{"title":"Tectonic reevaluation of West Cameroon domain: Insights from high-resolution gravity models and advanced edge detection methods","authors":"","doi":"10.1016/j.jog.2024.102061","DOIUrl":"10.1016/j.jog.2024.102061","url":null,"abstract":"<div><div>The West Cameroon region, characterized by a diverse geomorphology of highlands and plains resulting from tectonic processes across different geological ages, has been extensively explored for natural resources. Recognizing the significance of its tectonic and magmatic features associated with seismic and volcanic activity, this study focuses on geodynamic investigations of the Cameroon Volcanic Line (CVL). Despite previous efforts, detailed structural geophysical studies of the West Cameroon domain have proven inconclusive, prompting a comprehensive structural reinterpretation. Utilizing the high-resolution SGG-UGM-2 satellite gravity model and innovative processing techniques, including the horizontal gradient of a modified tilt (HG<sub>STDR</sub>), the balanced horizontal gradient (BHG), the tilt of the horizontal gradient (TAHG), the improvised horizontal gradient tilt angle (impTAHG), and the Tilt Depth method, our research aims to enhance the interpretational quality of tectonic lineaments. By separating regional and residual anomalies in the Bouguer gravity map and applying a combination of filters to delineate geological units, the BHG filter emerges as a robust tool that highlights subsurface edges without generating false features. This approach unveils previously undetected NNW-SSE-oriented lineaments, confirming the presence of deep fractures and faults in Bafoussam, Nkongsamba, and along the Benue Trough, corroborated by newly discovered NNW-SSW trending lineaments. The study suggests that the region’s topography is overcompensated by deep mountain roots and compressive tectonism. Digitizing the BHG filter produces a structural map, revealing predominant NE trends in identified geological margins, including NNE-SSW, N-S, NW-SE, E-W, and NE-SW directions. Geological contacts between granite and high-grade gneiss are indicated by NNW-SSE and NNE-SSW trending lineaments along the Benue Trough. These results contribute significantly to the understanding of the tectonic setting of the West Cameroon Domain.</div></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Alternative thermal histories of Earth-like planets: Influence of key parameters","authors":"","doi":"10.1016/j.jog.2024.102062","DOIUrl":"10.1016/j.jog.2024.102062","url":null,"abstract":"<div><div>The thermal evolution of any planet can be influenced by many factors: the initial temperature profile, the distribution of specific materials within the planet, the existence or lack of a gaseous atmosphere, the effects of early and “late” collision events. Insights concerning the influence of those factors can be obtained by examining solutions to the heat equation, applied to spherical bodies. General trends identified in this work include: 1) Moderate conductive materials contribute to efficiently flatten the temperature gradients, whereas insulating materials promote the preservation of steep temperature gradients. 2) It is not necessary to invoke convection to achieve a relatively flat temperature gradient; moderately conductive materials might achieve the same result without any advective motion involved. 3) Heat transport can take place both outwards and inwards, depending on the initial distribution of temperatures. 4) If the initial temperatures near the center of a planet are low, they will tend to remain low even if heat production takes place at its middle or upper parts. 5) Gradients of temperature near the surface of a planet may not reflect temperature variations at its middle or central parts. 6) Changes of phase exert a strong influence on the evolution of temperature profiles within a planet. 7) Highly insulating atmospheric layers can be important in determining the time of solidification of the upper layer of a magma ocean but not all atmospheres are equally efficient in that respect. As a result, models that give for granted the existence of deep mantle convection on Earth are justified only in the context of models of planet formation that require high initial temperatures; the standard model of a cold solar nebula is not consistent with such deep mantle convective movements.</div></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unveiling crustal deformation patterns along the north Tabriz fault from 2015 to 2022 using multi-temporal InSAR analysis","authors":"","doi":"10.1016/j.jog.2024.102060","DOIUrl":"10.1016/j.jog.2024.102060","url":null,"abstract":"<div><div>This paper presents a comprehensive study on the recognition of crustal deformation patterns surrounding the North Tabriz Fault in Northwestern Iran, utilizing Multi-Temporal InSAR analysis. The fault, despite its seismic inactivity for over two centuries, has a long history of ancient seismicity, with earthquake recurrence intervals exceeding two centuries. This makes it highly susceptible to future activity and the generation of significant and devastating earthquakes. However, limited research has been conducted on extracting and modeling deformation patterns of the North Tabriz Fault to identify its active segments. The primary objective of this study is to derive a general trend for fault displacement and investigate regions under pressure in terms of abnormal crustal movements. The results indicate that the Earth's crust in the surrounding regions of the central and northwest segments of the fault exhibits an upward movement ranging from approximately 2 to 10 millimeters per year from 2015 to 2022. In contrast, neighboring areas of the northwestern fault, as well as the northwestern, western, and southwestern parts of Tabriz County, experience ground subsidence with rates ranging from approximately 5 to 40 millimeters per year. These findings are consistent with GNSS-derived line-of-sight measurements obtained from some IPGN stations around the fault with an RMSE of 1.72 mm/yr. Furthermore, the study identifies critical points near the fault that exhibit varying and diverse displacement patterns over time, suggesting significant strain and notable stress within the subsurface environment. According to the analysis of time series data on crustal movements at the identified critical points, it has been found that the prevailing motion pattern of the Earth's crust within the fault zone largely conforms to a sinusoidal descending pattern. Additionally, recent earthquakes in the northwest vicinity of the fault have been observed to occur close to these critical points. Using line-of-sight (LOS) data acquired at these critical points, the study estimates a slip rate of 7.71 ± 0.01 mm/year and a locking depth of 11.27 ± 0.01 km, contributing to a better understanding of the fault's seismogenic behavior. These findings provide valuable insights into the crustal deformation patterns around the North Tabriz Fault, highlighting active segments and regions under pressure.</div></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Insights into the crustal and the magmatic feeding structure at the Payunia Volcanic Province highlighted by geophysical methods, in the retroarc of the Southern Central Andes","authors":"","doi":"10.1016/j.jog.2024.102059","DOIUrl":"10.1016/j.jog.2024.102059","url":null,"abstract":"<div><div>The Payunia Volcanic Province is a Quaternary volcanic plateau emplaced in the retroarc area in the northern Neuquén Mesozoic Basin, associated with a hydrocarbon system. At deeper levels, this basin is linked to different intrusive systems that developed in the retroarc region at different times, during the Jurassic, Cretaceous, Eocene, Miocene, and even the Quaternary which influenced the hydrocarbon system maturity. We analyzed the Moho structure through this retroarc region, as well as the crustal structure affected by different stages of regional extension. From continuous seismic noise data, we calculated the autocorrelograms to obtain the reflection response below each seismological station. This allowed imaging the surface of primary crustal reflectors and in a few stations the top of an asthenospheric anomaly (SWAP) found by magnetotelluric survey and in concordance with satellite magnetic data. The crustal reflectors were identified in all stations at a mean two-way travel time of about ∼8.5 s and ∼12.5 s using frequency bands of about 1.0–2.4 Hz. Therefore, this is the first geophysical research that estimates the depth of the magmatic system, hosted at the top of the lower crust and the Moho discontinuity. The deepest reflector, only recognized in 4 stations, was observed with a two-way travel time of 17.2 s to 19.6 s. We used a mean one-dimensional Vp model to obtain the corresponding reflector depths which constrain the two-dimensional forward gravity model that fits with the observed regional anomaly for the region. We finally established a relationship between the shallowest sublithospheric electrical conductivity anomalies determined in previous researches and the strong deep reflections observed in some of the seismological stations. This information may help to constrain geochemical and petrological models and re-evaluate the hydrocarbon system maturity of the northern Neuquén basin.</div></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Artificial intelligence for assessing the planets' positions as a precursor to earthquake events","authors":"","doi":"10.1016/j.jog.2024.102057","DOIUrl":"10.1016/j.jog.2024.102057","url":null,"abstract":"<div><div>Questions about interconnection possibilities between planets’ positions and seismic events on the earth have emerged recently in TV channels, social media, etc. In this study, an Artificial Neural Network (ANN) and Random Forest Regression (RFR) are used to predict the number of earthquakes that can occur on Earth, depending on the Earth’s position relative to other planets and solar positions. Our new integration dataset contains 9809 observations and nine features firstly from the global earthquake archive, which is an authoritative layer by Esri, and secondly from the accurate data web portal “theskylive.com.”.</div><div>The results obtained from RFR and ANN prove the partial influence of planets positions on sesimic activity on the earth. In other words, quantitatively through the ANN that gets an accuracy of 68.27 %, MAE of 5.36, MSE of 52.78, RMSE of 7.26, R-Squared of 0.65, and also through the RFR that gets an accuracy of 65.06 %, MAE of 5.60, MSE of 58.21, RMSE of 7.63, R-Squared of 0.67, prove the partial influence on one hand. Qualitatively through the curve of the training phase of the ANN, which is a decreasing and convex function, reinforces the aforementioned proof on the other hand. For these reasons, it can be deduced that there is a possible connection between tectonic stress triggers and the positions of the planets in the solar system. Our dataset was uploaded to the github(<span><span>https://github.com/mouddentarik/Earthquake01</span><svg><path></path></svg></span>.) as well as the code will be publicly available at the github(<span><span>https://github.com/mouddentarik/PythonCode_Earthquakes-</span><svg><path></path></svg></span>.) to share our results.</div></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tectonic evolution of the Circum-Moesian orocline of the Carpatho-Balkanides: Paleomagnetic constraints","authors":"","doi":"10.1016/j.jog.2024.102058","DOIUrl":"10.1016/j.jog.2024.102058","url":null,"abstract":"<div><p>The areas of the present study in eastern Serbia, the Danubicum and the Timok Magmatic Complex (TMC, part of the Geticum) are situated between the Vardar Zone and Moesia. The first is Moesia derived and thrust over the Geticum during the latest Cretaceous, the second represents the central segment of the subduction related Apuseni-Banat-Timok-Srednogorie (ABTS) metallogenic belt. The new results, based on 18 geographically distributed sampling points (228 field oriented drill cores) imply large CW vertical axis rotations for the Upper Jurassic (Lower Cretaceous) carbonates of the Danubicum and a moderate one for the Upper Cretaceous igneous and sedimentary rocks from the TMC. These, together with earlier published paleomagnetic data provide kinematic constraints to test the circum-Moesian backarc-convex orocline model. The strike test plot clearly documents that it is a progressive arc. The starting situation at the time of the volcanic activity in the metallic belt (90–70 Ma) must have been a generally E-W oriented S segment, continuing in NNW-SSE oriented ABT segments. The present geometry of the circum-Moesian belt, in the context of Miocene paleomagnetic results from the Vardar Zone and the Apuseni Mts, is interpreted as the result of two main tectonic processes. The first is an about 30° vertical axis CW rotation which took place in coordination with the Vardar Zone (20–17 Ma). The second is an additional 40–65° CW rotation (17–15 Ma) involving also the Danubicum, due to the subduction pull of the E Carpathians in combination with the corner effect of Moesia.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0264370724000413/pdfft?md5=059f99b466aba115078c6ffd6c917589&pid=1-s2.0-S0264370724000413-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Special Issue on “Seismic anisotropy – from rock samples to large-scale imprints in the lithosphere-asthenosphere system”","authors":"","doi":"10.1016/j.jog.2024.102042","DOIUrl":"10.1016/j.jog.2024.102042","url":null,"abstract":"","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141546687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Limited sensitivity of Antarctic GIA mass change estimates to lateral viscosity variations","authors":"","doi":"10.1016/j.jog.2024.102047","DOIUrl":"10.1016/j.jog.2024.102047","url":null,"abstract":"<div><p>The Gravity Recovery and Climate Experiment (GRACE) has revealed spatiotemporal mass changes in the Antarctic Ice Sheet. However, GRACE data must be corrected for the gravity changes due to glacial isostatic adjustment (GIA). Here we investigate the sensitivity of GIA-induced gravity changes in Antarctica to the lithospheric thickness and upper mantle viscosity using a one-dimensional (1-D) model that assumes a radially varying Earth structure. The sensitivity is assessed using several Antarctic ice-history models that have been widely used to correct GRACE data. The results indicate a trade-off between lithospheric thickness and upper mantle viscosity in evaluating the Antarctic GIA correction. This trade-off exists for all ice-history models; however, the reason for the trade-off differs among models. Furthermore, since there is a sharp contrast in the Earth structure between West and East Antarctica, the adopted ice histories are separated into West and East Antarctic components to examine their contributions to the Antarctic GIA correction. We consider 1-D Earth structures that are averaged from the seismically derived three-dimensional Earth structure for West and East Antarctica. These results indicate that the contributions of the East and West Antarctic loads do not significantly affect the GIA corrections for the West and East Antarctic regions, respectively, and that the trade-off between lithospheric thickness and upper mantle viscosity results in minimal divergence in the assessment of the Antarctic GIA correction between the averaged Earth models of West and East Antarctica. Therefore, the contrast in Earth structure beneath Antarctica may have a limited effect on the ice-mass change estimates for the entire Antarctic Ice Sheet.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142136875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Foreword from ILP","authors":"Hans Thybo","doi":"10.1016/j.jog.2024.102046","DOIUrl":"https://doi.org/10.1016/j.jog.2024.102046","url":null,"abstract":"","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142184244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deformation and pressure-temperature-time history of the External Tuscan Units in the Northern Apennines (Italy): The case of the Punta Bianca Unit","authors":"","doi":"10.1016/j.jog.2024.102045","DOIUrl":"10.1016/j.jog.2024.102045","url":null,"abstract":"<div><p>In this study we investigated through a multidisciplinary approach the still poorly known tectono-metamorphic evolution of the Punta Bianca Unit in the Northern Apennines. The Punta Bianca Unit is part of the Tuscan Metamorphic Units, a group of units derived from the Adria passive margin, metamorphosed at different conditions, and forming the backbone of the Northern Apennine belt. We combined meso- and microstructural analyses, <sup>40</sup>Ar/<sup>39</sup>Ar white-mica geochronology and multi-equilibrium geothermobarometry from high-resolution X-ray chemical maps, to unravel the deformation and metamorphic history of this part of the belt. Meso- and microstructural data indicate that the Punta Bianca Unit recorded two main phases of ductile deformation (here referred to D<sub>p-1</sub> and D<sub>p</sub>) associated with syn-kinematic growth of K-white mica, chlorite, calcite, quartz on the related tectonic foliations (S<sub>p-1</sub> and S<sub>p</sub>), followed by a later ductile deformation phase (D<sub>p+1</sub>) lacking of metamorphic blastesis. <em>P-T</em> estimates complemented by microstructural data suggest that peak metamorphic conditions reached ∼0.8 GPa and ∼350°C and occurred synchronously with the first deformation phase (D<sub>p-1</sub>). Temperature values were also confirmed by Raman spectroscopy of carbonaceous material on selected samples. This stage was followed by the exhumation of the Punta Bianca Unit, as testified by decreasing pressure and temperature down to ∼0.4 GPa and ∼300°C respectively, together with the development of the main foliation (S<sub>p</sub>). At the regional scale, the Tuscan Metamorphic Units have been mostly affected by <em>HP-LT</em> metamorphic gradients equilibrated under blueschist-facies conditions (up to ∼1.4 GPa). Results from the present work on the contrary, suggest that the Punta Bianca Unit never reached such <em>HP-LT</em> conditions, testifying that it was deformed at relatively upper structural levels, thus highlighting an important variation in the tectono-metamorphic evolution of the Tuscan Metamorphic Units along strike in the Northern Apennines. <sup>40</sup>Ar/<sup>39</sup>Ar laserprobe data (using both the in-situ and step-heating techniques) indicate a minimum age for the onset of continental subduction of ∼20 Ma (D<sub>p-1</sub>), which was followed in close succession by exhumation at ∼16 Ma. This approach, if applied to different tectonic units building up the nappe pile of the Northern Apennines, could be successful in better unravelling the tectonic history.</p></div>","PeriodicalId":54823,"journal":{"name":"Journal of Geodynamics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141954095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}