Viséan Fossil Plants from the Jiujialu Formation in Central Guizhou Province: Implications for Age of Bauxite and Palaeoenvironment

Fossil plants from the carbonaceous shale of upper part of the Lower Carboniferous Jiujialu Formation in Lindai bauxite deposit fill a gap regarding the distribution of Early Carboniferous flora in Central Guizhou Province. Here the Lindai plant assemblage is systematically described, and its composition and geological age are discussed. Research demonstrates that 9 species in 6 genera of the fossil plants are discovered in this study, and they belong to lycopsids, sphenopsids and ferns, respectively. Based on the analysis of the floral composition, the geological age of the Lindai plant assemblage belongs to the Early Carboniferous Viséan. The discovery of Lindai plant assemblage not only provides a new fossil evidence to restrict the age of bauxite deposits in Lower Carboniferous Jiujialu Formation of Central Guizhou Province, but also has great significance to further research the palaeoecological setting and floral evolution during the Early Carboniferous.     

A Seismic Hazard Map Based on Geology and Shear-wave Velocity in Rawalpindi–Islamabad,Pakistan

The ‘twin cities' district of Rawalpindi–Islamabad is among the most endangered seismic regions in Pakistan,with the seismic hazard assessed(0.32 g) to intensity IX MMI for a 475-year return period. A seismic hazard map for Rawalpindi–Islamabad is presented herein, based on 85 shear-wave velocity(VS) profiles obtained through geophysical H/V measurements and from the geological map of the region. Relationships between the average top thirty-meter shear-wave velocities(VS30) and surficial geological units have been determined. The peak ground acceleration(PGA) maps for 150,475 and 2475-year return periods were converted into a seismic intensity map. Intensity increments for different soils were used to compute PGA values for 150, 475 and 2475-year return periods. Sites located on softer ground experienced a higher degree of damage from moderate earthquakes. Due to the presence of soft clay or lique?able soil and lateral spreading, a few locations may be classified as hybrid sites class C and D. This map is a critical step in facilitating code-based site classification and seismic design throughout Rawalpindi–Islamabad. Although the seismic hazard map based on seismic intensities is no longer used in engineering geology, it is still important in seismological analysis and for civil protection purposes.     

Hot plasma waves in Schwarzschild magnetosphere

In this paper we examine the wave properties of a hot plasma living in a Schwarzschild magnetosphere. The 3+1 GRMHD perturbation equations are formulated for this scenario. These equations are Fourier analyzed and then solved numerically to obtain the dispersion relations for a non-rotating, rotating non-magnetized and rotating magnetized plasma. The wave vector is evaluated, which is used to calculate the refractive index. These quantities are shown in graphs which are helpful to discuss the dispersive properties of the medium near the event horizon.     

Modelling interannual variations in catchment evapotranspiration considering vegetation and climate seasonality using the Budyko framework

The Budyko framework is an efficient tool for investigating catchment water balance, focusing on the effects of seasonal changes in climate (S) and vegetation cover (M) on catchment evapotranspiration (ET). However, the effects of vegetation seasonality on ET remain largely unknown. The present study explored these effects by modelling interannual variations in ET considering vegetation and climate seasonality using the Budyko framework. Reconstructed 15-day GIMMS NDVI_3g timeseries data from 1982 to 2015 were used to estimate M and extract the relative duration of the vegetation growing season (GL) in the Yellow River Basin (YRB). To characterize S, seasonal variations in precipitation and potential ET were extracted using a Gaussian algorithm. Analysis of the observed datasets for 19 catchments revealed that interannual variation in the catchment parameter ϖ (in Fuh's equation) was significantly and positively correlated with M and GL. Conversely, ϖ was significantly but negatively correlated with S. Furthermore, stepwise linear regression was used to calibrate the empirical formula of ϖ for these three dimensionless parameters. Following validation, based on observations in the remaining 11 catchments, ϖ was integrated into Fuh's equation to accurately estimate annual ET. Over 79% subcatchments showed an upward trend (0.9 mm yr⁻¹), whereas fewer than 21% subcatchments showed a downward trend (−0.5 mm yr⁻¹) across YRB. In the central region of the middle reach, ET increased with increased M, prolonged GL, and decreased S, whereas in the source region of YRB, ET decreased with decreased M and shortened GL. Our study provides an alternative method to estimate interannual ET in ungauged catchments and offers a novel perspective to investigate hydrological responses to vegetation and climate seasonality in the long-term.     

Tillage and farm manure affect root growth and nutrient uptake of wheat and rice under semi-arid conditions

Tillage systems affect soil properties, crop growth and nutrient uptake under various agro-ecological conditions. The uptake of water and nutrients are largely dependent on the root systems of wheat (Triticum aestivum L.) and rice (Oryza sativa L.). The application of manure has direct influence on the nutrient uptake by the crop plants. A 2 year field experiment was conducted to evaluate the impact of tillage and farm manure on root growth by measuring the root length density on a sandy clay loam (Typic calciargid soil). Three tillage systems were used; (i) minimum tillage (MT), (ii) deep tillage (DT) and (iii) conventional tillage (CT). Three farm manure levels were used; (i) FM₀ (only chemical fertilizers), (ii) FM₁₅ (farm manure at 15 Mg ha^?1) and (iii) FM₃₀ (farm manure at 30 Mg ha^?1). The incorporation of farm manure into soil markedly improved the root length density (RLD) of both wheat and rice crops. For wheat, the application of FM₃₀ increased RLD by 16% and 9% in cases of deep tillage and minimum tillage, respectively. For rice, the increase in RLD at the same farm manure rate (FM₃₀) was 13% and 17%, during first and second year, respectively. Averaged across tillage, the trend of RLD for both wheat and rice was DT > CT > MT. The incorporation of FM has increased the uptake of N, P and K significantly (P < 0.05), thereby increasing the agronomic parameters. The manure may be used to ameliorate the deleterious effects of tillage for sustainable crop yield.     

Mineralogy and palynology of the Mesopotamian plain sediments, Central Iraq

This work was done on the representative section (230 cm) in Dora site which located in Baghdad in the central of the Mesopotamian Plain. Eleven soil samples were examined mineralogically and palynologically. Grain size analyses showed that silt is the higher fraction (61%), clay is the least (9%), whereas sand forms 30%. Translucent and opaque heavy minerals contributed 57% from the sand fraction, whereas the light minerals formed just 43%. The type of heavy minerals and its maturity defined four provenances—they are granitic, basic igneous and metamorphic rocks—that belong to the high lands of south Turkey and north of Iraq. The fourth provenance is the sedimentary rocks which are located north of Mesopotamian Plain around the Tigris River and their tributaries. Dinoflagellate within thin bed of marine origin clearly indicated the transgression of the Arabian Sea northward through Tigris and Euphrates valleys or high marine waves reached to Baghdad before 10,000 years P.B. approximately. This means that the marine sediments were also an additional source of the Mesopotamian Plain. Three specific climatic features are identified via palynological interpretation; a temperate-wet climate extended from 10,000 to 5,000 years P.B. followed by dry period extended from 5,000 to 3,500 years P.B. and the last climatic feature is characterized by oscillation of wet to dry periods which is dominant since 3,500 till now.     

Spectral analysis of local climatic fluctuations

This paper employs spectral analysis to detect regular cyclical patterns or periodicities of local climate parameters of five major cities of Pakistan. Our calculations show that the temperature of all major climate stations may be affected by ENSO or QBO or Sunspot Cycles. As for the rainfall, what we find is that Pakistan summer monsoon exhibits a fairly similar bienniality with that of the Indian monsoon.     

Ionic liquid as a medium to remove iron and other metal ions: a case study of the North Kelantan Aquifer,Malaysia

An alternative iron removal treatment method using liquid-liquid extraction with the room-temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, as a solvent medium was studied. The chelating agent 1,10-phenanthroline was used as the extractant. The extraction of Fe(III) and Fe(II) was influenced significantly by the pH of the aqueous phase. The successful removal of iron was achieved; more than 95 % of the initial iron concentration was removed from the groundwater samples. However, detailed research is needed before the ionic liquid method can replace the conventional groundwater treatment protocol because the recovery rate was very low upon reuse (approximately 25–60 %). This low recovery was due to the ion exchange process; the appearance of anions from ionic liquids was also detected in groundwater samples.