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Employing geochemical analysis to Reveal Pedogenic Processes in Wisconsin Bisequal Soils Having Spodic and Alfic Sequa

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Journal of Geoscience and Environment Protection 2020年第11期8卷 1-25页

作者： Michael Aide Christine Aide Southeast Missouri State University Cape Girardeau Missouri USA

Bisequal soils in northern Wisconsin were described and characterized with the intent to determine if a near total elemental analysis protocol may estimate the effect of selected soil pedogenic pathways on soil morphology. The protocol reveals that gross elemental soil profile distributions do provide evidence that certain pedogenic processes are operating within a group of soils. Concentration differences between instrumental neutron activation analysis and an aqua regia digestion protocol infer that alkali metals, alkaline earth metals, transition metals and the rare earth elements are only incompletely weathered from primary minerals. Transition metals, alkali metals, alkaline earths, metalloids, and the rare earth elements all show inter-horizon mobility. Lessivage and the mobility of elements presumably adsorbed on soluble or suspended organic materials are the dominant soil processes influencing the soil profile redistribution of elements and the majority of these elements are shown to correlate with the soil profile distribution of Fe. Base cycling by the forest vegetation was shown to support A horizon enrichment of Ca, Sr, Ba, P, S, Mn, Zn, Sn and Pb. For clinical practice, elemental analysis may reveal important soil profile elemental differences when applied to variation of one soil forming factors, such as a chronosequence or toposequence within a landscape or soil association. Advantages and limitations of the protocol in identifying pedogenic pathways are discussed.

关键词： geochemical analysis Alfisols Spodosols Bisequal Soils Soil Genesis

Delineation of spring capture zones in southern Great Basin,USA based on modeling results and geochemical data

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Water Science and Engineering 2022年第3期15卷 189-199页

作者： Anya Zhang Department of Geoscience University of NevadaLas VegasNV 89154-4010USA

The protection zones or capture zones of springs in desert environments can be hard to identify,but they are critical to spring *** springs fed by regional aquifers are susceptible to contamination and groundwater *** *** Protection Agency has established hydrogeologic mapping methods to delineate protection zones for ***,it is often difficult to determine a regional aquifer system's flow pattern with this technique alone,and the use of these methods is not conducive to efficient groundwater *** tracking analysis using a well-conceptualized and calibrated numerical model for the three-dimensional groundwater flow domain feeding a given group of springs can help facilitate the identification of spring capture zone *** upon this basis,a multifaceted approach was developed to define clear boundaries of the capture zones for the springs in the Furnace Creek,Ash Meadows,and the Muddy River areas in the southern Great Basin,*** zones were first delineated from inverse particle tracking and Hydrologic Unit 12 ***,they were adjusted based on water budgets,geology,and hydrologically significant ***,a geochemical analysis of the groundwater chemistry and isotopic data was conducted to verify the extent of each spring capture *** multifaceted approach adds confidence to the new delineations.

关键词： Spring capture zone Modeling geochemical analysis Multivariate statistics Spatial analysis Southern Great Basin

Holocene Moisture Variation Recorded by Aeolian Sand-Palaeosol Sequences of the Gonghe Basin, Northeastern Qinghai-Tibetan Plateau, China

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Acta Geologica Sinica(English Edition) 2020年第3期94卷 668-681页

作者： LIU Bing ZHAO Hui JIN Heling CHEN Fahu Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of ScienceLanzhou 730000China Key Laboratory of Western China's Environmental Systems Ministry of EducationLanzhou 73000China Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The northeastern Qinghai-Tibetan Plateau(QTP) of China is located at the triple junction of the Asian winter and summer monsoons and the westerlies, where paleoclimatic evolution has an important scientific significance for recognizing the spatial-temporal pattern of Asian monsoons in the past and predicting environmental change in the future. Nevertheless, the framework of the Holocene moisture variation and related mechanisms remain controversial, owing to complex hydroclimatic conditions triggered by the landform of the large mountain-arid basin. Here, we employed geochemical proxies from typical aeolian sand-palaeosol sequences in the Gonghe Basin, northeastern QTP, together with Optically Stimulated Luminescence(OSL) dating, to reconstruct the pattern of effective moisture variation and associated mechanisms in this region. Our results indicate that the regional effective moisture was at its lowest until 9–8 ka, and approached a maximum during 8–4/3 ka of the middle Holocene. Afterwards, the climate became relatively dry in general, but with a transient humid interval around 2–1 ka. Our geochemical evidence indicates that the dry early Holocene probably can be attributed to a strong winter monsoon forced by remnant ice sheet, combined with the high evaporation caused by solar insolation. Also, shifts of humid-dry are closely linked to the Asian summer monsoonal strength and therefore the balance of evaporation-precipitation in the middle and late Holocene. Thus, the pattern of the Holocene effective moisture variation is characterized as the ‘monsoon model’ in a closed intermontane arid and semi-arid basin near the western Asian monsoonal limit.

关键词： effective moisture geochemical analysis aeolian deposits Holocene Gonghe Basin

Outcrops as windows to petroleum systems:Insights from the southern Bida Basin,Nigeria

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Energy Geoscience 2024年第3期5卷 284-304页

作者： Godwin Okumagbe Aigbadon Felix Iwebunor Chinyem Tope Shade Alege Brume Overare Obinna Chigoziem Akakuru Ikenna Arisi Obasi Ernest Orji Akudo Azuka Ocheli Jeremiah Ayok Onimisi Abdullateef Jimoh Elesius Okey Akpunonu Mu'awiya Baba Aminu Bashir Ozovehe Aminu Department of Geology Faculty of SciencesFederal University LokojaKogi StateNigeria Department of Geology Faculty of ScienceDelta State UniversityAbrakaDelta StateNigeria Department of Earth Sciences Memorial University of NewfoundlandCanada Department of Earth Sciences Federal University of Petroleum ResourcesEffurunDelta StateNigeria Department of Geology School of Physical SciencesFederal University of TechnologyOwerriImo StateNigeria Department of Geology Nnamdi Azikiwe UniversityAwkaAnambra StateNigeria Department of Geology University of IlorinKwara StateNigeria

The study assessed petroleum systems in the southern Bida Basin,Nigeria,focusing on the Cretaceous *** comprise Lokoja and Patti Formation sandstones,while shales,claystone,and siltstone serve as source rocks and stratigraphic traps/*** studies delineating the key elements of the petroleum systems in the basin have not been conducted due to a lack of subsurface *** goal of the current study was to use field observations,Scanning Electron Microscopy(SEM),X-ray diffraction(XRD),and geochemical and geomechanical data to evaluate key components of petroleum systems in the southern Bida *** results presented in this investigation are intended to attain specific objectives,especially those lacking in the basin's study *** analysis revealed that the Lokoja Sandstone has porosity of 37%-39.5%and moderate permeability of 23.22-42.29 *** Patti Formation sandstone reservoirs exhibited high porosity(38%-42%)and moderate to good permeability(31.54-66.48 mD),suggesting good potential *** results revealed intragranular pores and micro-fractures in the Patti Shale,whereas the sandstone reservoirs in the Lokoja and Patti formations displayed fractures,facilitating hydrocarbon *** was the dominant mineral in the sandstone units of both *** analysis revealed that brittle and clay minerals influenced the microstructure of Patti *** analysis indicated promising petroleum potential in the Patti Shale,with a total organic carbon(TOC)content of 1.87 wt%,free hydrocarbon from kerogen(S1)of 0.41 mg/g,hydrogen index(HI)of 0.75 mg HC/g TOC,and production index(PI)of *** Patti and Lokoja formations'shale,claystone,and siltstone exhibited sealing potential,with a plasticity index of 24-35 and coefficient permeability of 2.8×10^(-4)-3.6×10^(-4)cm/*** studies,XRD,geochemical data,and geomechanical index values have confirmed the key components of the petroleum system,which in turn

关键词： geochemical analysis Plasticity index Source rock Reservoir rock Stratigraphic trap Bida Basin

Multielement analysis of Deep-Sea Sediments by Inductively Coupled Plasma Mass Spectrometry

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Journal of Ocean University of China 2008年第2期7卷 137-144页

作者： XIA Ning WU Zhaohui GUO Dongfa YAO De Qingdao Institute of Marine Geology Chinese Geological Survey Qingdao 266071 P R. China Beijing Uranium Ore Processing Institute Beijing 100029 P. R. China Institute of Environmental Science and Technology Shandong University of Technology Zibo 255049 P. R. China

Marine sediments were dissolved by HNO3-HF-HC104 in a sealed container at low pressure; HF was evaporated in an open container and salts were dissolved in HCl by heating, then transferred to 2% HNO3 solution. A total of 45 elements, including Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Sb, Cs, Ba, La, Ce, Pr, Nd, Sin, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Tl, Pb, Bi, Th and U, were measured by inductively coupled plasma mass spectrometry （ICP-MS）. Conditions and sample experiments showed that this procedure defines a good experimental method which has the advantages of clear interference, easy operation and reliable results. The concentrations of the 45 elements could be used for resource exploration, environmental assessment and academic research.

关键词： marine sediment deep-sea geochemical analysis multielement determination ICP-MS

Records in palaeo-notch sediment: changes in palaeoproductivity and their link to climate change from Svalbard

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Advances in Polar Science 2018年第4期29卷 243-253页

作者： YANG Zhongkang WANG Yuhong SUN Liguang Anhui Province Key Laboratory of Polar Environment and Global Change School of Earth and Space SciencesUniversity of Science and Technology of China Institute of Polar Environment School of Earth and Space Sciences University of Science and Technology of China

Palaeo-notch sediment, accumulated in lacustrine environment, is a reliable proxy material for palaeoclimatic and palaeoenvironmental research. In this study, we collected a palaeo-notch sediment profile from the Blomstrandhalv?ya, used multiple geochemical proxies to reconstruct palaleoproductivity variations, and investigated their link to climatic records from surrounding regions. C/N atomic ratios and carbon isotope indicate that organic matter in the sediment is mainly derived from lacustrine algae. Toward the surface sediment, the TOC, TN, P contents and the reconstructed palaeoproductivity show remarkable fluctuations with several peaks and troughs, opposite to the variation trend of the CaCO3 contents. Changes in the reconstructed palaeoproductivity are in good agreement with palaeoclimatic records from the surrounding regions, and three interruptions are likely linked to the well-known cooling periods around 1900 BP, 2800 BP and 4200 BP. Thus palaeoproductivity variations on the Blomstrandhalv?ya are mainly driven by climate changes; palaeoproductivity increase during warmer periods, and vice versa. This study will help the research of Arctic lake ecosystem and its response to climate change.

关键词： palaeo-notch sediment geochemical analysis palaleoproductivity climate change Svalbard

Evaluation of Source Rock Potential for Hydrocarbon Generation in Shallow Offshore, Lamu Basin, Kenya

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Journal of Geoscience and Environment Protection 2023年第5期11卷 60-85页

作者： Dennis Ombati Githiri John Maurice K’Orowe Department of Physics Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya Department of Physics Kisii University Kisii Kenya

The ever-increasing demand for oil and gas has driven its exploration in rather extreme conditions. In Lamu offshore, which is hitherto underexplored, most of the wells already drilled turned out dry save for a few wells with hydrocarbon shows despite the promising reservoir properties and related geological structures. This, therefore, necessitated a source rock evaluation study in the area to ascertain the presence and potential of the source rock by integrating the geochemical data analysis and petroleum system modeling. The shallow Lamu offshore source rock quantity, quality, and maturity have been estimated through the determination of the total organic carbon (TOC) average values, Kerogen typing, and Rock-Eval pyrolysis measurements respectively. geochemical data for Kubwa-1, Mbawa-1, Pomboo-1, and Simba-1 were evaluated for determining the source rock potential for hydrocarbon generation. Petroleum system modeling was applied in evaluating geological conditions necessary for a successful charge within a software that integrated geochemical and petrophysical characterization of the sedimentary formations in conjunction with boundary conditions that include basal heat flow, sediment-water interface temperature, and Paleo-water depth. The average TOC of 0.89 wt % in the study area suggests a fair organic richness which seems higher in the late cretaceous (0.98 wt %) than in the Paleocene (0.81 wt %). Vitrinite reflectance and Tmax values in the study area indicate the possible presence of both mature and immature source rocks. Type III Kerogen was the most dominant Kerogen type, and gas shows are the most frequent hydrocarbon encountered in the Lamu Basin with a few cases registering type II/III and type II. The charge properties (i.e. Temperature, transformation ratio, and Vitrinite reflectance) over geologic time at each of the wells have been estimated and their spatial variation mapped as seen from the burial history and depth curves overlaid with

关键词： geochemical analysis Petroleum System Modeling Rock-Eval Pyrolysis Kerogen Typing Vitrinite Reflectance and Transformation Ratio