Jurassic age and are correlative to the Scotian Shelf Mohawk, Mic Mac, and Abenaki Formations. The Mohawk(? ) sandstone and Mic Mac shale equivalents in the Baltimore Canyon Trough represent lower delta plain to predominantly prodelta environments, and the Abenaki-equivalent limestone represents a shelf-margin carbonate buildup. Delta progradation continued during the Early Cretaceous, and lower delta-plain and delta-front sand and shale, equivalent to the Scotian Shelf Missisauga Formation, were deposited. A destructional phase of the delta is represented by the Naskapi equivalent, a calcareous shale. Inundation by the sea was incomplete, however, and channel and distributary-mouth-bar sands (Logan Canyon equivalent) were deposited. A final marine transgression began during the Late Cretaceous and resulted in the deposition of mudstone, which is considered equivalent to the Sco ian Shelf Dawson Canyon Formation. Marine conditions prevailed through much of the remainder of the Cretaceous and Cenozoic in both the Scotian Shelf and Baltimore Canyon Trough areas. Lithologic similarities between Cenozoic units of the Scotian Shelf and Baltimore Canyon Trough are less significant. Although both basins exhibit an upward increase in sand content, the Scotian Shelf Cenozoic strata are more sandy than those in the Baltimore Canyon Trough. In ascending order, the Baltimore Canyon Trough Cenozoic section consists of the uppermost Dawson Canyon equivalent, a chalk unit, a mudstone unit, an unconsolidated sand unit, and an uppermost clay unit. Stratigraphic traps may be present in the Baltimore Canyon Trough Upper Jurassic and Lower Cretaceous deltaic sandstones and shelf-margin carbonates. The deltaic units contain channel and distributary-mouth-bar sandstones, which may be potential reservoirs. Seals may be formed by lateral and vertical contacts against the prodelta, interdistributary bay, and marine shales. The Abenaki stratigraphic-reef trend provides another potential target. Source rocks, reservoir rocks, and traps may be associated with the trend, but its potential can only be defined by future drilling.
Monoterpene emissions from Scots pine and Norwegian spruce

Rates of monoterpene emissions from Scots pine (Pinus sylvestris) and Norwegian spruce (Picea abies) have been measured at four sites in Sweden with a dynamic flow chamber technique. Forest floor emissions have been made in the pine forest with the static chamber technique. Sampling was done with Tenax TA and analysis and detection by GC and ion trap detection. The compounds Δ3-carene and α-pinene were the predominant terpenes emitted from the crown and floor of the Scots pine forest. Alpha-pinene was the main terpene emitted from Norwegian spruce at the sites in southern and central Sweden, while Δ3-carene was predominant at the northern site. The relative composition of the emission of both species underwent changes in early spring and fall. Emission rates, normalized to temperature, were seen to vary diurnally with a maximum at midday, and seasonally with maxima in early May and October, and a summer maximum in June–July. The possible dependence of the emission rate on needle growth rate and other plant-physiological processes is discussed. A higher emission rate and different relative composition of the emission was seen to occur when the vegetation was wet, as compared to dry vegetation. The emission from the pine forest floor was seen to have a composition different from that of the crown and a seasonality of the rate similar to that of the crown. The ground emission could not be explained by sources in the litter or ground vegetation alone, and it is suggested that the root system of the trees is also an emission source. The emission rate from the pine forest floor was of the order of 30% of the crown emission. The July rate of emission from the crown of Scots pine, normalized to 20°C and averaged over four sites in Sweden, was 0.8 ± 0.4 μg (gdw (grams dry weight) h)−1, and for Norwegian spruce, 0.5 ± 0.7 μg(gdw h)−1. It would seem that previous regional and global estimates of hydrocarbon fluxes to the atmosphere have used emission factors which are too high for boreal coniferous forests.
Dual‐Porosity Fractal Models for Transient Flow Analysis in Fissured Rocks

A dual-porosity fractal model is derived that considers transient flow from block to fissure, skin between the fissure and the block, and storage capacity and skin effect on the pumping well. Type curves for different flow dimensions are provided. They concern the pumping well and observation wells located either in the fissure system or in a matrix block. The interpretation of a field case using this model shows good agreement between the theoretical drawdown and the observed data, with consistent results from the pumping well and the observation well. A flow dimension of 1.45 is obtained.
Zircon fission-track ages from the Gasherbrum Diorite, Karakoram Range, northern Pakistan

The Gasherbrum Peaks, in the Himalaya of Pakistan, reach elevations of >8000 m. The relief between the peaks and the adjacent valley (Baltoro Glacier) is in excess of 3000 m. Eight samples of the Early Cretaceous Gasherbrum Diorite at elevations between 4880 and 7165 m on Gasherbrum IV were collected for fission-track dating. Zircon fission-track ages from the Gasherbrum Diorite vary from Early Cretaceous to middle Tertiary in age. There is no consistent pattern between age and elevation. The Cretaceous ages indicate that these rocks were never deeply buried, i.e., heated to temperatures in excess of 175 C, to reset the zircons during Cenozoic time. These results also indicate that the uplift of this part of the Himalaya has been either very rapid and recent, or very slow since Early Cretaceous time. This latter possibility is not consistent with the high relief at Gasherbrum and what is known about regional tectonics. Gasherbrum IV zircons, currently at {approximately}4880 m, have never been at depths greater than 6 km, and less than 3 km of material has been removed from the top of the range by erosion since the Early Cretaceous. Rapid uplift has occurred very recently, and erosion rates have notmore » been able to keep pace with this uplift. « less
The boundary between Proterozoic and Archaean crustal blocks in central West Greenland and northern Labrador

Summary The contact between the Early Proterozoic Nagssugtoqidian Mobile Belt and the Archaean craton in West Greenland, and that between the Churchill Province and the Archaean (Nain) craton in Northern Labrador represent two cross-sections of an Early Proterozoic orogenic boundary. The Archaean cratons in both regions display the peripheral effects of Proterozoic orogenic events. The best indicators of Proterozoic effects on the Archaean cratons are the Late Archaean-Early Proterozoic dykes and the Early Proterozoic supracrustal rocks which unconformably overlie the gneisses and dykes. In Greenland the boundary zone evolution is characterized by Late Archaean (Nag. 1) transcurrent shearing, Early Proterozoic Kangâmiut dyke intrusion and subsequent (Nag. 2) ductile overthrusting. Ductile overthrusts are characteristic of the Nagssugtoqidian-Archaean boundary and attest to substantial shortening of the crust in this region. In Labrador the boundary region has been divided into several distinct zones. Although facets of its evolution are analogous to the boundary in Greenland there are several fundamental differences, the most important of which is that transcurrent movement appears to have been dominant over ductile overthrusting. These differences are provisionally related to contrasting tectonic settings of the two areas during Early Proterozoic continental collision, the Greenland segment being the frontal collision zone whilst the Labrador segment documents slightly oblique transcurrent motion.
Social and economic factors affecting the adoption of soil and water conservation in West Usambara highlands, Tanzania

Accelerated soil erosion is one of the major constraints to agricultural production in many parts of the Tanzanian highlands. Although several soil and water conservation technologies have been developed and promoted, the adoption of many recommended measures is minimal and soil erosion continues to be a problem. This research was conducted in order to determine the social and economic factors that influence adoption of soil and water conservation (SWC) measures in the West Usambara highlands, Tanzania. For this research a household survey, group discussions and transect walks were undertaken. A total of 104 households were interviewed and several fields were visited during the transect walks. Data was analysed with the use of cross‐tabulation, cluster analysis, factor analysis and chi‐squared methods. The results obtained indicate that involvement in off‐farm activities, insecure land tenure, location of fields and a lack of short‐term benefits from SWC are among the major factors that negatively influence adoption of SWC measures. Membership in farmer groups, level of education, contacts with extension agents and SWC programmes were found to be positively influencing the adoption of SWC measures. Recommendations to facilitate adoption of different SWC measures include: integration of social and economic factors into SWC plans; the creation of more awareness among farmers of soil‐erosion effects and long‐term benefits of SWC; the development of flexible SWC measures to cater for different farm patterns and a participatory approach to SWC at catchment level rather than at individual farmers' fields. Copyright © 2004 John Wiley & Sons, Ltd.
Vegetation dynamics during the Younger Dryas‐Holocene transition in the extreme northern taiga zone, northeastern European Russia

Vegetation dynamics during the Younger Dryas‐Holocene transition in the extreme northern taiga zone of the Usa basin, northeastern European Russia, were reconstructed using plant macrofossil and pollen evidence from a sediment core from Lake Llet‐Ti. The pollen stratigraphy during the Younger Dryas (about 12 500–11 500 cal. yr BP) is characterized by pollen types indicative of treeless arctic vegetation, whereas the macrofossil evidence shows the occurrence of scattered spruce and birch trees around the lake. The Younger Dryas‐early Holocene transition is characterized by a rapid increase in vegetation density, including an increase in the birch population, followed by the expansion of the spruce population at about 10 000 cal. yr BP. Dense spruce‐birch forest dominated until 5000 cal. yr BP. Our results contribute to the debate about the Lateglacial environments in northern Russia, and illustrate the importance of plant macrofossil records in Lateglacial vegetation reconstructions.
Associations between the plant communities of floodplain wetlands, water regime and wetland type

Understanding how floodplain wetland vegetation is influenced by water regimes can inform the management of regulated river systems by targeting appropriate environmental water allocations. In this study, we examined plant community structure in 21 floodplain wetlands adjacent to the Murray River between Hume Reservoir and Tocumwal, south‐eastern Australia. Correlations between the water regime of the previous 25 years, and wetland type were investigated. We found the structure of plant communities, as assessed by the richness and percentage cover of plants, to be related to water regime, with clear differences between the communities of wetlands with historical ‘Wet’, ‘Dry’ and ‘Intermediate’ water regimes. Plant community structure was also related to wetland type, with differences being found between the communities of floodplain depressions, flood‐runners and cut‐off meanders. Managers of riverine/floodplain ecosystems need to consider both wetland type and water regime when planning strategies for the restoration or conservation of floodplain wetland vegetation in regulated river systems. Copyright © 2009 John Wiley & Sons, Ltd.
Temporal and spatial variations of carbon monoxide over the western part of the Pacific Ocean

[1] Systematic observations of atmospheric carbon monoxide (CO) have been carried out in the western part of the Pacific Ocean since February 1990. The average CO concentration showed a latitudinal gradient, with higher values in the northern hemisphere than in the southern hemisphere. A clear seasonal CO cycle was found nearly at all sampling locations, showing maximum and minimum concentrations in spring and summer, respectively. In the 30°–35°N latitude zone, the average CO concentration was higher and the seasonal amplitude was larger compared with other latitudes. The CO concentration also showed a large interannual variability mainly in association with forest fires. In particular, the forest fires in Siberia in 1998 and Indonesia in 1997–1998 contributed to a remarkable increase in the regional CO concentration, followed by a recovery that took several months to a year. A three-dimensional atmospheric global chemical transport model (CHASER) was used to simulate the observed characteristics of the latitudinal distribution, seasonal cycle, and interannual variability relatively well. Tagged CO experiments with the model revealed that the contribution of CO emissions from various regions in the northern hemisphere to the CO concentrations at our sampling locations varied seasonally in association with Asian outflows and long-range transport from Europe and North America. In the southern hemisphere, biomass burnings significantly affected the regional seasonal CO cycle, in addition to the effect of CO oxidation with OH. It was also found that CHASER underestimates the average CO concentration in the northern hemisphere and its interannual variability.
Tectonic sequence diagrams and the structural evolution of schists and gneisses in multiply deformed terranes

The current practice of numbering deformation phases (D1 . . . Dn) in a multiple deformed terrane obscures the link between data and inference, and can lead to erroneous interpretations. Routine production of tectonic sequence diagrams (TSDs) allows a method whereby all deformation and metamorphic mineral growth events, their overprinting and duration (based on relative timing) are systematically recorded. Different hypotheses as to correlation of TSDs across a region can then be assessed objectively, including correlation of characteristic sequences that can often be recognized in TSDs from single outcrops. TSDs ensure that absolute dating is applied to specific events within a sequence, eliminating the practice where a date is imprecisely correlated. TSDs also place a focus on the independent character of events, here confirmed by absolute dating. Here we demonstrate how TSDs show that many fold nappes are recumbent folds transected by later (unrelated) ductile shear zones. TSDs also show that P–T–t paths and exhumation rates must include starting and stopping of events, periods of quiescence and changes in tectonic mode from shortening to extension. TSDs allow objective analysis of the complexity present in many metamorphic tectonites, but which is obscured by conventional methodology.
Tracking the Saharan Air Layer with shipborne lidar across the tropical Atlantic

Saharan dust was observed with shipborne lidar from 60° to 20°W along 14.5°N during a 1‐month transatlantic cruise of the research vessel Meteor. About 4500 km off the coast of Africa, mean extinction and backscatter‐related Ångström exponent of 0.1, wavelength‐independent extinction‐to‐backscatter ratios (lidar ratios) of around 45 sr, and particle linear depolarization ratio of 20% were found for aged dust (transport time >10 days). In contrast, dust with a shorter atmospheric residence time of 2–3 days showed Ångström exponents of −0.5 (backscatter coefficient) and 0.1 (extinction coefficient), mean lidar ratios of 64 and 50 sr, and particle linear depolarization ratios of 22 and 26% at 355 and 532 nm wavelength, respectively. Traces of fire smoke were also detected in the observed dust layers. The lidar observations were complemented by Aerosol Robotic Network handheld Sun photometer measurements, which revealed a mean total atmospheric column aerosol optical thickness of 0.05 for pure marine conditions (in the absence of lofted aerosol layers) and roughly 0.9 during a strong Saharan dust outbreak. The achieved data set was compared with first Consortium for Small Scale Modeling‐Multi‐Scale Chemistry Aerosol Transport simulations. The simulated vertical aerosol distribution showed good agreement with the lidar observations.
Towards integrating tracer studies in conceptual rainfall‐runoff models: recent insights from a sub‐arctic catchment in the Cairngorm Mountains, Scotland

Hydrochemical tracers (alkalinity and silica) were used in an end‐member mixing analysis (EMMA) of runoff sources in the 10 km2 Allt a' Mharcaidh catchment. A three‐component mixing model was used to separate the hydrograph and estimate, to a first approximation, the range of likely contributions of overland flow, shallow subsurface storm flow, and groundwater to the annual hydrograph. A conceptual, catchment‐scale rainfall‐runoff model (DIY) was also used to separate the annual hydrograph in an equivalent set of flow paths. The two approaches produced independent representations of catchment hydrology that exhibited reasonable agreement. This showed the dominance of overland flow in generating storm runoff and the important role of groundwater inputs throughout the hydrological year. Moreover, DIY was successfully adapted to simulate stream chemistry (alkalinity) at daily time steps. Sensitivity analysis showed that whilst a distinct groundwater source at the catchment scale could be identified, there was considerable uncertainty in differentiating between overland flow and subsurface storm flow in both the EMMA and DIY applications. Nevertheless, the study indicated that the complementary use of tracer analysis in EMMA can increase the confidence in conceptual model structure. However, conclusions are restricted to the specific spatial and temporal scales examined. Copyright © 2003 John Wiley & Sons, Ltd.
Asteroid and Ophiuroid Trace Fossils from the Lower Cretaceous of Chile

Abundant asterozoan trace fossils in the Lower Cretaceous Apeleg Formation of southern Chile were produced by the infilling of traces made by asteroids and ophiuroids on a muddy surface. Most are preserved as hypichnial ridges formed as casts on the bottom of fine‐grained sandstone laminae. Star‐shaped Asteriacites lumbricalis are interpreted as the infillings of shallow excavations made by asteroids. Hook‐shaped and sinuous ridges of the newly defined ichnogenus and ichnospecies Ophioichnus aysenensis are interpreted as the casts of imprints made by the walking action of the arms of ophiuroids. Deposition probably took place in an offshore tide‐swept marine shelf environment. In life the animals formed an assemblage equivalent to echinoderm aggregations on the modern sea floor.