Journal of African Earth Sciences最新文献

{"title":"Coastal water quality dynamics of the Red Sea, southeast coast of Egypt using GeoAI and ChatGPT","authors":"Mohamed Alkhuzamy Aziz ,&nbsp;Ahmed El-Zeiny ,&nbsp;Fayrouz M. Hassan ,&nbsp;Doaa M. Naguib","doi":"10.1016/j.jafrearsci.2024.105409","DOIUrl":"10.1016/j.jafrearsci.2024.105409","url":null,"abstract":"<div><p>The Red Sea coastal environment of Halayeb and Shalateen area is renowned for its abundant marine flora and fauna. It also holds significant economic and cultural importance for local communities. However, this region is currently confronted with various challenges, including climate change and habitat destruction. To effectively address and mitigate these issues, advanced technologies that offer a holistic understanding of the area's environmental conditions are required. This paper applies the integration of Geospatial Artificial Intelligence (GeoAI) and ChatGPT to study the Red Sea Coastal water quality dynamics of Halayeb and Shalateen Area. Landsat imagery and Copernicus Marine Service were used to retrieve area boundaries and monitor the physicochemical characteristics of the coastal water respectively. ChatGPT was utilized to generate Python code that facilitates the creation of optimal distribution maps for each physical and chemical property criterion. The Python codes were incorporated into the Python program within the ArcGIS 10.7.1 and executed to generate the desired maps representing the dynamics of physical and chemical properties. It was found an observed fluctuation in chemical properties next to the coastline around the mouth of two main wadies; Wadi Hudain, and Wadi Da'eb. The degree of stability increased away from the coast toward the deep water. That proved the effect of the runoff on the seawater, as the runoff plays an essential role in the water state, especially in such semi-closed water bodies like the Red Sea where the flashfloods are the main source that can enrich water with sediment and nutrients. The state of seawater in terms of physical properties was not characterized by a specific pattern. The distribution of physical parameters in the Red Sea is influenced by factors such as regional climate variations, monsoonal winds, and local topography. This paper serves as a stepping stone for future research endeavors, exploring the full potential of this integrated approach. It can be concluded that the fusion of GeoAI and ChatGPT technologies has the potential to revolutionize our approach to studying and managing the coastal environment.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105409"},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142147895","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":"The yengejeh diasporic karst bauxite deposit, NW Iran: Constraints on distribution and fractionation of major and rare earth elements","authors":"Ali Abedini ,&nbsp;Ali Asghar Calagari","doi":"10.1016/j.jafrearsci.2024.105408","DOIUrl":"10.1016/j.jafrearsci.2024.105408","url":null,"abstract":"<div><p>The Yengejeh diasporic karst bauxite deposit (NW Iran) was developed as discontinuous layers and lenses along the contact of dolomitic limestone of the Ruteh Formation (middle-upper Permian) and dolomite of the Elika Formation (Triassic). This deposit is constituted by two conspicuous subset layers, (1) green bauxite (GB) and (2) red bauxite (RB). The XRD analytic data revealed that diaspore is accompanied by chlorite and anatase in the GB subset and by hematite in the RB subset. Minerals such as pyrophyllite, kaolinite, illite, and rutile are present within the both subsets. The antithetical distributions of Al with Fe and Al with Ti in the deposit are indicative of the controlling role of climatic changes of the depositional environment and the function of post-formation diagenetic processes. The increment in certain geochemical ratios like La/Y, (La/Yb)_N, and (LREE/HREE)_N from the top toward the bottom of the horizon is designative of pH increase in depositional milieu by buffering of the percolating solutions, and of preferential scavenging of LREE by hematite. The positive Ce anomaly in the GB subset took place as the result of change in the oxidation state of this element from Ce³⁺ to Ce⁴⁺. However, the positive Ce anomalies in the RB subset implicates preferential scavenging of Ce onto hematite. The marked variation range in anomaly values of Eu/Eu* (0.38–1.01) at Yengejeh reveals that this index acted as non-conservative during the evolution of this deposit, and this behavior is related most likely to influences of post-formation diagenetic processes.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105408"},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142098878","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":"Formation conditions and geochemistry of the Tütün Tepeleri (Baskil-Elazig/Türkiye) Fe-oxide-Cu-Au (IOCG) mineralization","authors":"Burcu Karataş ,&nbsp;Mustafa Akyildiz ,&nbsp;Nail Yildirim ,&nbsp;Tolga Oyman","doi":"10.1016/j.jafrearsci.2024.105407","DOIUrl":"10.1016/j.jafrearsci.2024.105407","url":null,"abstract":"<div><div>The Tütün Tepeleri Fe-Oxide-Cu-Au (IOCG) mineralization is located in the Eastern Taurus Mountains (Baskil-Elazığ/Turkey) and it is associated with Baskil magmatites (diorite, gabbro and tonalite) cut by Late Cretaceous Bilaser Tepe magmatites (quartized diorite, granite, granodiorite, tonalite porphyry, monzosyenite, monzonite, aplite and diorite porphyry). Baskil Magmatites are Coniacian-Santonian (82–86 Ma), calc-alkaline in character and I-type. Bilaser Tepe Magmatics are Campanian (73–74 Ma) and represent an extensional environment after the collision of oceanic arc and the Taurus platform. In this study, the Sodic-calcic alteration zone in the Tütün Tepeleri region, which was determined as Porphyry type mineralization by different researchers, was determined for the first time and the mineralizations were evaluated in terms of Fe-Oxide-Cu-Au (IOCG) deposits. Three types of alteration zones have been identified in the region, including the sodic-calcic alteration zone. These are sodic-calcic (tremolite-actinolite, albite, epidote, chlorite, magnetite), potassic (biotite, quartz, chlorite, K-feldspar, anhydrite) and sericitic (sericite, carbonate, quartz, chlorite, illite) alterations. Sodic-calcic alteration is more widespread in the region than &gt;1 km², reaches thicknesses of 500 m, and is occasionally overlain by potassic alterations, just like similar Fe-Oxide-Cu-Au (IOCG) deposits in the world. Tütün Tepeleri mineralizations are in the form of rare magnetite veins with intense magnetite dispersion within the sodic-calcic alteration developed in diorites. Mineral paragenesis is in the form of magnetite, molybdenite, pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, hematite, malachite and azurite, and Ti content in magnetites is determined as 0.13–0.64%. Fe content is 20.13% on average. Formation temperatures in fluid inclusions measured in ore-bearing quartz veins are 320.3 °C on average and salinity is 11.32% NaCl equivalent on average. Isotope analysis results of these mineralizations show δ³⁴S_pyrite = 6–8.9; δ³⁴S_c.pyrite = 3.8–5.5; δ¹⁸O_quartz was determined in the range of 10.8–13.2 and δD = (−37) – (−53). When the alteration types determined with isotope analysis results showing that the mineralization occurred in a magmatic-hydrothermal system, the low Ti content in the magnetites, the formation temperature and salinity values are evaluated together, it was anticipated that Tütün Tepeleri mineralization is an example of Fe-Oxide-Cu-Au (IOCG) deposits formed in a hydrothermal-magmatic system.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"220 ","pages":"Article 105407"},"PeriodicalIF":2.2,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322392","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":"Contribution of Magnetotelluric inversion and potential field modeling to map the Gour Oumelalen deep geological Structure, Central Hoggar, Algeria","authors":"Abdelghafour Boukar ,&nbsp;Mohammed Djeddi ,&nbsp;Mohamed Hamoudi ,&nbsp;Abderrezak Bouzid","doi":"10.1016/j.jafrearsci.2024.105398","DOIUrl":"10.1016/j.jafrearsci.2024.105398","url":null,"abstract":"<div><p>The Gour Oumelalen area is situated in the northern part of the Egere-Aleksod terrane (Central Hoggar, South of Algeria). This area is one of the best preserved Palaeoproterozoic and Archaean zones in Central Hoggar. The aim of this study based on a survey of 33 Magnetotelluric (MT) soundings, aeromagnetics and gravity data, is to investigate the crustal structure and its architecture beneath this area.</p><p>As the first stage, we have determined dimensionality of the regional electric conductivity structure. For this purpose, we have used the impedance and phase tensor approaches. Our results suggest that the underling regional conductivity structure is complex. In the central part it presents a 3D geometry, and beyond, it is mainly 2D; with a strike direction oriented in the North-South direction. Thus, the MT data were inverted using the Occam's inversion algorithm (v.3); which is a powerful tool to modeling and inverting the 2-D MT data. The obtained geo-eletric models, show clearly a high resistive upper crust with a resistivity up to 1000 Ω m; overlies a conductive lower crust with a resistivity approximately less then 100 Ω m. Although, our resulting cross-sections confirm the major Precambrian faults, especially the Ounan shear zone, which is characterized by a high conductivity anomaly.</p><p>At the second stage, using the joint modeling of gravity and magnetic data, we have characterized the different geological units. Although, our modeling reveals that the thicknesse of the upper crust is deeping toward the East, from 16 to 25 km. The Moho depth reaches an average value of 40 Km. Moreover, in the centre of the survey area, the Moho depth decreases and becomes equal to 20 Km. This uplifting of the upper mantle may corresponds to the high magnetic anomaly of the Tisseliline pluton. It seems also related to the magmatic intrusion along the Ounan Shear Zone.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105398"},"PeriodicalIF":2.2,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142136323","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":"Linking petrophysical heterogeneity and reservoir rock-typing of the post-rift shallow marine siliciclastics to their depositional setting: The Upper Cretaceous Bahariya reservoirs, north Western Desert, Egypt","authors":"Mahmoud Leila ,&nbsp;Fatma Ramadan ,&nbsp;Shehta Eweda ,&nbsp;Emad A. Eysa","doi":"10.1016/j.jafrearsci.2024.105401","DOIUrl":"10.1016/j.jafrearsci.2024.105401","url":null,"abstract":"<div><p>The upper Cretaceous clastic facies of the Bahariya Formation host the main reservoir intervals in the north Western Desert (NWD) of Egypt. These clastics were deposited in a parallic depositional environment characterized by different scales of reservoir heterogeneities. However, the link between these heterogeneities and the depositional setting of the reservoir facies is still blurred. In this study, we investigate a highly-heterogeneous reservoir facies of Bahariya Formation in Yasser Field wells, NWD in order to construct a predictive framework for the distribution of the best reservoir rock types (RRTs) and flow zones. Seismic stratigraphy was integrated with core sedimentology to understand the depositional architecture of the reservoir facies. Moreover, conventional core analysis and wireline logs were interpreted to evaluate the scales of lithological and petrophysical heterogeneities in the different RRTs.</p><p>In the studied Yasser Field, the Bahariya Formation consists of tidal facies deposited in a wide range of tidally-influenced conditions. The seismic facies varies greatly with variation in the tidal regime. Best reservoir rock types RRTs are associated with tidal channels and amalgamated tidal bars (RRTI). RRTI rocks represent the main fluid flow conduits in the studied Bahariya reservoir. Lithological and petrophysical heterogeneities are more prominent in the tidal mud flat and mixed tidal flat facies which form RRTIII rocks. Linking seismic with sedimentary facies enabled us to predict the distribution of the best reservoir flow zones in the study region. The present results establish a framework for predicting the optimum reservoir quality facies based on integrating seismic, sedimentary and petrofacies. This framework could be applied in analogous tidally-influenced reservoir facies with high depositionally-controlled pore system heterogeneity.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105401"},"PeriodicalIF":2.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142076781","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":"Facies controls and tectonic evolution on oil accumulation and entrapment in the Cenomanian Abu Roash G member, northern-central Egypt: Deltaic and channel sandstones as good reservoirs","authors":"Mohamed Moustafa Afife ,&nbsp;Maher El Ammawy ,&nbsp;Muhammad Naguib El Ghamry ,&nbsp;Adel Mady Afify","doi":"10.1016/j.jafrearsci.2024.105387","DOIUrl":"10.1016/j.jafrearsci.2024.105387","url":null,"abstract":"<div><p>Along northern-central Egypt, the oil accumulation and entrapment were mainly controlled by variable parameters including the stratigraphic architecture, sedimentary features, and tectonic evolutions. The present paper presents a new model for oil occurrences in the Abu Roash G Member (Cenomanian) along Gindi, Abu Gharadig and to a few extents the Beni Suef basins, in the northern-central part of the Western and Eastern Deserts of Egypt. The studied concessions include the Wadi El Rayan, East Bahariya and El Diyur (Gindi basin and Abu Gharadig basins, Western Desert) and the Ghariboun (Beni Suef Basin, Eastern Desert) fields. Twenty sedimentary facies were recorded from the studied subsurface sections of the Abu Roash G Member and grouped into three facies associations. A new depositional model is achieved where estuarine, open marine, deltaic distributaries, and tidal channel deposits are the main facies associations recorded in the studied Abu Roash “G\". These deltaic and channel deposits occurred as an arch like form between open marine and estuarine deposits. These deltaic and tidal channel sandstone deposits act as a good reservoir to accumulate oil from nearby areas. As well, these areas were subjected to the well-known Syrian arch compressional deformation that affected northern Egypt during the Mesozoic, up to late Senonian time. A regional NE-SW oriented fold system took place, forming NE-SW oriented ridges in addition to the dextral strike-slip movement that took place along these ridges because of this compressional deformation.</p><p>To sum up, oil accumulation in the studied Abu Roash G Member was mainly controlled by facies distribution mainly of channel sandstone enhanced by the tectonic movements (Syrian Arc System) affecting the areas studied.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105387"},"PeriodicalIF":2.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142098877","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":"Depositional environments and thermal maturity of the hydrocarbon source rocks in the Devonian–Early carboniferous Ora Formation from palynological organic petrographic investigations in northern and western Iraq","authors":"R.S. Al-Auqadi ,&nbsp;A.I. Al-Juboury ,&nbsp;M.W. Alkhafaji ,&nbsp;N. Alarifi ,&nbsp;W.A. Makled ,&nbsp;Harry Rowe ,&nbsp;Giovanni Zanoni ,&nbsp;D.L. Dettman","doi":"10.1016/j.jafrearsci.2024.105400","DOIUrl":"10.1016/j.jafrearsci.2024.105400","url":null,"abstract":"<div><p>The study investigates the palynofacies, organic matter character, and hydrocarbon generation potential of this rock unit, based on surface and subsurface samples from the Ora Formation type-section in extreme northern Iraq and the Akkas-3 well in western Iraq, respectively. Dark, mostly oxidized, gelified platy amorphous organic matter (AOM) dominates the palynological components in the surface section, in addition to a few rounded spores and structured phytoclasts. In contrast, palynomorphs, including <em>Ambitisporites avitus</em>, <em>Aneurospora</em> spp., <em>Vallatisporites verrucosus</em>, <em>Acinosporites</em> spp., <em>Verrucosisporites nitidus</em> and the algae <em>Botryococcus,</em> are predominant in studied samples from the Akkas-3 well. Statistical cluster analysis identified three palynofacies types in the surface section based on stratigraphic variations in the particulate organic matter. These vary from high amorphous organic matter (AOM), moderate phytoclast, and low palynomorph abundances that represent proximal suboxic–anoxic shelfal environments to moderate to good AOM and low to moderate palynomorph abundances that represent distal suboxic–anoxic or distal dysoxic–anoxic shelfal environments. The organic petrographic study of the outcrop section also revealed the strong effect of oxidation, where dispersed terrigenous and amorphous organic materials in the form of granular and gelified forms dominate and reflect a terrestrial origin of these components. In the subsurface section, a mixed terrestrial and less marine or lacustrine origin characterized the studied organic matter, where land plant spores (sporinite), in addition to vitrinite and inertinite, are dominant with a few scattered liptinite macerals. The difference in thermal maturity between the outcrop and subsurface samples is likely due to the higher tectonic burial of the outcrop samples that form part of the Northern Thrust Zone of Iraq. Nevertheless, higher abundances of AOM (oil-prone kerogen type II) accumulated in the northern outcrop type section. This might imply that the Ora Formation has a higher potential for hydrocarbon production north of the Akkas field.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105400"},"PeriodicalIF":2.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142048279","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":"Geochemistry of the Late Cretaceous to Paleogene sedimentary deposits of the SW Anambra Basin (Nigeria): Implications for provenance, tectonic conditions, and hydrothermal influence","authors":"Erepamo J. Omietimi ,&nbsp;Nils Lenhardt ,&nbsp;Renchao Yang ,&nbsp;Annette E. Götz ,&nbsp;Adam Bumby ,&nbsp;Joel A. Edegbai","doi":"10.1016/j.jafrearsci.2024.105399","DOIUrl":"10.1016/j.jafrearsci.2024.105399","url":null,"abstract":"<div><p>The Anambra Basin in southwestern Nigeria is part of the West and Central Africa Rift System (WCARS), with sedimentary successions comprising freshwater, deltaic, and marginal marine deposits. In the present study, we provide new mineralogical and geochemical data from mudrocks of the Campano-Maastrichtian Nkporo and Mamu formations and the Paleocene Imo Formation, intersected by the Owan-1 and Ubiaja wells. The analyses aim to identify source composition, sedimentary grain sorting, hydrothermal influence, and depositional environment, focusing on the understudied southwestern margin of the basin. Additionally, the data provide insights into the tectonic evolution of the Anambra Basin and its genetic link to the Benue Trough and other WCARS basins. The studied mudrocks contain detrital grains predominantly composed of quartz and clay minerals, with little feldspar. Major and trace element proxies used to evaluate sediment grain sorting reveal primarily fine-grained clastics, indicating long transport distances that correlate with the high clay mineral contents. The few coarse-grained deposits suggest periods of direct sediment input into the basin and less recycling. There is no evidence of hydrothermal influence in the basin. Therefore, a significant pelagic influence is proposed for the analysed sequence. This hypothesis is corroborated by the presence of gypsum, which is typically precipitated from seawater. Based on provenance-sensitive inorganic geochemical proxies (i.e., Cr/Th <em>vs.</em> Sc/Th, La/Th <em>vs.</em> Hf, Th/Co <em>vs.</em> La/Sc, Th/Sc <em>vs.</em> La/Sc, Th/U <em>vs.</em> Th/Sc, TiO₂ <em>vs.</em> Zr) and the identified detrital contributions to the Paleocene Imo Formation and Cretaceous Mamu and Nkporo formations, the studied siliciclastic rocks are interpreted to be derived primarily from proximal felsic plutonic rocks that were uplifted to the surface by tectonic processes. Distinction diagrams from discriminant functions show that the sediments of the Anambra Basin were deposited in a rift setting, which is consistent with the other WCARS basins.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105399"},"PeriodicalIF":2.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088622","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":"Active deformation in the central section of the East African Rift from tectonic, volcanic, and hydrologic processes: Observations from satellite geodesy","authors":"Kyle Dennis Murray ,&nbsp;Cynthia J. Ebinger","doi":"10.1016/j.jafrearsci.2024.105390","DOIUrl":"10.1016/j.jafrearsci.2024.105390","url":null,"abstract":"<div><p>The East African Rift System (EARS) is an active continental rift zone that hosts a diverse range of processes that result in recent and ongoing crustal deformation. To analyze these processes, we used Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) to complement the sparse GNSS velocity field with high resolution measurements of line-of-sight (LOS) deformation between 2015 and 2022. A broad survey approach was employed to detect new signals within the central section of the EARS, and to establish a baseline for future studies focused on tectonic, volcanic, and/or hydrologic deformation and change spanning geodetic time scales. With this regional approach, we were able to resolve signals varying over time-spans of a few weeks to several years that have magnitudes greater than ∼1 cm/yr. Our resulting deformation field shows a diverse range of signals related to the processes listed above as well as other unknown sources. This includes up to 8.5 cm/yr of groundwater-related subsidence in Nairobi, up to 70 cm of LOS displacement during the eruption of Nyiragongo in 2021, and steady uplift in the Manyara basin with a rate of 2.8 cm/yr. We update previously published InSAR measurements of Mount Suswa volcano, and the geothermal fields in Olkaria. We also show LOS change ranging between 2 and 5 mm/yr over a distances of approximately 200 km spanning the Kenya Rift with the greatest differential rates occurring south of Lake Turkana. More generally, our results highlight the ambiguity of relying solely on the sparse network of GNSS for studies such as those characterizing tectonic motion and rift opening. Such studies are likely missing many important signals and/or includes sites that are contaminated with signals unrelated to the target process.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105390"},"PeriodicalIF":2.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142048282","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":"Analysis of very small-small theropod footprints data from Imilchil tracksite (Hig Central Atlas. Morocco). A concordance model for a global scale","authors":"Judit Minguez Ceniceros ,&nbsp;Moussa Masrour ,&nbsp;Mohamed Boutakiout ,&nbsp;José Ignacio Extremiana ,&nbsp;Félix Pérez-Lorente","doi":"10.1016/j.jafrearsci.2024.105389","DOIUrl":"10.1016/j.jafrearsci.2024.105389","url":null,"abstract":"<div><p>In the ensemble of theropod footprints from the Imilchil macrosite, a group of small size separated from the rest is distinguished. We had detected this grouping in other sites studied by our team in La Rioja and in the work of drawing up scatter plots and frequency histograms of the measurements, on a global scale, of the length and width of the theropod footprints (these data are available on request from Farlow [<span><span><span>[email protected]</span></span><svg><path></path></svg></span>]). We analyze the particular grouping of small footprints, providing the study of the theropod footprint measurements of 14 new sites with dinosaur footprints in Imilchil and the graphical representation (frequency histograms and scatter plots) of the global data. The work has been done by projecting and comparing the length and width measurements of the Imilchil footprints and the global ones of what we call circumscribed geographical environments (TGC or Temporal Geographical Circumscriptions [cf. Mínguez Ceniceros et al., 2022]). The ichnotaxonomic study of the footprints referred to in this work can be found in Masrour et al., (2023). Finally we interpret the position of maxima and minima in the frequency diagrams, both of Imilchil, and of the other areas in which Farlow has found records (up to the year 2022).</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"219 ","pages":"Article 105389"},"PeriodicalIF":2.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1464343X2400222X/pdfft?md5=ed43afa4cc9c53490e24a906fb4f8bf8&pid=1-s2.0-S1464343X2400222X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142084109","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}