Miracle-dz/UniFAR-FTUs huggingface dataset:
3D Analogue Models of Rift Systems: Templates for 3D Seismic Interpretation

Abstract 3D visualizations of modern, high-resolution seismic data have provided valuable insights into the finite geometries and spatial extent of extensional fault systems, but their evolution in time is poorly understood. Scaled 3D analogue models of rift basin evolution provide kinematic templates for understanding the 4D evolution of extensional fault systems. This paper reviews the development of extensional fault systems in analogue models of orthogonal, oblique and offset rifts. In orthogonal and oblique models, stretching above a zone of ductile deformation at the base of the model initially produced segmented rift border faults whose orientations were strongly controlled by the underlying baseplate configuration. In contrast, the intra-rift faults generally initiated at high angles to the extension direction. With increased extension both the rift border faults and the intra-rift faults propagated along strike, first producing segmented fault systems separated by relay ramps, which, with increased extension, became breached as fault linkage occurred. Kinks in the fault traces indicate linkage points. Within the models, asymmetric intra-rift sub-basins were formed where the extensional fault arrays had a dominant dip polarity. Intra-basin accommodation zones, separating individual sub-basins along the rift axis, were formed by interlocking oppositely dipping fault systems. Offset oblique rift models, formed above a zone of ductile stretching with basement offsets, generated intra-basin accommodation zones whose orientation was controlled by the underlying basement fabric. The results of the analogue models can be directly compared with fault systems in the Northern Ethiopian rift system, with the accommodation zones in the Gulf of Suez, Egypt, with extensional fault arrays in Canyonlands, Utah, and with rift fault systems in the Gulf of Thailand and the southern North Sea.
A currently forming petroleum associated with hydrothermal mineralization in a submarine caldera, Kagoshima Bay, Japan

Petroleum-like products have been found in hydrothermally altered recent sediments of the submarine Wakamiko Caldera (depth = 200 m) in the northern Kagoshima Bay, southern Kyushu, Japan. High concentrations of polynuclear aromatic hydrocarbons (PAHs) of pyrolytic origin and biomarkers signatures representing diverse degrees of maturation have indicated that the associated bitumen is a typical hydrothermal petroleum. This is the first report on a significant content of hydrothermal petroleum related with a submarine volcanism of island-arc. The petroleum was generated by pyrolysis of organic matter in recent sediments deposited in the caldera. The hydrothermal petroleum and massive sulfide deposits are concluded to be currently forming within the caldera by hydrothermal activities below the seafloor where presently forming Kuroko-type sulfide deposits were also reported. Considering simultaneous formation of the hydrothermal petroleum and the Kuroko-type deposits in the Wakamiko Caldera, we propose a hypothesis that, during the middle Miocene, the same phenomena happened extensively in northeast Japan in association with the large-scale marine volcanisms, resulting in the formation of both petroleum and sulfide ore deposits (Kuroko) in the same geological horizons.
Carbonate platform dominated by peloidal sands: Lower Ordovician La Silla Formation of the eastern Precordillera, San Juan, Argentina

The Lower Ordovician La Silla Formation of the Precordillera of west‐central Argentina is part of the west‐facing early Palaeozoic, tropical carbonate platform succession that comprises the core of the Cuyania terrane. Up to 360 m thick, it is exposed in several thrust sheets over a distance of some 250 km along and across depositional strike over a palinspastically unrestored distance of about 35 km. La Silla Formation is a strikingly pure limestone with subordinate finely crystalline dolomite and rare chert. It accumulated on a more or less uniformly subsiding passive margin. Copious precipitation of microcrystalline calcite, probably influenced by microbial activity to varying degrees, led to the generation of peloids, ooids and aggregates of these grains, as well as small amounts of lime mud, intraclasts, stromatolites and thrombolites. Rare bioclasts are limited mostly to scattered gastropods and trilobite sclerites; bioturbation is present locally. The array of carbonate rock types is grouped into eight recurring lithofacies, in order of decreasing abundance: (i) peloidal grainstone; (ii) laminated dolostone; (iii) intraclastic rudstone; (iv) microbial laminite; (v) peloidal packstone; (vi) ooidal grainstone; (vii) thrombolite boundstone; and (viii) mudstone. These facies represent sediments that formed solely in a shallow subtidal marine environment, with no evidence of restricted conditions, hypersalinity or subaerial exposure. No events of eustatic sea‐level change are recorded. By far the dominant facies is grainstone composed of well‐sorted, fine sand‐sized peloids and peloidal aggregates in homogeneous, tabular to gently undulating, medium to thick beds; cross‐lamination is scarce. Clusters of sub‐metre‐sized microbial patch reefs developed sporadically. The shallow platform is envisaged to have been covered by extensive peloidal sand flats and low‐relief banks, and little lime mud was generated. The setting was probably microtidal and may not have been affected by strong trade winds. It was washed by frequent, relatively gentle wave action but without experiencing powerful storms. In the middle member, anomalous lenses of intraclastic rudstone and laminated dolostone occur as graded beds overlying sharply downcut scoured surfaces up to 20 cm deep; these are interpreted to indicate a phase when accretion was punctuated occasionally by tsunamis generated from rift‐faulting seaward of the platform margin. The remarkably uniform peloidal grainstone composition over a broad area shows that, given the appropriate combination of climate, environmental and ecological factors, large portions of some early Palaeozoic platforms were dominated by grainy sediment and remained under well‐agitated conditions within fair‐weather wave‐base, without distinct lateral facies differentiation or tidal‐flat aggradation.
A Comparative Study on Precipitation Climatology and Interannual Variability in the Lower Midlatitude East Asia and Central Asia

AbstractThis study examines precipitation climatology and interannual variability in two regions in the lower midlatitude Asia to the east and west of the Tibetan Plateau, one located in monsoonal East Asia (the M region) and the other in semiarid central Asia (the W region). The focus is on the 5-month summer half year (May–September) for the M region and the winter half year (December–April) for the W region, corresponding to their respective rainy seasons. The main mechanism of moisture transport for the M region is the summer lower-tropospheric southerly winds, whereas the winter midtropospheric westerly circulation between 25° and 45°N is responsible for conducting moisture fluxes to the W region. It is further discovered that the winter precipitation series are positively correlated between the two regions (r = 0.47). There is also a weak cross-seasonal correlation between the winter W region precipitation and summer M region precipitation (r = 0.27). Winter westerly circulation over the W region is.
Calibration changes in the isotopic thermometer for snow according to different climatic states

Bore hole thermometry indicates that the estimated temperature shift at Summit (Greenland) from the Last Glacial to Holocene times was ∼50% higher than the value obtained using the traditional isotopic δ (T) thermometer calibrated with today's data. A mechanism offered by Boyle [1997] to explain the anomalous ice core δ shift is examined. The mechanism, called the Boyle Effect, is theoretically possible but if it operated at Summit, it appears to be only capable of accounting for slightly more than half of the Summit δ 18O anomaly of ∼4.3‰. A new semi‐quantitative mechanism is proposed that could account for the remaining part of the anomaly. Other mechanisms have been advanced but they are not so amenable to quantitative application and testing.
A complete daily precipitation database for northeast Spain: reconstruction, quality control, and homogeneity

This paper reports the procedure used in creating a homogeneous database of daily precipitation in northeast Spain. The source database comprised 3106 daily precipitation observatories, with data ranging from 1901 to 2002. Firstly, a reconstruction of the series was performed. Data from adjacent observatories were combined to provide long temporal coverage. Data gaps were filled using values from the nearest neighbour observatories. A distance threshold was set to avoid the introduction of spurious information in the series. Secondly, the reconstructed series were subjected to a quality control process. Empirical percentiles corresponding to each precipitation observation were compared to the percentiles corresponding to the closest neighbour observatory, and a threshold difference was set to identify questionable extremes. After careful inspection of each case, 0.1% of the data was rejected and replaced with information from the nearest neighbour. Thirdly, the homogeneity of the series was checked using the standard normal homogeneity test. This allowed detection of inconsistencies present in the original database or introduced by the reconstruction process. Four parameters were assessed at a monthly level: amount of precipitation, number of rainy days, daily maxima, and number of days above the 99th percentile. A total of 43% of the series had some periods of inhomogeneity and were discarded. The final database comprised 828 series with varying time coverages. The greatest number of stations existed during the 1990s, but more than 300 series contained information from the 1960s, and 34 series contained a complete record since 1920. Comparisons of the spatial variability of several parameters describing the daily precipitation characteristics were made. The results showed that the final database had improved spatial coherence. The process described here is proposed as a model for developing a standard procedure for the construction of databases of daily climate data. Copyright © 2010 Royal Meteorological Society
Predictable Components in Australian Daily Temperature Data

AbstractDynamical components of Earth’s ice–ocean–atmosphere system evolve along characteristic trajectories, which make these components partly predictable. This paper reviews several methods for extracting these predictable components from space–time fields. These methods are optimal persistence analysis (OPA), slow feature analysis (SFA), principal trend analysis (PTA), average predictability time decomposition (APTD), and forecastable components analysis (ForeCA). These methods generally find a set of components that are ordered by their predictability, but each method uses a different measure of predictability. Also, a new bootstrap test for investigating the type of predictability exhibited by these components is introduced. This new test is based on an “integrated red noise” hypothesis. The five methods and new test are applied to a dataset of Australian daily near-surface minimum air temperature, spanning 1910–2013. For all five methods, the two leading predictable components are a long-term trend.
Striking the right balance: health workforce retention in remote and rural areas.

Ensuring universal access to skilled, mo-tivated and supported health workers, especially in remote and rural communi-ties, is a necessary condition for realizing the human right to health, a matter of social justice. It is also at the core of each and every global health goal – the United Nations’ Millennium Development Goals, primary health care, immunization, and control of HIV/AIDS, malaria and tuber-culosis. For none of these goals is attainable if significant population groups are denied access to health workers.Despite recent increased rhetoric, human resources remain a sorely neglected and grossly under-financed engine for health improvement. That is why 1500 global health leaders issued the Kampala Declaration in 2008: “to assure adequate incentives and an enabling and safe envi-ronment for effective retention and equi-table distribution of the health workforce”.
Centrosome age regulates kinetochore–microtubule stability and biases chromosome mis-segregation

The poles of the mitotic spindle contain one old and one young centrosome. In asymmetric stem cell divisions, the age of centrosomes affects their behaviour and their probability to remain in the stem cell. In contrast, in symmetric divisions, old and young centrosomes are thought to behave equally. This hypothesis is, however, untested. In this study, we show in symmetrically dividing human cells that kinetochore–microtubules associated to old centrosomes are more stable than those associated to young centrosomes, and that this difference favours the accumulation of premature end-on attachments that delay the alignment of polar chromosomes at old centrosomes. This differential microtubule stability depends on cenexin, a protein enriched on old centrosomes. It persists throughout mitosis, biasing chromosome segregation in anaphase by causing daughter cells with old centrosomes to retain non-disjoint chromosomes 85% of the time. We conclude that centrosome age imposes via cenexin a functional asymmetry on all mitotic spindles. DOI: http://dx.doi. org/10.7554/eLife.07909. 001
Buckling of the lithosphere in western Himalaya: Constraints from gravity and topography data

The deformation of the lithosphere in western Himalaya and Karakoram is analyzed by correlating Bouguer gravity anomalies and topographic heights sampled along profiles in the direction of the Indo-Asian collision. The spectral features of the coherence, linear admittance, and correlation coefficients between topography and deformation at depth support the hypothesis that the flexural mode of lithospheric deformation is complemented by a folding mode, with typical wavelengths concentrated in bands centered at 250 and 120 km. When combined with realistic models of a rheologically stratified lithosphere with two strong layers (upper crust and upper mantle) sandwiching a weak, very ductile layer (the lower crust), the data are consistent with a model of response to horizontal deformation in which a coupled, biharmonic folding instability develops: The lithosphere as a whole warps with the longer wavelengths and the upper layer alone also with the shorter wavelengths. Major faults, such as the Main Boundary Thrust, or the Main Karakoram Thrust and the computed folds of the upper layer are phased, as if there were a causal relationship between the position of the faults and the zones of highest strain in the crust.
Three‐dimensional magnetic imaging of the Chicxulub Crater

Although few magnetization measurements are available for the structural elements of the Chicxulub impact crater, the magnetization intensities of the melt sheet, upper breccia unit, and central uplift are 3–4 orders of magnitude greater than the 3- to 4-km-thick carbonate and evaporite stratigraphy covering the Yucatan block. This allows three-dimensional modeling of the crater's structure by inversion using a two-layer model. Two layers are separately inverted by dividing the crater's magnetic field expression into 40-km wavelength components. The upper layer (average depth 2 km) models the distribution of highly-magnetized zones in the crater's melt sheet. The lower layer (average depth 5 km) represents relief on the Yucatan block's basement surface and effectively maps the crater's ∼50-km-diameter central uplift and possibly the expression of the surrounding collapsed disruption cavity fill. The shallower magnetized zones consist of two generally concentric distributions, at radii of ∼20 and ∼45 km. These highly magnetized zones are thought to result from hydrothermal systems, localized at the edge of the central uplift and the collapsed disruption cavity, having produced magnetic phases during alteration of the melt sheet.
Geochemical characterization of gases from the Mississippian Barnett Shale, Fort Worth Basin, Texas

Molecular and isotopic compositions of 51 gas and 7 condensate samples produced from the Barnett Shale were determined by gas chromatography–isotope ratio mass spectrometry to investigate their origin and maturity at the time of generation. Additionally, two hydrous pyrolysis experiments were performed to calibrate maturity values predicted for gas generation. Molecular and carbon and hydrogen isotopic compositions of the gases indicate that gas produced from the Barnett is thermogenic. To estimate generation maturity, additional analyses were performed on the condensates and available core samples. Diamondoid indices combined with vitrinite reflectance (Ro) measurements, isotopic and molecular composition, and hydrous pyrolysis experiments suggest that gas produced from the Barnett Shale was generated within the condensate–wet gas window (1.3–2.0% Ro) at a later stage than hydrocarbons accumulated in shallower reservoirs. The origin of the gas is thermogenic, probably derived from both kerogen cracking and secondary cracking of previously generated nonmigrated hydrocarbons. Additionally, the occurrence of a methane isotope reversal in group 1 gases corroborates that in-situ oil or gas cracking is occurring in the easternmost part of the study area.
Turbidites, the principal mechanism yielding black shales in the early deep Atlantic Ocean

Summary A series of organic and inorganic geochemical parameters and facies indicators were studied in Late Jurassic and Cretaceous black shales and organic rich sediment sections from basins offshore Angola, Ghana and North Carolina, and from the western Wealden Basin in NW-Germany. Based on these data the sediments can be grouped into: (i) intracratonic (Bueckeberg Formation, NW Germany), (ii) shelf (Cretaceous basins offshore Ghana), (iii) continental rise turbidite (Hatteras Formation of Leg 93, Hole 603B, Section IV), and (iv) deep basin (Leg 75, Hole 530B, Section VIII) black shales. Trends of geochemical evolution are interpreted as the effect of multiple reworking and equilibration, when organicrich sediments from shelfbound basins are transferred into oceanic depocentres as turbidites. It is suggested: (i) that during turbidite phases, organic-rich suspensates originating from these primary basins on continental margins are advected along density boundaries within the water column overlying oceanic basins, and (ii) that these substrates are introduced into zones where responding microbial populations create expanded zones of oxygen depletion. Microbial degradation affects predominantly marine organic compounds contained in these recycled sediments, leaving a residual kerogen composed of structureless organic matter with pronounced terrigenous signals. During slow sinking of these suspensions, chemical equilibration, possibly with the ambient water, leads to an association of certain meals, i.e. vanadium, zinc, and nickel, with the organic fraction. Pyrite placers form as the result of gravitational separation from oxygen depleted suspensates at the bottom of black shale beds. It appears that oceanic anoxia is not a prerequisite for black shale sedimentation in the Cretaceous basins of the Atlantic Ocean.
Optical Depth of Overcast Cloud across Canada: Estimates Based on Surface Pyranometer and Satellite Measurements

Abstract Overcast cloud optical depths τ are inferred from hourly, broadband surface pyranometer measurements of global irradiance for 21 Canadian stations. A radiative transfer model that treats the atmosphere as plane-parallel and horizontally homogeneous is used so inferred τ are effective values that should resemble those used by GCM radiation routines. Results are presented mostly for June, July, and August (JJA), thus minimizing the impact of surface albedo errors that arise from unreported sea–ice and ground snow. Measurement periods for several sites exceed 20 yr. Frequency distributions of τ for JJA can be described well by gamma distributions with mean values τ that tend to be largest (30–35) for southern continental sites and smallest (20–25) for continental subarctic sites. Corresponding standard deviations are generally near ∼1. 4τ. Diurnal amplitudes of hourly mean τ (dayside) are negligible for most sites but exceed 5 for some. There is some evidence of weak, yet occasionally significant, in.
Azimuthal variation of ion density and electron temperature in the Io plasma torus

We analyzed about 47 hours of Voyager 1 ultraviolet spectrometer observations of the Io plasma torus in order to determine the distributions of ion and electron density and electron temperature as five-dimensional functions of (1) radius (L), (2) System III longitude (λIII), (3) System IV longitude (λIV), (4) Jovian local solar time (ϕ⊙), and (5) azimuth relative to Io (ϕIo). We present averaged profiles of electron density (ne) and temperature (Te) as one-dimensional functions of each of these five variables in turn. Each of these profiles is an average of the full five-dimensional distribution over the other four variables. Our Te(L) estimate is substantially the same as that determined from in situ observations by the Voyager 1 plasma science investigation. As for the azimuthal profiles, we find that the ne(λIII) profile has a peak near λIII=180°, as expected from ground-based observations, while the Te(λIII) profile peaks around λIII=300°. The Jovian surface magnetic field reaches its lowest magnitude on the Io footprints near the Te(λIII) maximum, suggesting that part of the torus electron heating might be associated with Birkeland currents or some other magnetosphere-ionosphere coupling. In the Io frame, we find an apparent ne(ϕIo) maximum about 90° downstream from Io while the highest Te(ϕIo) occurs near Io, suggesting that electrons are locally heated by the Io atmosphere-torus MHD interaction. These two Te profiles suggest that field-aligned currents might comprise the long-sought additional (i.e., besides fresh ion pickup) electron-heating power source for torus emissions needed to resolve the torus “energy crisis”. In local solar time, we find that the Te(ϕ⊙) and ne(ϕ⊙) profiles peak between dusk and local midnight, with the former maximum nearer dusk and the latter nearer midnight. This combination suggests that the variation is due to an offset of the torus toward local midmorning, and perhaps that the cooling time is short. We also describe a general method for constraining solutions to be nonnegative when fitting data using the singular value decomposition least squares technique.