Earth Sciences Commons^™

Eocene (50–55 Ma) Greenhouse Climate Recorded In Nonmarine Rocks Of San Diego, Ca, Usa, Adrian P. Broz, Devin Pritchard-Peterson, Diogo Spinola, Sarah Schneider, Gregory Retallack, Lucas C.R. Silva

Purdue University Libraries Open Access Publishing Fund

Nonmarine rocks in sea cliffs of southern California store a detailed record of weathering under tropical conditions millions of years ago, where today the climate is much drier and cooler. This work examines early Eocene (~ 50–55 million-year-old) deeply weathered paleosols (ancient, buried soils) exposed in marine terraces of northern San Diego County, California, and uses their geochemistry and mineralogy to reconstruct climate and weathering intensity during early Eocene greenhouse climates. These Eocene warm spikes have been modeled as prequels for ongoing anthropogenic global warming driven by a spike in atmospheric CO2. Paleocene-Eocene thermal maximum (PETM, ~ 55 Ma) kaolinitic …

Application Of Remote Sensing And Spectroradiometry In Geological Mapping: A Case Study Of Handeni (Qds 148) Block, Eastern Mozambique Belt, Tanzania, Masota M. Magigita, Elisante Mshiu, Cassy Mtelela

Tanzania Journal of Science

This study applies remote sensing (RS) as a geologic mapping aid tool , using Handeni Block of Tanzania as a case study. To achieve the objective of this study, we have utilized various RS processing and image enhancement techniques on multispectral data, including ASTER, Landsat 5, Landsat 8, and Sentinel 2A. The method proved successful whereby both Landsat-5-data with band combination (BC) 7:4:2 and 7:5:4 and band ratio (BR) 5/3:5/1:7/5 and Landsat-8 data with BCs 5:6:7 and 7:6:4 mapped out marble units. Sentinel 2A data (with BC 8:11:3, BRs 12/2:11/2:8/11; 12/4:11/3:11/2 and 12/4:12/2:11/3) together with image enhancement decorrelation stretch on …

Modelling Spatial Distributions Of Sediments Fingerprinting In The Ruvu Basin Of Tanzania Without Continuous Sediment Monitoring, Charles H. Kasanzu

Tanzania Journal of Science

This study investigates various hinterlands’ contribution of sediments into the sub-basin known as Ruvu that comprises Mindu, Kibungo, Mvuha and Mindu catchments of Morogoro, Eastern Tanzania. An integrated geochemical and isotopic data were used to constrain this. Strategic sampling of basement and silty-sized sediments was conducted and the data were modelled using mass-balance computations. This approach revealed that, more than 70% of suspended sediments in the Mgeta River originate from Kigalamila, Sezima, Kingule, Mafumbo and Kibuko areas. Thus, hills north of Kisaki are major contributors of sediments with less contribution from the southern terrain. After modelling of the data from …

Inventory Of Western United States Glaciers- 2020, Shrinidhi Ambinakudige, Bernard Abubakari

CAS Publications

The dataset employed for delineating glacier boundaries in the Western United States comprises a compilation of original Sentinel-2 images obtained from the European Space Agency's Copernicus website. These images were instrumental in generating the glacier inventory. Additionally, the dataset includes a Python and R script specifically crafted for processing and classifying Sentinel images. The outcome of this process is represented in an ESRI shapefile, which contains an inventory of glaciers extracted from Sentinel images.

Joint Map Of Hardin County, Kentucky, Steven L. Martin, Emily Morris

Map and Chart--KGS

New field mapping of joints with previously published joint and fault locations. This fracture map can be used as a critical data source for hydrological, karst or geotechnical applications. Joint orientations were measured in 2009, 2022 and 2023, and are combined with joint and fault locations for Hardin County, Kentucky from 1:24,000-scale USGS geologic quadrangle maps that were published from 1962 to 1977. The geologic quadrangle maps for the county were digitized from 2002 to 2007.

The geology of Hardin County consists of Upper Devonian New Albany Shale overlain by Lower to Upper Mississippian-age sequences of limestone, dolomite, sandstone and …

Clouds In The Ancient Lunar Atmosphere: Water Ice Nucleation On Aerosol Simulants, Mariana C. Aguilar

The Journal of Purdue Undergraduate Research

Today’s moon is vastly different from what it was 3 billion years ago. At that time, it was home to a collisional atmosphere formed through massive amounts of volcanism, releasing enough subsurface gas to sustain surface pressures of up to 1 kPa. Observations of our solar system have taught us that all dense atmospheres are host to clouds and aerosols, and we expect the Moon’s to be no different. Knowing when, where, and under what conditions cloud particles form is important for understanding the evolution of the lunar atmosphere, how it reacted to temperature gradients, and how it cycled volatiles. …

Evaluating The Neotectonic Activities Of The Eastern Makran At The Northern Edge Of The Triple Junction In Southwest Pakistan, Waseem Khan, Ke Zhang, Hao Liang

Turkish Journal of Earth Sciences

A number of five GIS-based indices, such as stream slope (Ss), surface roughness (Sr), asymmetric factor (Af), hypsometry integral (Hi), and stream-length gradient (SL), were summarised to examine the intensity of the index of tectonic activity (IAT) in 43 subbasins of Hingol Basin at the northern edge of the triple junction in southwest Pakistan. In addition, tectonic influences were identified by knickpoints spatial distribution and field surveys. The majority of the indices are consistent and display roughly the same classifications. The uncertain results have a less substantial impact on the obtained results in most of the 43 subbasins. Using these …

Mineralogical And Geochemical Characteristics Of The Upper Cretaceous And Lower Paleocene Parts Of The Germav Formation: Southeastern Türkiye, Sema Teti̇ker

Turkish Journal of Earth Sciences

The mineralogical and chemical characteristics of Upper Cretaceous-Lower Paleocene claystone sediment samples taken from Mardin and Batman, located in southeastern Türkiye, were analyzed in the present study. The clay mineral paragenesis in the Upper Cretaceous units consisted of chlorite-smectite (C-S) and illite, whereas the Lower Paleocene unit consisted of chlorite-vermiculite (CV) and vermiculite minerals. Analyses conducted on clay samples indicated high levels of Al, Mg, Fe, Cr, V, Ni, and Zr. Low levels of alkali and alkaline earth elements (Mg, Na, Ca, K) in the clay-rich sediments suggest relatively high-grade weathering in the source area. The mineralogical compositions, major elemental …

An Experimental Investigation On The Discrete Poisson’S Upward Continuation Of Anomalous Gravity Field Data, Mehmet Si̇mav, Bi̇hter Erol, Muhammet Aki̇f Gülender, Serdar Erol

Turkish Journal of Earth Sciences

The Poisson upward continuation of gravity field functionals, typically given on the Earth’s irregular topography with limited spatial extent, necessitates some proper treatments due to the theoretical requirements. This study reviews the Poisson theory and investigates a more rigorous methodology for the numerical solution of the spherical integral equation by addressing many issues such as spherical-Earth model implementation, far-zone effect, Poisson kernel modification, and suitable ground data reduction scheme. We first explore the far-zone effect and search for an optimal near-zone spherical cap radius above which the truncation error is negligible. We then compare different variants of remove-restore technique with …

Microfacies, Geometry And Growth Phases Of Microbial Mound In Gucheng Area, Southeastern Tarim Basin, China, Xu Chen, Iftikhar Satti, Yuwen Dong

Turkish Journal of Earth Sciences

Microbial mound is favorable carbonate reservoir for petroleum exploration, especially for the deep tight reservoirs in the Tarim petroliferous basin. Due to lack of effective research methods, it is difficult to analyze its unique sedimentary structure and evolution process. In this study, based on cores, thin-sections, logging, 3D seismic data and geochemical test data, the petrographic texture, microfacies, geometry and growth phases of microbial mound in Gucheng area, Southeastern Tarim Basin were investigated, which can be used to reconstruct dynamic evolution of the microbial mounds and discuss the controlling factors. The major results are as follows: (1) Gucheng area is …

Genesis Of Efficient Reservoirs In Mixed Sedimentary Setting: A Case Study Of Benxi Formation In The Gaoqiao Area, Ordos Basin, Shu Liu, Jinbu Li, Fengbo Jin, Haifeng Liu, Meng Wang, Yulin Cheng, Yulin Cheng, Xiaohong Zhong, Hao Lu

Turkish Journal of Earth Sciences

The Benxi-Taiyuan Formation in the southern region of the Ordos Basin represents a typical mixed sedimentary system, which has witnessed recent breakthroughs in the exploration of tight sandstone gas within the Benxi Formation. However, the development patterns of reservoirs in this mixed sedimentary area remain unclear, influenced by the sedimentary model and the distribution scale of sedimentary sandstone bodies. This study investigates the paleogeomorphology, sedimentary model, sandstone body type, petrological characteristics, and pore structure of the Benxi Formation. Field profiles, drilling core observations, microscopic section analysis, scanning electron microscopy (SEM), high-pressure mercury injection (HPMI), and physical property analysis are employed. …

Dinsar Analysis And Geophysical Modeling Of 2022 November 23 Gölyaka-Düzce Earthquake, Şükrü Onur Karaca, Gülteki̇n Erten, Batuğhan Yikmaz, Seli̇m Özalp

Turkish Journal of Earth Sciences

Numerous significant earthquakes have occurred along the North Anatolian Fault Zone (NAFZ), Türkiye’s most important fault zone. An earthquake with magnitude of Mw 6.0 occurred near the Gölyaka District of Düzce Province at 04:08 local time on November 23, 2022. According to the moment tensor solutions published by national and international seismology centers, the earthquake occurred at the northeast end of the Karadere segment within the NAFZ and was caused by a right-lateral strike-slip fault in the NW-SE direction. In this study, the differential interferometric synthetic aperture radar (InSAR) method was employed to analyze the deformation. Four Sentinel-1A complex datasets …

Landslide Susceptibility Assessment Of The Asi Watershed, Southern Türkiye, Senem Teki̇n, Adolfo Quesada Román, Tolga Çan

Turkish Journal of Earth Sciences

Landslides constitute recurrent natural hazards worldwide with greater socioeconomic impacts in low-income places. Landslide susceptibility studies are carried out to determine the potential for landslides to occur in a region, to predict possible risks in the future and to integrate this information into sustainable planning and management strategies. Slip-type landslides occur in limited areas of less than 1% of the Asi watershed in Southern Türkiye. Therefore, meaningful estimations cannot be made with classical statistical models. So, using the maximum entropy approach (MaxEnt), a technique for estimating based on a small number of observations, a landslide susceptibility assessment was constructed. The …

Genetic Mechanisms Of Hot Dry Rock Geothermal Resources In Central Inner Mongolia, Xiong Bo, Xu Hao, Tang Shuling, Wang Shejiao, Fang Chaohe, Xin Fudong, Wu Jingjie, Wei Xiangquan, Song Xuejing, Wang Jinwei

Coal Geology & Exploration

Central Inner Mongolia, located at the junction of plates, has undergone multi-phase tectono-magmatic activities and boasts abundant shallow hydrothermal resources. However, there is a lack of in-depth research on deep hot dry rock (HDR) geothermal resources in this region. Based on the regional geological and tectonic settings, magnetotelluric sounding results, and geothermal anomaly manifestations, this study systematically explored the genetic mechanisms and geodynamic process of HDR geothermal resources in central Inner Mongolia and determined the genetic modes of HDRs. The results show that the major heat sources of deep HDR geothermal resources in the region include deep local melts and …

Heat Source-Related Mechanisms And Genetic Modes For The Formation Of Hot Dry Rocks In The Reshuiwei Geothermal Field, Hunan Province, Du Jiang, Cai Ningbo, Zhang Baojian, Wang Keying, He Lihong, Liao Fengchu

Coal Geology & Exploration

Hot springs with temperatures exceeding 90℃ indicate that the Reshuiwei geothermal field in Hunan Province enjoys sound geothermal geological conditions, making this geothermal field a potential favorable area for hot dry rock (HDR) exploration. To carry out a reasonable evaluation of the geothermal reservoir and prospects for exploration and exploitation of HDRs in the Reshuiwei geothermal field in the Rucheng area, this study comprehensively analyzed the deep geological structures, geochemical characteristics, geophysical characteristics including gravity, magnetic, electrical, and seismic properties, and geothermal field characteristics of the geothermal field. Furthermore, it revealed the deep thermal structures of the geothermal field from …

Heating Experiments Of A Solar-Assisted Heat Pump And Thermal Equilibrium Simulations Of Geothermal Fields, Jia Zilong, Zheng Jia, Zhang Yaobin, Chen Ke, Liu Aihua, Li Juan

Coal Geology & Exploration

This study aims to explore technologies required for clean energy heating by means of multi-energy complementation, with the purpose of meeting the demand for clean heating in decentralized buildings in Beijing's villages and towns. To this end, this study built a solar-ground source heat pump (SGHP) compound system in a rural area of Beijing. Then, it carried out heating experiments of the solar-assisted heat pump system and thermal equilibrium simulations of geothermal fields using the COMSOL software. The results are as follows: (1) Compared to a single SGHP system, the solar-assisted heat pump scheme increased the outlet water temperature on …

Geodatabase And Modeling Code Used For Dynamic Landslide Hazard Maps In Eastern Kentucky, Nathaniel O'Leary, L. Sebastian Bryson

Earth and Environmental Sciences Research Data

We developed spatiotemporal landslide hazard maps (LHMs) using soil, hydrologic, and geomorphic parameters from the subaerial infinite slope factor of safety (FS) equation under unsaturated conditions. Soil properties were extracted from the NRCS WSS, while geomorphic variables were derived from a 1.5 m LiDAR-based DEM and ArcGIS Online. Soil moisture from Hydrus-1D, driven by precipitation and evapotranspiration (ET) data from Irrigation Manager, introduced temporal variability. Validation against known landslide sites showed spatial and temporal FS accuracy despite some false positives. We also developed a landslide susceptibility maps (LSM) after comparing three machine learning algorithms, with bagged trees achieving the highest …

Genetic Mechanisms Of Low-Temperature Geothermal Water And Its Associated Helium Gas In Meixian County In The Piedmont Of Qinling Mountains, Han Yuanhong, Lyu Jun, Zhang Yuping, Luo Naning, Li Bing, Shen Xiaolong

Coal Geology & Exploration

Meixian County in the piedmont of the Qinling Mountains boasts abundant geothermal water resources with high-abundance associated helium gas. However, the characteristics and origin of geothermal fluids in the study area are yet to be studied. By analyzing the chemical composition and isotopic geochemistry of geothermal fluids and combining the distributions of regional structures and faults, this study delved into the characteristics and genetic mechanisms of geothermal fluids in the study area. The results show that the geothermal water exhibits salinity ranging from 638.96 to 1026.83 mg/L and a hydrochemical type of HCO₃-Na. The low-degree metamorphism suggests that …

Sensitivity Analysis Of Development Parameters On The Production Temperature Of Karst Geothermal Reservoirs: A Case Study Of The Qingfeng Area In Henan, China, Han Yun, Li Kewen, He Jifu, Wang Xinwei, Gao Nan’An

Coal Geology & Exploration

The temperature of produced geothermal water serves as a pivotal indicator influencing the efficiency of geothermal energy utilization, with a higher temperature corresponding to more effective geothermal reservoir exploitation. For karst geothermal reservoirs, recognized as a significant type of geothermal reservoir, the temperature of produced geothermal water is influenced by reservoir parameters. Focusing on the Ordovician karst geothermal reservoirs in the Qingfeng area, Henan Province, this study established a geological model of the reservoirs, followed by numerical simulations based on thermal flow and well-reservoir coupling using the data of seven geothermal wells. The purpose is to explore the effects of …

A Joint Operation Mode Of Multi-Production Wells For Deep Geothermal Water Exploitation, Ping Yu, Li Fang, Ji Wenqing, Yuan Xiaoying, Qi Yufeng, Deng Xiaoying, Wang Xinyi

Coal Geology & Exploration

Deep geothermal water, a type of clean and low-carbon renewable energy, plays a significant role in achieving the goals of peak carbon dioxide emissions and carbon neutrality. However, its irrational exploitation will lead to many problems such as decreased water quantity, lowered water level, and low engineering benefits. Based on the available exploration data of geothermal wells in the urban area of Kaifeng City, Henan Province, this study constructed a hydrogeological model used to characterize the migration of geothermal water and a corresponding mathematical model, which was identified and verified using the Galerkin finite element method. Focusing on geothermal reservoirs …

Evaluating The Exploitation And Utilization Prospects Of Hot Dry Rock In Bohai Bay Basin: Understanding Based On Numerical Simulations For Exploitation Optimization, Jiang Xiaoxue, Zhu Chuanqing, Ding Rui, Xie Fang, Qiu Nansheng

Coal Geology & Exploration

The Bohai Bay Basin, characterized by high terrestrial heat flow, formation temperatures average of 175℃ at a depth of 5000 m, and reservoirs with lithologies dominated by low-porosity and low-permeability metamorphic and igneous rocks, meets the requirements for the formation of hot dry rock (HDR) resources. Based on geothermal parameters such as terrestrial heat flow, rock thermal conductivity, and heat production rate, this study established a three-dimensional HDR exploitation model with thermo-hydro coupling using the COMSOL software. Furthermore, this study analyzed the effects of spacing between production and reinjection wells, reinjection and production rates, and well arrangement mode on the …

Influencing Patterns Of Multiple Factors On The Heat Transfer Performance Of Moderately Deep Geothermal Wells, Han Yongliang, Wang Kaipeng, Wang Yijie, Gou Li, Yang Yanbin, Lei Yanzi, Wu Fangli, Shen Hao

Coal Geology & Exploration

Vigorously promoting the technology for heating using moderately deep geothermal energy serves as an important measure for China’s pursuit of carbon neutrality and peak carbon dioxide emissions. A coaxial double-pipe heat transfer system for moderately deep geothermal wells can avoid damage to groundwater resources and the environment. Furthermore, the influencing factors of the wells exhibit complicated and nonlinear interactions. Based on the theoretical analysis and mathematical description of a moderately deep well with a coaxial double-pipe heat exchanger, this study established a layered heat transfer model for the geothermal well and verified its reliability. This study investigated a moderately deep …

Effects Of Fracture Distribution On Heat Extraction Through Co2-Egs, Zhou Qing, Liao Jianxing, Xu Bin, Yao Liang, Zhou Haoyu, Zhao Quan

Coal Geology & Exploration

Geothermal energy, a promising source of renewable energy, has attracted considerable attention. In deep geothermal reservoirs, complex fracture networks formed by artificial stimulation provide predominant channels for heat extraction. Therefore, the spatial distribution of fractures directly affects the heat extraction efficiency. This study aims to explore the effects of different spatial distributions of fractures on the heat recovery performance. Based on the fracture network following a power-law distribution, this study systematically investigated the effects of the fracture network with different values of fracture length index (a) and density (β) on the heat recovery performance of a …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Major Challenges Of Deep Geothermal Systems And An Innovative Development Mode Of Regs Integrated With Energy Storage, Hou Zhengmeng, Wu Xuning, Luo Jiashun, Zhang Liehui, Li Zaoyuan, Cao Cheng, Wu Lin, Chen Qianjun

Coal Geology & Exploration

China has long been a global leader in the direct utilization of moderate- to low-temperature geothermal energy, in contrast to its sluggish progress in power generation using deep geothermal energy. Rocks in deep reservoirs exhibit decreased permeability under high-temperature and high-pressure conditions, necessitating the establishment of engineered geothermal system (EGS) for the exploitation of deep geothermal energy. In an EGS, hydraulic fracturing is employed for reservoir stimulation to create artificially enhanced geothermal reservoirs with higher permeability. The current techniques for deep geothermal reservoir stimulation are predominantly borrowed from hydraulic fracturing processes employed in the oil and gas sector, placing limitations …

Dating Methods For Travertine And Siliceous Sinter In Geothermal Systems: Progress And Applications, Li Bin, Li Yiman, Pang Zhonghe, Huang Tianming, Gao Binbin

Coal Geology & Exploration

Sinters of geothermal system are usually dominated by travertine and siliceous sinter. With rich information on multi-temporal and spatial scales, they can be used to restore paleohydrological and paleoclimatic histories, reconstruct the evolutionary process of regional hydrothermal activity, and constrain tectonic modes. Accurate dating of sinters is the basis of relevant researches. Common dating methods include radiocarbon dating (based on inorganic and organic carbon), uranium series disequilibrium dating, cosmogenic nuclide dating, optically stimulated luminescence (OSL) dating, and electron spin resonance dating. Radiocarbon dating has primarily used for the dating of hot-spring sinters in China, followed by electron spin resonance dating …

Thermal Conductivity Column Of Rocks And Distribution Characteristics Of Paleo-Geothermal Field In The Songliao Basin, Tang Boning, Qiu Nansheng, Zhu Chuanqing, Chang Jian, Li Xiao, Huang Yue, Yang Junsheng, Fu Xiuli

Coal Geology & Exploration

The paleo-geothermal field of a basin is closely related to the formation and evolution of geothermal, oil, and gas resources. To ascertain the characteristics of the paleo-geothermal field in the Songliao Basin during some critical periods, this study established the thermal conductivity column of rocks in the basin using measurements from 269 samples and compiled previous data. Then, it simulated the burial and thermal histories of multiple wells under the constraint of vitrinite reflectance (R_ran). The results indicate that the thermal conductivity of the Songliao Basin increases with the depth, with increasing rates higher in the upper …

Characteristics And Genetic Mechanism Of Geothermal Reservoirs In The Neogene Guantao Formation, Qikou Sag, Xia Guochao, Lou Da, Zhao Yanting, Wang Hui, Duan Zhongfeng, Sun Xiaolin, Zhang Feipeng, Luo Rong, Ge Jiacheng

Coal Geology & Exploration

The Qikou Sag in the Huanghua Depression, Bohai Bay Basin boasts extremely abundant geothermal resources. Among them, the geothermal reservoirs of the Neogene Guantao Formation have the greatest potential for exploitation. To ascertain the properties of geothermal resources in this formation and rationally exploit these resources, it is significant to investigate the geothermal field, porosity, permeability, geothermal water circulation patterns, and genetic mode of geothermal reservoirs in the formation. Based on data from drilling, geophysical exploration, thermometry, and production of the study area, this study determined that the geothermal reservoirs of the Guantao Formation in the Qikou Sag constitute a …

Hydrochemistry Characteristics And Genesis Mode Of Hot Springs In The Luolou River Basin, Yunnan, China, Luo Huan, Liu Zhennan, Ma Yiqi, Zhang Yunhui, Tao Lanchu, Chen Qingsong, Fu Dunkai, Wu Xiangchuan

Coal Geology & Exploration

The hydrochemistry and genesis mechanism of thermal springs hold great significance for the exploitation and utilization of low to intermediate temperature geothermal resources. Under the influence of a concealed fault zone, thermal springs in the Luolou River basin, Yunnan Province, are distributed along both sides of valleys and exposed in Quaternary loose deposits and Permian basalt strata. It belongs to low to intermediate temperature thermal spring water, with temperatures ranging between 34.5 and 50.0℃, pH is between 7.62-9.73, TDS is between 262-702 mg/L. Based on the hydrochemical and isotopic tests of thermal spring samples and nearby cold water samples from …

Long-Term Operation Performance Of Medium-Deep Borehole Heat Exchangers In The Guanzhong Area, Zhang Zhibin, Ma Zhendi, Hao Jianke, Jia Guosheng, Ke Tingting, Cheng Chonghua, Jin Liwen

Coal Geology & Exploration

Technologies for heating utilizing medium-deep geothermal energy exhibit promising application prospects in the Guanzhong area of China, which boasts abundant geothermal resources. Geological parameters serve as determining factors in the performance of medium-deep borehole heating systems. This study aims to explore the performance of medium-deep borehole heating systems in the Guanzhong area, Shaanxi Province. First, this study analyzed the geological parameters of five typical areas in Guanzhong: Xingping City under the jurisdiction of Xianyang City, Weicheng District of Xianyang, and Gaoling, Huyi, and Chang’an districts of Xi’an City. Then, by combining the typical structural parameters of buried pipes, this study …