Geochemical Characteristics Research Articles

Research on Geochemical Response Characteristics of Dry Hot Rocks Injected with Scale Removal pH Modified Fluid

Research on Geochemical Response Characteristics of Dry Hot Rocks Injected with Scale Removal pH Modified Fluid

Source Rock Prediction Using Well Log and Seismic Data: A Study of the Albian Stage in the Côte d’Ivoire Basin

The Côte d’Ivoire Basin is one of the most important oil production areas in Africa; and it is also the focus of global oil and gas exploration, but the degree of oil exploration and development in this basin are still in the early stages. Based on a comprehensive analysis of drilling, logging, and geochemical data in the Côte d’Ivoire Basin, this study comprehensively evaluates the Cretaceous lacustrine source rocks in the study area, establishes a total organic carbon (TOC) quantitative prediction model by using the total organic carbon method, determines the relationship between seismic reflections and the geochemical characteristics of the source rocks, and tracks the main source rocks horizontally. The results show that the TOC of the Lower Cretaceous Albian stage source rocks is 2.63 wt.%, the kerogen type II is dominant, and the vitrinite reflectance (RO) ranges from 0.3% to 0.9%. The source rocks are mainly in the low-mature to mature stage, and they are generally of good and premium quality. The distribution range of high-quality source rocks with TOC values of 4.00~5.00% is predicted using the total organic carbon method, and useing the seismic method, we determine that high-quality source rocks with larger thickness values and better continuity are mainly developed in the eastern depression center of the basin.

Fractionation of Inorganic Phosphorus in Cold Temperate Forest Soils: Associating Mechanisms of Soil Aggregate Protection and Recovery Periods after Forest Fire Disturbance

The soil aggregate is the fundamental unit of soil structure. The fractionation characteristics and influencing factors of phosphorus (P) in soil aggregates inherently link its geochemical characteristics and recycling mechanism. This work investigated the fractionation characteristics of inorganic P in cold temperate forest soils and studied the impacts of recovery periods after forest fires and soil aggregate protection mechanisms on P fractionation. Our results showed that the TP, active P, stable P, and total organic carbon (TOC) contents varied with increasing recovery years after forest fire disturbance. The TP content in the coarse particulate organic matter fraction (cPOM) exhibited an increasing trend with the number of recovery years. Redundancy analysis (RDA) and correlation analysis indicated that TOC played a crucial role in influencing the dynamics of P fractionation during the recovery process. The order of TP levels in different soil aggregate fractions was as follows: μClay > dClay > LF > cPOM > dSilt > μSilt > iPOM, with significant contributions from the cPOM and dSilt fractions. The ranking of P fractions in bulk soils was as follows: ACa-P > Fe-P > Oc-P > Or-P > De-P > Al-P > Ex-P. The protective mechanism of soil aggregates had a more significant effect on TOC than TP, with the order of protective abilities being: Phy×biochem-protected > Biochem-protected > Phy-protected > Non-protected mechanism. TOC and recovery years emerged as critical factors influencing the dynamics of different P fractions during post-fire recovery. Soil aggregate protection mechanisms demonstrated significantly higher effects on TOC than on TP. This study provides insights into the fractionation mechanisms of P in the soil–forest ecosystem of the Greater Khingan Mountains, contributing to the sustainable development and utilization of cold temperate forest ecosystems.

Origin of the Site U1504 alkaline basalts in the South China Sea continental margin: Insights on deep mantle diversity and subduction dynamics under continental arcs

Alkaline basalts produced in continental arcs should contain information different from the arc tholeiite-calc-alkaline-series magmas, and their origin could provide unique constraints on deep mantle composition and material cycling. However, due to their sparse occurrence, alkaline basalts in continental arcs have not been studied thoroughly, which hinders our understanding of the mantle diversity and subduction dynamics under continental arcs. In this study, we present new 40Ar/39Ar ages, major and trace elements, and Sr-Nd-Hf isotopic data for the International Ocean Discovery Program Site U1504 alkaline basalts in the continental arc developed on the South China Block (SCB). These alkaline basalts were generated at ca. 121 Ma and display typical oceanic-island basalt geochemical characteristics. Their relatively high εNd(t) (3.5−3.7) and low (87Sr/86Sr)i (0.7034−0.7040) and La/Nb (0.5−1.0) values suggest that they were mainly derived from an asthenosphere mantle source. Compared to alkaline basalts in the SCB inland, U1504 alkaline basalts exhibit lower K2O/Na2O, Zr/Sm, Zr/Y, εNd(t), and εHf(t) values, indicating the addition of minor sub-continental lithospheric mantle. The enrichment of Nb, Ta, light rare earth elements, and slight depletion of Zr, Hf, and Ti, as well as elevated Fe/Mn and Sm/Yb and low CaO, indicate that their mantle lithology was mainly garnet pyroxenite. Based upon these findings and previous studies, the garnet pyroxenite was probably formed by the interaction of upwelling asthenosphere with slab edges in the scenario of break-off of the Paleo-Pacific Plate, and such interaction diversified the mantle chemistry beneath continental arcs. In conjunction with other reported alkaline basalt data, it is proposed that the enriched asthenosphere mantle beneath the SCB had formed sequentially from inland to coastal since the late Mesozoic, and this may be related to lateral and vertical flow in the deep asthenosphere controlled by the break-off of subducted plates.

Geochemistry of I-type Volcanic Arc Granitoid From Tanggamus Regency, Southern Sumatra

Granitoid intrusion of several provinces on Sumatra is correlated with Southeast Asia tectonics that have occurred since the Permian. Granites from several volcanic arc provinces are located along the western part of Sumatra Island and are found near Bukit Barisan. This study describes the geochemical character of granitoid from the Tanggamus region and its surroundings near the Bukit Barisan cluster. After megascopic description in the field, major oxides, trace elements, and rare earth elements in rock samples were measured using X-ray fluorescence and inductively coupled plasma-mass spectrometry devices. The samples were intermediate to acidic intrusive rocks with SiO2 ranging between 61.35% and 75.29%. The rocks can be described as diorite to granodiorite and were formed as a result of subduction processes. The granitic rock samples showed I-type features of A/CNK value <1.1, volcanic arc granite affinity, K2O/Na2O ratio, and magnesian properties. The total rare earth content was medium with an average of 43.97 ppm. The similarity of the rare earth normalized diagram against the chondrite value indicates that the samples come from an identical origin.

Origin and Geochemical Characterization of Groundwater from Coal Seam: A Case Study of Balasu Coalfield, Ordos Basin

Origin and Geochemical Characterization of Groundwater from Coal Seam: A Case Study of Balasu Coalfield, Ordos Basin

Agates of the Lece Volcanic Complex (Serbia): Mineralogical and Geochemical Characteristics

Agates of the Lece Volcanic Complex (Serbia): Mineralogical and Geochemical Characteristics

Geochemical characteristics, mechanisms, and suitability of groundwater resource for sustainable water supply in Quetta valley

ABSTRACT Groundwater is a crucial water resource for various usages worldwide. The Quetta Valley of Pakistan was investigated regarding its groundwater quality sustainability based on integrated approaches of hydrochemistry, geographic information system, and multivariate statistics. A total of 29 groundwater samples were collected from monitoring wells to get insights into the hydrochemical suitability of groundwater for sustainable irrigation and drinking utilization. The results indicate groundwater is mainly featured by the hydrochemical facies of HCO3·Cl-Ca. Groundwater hydrochemical composition is dominantly governed by the dissolution of carbonates and silicate minerals in combination with positive cation exchange in the valley. Principal component analysis reveals a significant influence of geogenic factors on groundwater chemistry, further supported by PHREEQC simulation that detects a supersaturation of calcite, dolomite, and sulphate minerals in the aquifer. The irrigation water quality index divides groundwater in the study area into three zones, which signify low restriction and no restriction, except for a severe restriction in the southwestern part of the valley. Groundwater is generally suitable for irrigation across the valley. The entropy-weighted water quality index classifies groundwater as excellent and good quality for drinking. This study can provide crucial insights for authorities on groundwater suitability in Quetta Valley and similar regions worldwide.

Geological and geochemical analyses of pegmatites in Egbe, Isanlu (sheet 225), Southwestern Nigeria

The hitherto pegmatite of the Egbe area has been known to bear valuable economic minerals. They are associated with other rock types including banded gneiss, schist, amphibolite, and granites. These pegmatites and the host rocks were studied in detail to elucidate their petrochemical and geochemical features and also to assess the mineralization of Tantalum- iobium and other minerals. Geological field mapping was done, thin section-petrographic analysis of ten representative rock samples was performed and nineteen whole-rock samples were analyzed for major and trace elements including REES aided by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Boron- Fusion-Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Ion-Selective Electrode (ISE) for Fluorine at Acme Laboratory, Vancouver, Canada. The general structural trend of the area under study is WNW-ESE and foliations of N-S strike were observed in the banded gneiss and schist which also exhibit asymmetric and isoclinals folding respectively. The tantalite-columbite mineralization is associated with the NE-SW trending pegmatite dykes. The mineralized pegmatites are genetically related to the peraluminous S-type granite. The minerals (i.e., Albite, lepidolite and muscovite) extracted from the pegmatites are well enriched in Li, Rb, Cs, Nb and Ta compared to the host rocks. The rare-metal pegmatites exhibit pronounced negative Ce and Eu anomalies and also show weak negative Yb anomalies while the barren pegmatites have positive Ce and weak negative Eu anomalies and exhibit weak positive Yb anomalies. The pegmatites are moderately evolved compared with other highly mineralized pegmatites. The pegmatites from Igbaruku and one from the Okere area are of the rare-metal pegmatite and they are moderately fractionated while the barren pegmatite from Egbe and one from Okere are unfractionated. The economic mineral within the Egbe area is tantalite, with every possibility that the tantalite-columbite enrichment is ferrotantalite-columbite and manganotantalite columbite.

Integrated geophysical and geochemical characterization of hydrocarbon contaminated site in Erhoike-Kokori, Southern Nigeria

The effectiveness of geophysical and geochemical methods in delineating hydrocarbon contamination in a spill site is carried out around theErhoike flow station in Kokori, Ethiope East LGA, Delta State. Wenner array was used for the transverse in acquiring the data which spanned a transverse of 200m and 3D model resistivity images were obtained from the inversion and presented in horizontal depth slices. Well water samples were also taken for Total Petroleum Hydrocarbon (TPH) content while soil samples from the location were also taken for Porosity and coefficient of permeability. The result of the 3D horizontal depth slices in the location reveals that Erhoike is impacted with hydrocarbon plume to a depth of 31.7m. The concentration of TPHCs from the water analysis shows that the wells around the suspected zones are affected by hydrocarbon. The laboratory tests for porosity (Փ ) and coefficient of permeability (k) for the soil samples are indicative of sand/silty sand which thus allows the flow of PHCs plume to the soil and groundwater in the study area. The results of the study have shown that the soil is permeable and porous which would allow the passage of the leaked and spilled PHCs through the soil to groundwater where the PHCs could mix, float and sink into groundwater. The 3D analysis revealed the presence of PHCs up to a depth of 33.7m but prominent at a depth of 10m which indicates the presence of PHCs in the wells. The hydrochemical analysis also proved the same results as that of the 3D which authenticated the reliability of the method used in the study.

Palaeodepositional environment, implications of Glossopteris flora, and organic matter characteristics from the lower Permian, Karo Open Cast Mine, East Bokaro Coalfield, Damodar Basin, India

The present study deals with the Early Permian floral diversity, palaeoenvironment, palaeoclimate and depositional setting using a multiproxy approach that includes morphotaxonomy, palynology, and organic geochemistry of Karo OCM (Open Cast Mine), East Bokaro Coalfield, Damodar Gondwana Basin, India. The Permian sediments of Peninsular India are widely regarded as fluvial, along with some marine incursions. The macroplant fossil assemblage exhibits the presence of Glossopteridales, comprising Glossopteris, Gangamopteris, and Vertebraria, as well as Coniferales, which includes Noeggerathiopsis. The palynological assemblage encompasses the dominance of the striate bisaccate pollen Faunipollenites sp. and the sub-dominance of the non-striate bisaccate pollen Scheuringipollenites sp. with glossopterid affinities. The megafloral and palynofloral assemblage confirms the biostratigraphical age to be Late Barakar palynoflora of Kungurian affinity. The studied morphological characteristics, including small to large Glossopteris leaves exhibiting a lanceolate shape, acute apices, and acute cuneate or tapering bases, as well as entire margins with narrower lamina and narrow meshes, suggest the existence of a dense forest with the prevalence of a warm and humid climate during their deposition. The organic geochemical characterization based on functional group and biomarker analyses reveals the diagenetic effects on organic matter. Aliphatic symmetric (∼2865–2855 cm-1) and asymmetric stretching (∼2930–2910 cm-1) peaks are identifiable in coal samples, whereas they are absent in carbonaceous shale. The A-factor vs. C-factor plot suggests that the kerogen type is type III, which can generate mainly gaseous kerogen. The vitrinite reflectance studies (Rr av. 1.1%) show increased maturity of the samples, which is supported by the n-alkane distribution pattern and the absence of hopane terpenoids. The Indian floral assemblages in contemporary of southern Gondwana continents reveal a stronger inclination/affinity with the flora of Africa than that of South America, thereby supporting the age to be of Artinskian–Kungurian.

The formation of the granite complex in the Wuhe Mari area of Bayankala Mountain on the northeastern margin of the Tibetan Plateau: constraints from lithogeochemistry and U–Pb zircon dating

The granite complex in the Wuhe Mari area lies in the tectonic magma belt of the North Bayankala Mountains on the northeastern edge of the Qinghai-Tibet Plateau. It is located in the middle of the first member of the Changmahe Formation of the Early and Middle Triassic Bayankala Mountains Group. This article presents a systematic study of the petrological and geochemical characteristics and chronology of porphyrite granilite, monzogranite, porphyritic monzogranite and diorite in the granite complex in Wuhe Mari area. The genetic relationship between these four rock types as well as the type of source area and tectonic environment are clarified. Zircon LA-ICP-MS-U–Pb dating shows that the porphyritic granodiorite, monzogranite, porphyritic monzogranite and diorite have ages of 221.0 ± 2.7 Ma, 219.8 ± 3.0 Ma, 216.6 ± 4.3 Ma and 213.4 ± 1.6 Ma, respectively. The petrogeochemical characteristics show that the porphyritic granodiorite, monzogranite and porphyritic monzogranite in the granite complex have the characteristics of high Si, Al2O3, K, low Na, Ca, Mg, Fe, K, Rb and Th—Content in the strongly incompatible elements of the granite complex have three, the relative loss of Ba, Ta, Nb, Ce, slight enrichment or no anomaly, the loss of Sm, Hf and Zr, the strong loss of Y and Yb and the aluminum saturation index < 1.1. Combined with the geological data all three samples belong to Type I granite formed in the same collision environment. Based on the lithogeochemical characteristics and the results of U–Pb chronology, these three rock formations are believed to have been formed by a series of magmatic melting events and are the result of homologous magma crystallization and differentiation. The diorite forms in an intraplate tectonic setting as a result of the evolution of co-collision granite to intraplate granite.

A comprehensive petrochemical study of coals of Jaintia Hills: unveiling their industrial applicability and potential as hydrocarbon source rocks

ABSTRACT The current investigation aims to classify Jaintia Hill coals into different types, ranks, and grades based on their geochemical and petrographic characteristics and to evaluate the potential utilization of these coals under the framework of different coal classification schemes, essential for various industrial, commercial, and residential applications. During the present study, representative coal samples were collected from the working coal mines of Khliehriat and Lad Rymbai areas of the East Jaintia hills of Meghalaya, India, and subjected to proximate analysis, ultimate analysis, and micro petrographic study. Using international and Indian classification schemes, an attempt has been made to propose the appropriate utilization of these coals. It has been observed that these coals have high vitrinite content and low ash content but have high sulfur content. The petrographic and geochemical data suggest that these coals can be utilized for gasification, hydrogenation, and as a coal blend for metallurgical coke-making in the steel industries. The coal samples were also investigated from the perspective of hydrocarbon source rock potential, and it was concluded that these coals have good source rock potential for gas and liquid hydrocarbon.

Phase change of the Ordovician hydrocarbon in the Tarim Basin: A case study from the Halahatang–Shunbei area

Abstract To clarify the genetic mechanism for phase change of the hydrocarbon in the ultra-deep reservoirs, a case study from the Ordovician hydrocarbon in the Halahatang–Shunbei area (HSA), Tarim Basin, NW China, was conducted. The results show that the Ordovician reservoirs in the HSA are characterized as multi-phase reservoirs with a lateral co-existence of condensates, volatile-oil reservoirs, normal oil reservoirs, and heavy oil reservoirs. From north to south, there are regular variations in the geochemical characteristics of the Ordovician hydrocarbon in different blocks of the HSA, showing an increasing trend in GOR, dryness coefficients, methane contents, methane carbon isotope values, and ethane carbon isotope values, while a decreasing trend in oil densities and wax contents. Because the same Cambrian–Lower Ordovician source for the Ordovician hydrocarbon is observed and the kerogen-cracking gas is dominated in the HSA, the regular variations of the hydrocarbon phases and geochemical characteristics can be interpreted as records of biodegradation and multistage oil–gas filling rather than controlled by the source rock organofacies, oil cracking, and gas invasion. The formation mechanism of the Ordovician multi-phase reservoirs in the HSA suggests that the deep strata of the Tarim Basin hold potential for the exploration of natural gas resources.

Provenance of mixed volcaniclastic-carbonaticlastic gravity-flow deposits: a case study from the Cretaceous of the southern Central Alborz (Iran)

ABSTRACT Understanding the petrographic and geochemical characteristics of different tectonic settings is essential to improving traditional methods of identifying the provenance of palaeo-sedimentary environments. This research focuses on the K2b unit, which consists of mixed carbonate and volcanic lithic sandstones located in Iran with the age of the Turonian-Early Campanian period. Five sedimentary lithotypes with distinct petrographic and geochemical signatures were identified in the Turonian/Lower Campanian K2b unit, which consists of coarse-grained fan-delta strata. Carbonate and volcanic lithic fragments are the most characteristic components of mostly quartzo-lithic to felspatho-litho-quartzose sandstone layers, documenting a unidirectional paleocurrent pattern with the north-eastward direction. The original composition has undergone diagenesis, resulting in the precipitation of authigenic carbonates and depleting Rare Earth Elements (REE) except for Eu, which shows a positive anomaly. The K2b fan delta was situated on the margin of the proto-south Caspian back-arc basin, and the sediments were sourced from the undissected magmatic arc. The gravity flow deposits in the K2b unit were likely triggered by tectonic activity in the catchment area of the fan delta, leading to uplift and formation of relief associated with the regional Mosha Fault and, on a larger palaeogeographic scale, with subduction of the Arabian plate beneath the Iranian plate during Turonian-Early Campanian.

Mineral chemistry and P-T conditions of the Karakaya volcanites at Kırka-Afyon-Isparta volcanic province, Afyon, Turkey

The Kırka-Afyon-Isparta Volcanic Province (KAIVP) is one of the best known regions in Turkey for the origin and petrological evolution of the high potassium volcanic activity. The temporal and spatial variability of volcanic rocks in the region exerts significant control over their geochemical diversity. Alkaline and ultrapotassic volcanic rocks of the Afyon volcanism are the first products of asthenospheric origin after the orogenesis in western Anatolia. We have determined the mineralogical and petrographic properties of the Karakaya volcanites surrounding Afyon with the help of microprobe analyses. Estimated thermobarometers are calculated. The Karakaya volcanites have been grouped into four different units according to their their mineralogical, petrographic and geochemical characteristics: Seydiler ignimbirite, basaltic trachyandesite, trachyandesite, trachyte and lamproite. Most samples display hypocrystalline porphyritic texture, whereas samples of lamproite unit have a holocrystalline texture. Generally, volcanic units also exhibit some textural evidence of disequilibrium crystallisation, such as sieve texture and corrosion in plagioclase phenocrysts, zoning and inclusions in clinopyroxene phenocrysts. Mineral thermobarometric estimations in all suites were tested on clinopyroxene and feldspar compositions, considering different authors’ approaches. Values of temperatures and pressure range from 1105 to 1273ºC and 5.6 to 12.2kbar, respectively. The temperature and pressure values calculated from the mineral-melt associations in the volcanics suggest that the Afyon Volcanites were affected by magma mixing processes and crystallised at different depths during the transport of magma.

Analysis of the Sedimentary and Geochemical Characteristics of Sedimentary Clastic Rock Samples from the Alpha–Mendeleev Rise

Analysis of the Sedimentary and Geochemical Characteristics of Sedimentary Clastic Rock Samples from the Alpha–Mendeleev Rise

Typhoon and flooding occurrences on Chongming Island, Changjiang Estuary, as revealed by a newly acquired sedimentary record

Typhoon-induced storms surges and river flooding events represent two types of natural disasters that affect a wide range, occurring with high frequency and causing serious societal losses. Due to the limited duration of instrumental records, there is an inadequate understanding of the patterns and mechanisms underlying the variations in typhoons and floods. The interpretation of sedimentary records aptly compensates for these deficiencies in terms of the temporal scale, becoming a crucial medium for extending the temporal span of typhoon and flood records. Previous studies in this field have primarily focused on the identification of single types of extreme events. The Changjiang Estuary, particularly Chongming Island, is significantly affected by both typhoons and river floods, making it an excellent area for synchronous comparative studies of these two types of extreme events. Based on the analysis of a core sample, ZP02, collected from Chongming Island, in terms of chronological, sedimentological, and geochemical characteristics, specific tracing fingerprints for event deposits from typhoon and flood events are established. Sediments from typhoon events generally exhibit erosive contact surfaces, coarser grain sizes, and a tendency to become finer upwards, often featuring layers mixed with coarse sand and shell fragments. In contrast, flood event deposits vary in grain size, either coarser or finer, with abrupt contact surfaces compared to normal sediment layers, and are predominantly brownish-yellow in color. The fingerprint tracing results indicate that the typhoon event layers are characterized by high values in principal component 2 (PC2) of the elements, Zr/Fe and Sr/Fe ratios, with low values in principal component 1 (PC1) the elements and Ti/Ca ratio. Flood event deposits are marked by high values in PC1 and Ti/Ca ratio, low values in PC2 and Sr/Fe ratio, and an increase in Zr/Fe ratio in coarser flood layers but no significant change in finer layers. Based on these fingerprints, 19 layers of typhoon and the same number of flood events were identified in core ZP02, which correspond well with documentary records. The establishment of tracing fingerprints for typhoon and flood event deposits provides methodological support for the identification and interpretation of various extreme event deposits.

Ecological and Geochemical Characteristics of Potassium Industry Waste

The analysis of the ecological and geochemical characteristics of waste from the extraction and processing of potash salts, which determine the ecological state of the areas of development of these deposits, is carried out. Objects are salt dumps, sludge storages, drainage waters formed on the territory of the Verkhnekamskoye potassium-magnesium salt deposit. Under research of chemical composition of waste and the drainage waters of the sludge storage it was determine that high concentrations of mobile forms of chemical elements in drainage sodium chloride waters of waste storage facilities, an increase in the concentration of nitrogen compounds in filtration waters have been established. The active role of salt solutions in the leaching of clay minerals of salt dumps and sludge dumps, clay protective screens is determined, which leads to active filtration of salt solutions through the bed of the sludge dump, salt dump, migration of microelements in a readily soluble form into the environment.

Petrographic and geochemical analyses of pottery from Wadi Tanuf, Oman: Approaching pottery production in south‐eastern Arabia during the second and first millennia BCE

AbstractThis study describes the petrographic and geochemical characteristics of pottery collected from Mugharat al‐Kahf and WTN02 in Wadi Tanuf, north‐central Oman, to clarify interregional similarities and differences in pottery production techniques and examine the existence of interregional trade in pottery with respect to changes in mobile communities. Potsherds from these sites were characterised using thin‐section petrography and instrumental neutron activation analysis. Results revealed that several clay fabrics and tempers were used during the Wadi Suq period (2000–1600 BCE). A region‐wide similarity exists in pottery‐making techniques in terms of the tempering of specific minerals (Oman ophiolite) used in the Early Iron Age (1300–300 BCE). Geochemical results indicate differences in clay sources between the Wadi Suq period and the Early Iron Age in Wadi Tanuf and the unlikelihood of the interregional trade of domestic pottery.