Tectonic-thermal history and hydrocarbon potential of the Pearl River Mouth Basin,northern South China Sea:Insights from borehole apatite fission-track thermochronology

The Pearl River Mouth Basin(PRMB)is one of the most petroliferous basins on the northern margin of the South China Sea.Knowledge of the thermal history of the PRMB is significant for understanding its tectonic evolution and for unraveling its poorly studied source-rock maturation history.Our investigations in this study are based on apatite fission-track(AFT)thermochronology analysis of 12 cutting samples from 4 boreholes.Both AFT ages and length data suggested that the PRMB has experienced quite complicated thermal evolution.Thermal history modeling results unraveled four successive events of heating separated by three stages of cooling since the early Middle Eocene.The cooling events occurred approximately in the Late Eocene,early Oligocene,and the Late Miocene,possibly attributed to the Zhuqiong II Event,Nanhai Event,and Dongsha Event,respectively.The erosion amount during the first cooling stage is roughly estimated to be about 455-712 m,with an erosion rate of 0.08-0.12 mm/a.The second erosion-driven cooling is stronger than the first one,with an erosion amount of about 747-814 m and an erosion rate between about 0.13-0.21 mm/a.The erosion amount calculated related to the third cooling event varies from 800 m to 3419 m,which is speculative due to the possible influence of the magmatic activity.

Research and Application of In-seam Seismic Survey Technology for Disaster-causing Potential Geology Anomalous Body in Coal Seam

In order to effectively detect potential geology anomalous bodies in coal bearing formation,such as coal seam thickness variation,small faults,goafs and collapse columns,and provide scientific guidance for safe and efficient mining,the SUMMIT-II EX explosion-proof seismic slot wave instrument,produced by German DMT Company,was used to detect the underground channel wave with the help of transmission method,reflection method and transflective method.Region area detection experiment in mining face had been carried out thanks to the advantage of channel wave,such as its great dispersion,abundant geology information,strong anti-interference ability and long-distance detecting.The experimental results showed that:(1)Coal seam thickness variation in extremely unstable coal seam has been quantitatively interpreted with an accuracy of more than 80%generally;(2)The faults,goafs and collapse columns could be detected and predicted accurately;(3)Experimental detection of gas enrichment areas,stress concentration regions and water inrush risk zone has been collated;(4)A research system of disaster-causing geology anomalous body detection by in-seam seismic survey has been built,valuable and innovative achievements have been got.Series of innovation obtained for the first time in this study indicated that it was more effective to detect disaster-causing potential geology anomalies by in-seam seismic survey than by ground seismic survey.It had significant scientific value and application prospect under complex coal seam conditions.

Digital literacy as a potential barrier to implementation of cardiology tele-visits after COVID-19 pandemic: the INFO-COVID survey

BACKGROUND During the COVID-19 pandemic,the implementation of telemedicine has represented a new potential option for outpatient care.The aim of our study was to evaluate digital literacy among cardiology outpatients.METHODS From March to June 2020,a survey on telehealth among cardiology outpatients was performed.Digital literacy was investigated through six main domains:age;sex;educational level;internet access;availability of internet sources;knowledge and use of teleconference software programs.RESULTS The study included 1067 patients,median age 70 years,41.3%females.The majority of the patients(58.0%)had a secondary school degree,but among patients aged≥75 years old the most represented educational level was primary school or none.Overall,for internet access,there was a splitting between"never"(42.1%)and"every day"(41.0%),while only 2.7%answered"at least 1/month"and 14.2%"at least 1/week".In the total population,the most used devices for internet access were smartphones(59.0%),and WhatsApp represented the most used app(57.3%).Internet users were younger compared to non-internet users(63 vs.78 years old,respectively)and with a higher educational level.Age and educational level were associated with nonuse of internet(age-per 10-year increase odds ratio(OR)=3.07,95%CI:2.54-3.71,secondary school OR=0.18,95%CI:0.12-0.26,university OR=0.05,95%CI:0.02-0.10).CONCLUSIONS Telemedicine represents an appealing option to implement medical practice,and for its development it is important to address the gaps in patients’digital skills,with age and educational level being key factors in this setting.

Characteristics of Zhangsanying-Tongshanzi aeromagnetic anomaly zone and prospecting potential of iron deposits in northern Hebei,China

Based on the latest high-precision aeromagnetic data,an aeromagnetic anomaly zone is identified at Zhangsanying--Tongshanzi in northern Hebei Province.By the potential field conversion processing,including the reduction to the pole,vertical derivative,upward continuation and residual anomaly,the authors analyzed the characteristics of three typical aeromagnetic anomalies in Zhangsanying--Tongshanzi aeromagnetic anomaly zone and their geological origin.The methods include the forward and inversion methods,such as 2.5D optimization fitting and Euler deconvolution.Moreover,combined with the geological outcrop,known iron deposits,ground magnetic survey and verification,the authors studied the relationship between the aeromagnetic anomalies and iron deposits.The result shows that the Zhangsanying--Tongshanzi aeromagnetic anomaly zone is composed of 10 large magnetic anomalies with high amplitude and clear boundary.The aeromagnetic anomalies are comparable and intrinsically related to the ground magnetic anomalies and IP anomalies,indicating that the anomalies are caused by magnetite deposits.It has good magnetite prospecting potential in the Zhangsanying--Tongshanzi aeromagnetic anomaly zone.

Contamination assessment,source apportionment and associated health risks of PTEs in agricultural soil under five land-use patterns in Sanya,China

To understand the levels of potentially toxic elements(PTEs)contamination in soils and their effects on human health from different agricultural land use in Sanya,China.128 soil samples(64 topsoil samples and corresponding subsoil samples)were collected from the five representative land-use patterns.Inductively coupled plasma mass spectrometry(ICP-MS),Atomic fluorescence spectrometry(AFS),and Inductively coupled plasma optical emission spectrometry(ICP-OES)were used to determine the content of PTEs(As,Cd,Hg,Cu,Cr,Ni,Pb,Zn,Co,Mo,Sb,and V).Correlation analysis and factor analysis were used to determine the source of PTEs.Geo-accumulation index(I_(geo)),hazard quotient(HQ),and total carcinogenic risk index(TR)were used to measure the PTEs contamination and its relative health impacts.Results showed that the average values of 12 PTEs in topsoil were higher than the Hainan soil geochemical baseline,showing different degrees of PTEs accumulation effect.The concentration of PTEs in the topsoil was lower than those in the subsoil except for Cd and Hg.The I_(geo)revealed that the major accumulated element in soils was As followed by Mo.Source apportionment suggested that parent materials and agricultural practices were the dominant factors for PTEs accumulation in the topsoil.Noncarcinogenic risks of soil samples from five land-use patterns presented a trend of paddy field>dry field>woodland>orchard>garden plot.However,the HQ values of 12 PTEs were less than the recommended limit of HQ=1,representing that there are no non-carcinogenic risks of PTEs for children and adults in the study area.The TR values are within 6.95×10^(-6)-1.38×10^(-5),which corresponds to the low level.Therefore the PTEs in the agricultural soil of the study area show little influence on the health status of the local population.

Effect and Prospect of Basic Geological Survey Based on Airborne Gravimetry in China

The airborne gravimetry was an important leap and innovation in the world＇s history of geophysical exploration. China＇s first test of the airborne gravity geological survey in the onshoreoffshore transitional area of the western and southern part of the Bohai Sea was successful and effective in geology. Based on the airborne gravity data, and combining previous ground gravity, seismic and drilling data etc., we carried out the geological interpretation by forward and inverse methods. The result shows that the airborne Bouguer gravity anomaly was clear, the fracture interpretation was reliable, and the inversion depth of the main geological interfaces was relatively accurate. This airborne gravity geological survey not only filled the exploring gaps in the onshore- offshore transitional area, and realized the geological and tectonic junction between the sea and the land, but also discovered four local gravity anomalies, 11 fractures and three sags or subsags, and so on. The good geological effect of airborne gravimetry not restricted by terrain condition shows that it can be served as a new geophysical method in the exploration of complex terrain physiognomy area such as mountain, jungle, desert, marsh, onshore-offshore transitional area and so on, and has an extensive application prospect in China in the future.

Ecological risk assessment and early warning of heavy metal cumulation in the soils near the Luanchuan molybdenum polymetallic mine concentration area,Henan Province,central China

The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.

Assessment of groundwater potential using multi-criteria decision analysis and geoelectrical surveying

A precise map of the dispersion of the groundwater potential across each watershed can help decision-makers to exert optimal water management in each region.In this research,the potential of groundwater resources in both the Zanjanrood Catchment and the Tarom Region,located in the northwest of Iran,has been studied.Seven effective criteria including slope,land-use,drainage density,spring density,lithology,lineament density,and rainfall are considered.Criteria were first weighted using the Analytical Hierarchical Process(AHP)method and then overlaid by the Technique for Order Preferences by Similarity to Ideal(TOPSIS)model.Finally,the spatial zoning map of groundwater potential was obtained in four categories.A sensitivity analysis was performed to determine the influence of each criterion on the obtained map.The model was verified using both the spatial distribution of the high-discharged production wells and the geophysical-based geoelectric field surveys.The results indicate that the high-discharged wells(>40 l/s)in both regions are dispersed predominantly in the very good zone and,in several cases,in the good zone.Besides,the results from the two-dimensional models of resistivity and induced polarization of geoelectrical field survey are inappropriate agreement with those from the TOPSIS method.Notably,there is no suitable potential zone of groundwater in the surrounding highlands to be used in the future for drinking purposes since the highlands water supply is a strategic supply for drinking.The strategies employed in this study,the results of GIS modeling,and the geoelectrical analysis can be considered for sustainable development of similar arid and semi-arid areas since groundwater is considered as the main supplier of water in such regions.

Characterizations of Abandoned Peatlands from Acadian Peninsula： Agro-ecologic and Environmental Value-Added Alternatives

In the northeast region of New Brunswick, the majority of peatlands are mainly used for horticultural purposes. Abandoned peatlands after peat extraction could represent one of the most important ecological resources through their remaining substrates： serving as agronomic, ecological or environmental value-added support to local development; and giving a second economic life to peatlands. To evaluate this innovative peat soil management, a study was conducted on three residual peatlands from the Acadian Peninsula. Their status was described through a physic-chemical characterization. The results suggest that the peat thickness and the mineral horizon characteristics are good indicators to identify these post-harvest peat soils. The studied sites were characterized by a flat topography, poor and unequal drainage inducing a variation of the water table level. The peat thickness ranged from 18 cm to 40 cm, while the thickness of the mineral horizon--mostly sandy--ranged between 20 cm and 30 cm. The chemical properties revealed an electrical conductivity above 50 μS·cm^-1, an acid pH, and a variable cation exchange capacity （1.3 cmolc·kg^-1 to 11.4 cmolc·kg^-1）. This preliminary study gives basic knowledge on Acadian Peninsula abandoned peatlands soils and gives information about the conditions of their agro-economic, ecological and/or environmental management.

Investigation of Geology and Hydro-geophysical Features Using Electromagnetic and Vertical Sounding Methods for Abu Zabad Area,Western Kordofan State,Sudan

The geology and hydro-geophysical features can aid in identifying borehole location.The study aims to investigate groundwater aquifers and best location of boreholes in the crystalline basement area of Abu Zabad near El Obeid Southwest,Sudan.The study area is underlain by two aquifers formations from Precambrian age.The oldest units of basement complex of area under investigation consist of metamorphic rocks including gneiss,schist,and quartzite.The geophysical methods electromagnetic(EM)and vertical electrical sounding(VES)surveys showed that best aquifers yield for construction of boreholes are in weathering and fractures formation.The EM results revealed that structural features are significant for groundwater potential and interpretation of the VES data also revealed four geo-electric layers,but generally two distinct lithologic layers,which include Superficial deposit and bedrock-basement respectively.The curves generated from the data revealed H curve and HK curve,and thickness of these layers varies from 15 m to 50 m in the area.The aquifer thickness range from 20 m to 30 m.The study concludes that these techniques are suitable for identifying borehole location in the basement rock in Abu Zabad Area Sudan.

Mapping rice-fallow cropland areas for short-season grain legumes intensification in South Asia using MODIS 250 m time-series data

The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia,using MODIS 250 m time-series data and identify where the farming system may be intensified by the inclusion of a short-season crop during the fallow period.Rice-fallow cropland areas are those areas where rice is grown during the kharif growing season(June–October),followed by a fallow during the rabi season(November–February).These cropland areas are not suitable for growing rabi-season rice due to their high water needs,but are suitable for a short-season(≤3 months),low water-consuming grain legumes such as chickpea(Cicer arietinum L.),black gram,green gram,and lentils.Intensification(double-cropping)in this manner can improve smallholder farmer’s incomes and soil health via rich nitrogen-fixation legume crops as well as address food security challenges of ballooning populations without having to expand croplands.Several grain legumes,primarily chickpea,are increasingly grown across Asia as a source of income for smallholder farmers and at the same time providing rich and cheap source of protein that can improve the nutritional quality of diets in the region.The suitability of rainfed and irrigated rice-fallow croplands for grain legume cultivation across South Asia were defined by these identifiers:(a)rice crop is grown during the primary(kharif)crop growing season or during the north-west monsoon season(June–October);(b)same croplands are left fallow during the second(rabi)season or during the south-east monsoon season(November–February);and(c)ability to support low water-consuming,short-growing season(≤3 months)grain legumes(chickpea,black gram,green gram,and lentils)during rabi season.Existing irrigated or rainfed crops such as rice or wheat that were grown during kharif were not considered suitable for growing during the rabi season,because the moisture/water demand of these crops is too high.The study established cropland classes based on the every 16-day 250 m normalized difference vegetation index(NDVI)time series for one year(June 2010–May 2011)of Moderate Resolution Imaging Spectroradiometer(MODIS)data,using spectral matching techniques(SMTs),and extensive field knowledge.Map accuracy was evaluated based on independent ground survey data as well as compared with available sub-national level statistics.The producers’and users’accuracies of the cropland fallow classes were between 75%and 82%.The overall accuracy and the kappa coefficient estimated for rice classes were 82%and 0.79,respectively.The analysis estimated approximately 22.3 Mha of suitable rice-fallow areas in South Asia,with 88.3%in India,0.5%in Pakistan,1.1%in Sri Lanka,8.7%in Bangladesh,1.4%in Nepal,and 0.02%in Bhutan.Decision-makers can target these areas for sustainable intensification of short-duration grain legumes.

Hunting of hunted:an ensemble modeling approach to evaluate suitable habitats for caracals in India

Background:Large-scale hunting and various anthropogenic pressures in the recent past have pushed the Asiatic caracal(Caracal caracal schmitzi),an elusive medium-sized and locally threatened felid species towards local extinction in India.Though widely distributed historically,it has been sparsely reported from several regions of central and northern states in India till twentieth century.Later,the species distribution became confined only to the states of Rajasthan,Gujarat and Madhya Pradesh,which have had reported sightings in the twenty-first century.In order to highlight the potentially suitable habitats for Asiatic caracals in India,we targeted forth-filtering of the spatial model ensemble by creating and utilizing the validated and spatially thinned species presence information(n=69)and related ecological variables(aridity,NDVI,precipitation seasonality,temperature seasonality,terrain ruggedness),filtered with anthropological variable(nightlight).Results:Out of eight spatial prediction models,the two most parsimonious models,Random Forest(AUC 0.91)and MaxEnt(AUC 0.89)were weighted and ensembled.The ensemble model indicated several clustered habitats,covering 1207.83 km^(2)areas in Kachchh(Gujarat),Aravalli mountains(Rajasthan),Malwa plateau(Rajasthan and Madhya Pradesh),and Bundelkhand region(Madhya Pradesh)as potentially suitable habitats for caracals.Output probabilities of pixels were further regressed with converted vegetation height data within selected highly potential habitats,i.e.,Ranthambore Kuno Landscape(RKL)(suitability~0.44+0.03(vegetation height)^(**),R^(2)=0.27).The regression model inferred a significant positive relation between vegetation height and habitat suitability,hence the lowest ordinal class out of three classes of converted vegetation height was masked out from the RKL,which yielded in an area of 567 km^(2) as potentially highly suitable habitats for caracals,which can be further proposed as survey areas and conservation priority areas for caracals.Conclusion:The study charts out the small pockets of landscape in and around dryland protected areas,suitable for caracal in the Indian context,which need attention for landscape conservation.