International Journal of Coal Geology最新文献

Although the Monterey Formation has been studied extensively for its petroleum system and Miocene climate insights, debates persist regarding its paleo-redox conditions. Furthermore, its characteristic lithofacies offer a natural laboratory for developing tools to differentiate siliceous and calcareous rocks in deepwater environments. This study evaluated the potential of the Sulfur Index (SI = mg S_org/g TOC), measured by Rock-Eval 7S, as a proxy for assessing paleoredox conditions by comparing the SI with iron speciation data. Additionally, high-resolution molecular analyses were performed to investigate possible relationships between sulfur compounds and rocks with different carbonate content. The findings indicate higher SI values and higher concentrations of benzothiophenes over dibenzothiophenes in the siliceous lithofacies compared to the calcareous lithofacies. This suggests that the mineral matrix plays a crucial role in influencing the process by which sulfur-rich kerogen undergoes cracking when placed under thermal stress. The SI may support a paleoredox interpretation for the Monterey Formation, differing from previous interpretations based only on iron speciation. This alternative interpretation involves a more extensive water-column euxinia, distinct from the seasonal euxinia suggested in previous work. This study represents a practical and pioneering workflow based on sulfur data derived from Rock-Eval 7S for paleoredox and lithofacies assessments, opening avenues for further research.

As a critical element, Li is currently in high demand due to rapid technological development. Anomalous Li enrichment in Pennsylvanian coals, such as those in Shanxi Province, has been discovered in China. Previous studies have shown that Li enrichment in coal and coal-bearing strata in Shanxi Province is generally evident in clay minerals and is related to mineral matter originating from nearby granite or bauxite and, in some cases, it is associated with hydrothermal fluid. Determining the exact sources of Li responsible for the Li enrichment in these coals is essential. This study investigated the spatiotemporal provenance of mineral matter evolution and source-to-sink system of No. 9 coal seam in the Anjialing Mine, Ningwu Coalfield, northeastern Shanxi Province, China. In total, 17 coal samples, six parting samples, one roof sample, and one floor sample from No. 9 coal seam were collected. Geochemical, mineralogical, and geochronological analyses were conducted using X-ray powder diffraction (XRD) and Raman spectroscopy for minerals, inductively coupled plasma–optical emission spectroscopy (ICP–OES) for major-element oxides, inductively coupled plasma–mass spectrometry (ICP–MS) for trace elements, and laser ablation–ICP–MS (LA–ICP–MS) for geochronology. The mineral matter in the coal samples consists mainly of kaolinite, boehmite, quartz, with varying proportions of calcite, pyrite, nacrite, anatase and goyazite, whereas in non-coal samples, the mineral matter is dominated by kaolinite, quartz, with minor amounts of anatase and pyrite. There are two heavy mineral assemblages: titanite–biotite–zircon–apatite and titanite–biotite–anatase–apatite. Relative to the elemental composition of the World hard coal, the coal benches are enriched in Li and Sr and slightly enriched in Ga, Zr, Hf, and Th. Relative to the elemental composition of the World clays, the parting samples in No. 9 coal seam are enriched in Li and slightly enriched in Mo, the roof sample is slightly enriched in Hf, and the floor sample is slightly enriched in Li and Hf. Detrital zircon ages in the roof and floor samples can be divided into two main ages: 2500–1700 and 326–293 Ma. The youngest UPb ages of zircon grain in the roof and floor samples are 292.7 ± 7.1 and 295.5 ± 9.7 Ma, respectively, indicating a well-constrained Early Asselian–Sakmarian stage. Detrital zircons, with ages of 326–293 Ma, in No. 9 coal seam are mainly derived from granitic intrusions and volcanic rocks in the Inner Mongolia Paleo-uplift (IMPU) rather than bauxite deposits. Based on mineralogical, geochemical, and geochronological evidence, the high Li enrichment in the studied samples is mainly caused by detrital material input. The dominant detrital materials in the coal and non-coal samples originate from felsic-intermediate igneous rocks in the IMPU.

Organic petrology developed from coal petrology, and, in the 1960s, it began to be applied to the study of dispersed organic matter (DOM) in sedimentary rocks other than coal. Over the last few decades, the petrology of DOM has been used to characterize organic matter in sedimentary basins with an emphasis on fossil fuel resource exploration. Today, due to the global research shift on topics related to climate, organic petrology has expanded into new application areas, such as geothermal exploration, biological carbon storage (biochar), disposal, and management of radioactive waste.

From the publication of the International Handbook of Coal Petrology (mid-20th century) to the present day, a large number of standards, books, and articles have been published as a result of the work of organic petrographers and petrologists around the world and efforts of the International Committee for Coal and Organic Petrology (ICCP) and The Society for Organic Petrology (TSOP) to promote the study of organic petrology. The current fundamentals and standards of organic petrology provide the international scientific community with well-informed guidance and recommendations to promote in-depth research. However, this information is currently widely scattered, leading to discrepancies in methodology and terminology. Therefore, this paper aims to present a comprehensive review of the main analytical standard test methods and techniques currently used in the petrology of DOM under reflected white light and UV and blue-light excitation, and to provide an efficient and well-defined reference guide. Furthermore, considering the important role of the ICCP in the development of organic petrology since the 1950s, a brief review of the ongoing activities of ICCP dealing with DOM is also presented.

The commercial management of coal and its by-products has the potential to negatively impact natural coastal environments. The coal conversion processes and coke production are sources of polycyclic aromatic hydrocarbons (PAHs) emissions that also contribute to the pollution of those aquatic environments. This research assesses the contamination by carbonaceous anthropogenic particles and by polycyclic aromatic hydrocarbons of some recreational sites (Arañón, Peña del Caballo and San Balandrán area) located in the Avilés' estuary, an area in Northern Spain that has been heavily industrialized since the 1950s. The results obtained indicate a low concentration of solid organic anthropogenic particles in the intertidal sediments of the recreational sites in the estuary, probably due to the protective measures set in place at the facilities managing bulk coal and coke, which prevents the dispersion of coal dust (and other materials) as well as the eventual failure into the estuary. The characteristics of 16 priority pollutants PAHs analyzed in two recreational sites of the estuary (San Balandrán area), their distribution by aromatic ring number together with their diagnostic ratios demonstrate a pyrogenic nature with a main source from processes of coal and coke conversion (including combustion) in the facilities around the estuary. Some contribution of PAHs derived from petroleum cannot be ruled out. This contamination by PAHS is constant and sustained over time. The majority of the considered PAHs are well above the Spanish Generic Reference Level, (GRL) established for “protection of ecosystems with aquatic organisms”, and only a few of them are notably above the corresponding Spanish GRL established for “other uses of land”, which should include lands for recreational activities. The analysis of the potential toxicity risk of PAHs for human health and the organisms of the aquatic ecosystem suggests a relatively low toxicity risk to very high toxicity risk in the San Balandrán environment according to the concentration and distribution trend of PAHs identified in this area. This trend is dependent on the coastal dynamics and the protection level of the site, which also affect the distribution of the anthropogenic carbonaceous particulates in the same way.