Geological Journal最新文献

{"title":"Multi-Parameter Investigation of Cretaceous to Palaeocene Sedimentary Sequences in the Anambra and Niger Delta Basins, Nigeria: Organic Matter Characterisation, Palynofacies and Implications for Palaeoclimate and Sea-Level Changes","authors":"Erepamo J. Omietimi,&nbsp;Nils Lenhardt,&nbsp;Renchao Yang,&nbsp;Annette E. Götz,&nbsp;Aitalokhai J. Edegbai,&nbsp;Adam J. Bumby","doi":"10.1002/gj.5084","DOIUrl":"https://doi.org/10.1002/gj.5084","url":null,"abstract":"<p>The Anambra Basin of Nigeria, part of the larger West and Central African Rift System (WCARS) across Africa, contains primarily Cretaceous to Palaeocene shallow to marginal marine and freshwater sedimentary deposits. The organic-rich deposits of the Cretaceous Nkporo and Mamu formations within the Anambra Basin and the Palaeocene Imo Formation of the Niger Delta Basin constitute important conventional source rocks. Despite its economic significance, research on organic matter characterisation, palynofacies, sea-level fluctuations, palaeoclimate, hydrogeography, basin restriction, palaeobathymetry and the factors controlling organic matter preservation remains largely undocumented. The here presented new inorganic and organic geochemical and organic petrography data of the Cretaceous to Palaeocene deposits serve to refine the regional interpretation at a basinal scale and within the supra-regional context of the WCARS. Geochemical palaeotemperature proxies suggest a warm and humid tropical palaeoclimate during the Late Cretaceous within the study area. Furthermore, the measured TOC values indicate poor to very good organic content. Palynofacies analysis revealed high abundances of opaque and translucent phytoclasts and low amounts of palynomorphs with negligible amorphous organic matter (AOM) in the studied mudrocks. Two palynofacies groups suggest shallow-marine conditions in a proximal shelf setting and a heterolithic oxic basin. The palynofacies of the upper Imo Formation reveal higher percentages of dinoflagellate cysts during the early highstand phase, with equidimensional, opaque phytoclasts representing the maximum flooding phase, accompanied by warmer conditions. Additionally, abundant terrestrial phytoclasts, <i>Deltoidospora</i> spp., <i>Classopollis</i> spp. and geochemical indicators collectively indicate warm tropical climatic conditions consistent with geochemical interpretations. The palaeobathymetry reconstructions suggest a shallow seaway during the Upper Cretaceous in the Anambra Basin.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"196-222"},"PeriodicalIF":1.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.5084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Mesozoic Tectonic Evolution of the Baiyun Sag, Northern South China Sea Margin","authors":"Wei Guan,&nbsp;Lei Huang,&nbsp;Guangrong Peng,&nbsp;Chiyang Liu,&nbsp;Han Li,&nbsp;Chao Liang","doi":"10.1002/gj.5092","DOIUrl":"https://doi.org/10.1002/gj.5092","url":null,"abstract":"<div>\u0000 \u0000 <p>The northern South China Sea (SCS) divergent margin developed on a heterogeneous crust that inherited the structures of the Mesozoic convergent margin. However, in the past, studies focused mainly on Cenozoic structures and neglected Mesozoic basement structures. On the basis of the latest high–resolution 3D seismic volumes, we first identify the fault features and evidence in the granite basement. We then identify three sets of Mesozoic fault systems in the northern SCS and discuss their properties and genesis. The NE–trending thrust system (Seismic Reflection 1), formed by forward compression, corresponds to the NW-ward subduction of the palaeo-Pacific plate; the NE–trending extensional system (Seismic Reflection 2 and small residual half-grabens) is related to post-orogenic extension caused by slab rollback and retreat of the palaeo-Pacific plate; and the NNE–trending thrust system (Seismic Reflection 3) formed by a transpressional effect related to the palaeo-Pacific plate and the Eurasian plate changed from the long-term NW-ward orthogonal convergence to a NNW-ward oblique convergence. Finally, by combining previous results on the regional tectonic evolution of onshore and offshore South China, we establish a model for the late Mesozoic evolution of the northern SCS from the Andean-type margins to the western Pacific-type margins.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 3","pages":"629-641"},"PeriodicalIF":1.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Euungulate Fossils from the Middle Siwalik Subgroup of the Potwar Plateau of Northern Pakistan","authors":"Chaman Ara,&nbsp;Riffat Yasin,&nbsp;Hafiz M. Ishaq,&nbsp;Shakila Naz,&nbsp;Tayyaba Sultana,&nbsp;Khizar Samiullah,&nbsp;Fahad A. Al-Misned,&nbsp;Kifayait Ullah,&nbsp;Holly E. Anderson,&nbsp;Sergi López-Torres,&nbsp;Asghar Abbas","doi":"10.1002/gj.5081","DOIUrl":"https://doi.org/10.1002/gj.5081","url":null,"abstract":"<div>\u0000 \u0000 <p>This article provides a detailed taxonomic study of mammalian fossil fauna from five localities situated within the Middle Siwalik subgroup including the Nagri and Dhok Pathan formations in Punjab, Pakistan. Twenty-three euungulate specimens comprised of isolated teeth, and maxillary and mandibular fragments, are described. This collection includes the bovid, <i>Elachistoceras</i>; a very rare faunal element in the Siwaliks of Pakistan, as well as <i>Elachistoceras khauristanensis</i>, <i>Pachyportax latidens</i>, <i>Giraffa punjabiensis</i>, <i>Bramatherium grande</i>, <i>Merycopotamus dissimilis</i>, <i>Dorcatherium minus</i>, <i>Dorcatherium majus</i>, <i>Hippopotamodon sivalense</i>, <i>Sivalhippus theobaldi</i>, <i>Sivalhippus nagriensis</i> and <i>Brachypotherium perimense</i> These fossil remains add important new insights into the taxonomy and diversity of Late Miocene mammal faunas of the Middle Siwaliks. The data is important for understanding the biogeographical and palaeoenvironmental history of the region. The characteristics of the fossils described in this study further support the currently hypothesised presence of a massive open land environment with variable wet and dry seasons alike to that of the current climate in Eurasia and Africa. The variable habitat niches of these co-existing fauna also give further support to the supposition that there was a much more mixed array of palaeoenvironments ranging from a prevalence of woodland to expansive savannah territory during the deposition of Nagri and Dhok Pathan formations.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"133-162"},"PeriodicalIF":1.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143115194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geology of Mudstones Atop the Sangonghe Formation, Shuixigou Group, Turpan-Hami Basin: New Insights and Their Implications for Petroleum Geology","authors":"Weiming Wang,&nbsp;Meishuo Hu,&nbsp;Xuan Chen,&nbsp;Qingguo Liu,&nbsp;Weihao La,&nbsp;Hua Zhang,&nbsp;Yuzhong Yang,&nbsp;Changsheng Miao,&nbsp;Tingting Li","doi":"10.1002/gj.5094","DOIUrl":"https://doi.org/10.1002/gj.5094","url":null,"abstract":"<div>\u0000 \u0000 <p>As the exploration of deep-seated oil and gas resources in the Turpan-Hami Basin intensifies, there is an urgent need to thoroughly depict the geological characteristics of newly uncovered, underexplored strata in sub-sag centers. This study undertakes the inaugural systematic geochemical analysis of mudstones atop the Sangonghe Formation, including palynological identification, maceral identification, biomarker analysis, total organic carbon (TOC) analysis, and pyrolysis. The findings reveal that the mudstone sequence, as the target layer, was deposited in a warm and moist paleoclimate and a weakly reducing to weakly oxidising saline water environment, fostering the growth of prolific algae and bacteria, thus ensuring substantial foundational materials for source rock formation. The organic matter in the mudstone sequence displays pronounced laminar accumulation. Despite the overall modest abundance, the organic matter features notable hydrocarbon-generating potential per unit of organic carbon and favourable types. Humic-sapropelic kerogens (type II₁) are found in the mudstones, with organic matter generally reaching a mature to highly mature stage. These characteristics establish the mudstones as effective source rocks, furthermore, the hydrocarbon expulsion in the Xishanyao Formation precedes that of the Sangonghe Formation and that both formations constitute a sequential process in terms of hydrocarbon generation and expulsion timing and hydrocarbon contribution. Reanalyzing this mudstone sequence not only revises prior geological understanding of it as direct cap rocks, but also facilitates the reclassification of deep-seated strata into three distinct petroleum systems. Centered around this source rock layer, dual modes, namely the “lower-source rock and upper-reservoir” and the “ lower-reservoir and upper-source rock” modes can be formed. These new insights will offer profound implications for hydrocarbon resource evaluation and future hydrocarbon exploration endeavours in the Shuixigou Group within the Taibei sag.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 3","pages":"659-673"},"PeriodicalIF":1.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RAMAN Analysis of Carbonaceous Material and Deduced Peak Metamorphic Temperatures of Metasediments From Western Himalaya, NW Pakistan","authors":"Nasir Ahmad,&nbsp;Shah Faisal,&nbsp;Asad Khan,&nbsp;Hafiz U. Rehman","doi":"10.1002/gj.5083","DOIUrl":"https://doi.org/10.1002/gj.5083","url":null,"abstract":"<p>Raman spectroscopy of carbonaceous materials (RSCM) was applied to 10 carbonaceous material (CM) -rich low- to medium-grade metasedimentary rock samples of Western Himalaya, Pakistan to assess their optimum thermal evolution. The RSCM thermometry is based on the degree of graphitisation of CM as a function of peak metamorphic temperature. Petrographic observations of the studied samples revealed two dominant CM morphologies. Type-I CM, represented by fine-grained discontinuous dust-like and scattered to thin sporadic layers, was more prevalent in low-grade metamorphic samples. Type-II CM, corresponding to continuous and extended thick fibres and elongated grain constellations, was dominant in medium- to high-grade metamorphic samples. The degree of crystallinity of CM and subsequent metamorphic temperatures were quantified by considering the intensity-based <i>R</i>1 and the area-based <i>R</i>2 ratio parameters. Low-grade samples from the Lesser Himalayan Sequence (LHS), having Type-I CM, resulted in RSCM peak temperatures between 306°C and 403°C. Medium- to high-grade samples from Higher Himalayan Crystalline (HHC), containing Type-II CM, yielded peak temperatures in the 482°C–560°C range. The extremely deformed sample from a fault zone in the LHS produced relatively higher temperature of 403°C, thereby suggesting heat associated with shearing due to fault activities resulting in CM recrystallisation and elevated temperature values. The study revealed that the peak metamorphic temperatures increase from south towards north following a progressive path of metamorphism in the region.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 2","pages":"387-403"},"PeriodicalIF":1.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.5083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Tale of Evolution of the Central Indian Tectonic Zone (CITZ) With Glimpses on Pre-Suture Plate Margin Depositional History","authors":"A. Sharma,&nbsp;P. P. Chakraborty,&nbsp;A. K. Pandey,&nbsp;K. Das","doi":"10.1002/gj.5087","DOIUrl":"https://doi.org/10.1002/gj.5087","url":null,"abstract":"<p>Comprehending pre-suture geological setting and post-suture intricate tectono-thermal chronicle in a crustal-scale orogeny and discerning the temporal connections among different tectonic domains within an orogen yields valuable insights into worldwide tectonic phenomena leading to the reconstruction of paleogeographic configurations of fragmented crustal components within erstwhile supercontinents. Since the tectonic evolution of the Indian subcontinent during the Proterozoic remains a topic of discussion due to multiple controversial views, the Central Indian Tectonic Zone (CITZ) offers a great archive for the protracted geological history of subduction, collision, and suturing of northern Indian cratonic blocks (NIC; composed of Bundelkhand and Aravalli cratons) and southern Indian cratonic blocks (SIC; composed of Bastar, Singhbhum, and Dharwar cratons). Events belonging to two Supercontinents namely, Columbia (ca. 2100 to 1800 Ma) and Rodinia (ca. 1200 to 900 Ma) are embedded within the geological history of CITZ, as it records multiple events that occurred between the Paleoproterozoic and Neoproterozoic. In this backdrop, the present contribution attempts (i) the deconvolution of pre-suture (pre-CITZ formation) plate margin basin depositional history including tracking of detrital provenance, and (ii) a review of different stages of collision and suturing as the plate margin evolved in the form of an orogen subsequent to the closure of the basin. A back-arc basin setup in a subduction margin is recommended for the Mahakoshal Basin which witnessed several tectonic pulses resulting in the formation of alluvial fans/fan deltas along the basin shoreline. It is suggested that the basin was open, at places, even after ca. 1700 Ma, and received sediments.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 2","pages":"404-430"},"PeriodicalIF":1.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.5087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tectonic Evolution and Sedimentary Responses of Palaeocene–Eocene Tethys Himalayan Foreland Basin in Southern Tibet","authors":"Songtao Yan,&nbsp;Ailing Ding,&nbsp;Lidong Zhu,&nbsp;Jie Wang,&nbsp;Hu Li,&nbsp;Xuejian Dai,&nbsp;Yangchun Wei,&nbsp;Hao Huang,&nbsp;Qingsong Wu","doi":"10.1002/gj.5082","DOIUrl":"https://doi.org/10.1002/gj.5082","url":null,"abstract":"<div>\u0000 \u0000 <p>The tectonic evolution of the Palaeocene–Eocene Tethys Himalayan foreland basin plays a crucial role in reshaping the collisional orogenic process of the Yarlung–Tsangpo oceanic basin. However, studies examining the sedimentary response during the tectonic evolution of the foreland basin are lacking. In this study, through a detailed field investigation and analysis of Palaeocene–Eocene strata in the Tingri area, we clarified the evolution of the Tethys Himalayan tectonic regions and its sedimentary response. Carbon and oxygen isotopes, geochemistry and detrital zircon U–Pb dating demonstrated that the lower Palaeocene Jidula Formation and upper Palaeocene–lower Eocene Zongpu Formation were deposited in a coastal–shallow marine environment, with the detritus sourced from the northern Indian passive margin. The upper Eocene Pengqu Formation was deposited in a deltaic environment, with its detritus sourced from the Gangdese arc and the Yarlung–Tsangpo suture zone at the active continental margin. Combined with the nearshore subaqueous fan branch channel of the Jidula Formation and the slump deformation of the Zongpu Formation, the Palaeocene–Early Eocene southern Tethys Himalaya in the Tingri area was located in the forebulge of the peripheral foreland basin. The marine–continental interactive delta of the Pengqu Formation and its provenance from the Gangdese magmatic arc indicate that the Tingri area was situated in the foredeep of the peripheral foreland basin during the Late Eocene. The study provides valuable insights into the collisional orogenic processes between the Indian and Eurasian plates.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"163-195"},"PeriodicalIF":1.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-Vegetation Mixed (Wave-Tide) Energy Trangressive Nearshore Sedimentation: Evidence From the Proterozoic Passive Margin Sequence of NW Himalaya, India","authors":"Subhojit Saha","doi":"10.1002/gj.5078","DOIUrl":"https://doi.org/10.1002/gj.5078","url":null,"abstract":"<div>\u0000 \u0000 <p>The coupled evolution of the Earth's atmosphere–biosphere system through time has caused irreversible changes in the geodynamics as well as surface processes and sedimentation patterns. One such significant change took place in sedimentation in the Palaeozoic (i.e., Silurian) by the appearance of vascular vegetation. While the impact of evolving vegetation on the terrestrial fluvial environment has been relatively well documented, vegetation-induced effects down the system in marginal or nearshore marine settings have undergone little study. The Meso- to Neoproterozoic Rautgara Formation exposed in the Himalayan Orogenic Belt of NW India, offers a chance to study a well-preserved fluvial–marine transition to nearshore sedimentation before the appearance of vascular vegetation. A detailed sedimentological analysis identifies six genetically linked facies associations (FA) probably deposited in barrier, back-barrier, and subtidal deltaic environments. Contrary to the other transgressive barrier models (where beach-barrier overlie the back barrier environments), in the present case, wave-dominated barrier deposits mostly occupy the basal part of the stratigraphy. In the middle stratigraphic level, back-barrier deposits lack thick mud flats and show a dominance of sandstone over mudstone. Stacked subtidal sand bar facies association represents the top part of the sequence. Two sequence stratigraphic surfaces, that is, subaerial unconformity and maximum flooding surface, have been identified and the whole succession is interpreted in terms of HST and TST. Barrier and back-barrier sediments are deposited during HST and TST, respectively. Subtidal deltaic system developed in late TST. The lack of frequent interbedding between the barrier and back-barrier facies indicates negligible landward migration of the barrier and demonstrates system stability. The barrier system might have resulted from vertical aggradations akin to modern vegetated systems. The study portrays that sandy barrier systems are common in the Proterozoic. Vegetation and thick mud flats are not always essential for the stability of a barrier-beach system.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 2","pages":"359-386"},"PeriodicalIF":1.4,"publicationDate":"2024-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Multicriteria Approach for Landslide Hazard Zonation in the Lesser Kumaun Himalaya","authors":"Rahul Kumar Verma,&nbsp;Rajesh Singh,&nbsp;Prateek Sharma,&nbsp;Ravi Kumar Umrao,&nbsp;T. N. Singh","doi":"10.1002/gj.5076","DOIUrl":"https://doi.org/10.1002/gj.5076","url":null,"abstract":"<div>\u0000 \u0000 <p>The socioeconomic prosperity of a region is intricately tied to its infrastructure development, particularly the connectivity provided by highways. Preserving the economic well-being of an area demands meticulous planning and the execution of construction projects with minimal risk. Landslide hazard zonation (LHZ) is a crucial tool for assessing the likelihood of landslide occurrences in specific regions. This study delves into the LHZ of a 171.2 km² area, focusing on critical causative factors such as slope inclination and aspect, slope mass material, Land Use/Land Cover (LULC), distance from fault lines, roads, and drainage systems. The classification resulted in four distinct zones along the National Highway (NH-109) stretch from Bhowali to Almora. Notably, the moderate-hazard zone encompasses 60.4% of the area, followed by the high-hazard zone at 24.4%, the low-hazard zone at 11.9%, and the very high-hazard zone at 3.3%. To enhance the reliability of the study, 63 previously identified landslide locations were marked based on diverse sources, including field studies and landslide inventory data from the Geological Survey of India (GSI). In the validation process, 12 past landslide occurrences were situated within the very high-hazard zone, 32 in the high-hazard zone, 18 in the moderate-hazard zone, and only one in the low-hazard zone. The receiver operating characteristic (ROC) curve yielded a commendable quality with a % area under the curve (AUC) of 71.2%. In summary, this research underscores the importance of LHZ in assessing and mitigating landslide risks along a stretch of the NH-109 corridor. The findings provide valuable insights for informed decision-making in infrastructure development and risk management, contributing to the sustainable growth and protection of the region's livelihood.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"87-103"},"PeriodicalIF":1.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143118546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimising Neural Networks for Enhanced Fracture Density Prediction in Surrounding Rock of Coalbed Methane Reservoir","authors":"Xinyang Men,&nbsp;Shida Chen,&nbsp;Heng Wu,&nbsp;Bin Zhang,&nbsp;Yafei Zhang,&nbsp;Shu Tao","doi":"10.1002/gj.5075","DOIUrl":"https://doi.org/10.1002/gj.5075","url":null,"abstract":"<div>\u0000 \u0000 <p>Fractures influence the mechanical strength of coal roof and floor, constraining the design of hydraulic fracturing for coalbed methane production. Currently, the predominant approach involves the integration of petrophysical logging with machine learning for fracture prediction. Nevertheless, challenges exist regarding the model's accuracy. In this study, we present a novel approach to predict fracture density. Our method optimises a back-propagation (BP) neural network and utilises principal component analysis for feature extraction. We employ logging parameters (density, compensated neutron and acoustic time difference) obtained from Shouyang Block well SY-1 and fracture density data from electrical imaging logging to construct the FVDC model's dataset. The BP neural network model is optimised using the Sparrow Search algorithm and Tent Chaotic Mapping. The results demonstrate a substantial enhancement over the BP neural network model, with reductions of 80.102% in mean absolute error, 94.182% in mean square error, 75.879% in root mean square error and 79.764% in mean absolute percentage error. When considering accuracy, the optimised model (97.098%) surpasses the support vector regression model (96.478%), the random forest model (94.404%) and the BP neural network model (85.657%). Scalability testing for the optimised model was conducted using data from well SY-2, yielding a remarkable prediction accuracy of 96.775%. This performance exceeds that of the BP neural network (with an accuracy of 85.102%), as well as the random forest and support vector regression models (with accuracies of 91.234% and 90.384%, respectively). These results underscore the potential of well logging and machine learning in FVDC prediction.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"73-86"},"PeriodicalIF":1.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143118200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}