Detrital apatite fission track constraints on Cenozoic tectonic evolution of the northeastern Qinghai-Tibet Plateau,China: Evidence from Cenozoic strata in Lulehe section,Northern Qaidam Basin

The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due to compressional deformation during the Indo-Asian collision. In this paper, we used detrital apatite fission-track thermochronology, including 4 sandstones and 2 conglomerates samples from the Lulehe section, to reveal the Cenozoic evolution of the northern Qaidam Basin. Fission-track dating indicated the source region of the Lulehe section has experienced important cooling and uplifting in the Late Cretaceous (at ~85.1 Ma and ~65 Ma) and the Eocene (~52 Ma), respectively. The AFT age distribution on the section suggested that the provenance of Lulehe section sediments were mainly derived from the south Qilian Shan (Qilian Mountains) and Altun Shan (Altun Mountains), and two significantly provenance changes may occur at 43.4-46.1 Ma and ~37.8 Ma, respectively. The results may have strong constrains on the Cenozoic deformation and tectonic evolution of the northern Qaidam Basin and Qinghai-Tibet Plateau.     

Statistically downscaled probabilistic multi‐model ensemble projections of precipitation change in a watershed

This paper presents the development of a probabilistic multi‐model ensemble of statistically downscaled future projections of precipitation of a watershed in New Zealand. Climate change research based on the point estimates of a single model is considered less reliable for decision making, and multiple realizations of a single model or outputs from multiple models are often preferred for such purposes. Similarly, a probabilistic approach is preferable over deterministic point estimates. In the area of statistical downscaling, no single technique is considered a universal solution. This is due to the fact that each of these techniques has some weaknesses, owing to its basic working principles. Moreover, watershed scale precipitation downscaling is quite challenging and is more prone to uncertainty issues than downscaling of other climatological variables. So, multi‐model statistical downscaling studies based on a probabilistic approach are required. In the current paper, results from the three well‐reputed statistical downscaling methods are used to develop a Bayesian weighted multi‐model ensemble. The three members of the downscaling ensemble of this study belong to the following three broad categories of statistical downscaling methods: (1) multiple linear regression, (2) multiple non‐linear regression, and (3) stochastic weather generator. The results obtained in this study show that the new strategy adopted here is promising because of many advantages it offers, e.g. it combines the outputs of multiple statistical downscaling methods, provides probabilistic downscaled climate change projections and enables the quantification of uncertainty in these projections. This will encourage any future attempts for combining the results of multiple statistical downscaling methods. Copyright © 2011 John Wiley & Sons, Ltd.     

Climatic changes and desertification in some regions of the Middle East

It is generally believed that more than 100 tropical countries are suffering from desertification or land degradation as a result of climatic changes. There is also concern that the rising temperature would lead to further environmental degradation and cause economic, social and other environmental impacts (1) in the Middle East. This paper is a modest attempt to investigate temperature and rainfall data in three countries of the Middle East (Oman, Bahrain, and Sudan) to determine if any change has taken place in the weather conditions. The short term environmental impact of the GulfWar in 1991 has been included in the study.The study confirms that temperatures are rising and rainfall is decreasing in Oman (2, 3) and other two countries, leading to increasing desertification processes. Here, following Hume and Kelly (4) desertification is taken to mean degradation in dryland regions or the permanent decline in the potential of the land to support biological activity and hence human welfare. A brief geographical discussion of Oman, Bahrain, and Sudan precedes a detailed analysis of temperatures and rainfall regimen in all three countries.     

Application of Generalized Likelihood Uncertainty Estimation (GLUE) at different temporal scales to reduce the uncertainty level in modelled river flows

ABSTRACT

In this study, the distributed catchment-scale model, DiCaSM, was applied on five catchments across the UK. Given its importance, river flow was selected to study the uncertainty in streamflow prediction using the Generalized Likelihood Uncertainty Estimation (GLUE) methodology at different timescales (daily, monthly, seasonal and annual). The uncertainty analysis showed that the observed river flows were within the predicted bounds/envelope of 5% and 95% percentiles. These predicted river flow bounds contained most of the observed river flows, as expressed by the high containment ratio, CR. In addition to CR, other uncertainty indices – bandwidth B, relative bandwidth RB, degrees of asymmetry S and T, deviation amplitude D, relative deviation amplitude RD and the R factor – also indicated that the predicted river flows have acceptable uncertainty levels. The results show lower uncertainty in predicted river flows when increasing the timescale from daily to monthly to seasonal, with the lowest uncertainty associated with annual flows.     

Toward an Ecological Explanation of Agricultural Unemployment in Bangladesh

Cultural ecology theoretical framework was found suitable to explain unemployment in agriculture in three villages in Bangladesh. Path analysis and multiple regression statistics were used to examine the direct, indirect, and total effects of eight independent human, social, environmental, and technology variables as well as their aggregate contribution on agricultural unemployment. The multiple regression model explains 86.2% of the total variation in unemployment in agriculture; they were followed by environmental constraints and labor saving technology variables.     

Geochemistry and hydrothermal alteration of the Kern Mountains plutonic complex,White Pine County,Nevada and Juab County,Utah

The Kern Mountains plutonic complex is composed of multiple intrusions referred as the Cove, Tungstonia and Hoodoo Canyon plutons, whose emplacement was structurally controlled. The plutons are members of the calc-alcaline granite series, leucogranite type that are relatively alkali rich. The complex is of epizone (4–10 km) and was emplaced during Jurassic time into the carbonates and quartzite of Paleozoic age. Trace and major element data indicate that the complex was derived from the partial melting of rocks similar to Canadian Shield rocks. Analysis of variance of chemical data suggets that hydrothermal solutions carried K₂O, Na₂O and SiO₂ and raised the levels of original oxides in the plutons. Hydrothermal activity is evidenced by the occurrence of second generation muscovite, potassium feldspar and quartz in the complex and tungsten and sulphide mineralization in the area.

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Zusammenfassung Der plutonische Komplex des Kerngebirges besteht aus mehrfachen Instrusionen, genannt Cove-, Tungstonia- und Hoodoo Canyon-Pluton, deren Platznahme tektonisch kontrolliert wurde. Die plutonischen Gesteine gehören zu den Kalkalkaligraniten; sie sind leucogranitisch und damit ziemlich alkalireich. Der Komplex ist epizonal (4–10 km), er drang während des Jura in die Karbonate und Quarzite des Paläozoikums ein. Spuren- und Hauptelementmeßwerte zeigen an, daß der Komplex von aufgeschmolzenen Gesteinen abgeleitet werden kann, die den Gesteinen des Kanadischen Schildes ähneln. Die Analyse der Variation von chemischen Meßwerten deutet an, daß hydrothermale Lösungen K₂O, Na₂O und SiO₂ enthielten, die das Niveau der ursprünglichen Oxide in den plutonischen Gesteinen erhöhten. Die hydrothermale Tätigkeit wird durch das Vorhandensein von Muskowit, Kaliunifeldspat und Quartz der zweiten Generation innerhalb des Komplexes und durch Wolfram- und Sulfidmineralisation in der Umgebung bewiesen.

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Résumé L'ensemble plutonique des montagnes de Kern, consiste en de nombreuses intrusions dénommées plutons du »Cove«, de »Tungstonia«, et du »Hoodoo Canyon« dont la mise en place a été tectoniquement controlée. Ces plutons font partie de la série granitique calco-alkaline; ce sont des leucogranites relativement riches en alcali. L'ensemble est épizonal (4–10 km), et s'est mis en place au cours du Jurassique dans des Calcaires et quartzites d'âge paléozoique. Les données analytiques relatives aux élements majeurs et en trace indiquent que cet ensemble peut provenir de la fusion partielle de roches similaires à celles du Bouclier Canadien.L'analyse de la variation des données chimiques suggère aussi que l'enrichissement de ces plutons en K₂O, Na₂O, et SiO₂ s'est fait à partir de solutions minéralisantes hydrothermales, comme en témoignent non seulement la présence d'une deuxième génération de muscovite, de feldspath potassique et de quartz, mais aussi par la mineralisation en tungstène et en minerais sulfurés à leur voisinage.

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, Cove, Tungstonia Hoodoo Canyon, . - ; , , . (4–10 ); . - , , . , K₂O, Na₂O SiO₂, . , .

     

Source Sector Contributions to Aerosol Levels in Pakistan

Urban air pollution in Pakistan is a serious challenge and it causes significant damage to human health and ecosystems. This paper presents a modelling study using the Weather Research and Forecasting Model coupled with Chemistry(WRF-Chem) to simulate the spatial distributions and temporal variations of aerosol concentrations over Pakistan, focusing on contributions of domestic emission sectors(transport, industry, residential, and energy) to mass concentrations of sulfate(SO2–4), nitrate(NO–3), ammonium(NH+4), black carbon(BC), and organic carbon(OC) during the months of January, April, July, and October in 2010. Sensitivity studies indicate that, averaged over January, April, July, and October of 2010, energy and industry sectors have the largest contributions to SO2–4 concentrations, each of which contributes about 10%?20% to SO2– 4over the polluted eastern Pakistan. The contributions from residential and transport sectors to NO–3 concentrations reach 40%?50% in central Pakistan. The residential sector has the highest contribution of 50%–80% to BC and OC loading in northeastern and southern Pakistan. Examination of sector contributions to aerosol levels in Lahore, the most polluted city in Pakistan, suggests that reductions in emissions in the residential sector should be an efficient measure for improving particulate matter air quality in this region.     

A multi-proxy reconstruction of spatial and temporal variations in Asian summer temperatures over the last millennium

To investigate climate variability in Asia during the last millennium, the spatial and temporal evolution of summer (June–July–August; JJA) temperature in eastern and south-central Asia is reconstructed using multi-proxy records and the regularized expectation maximization (RegEM) algorithm with truncated total least squares (TTLS), under a point-by-point regression (PPR) framework. The temperature index reconstructions show that the late 20th century was the warmest period in Asia over the past millennium. The temperature field reconstructions illustrate that temperatures in central, eastern, and southern China during the 11th and 13th centuries, and in western Asia during the 12th century, were significantly higher than those in other regions, and comparable to levels in the 20th century. Except for the most recent warming, all identified warm events showed distinct regional expressions and none were uniform over the entire reconstruction area. The main finding of the study is that spatial temperature patterns have, on centennial time-scales, varied greatly over the last millennium. Moreover, seven climate model simulations, from the Coupled Model Intercomparison Project Phase 5 (CMIP5), over the same region of Asia, are all consistent with the temperature index reconstruction at the 99 % confidence level. Only spatial temperature patterns extracted as the first empirical orthogonal function (EOF) from the GISS-E2-R and MPI-ESM-P model simulations are significant and consistent with the temperature field reconstruction over the past millennium in Asia at the 90 % confidence level. This indicates that both the reconstruction and the simulations depict the temporal climate variability well over the past millennium. However, the spatial simulation or reconstruction capability of climate variability over the past millennium could be still limited. For reconstruction, some grid points do not pass validation tests and reveal the need for more proxies with high temporal resolution, accurate dating, and sensitive temperature signals, especially in central Asia and before AD 1400.     

Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water

Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.