Geothermal distribution characteristics and sedimentary basin geothermal system in the severe cold region of Northeast China

2020 ◽  
Vol 17 (3) ◽  
pp. 321-337
Author(s):  
Zhen-Yu Fan ◽  
Sheng-Qing Xiong ◽  
Chang-Chun Yu ◽  
Gui-Bin Zhang ◽  
Xin-Yong Zhang ◽  
...  
2021 ◽  
Vol 23 (1) ◽  
pp. 195-211
Author(s):  
I.M. Okiyi ◽  
S.I. Ibeneme ◽  
E.Y. Obiora ◽  
S.O. Onyekuru ◽  
A.I. Selemo ◽  
...  

Residual aeromagnetic data of parts of Southeastern Nigerian sedimentary basin were reduced to the equator and subjected to magnetic vector inversion and spectral analysis. Average depths of source ensembles from spectral analysis were used to compute depth to magnetic tops (Z), base of the magnetic layer (Curie Point t Depth (CPD)), and estimate geothermal gradient and heat flow required for the evaluation of the geothermal resources of the study area. Results from spectral analysis showed depths to the top of the magnetic source ranging between 0.45 km and 1.90 km; centroid depths of 4 km - 7.87 km and CPD of between 6.15 km and 14.19 km. The CPD were used to estimate geothermal gradients which ranged from 20.3°C/km to 50.0°C/km 2 2 and corresponding heat flow values of 34.9 mW/m to 105 mW/m , utilizing an average thermal conductivity -1 -1 of 2.15 Wm k . Ezzagu (Ogboji), Amanator-Isu, Azuinyaba, Nkalagu, Amagunze, Nta-Nselle, Nnam, Akorfornor environs are situated within regions of high geothermal gradients (>38°C/Km) with models delineated beneath these regions using 3D Magnetic Vector Inversion, having dominant NW-SE and NE-SW trends at shallow and greater depths of <1km to >7 km bsl. Based on VES and 2D imaging models the geothermal system in Alok can be classified as Hot Dry Rock (HDR) type, which may likely have emanated from fracture systems. There is prospect for the development of geothermal energy in the study area. Keywords: Airborne Magnetics, Magnetic Vector Inversion, Geothermal Gradient, Heat Flow, Curie Point Depth, Geothermal Energy.


2021 ◽  
Author(s):  
Chen Zhao ◽  
Chenyu Li ◽  
Xiaoming Wang ◽  
Zhuosong Cao ◽  
Chao Gao ◽  
...  

Abstract Background: Antibiotic resistance genes (ARGs) have become an important public health problem. In this study, we used metagenomic sequencing to analyze the composition of ARGs in certain original habitats of northeast China, comprising three different rivers and riverbank soils of the Heilongjiang River, Tumen River, and Yalu River. Results: Twenty types of ARG were detected in every water sample. The major ARGs were multidrug resistance genes, at approximately 0.5 copies/16s rRNA, accounting for 57.5% of the total ARG abundance. The abundance of multidrug, bacitracin, beta-lactam, macrolide‑lincosamide‑streptogramin, sulfonamide, fosmidomycin, and polymyxin resistance genes covered 96.9% of the total ARG abundance. No significant ecological boundary of ARG diversity was observed. The compositions of the resistance genes in the three rivers were very similar to each other, and 92.1% of ARG subtypes were shared by all water samples. Except for vancomycin resistance genes, almost all ARGs in riverbank soils were detected in the river water. About 31.05% ARGs were carried by Pseudomonas. Opportunistic pathogenic bacteria carrying resistance genes were mainly related to diarrhea and respiratory infections. Multidrug and beta-lactam resistance genes correlated positively with mobile genetic elements (MGEs), indicating a potential risk of diffusion.Conclusions: The composition of ARGs in three different rivers was similar, indicating that climate played an important role in ARG occurrence. ARG subtypes in river water were almost completely the same as those in riverbank soil. ARGs had no significant geographical distribution characteristics. Many ARGs were carried by human pathogenic bacteria related to human diarrhea and respiratory infections, such as Pseudomonas aeruginosa and Aeromonas caviae. In general, our results provide a valuable dataset of river water ARG distribution in northeast China. The related ecological geography distribution characteristics should be further explored.


2020 ◽  
Vol 171 ◽  
pp. 102957 ◽  
Author(s):  
Pengyu Zhao ◽  
Jianxun Chen ◽  
Yanbin Luo ◽  
Yao Li ◽  
Lijun Chen ◽  
...  

2012 ◽  
Vol 178-181 ◽  
pp. 922-925
Author(s):  
Cheng Xue Ma ◽  
Jing Zhang ◽  
Hong Xian Yu ◽  
Yin Xin Wei ◽  
Xiu Ping Yuan

This first survey in 2009 and 2010 on silica-scaled Chrysophytes in Zhenbao Island Wetland Preserve, Northeast China, recorded 32 taxa (5 in Chrysophyceae and 27 in Synurophyceae), of which 29 were previously found in other parts of China, three species, Spiniferomonas serrata, Mallomonas transsylvanica and Synura punctulosa are new records to China. In terms of biogeography, 1 taxon is endemic, 2 bipolar, 1 northern temperate, 9 cosmopolitan, and 18 of wide distribution. The endemism of Synura punctulosa, appears due to its poor dispersal ability; lack of sampling data may also contribute its known distribution range. Spiniferomonas serrata and Mallomonas transsylvanica, two bipolar taxa, are the first report in China. More research efforts are needed for adequately understanding the distributions of this group of algae.


2016 ◽  
Vol 62 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Junjie Liu ◽  
Zhenhua Yu ◽  
Xinzhen Wang ◽  
Jian Jin ◽  
Xiaobing Liu ◽  
...  

2013 ◽  
Vol 71 (3) ◽  
pp. 2063-2085 ◽  
Author(s):  
Binquan Li ◽  
Zhongmin Liang ◽  
Zhongbo Yu ◽  
Kumud Acharya

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