Cosmogenic ^(26)Al/^(10)Be Burial Dating of the Uplift Rate of Southern Qinling Mountains since the Middle Pleistocene

Objective The Qinling Mountains （QM） in Central China is a natural harrier that corresponds to the boundary between the southern and northern climate and environment （Gong Hujun et al., 2017）. Northern QM is relatively steep, and southern QM is in contrast relatively low and gentle. Investigations have shown that the average uplift rate of northern QM since 17.8 Ma is approximately 0.19 mm/a （Yin Gongming et al., 2001）, whereas that of central QM since 0.36 Ma is approximately 0.32 mm/a （Wang Fei et al., 2004）. To date, however, few investigations have yet been conducted on the uplift rate of southern QM. Accordingly, we aim to obtain the uplift rate of southern QM by using the cosmogenic ^26A1/^10 Be burial dating method to determine the age of the highest river terrace on the southern slope of QM.

Cosmogenic 26Al/10Be Burial Dating of the Birth of the Present Hanjiang River

Objective Structural lows and major rift systems provide the basis for the creation of large rivers.The uplift of the Qinling and Daba Mountains structural belts and Tibetan Plateau would have provided the basis for the origin and northwest–southeast flow of the ancient Hanjiang River(Lu et al.,2018).After a long-term evolution,the present pattern of Hanjiang River has been formed.Five to six river terraces in the Hanzhong and Yunxian basins along the flanks of Hanjiang River valleys had been identified and some terraces had been dated by using optically stimulated luminescence(OSL),paleomagnetic,and electron spin resonance(ESR)dating methods,and correlating the pedostratigraphy and magnetic susceptibility with the Luochuan loess section by our team(Sun et al.,2016,2017).These terraces are composed of fluvial deposits overlaid with eolian deposits,and record the evolution history of the Hanjiang River.(Fig.1).This study is aimed to deduce the birth time of the present Hanjiang River by using 26Al/10Be burial dating method to date the highest fluvial terraces of the Hanjiang River.

Cyclostratigraphy of the Induan (Early Triassic) in West Pingdingshan Section,Chaohu,Anhui Province

The Induan sequence in the West Pingdingshan Section, Chaohu, Anhui Province, displays a series of superimposed mudstone/limestone cycles. The lithological character of the cycles, combined with power spectral and wavelet analysis of magnetic susceptibility readings, reveals 12 short eccentricity and 56 precession Milankovitch cycles - obliquity cycles are not apparent. The uniformity of cycle thicknesses indicates a stable depositional setting making this section ideal to perform various geo-logical studies. Accordingly, the Induan Stage is estimated to have lasted 1.1 Ma, and the depositional rate for this part of the section is about 3.7 cm/ka. This places the Induan-Olenekian boundary in the West Pingdingshan Section at about 251.5 Ma based on an age of 252.6 Ma for the Permian-Triassic boundary.

Phytolith records of the climate change since the past 15000 years in the middle reach of the Yangtze River in China

Based on 14C dating and core sediments survey, phytolith records are employed to reconstruct paleovegetation and paleoclimate in the Jianghan Plain in the middle reach of the Yangtze River. Phytoliths identified are assigned into 21 well-described morphotypes and divided into four groups （Poaceae, fern, coniferous and broad-leaved）. The phytolith assemblages together with warmth index （Iw） are divided into 18 ecological zones, which reflect a complete vegetation history related to climate change in the middle reach of the Yangtze River during the past 15000 years. On the basis of the correlation ofphytolith records with the paleoclimatic indicators from stalagmite, peatland, North Atlantic deep-sea sediments, Loess Plateau of Central China, and Arabic Sea sediments, eight climatic phases are identified included Last Glacial Maximum （LGM） （20- 14.8 cal kaBP）, Last Deglaciation （LDG） （14.8-11.9 cal kaBP）, low-temperature phase in the Early Holocene （11.9-8 cal kaBP）, Holocene Opti- mum （8-4.9cal kaBP）, Holocene Katathermal （4.9- 1.1 cal kaBP）, Medieval Warmth Period （MWP） （1.1- 0.7 cal kaBP）, Little Ice Age （LIA） （0.7-0.15 cal kaBP）, and Modem Warming （0.15 cal kaBP-present）. Climatic events such as Bolling-Allerod warm intervals, Older Dryas, Inter-Allerod Cold Period, and Younger Dryas, and eight Holocene Bond events （B1-8） have been identified since the LDG. Our results demonstrate that the evolution of the climate in the research area has a strong link with the Indian Summer Monsoon （SW Monsoon）, Asian Summer Monsoon （SE Monsoon）, and Holocene events in North Atlantic simultaneously, which might indicate that solar variability affects the Earth surface climate system at the centennial and millennial scales.

中国中部地区洛南盆地刘湾旧石器遗址的宇生核素埋藏测年研究（英文）

The Luonan Basin is a key region of early human settlement in Central China with more than 300 discovered Paleolithic sites. Artifact layer 1 of the Liuwan site was dated to approximately 0.6 million years(Ma) based on correlation with the well-dated loess–paleosol sequence of the central Chinese Loess Plateau. This study reassessed the age of the Liuwan artifact layer via an absolute dating method, namely, ^(26)Al/^(10)Be burial dating. We determined the burial age of artifact layer 1, which was most likely at least 0.60 ± 0.12 Ma(1?), using three simple burial ages. The new burial age confirmed the previous estimated age and provided a considerably accurate age range. Therefore, we suggest the use of the ^(26)Al/^(10)Be burial dating method in thin loess-covered Paleolithic sites around the Qinling Mountain Range is helpful to understand the early human behavior.

The biosorption of Cr（VI） ions by dried biomass obtained from a chromium-resistant bacterium

The biosorption potential of many different kinds of biomaterials has been widely studied. However, there is little data on the biosorption mechanism of Cr（VI） by dried biomass. So the bio-removal of Cr（VI） ions from aqueous solutions was investigated using dried biomass from a chromium-resistant bacterium. The bacterium was isolated from dewatered sludge samples that were obtained from a sewage treatment plant. Equilibrium and kinetic experiments were performed at different metal concentra- tions, pH values, and biosorbents dosages. The biomass was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The functional groups in the Bacillus cereus biomass which may play a role in the biosorption process were identified by Fourier transform infrared spectroscopy. The biosorption process was found to be highly pH dependent and the optimum pH for the adsorption of Cr（VI） was 2.0：k0.3 at 30-4-2 ℃. The experimental data fit well with Langmuir and Freundlich models as well as a pseudo-second order kinetic model. The mechanism for the biosorption was also studied by fitting the kinetic data with an intra-particle diffusion model and a Boyd plot. External mass transfer was found to be the rate-determining step for the adsorption process. Biosorption could be an alternative mechanism besides bio-oxidation and bio-reduction for the bioremediation of heavy metals.

Exposure-response of Cr(Ⅲ)-organic complexes to Saccharomyces cerevisiae

Hexavalent chromium[Cr(VI)]bioreduction produces soluble Cr(Ⅲ)-organic complexes.The Cr(Ⅲ)-organic complexes are relatively stable once they are formed,and no data about their toxicity were reported.Therefore,this study aims to investigate the bioavailability and toxicity of the soluble Cr(Ⅲ)-organic complexes.Saccharomyces cerevisiae L^(-1)wild type yeast strain was chosen as the model organism and Cr(Ⅲ)-citrate was selected as the representative compound of the Cr(Ⅲ)-organic complexes.The short-term chronic aquatic toxicity tests of the Cr(Ⅲ)-citrate was explored by measuring growth inhibition,direct viable cell count,dry biomass,biosorption,and the amount of CO_(2)production.Cr(Ⅲ)-citrate exerted a toxicity of 51 mg/L with an EC_(50),which was calculated from the percent growth inhibition.These toxicity data would be helpful to define the toxic potential of the organo-chromium-Ⅲcompounds in the environment.