Karst and Cave Systems in Bosnek Region (Vitosha Mountain, Bulgaria) and Wintimdouine (High Atlas Mountain, Morocco)

 The study of both endokarstic systems Bosnek (Vitosha Mountain, Bulgaria) and Wintimdouine (High Atlas Mountain, Morocco) is presented in this work. Both regions are standard for the study of geodynamic processes in Bulgaria and Morocco, and they could be used as geodynamic polygons in the Mediterranean region. The karst is developed in Triassic and Jurassic limestones. The karst processes in both endokarstic systems occur under the conditions of active Quaternary and recent tectonics. A typical structural karst is formed. The present work shows also the results of the comprehensive studies performed in the field of geology, tectonics, geomorpholody, hydrology, climatology, etc., of the karst. It is accented on the genesis and the evolution of the greatest cave systems in Bulgaria (Duhlata cave – more than 17 km) and Morocco (Wintimdouine cave – more than 19 km long). Both cave systems are situated in zones with high seismicity, with open surface and sud-surfase paleoseismic disruptions. The karst study and monitoring of its processes has great practical value in Bulgaria and Morocco because they are related to one of the largest urbanized territories ( Pernik and Sofia for Bulgaria, and Agadir for Morocco) and they are protected natural objectives as well. V prispevku so predstavljene raziskave jamskih sistemov Bosnek (Vitoša, Bolgarija) in Wintimdouine (Visoki Atlas, Maroko). To sta standardni območji za preučevanje geodinamičnih procesov v Bolgariji in Maroku in bi lahko služili kot geodinamični poligon za celotno Sredozemlje. Tamkajšnji kras je razvit v triasnih in jurskih apnencih. V obeh jamskih sistemih potekajo kraški procesi pod vplivom aktivne kvartarne in recentne tektonike. Izoblikovan je značilni strukturni kras. V članku so predstavljeni tudi izsledki podrobnih preučevanj krasa na področju geologije, tektonike, geomorfologije, hidrologije, klimatologije, itd. Osredotočen je na največja jamska sistema v Bolgariji (preko 17 km dolga jama Duhlata) in Maroku (preko 19 km dolga jama Wintimdouine). Oba sistema sta v območju močne seizmičnosti z odprtimi površinskimi in podpovršinskimi paleoseizmičnimi razpokami. Preučevanje in redno opazovanje krasa in kraških procesov je za Bolgarijo in Maroko velikega praktičnega pomena, saj so vezana tako na največja urabnizirana ozemlja (Pernik in Sofija v Bolgariji, Agadir v Maroku), kot so to tudi zavarovani naravni pojavi. 

Paleoseismic Phenomena in Karst Terrains in Bulgaria and Morocco

V zadnjih letih narašča zanimanje za beleženje in raziskovanje učinkov paleoseizmičnih dogodkov na kraškem površju in v podzemlju. Kras je lahko zanesljiva referenčna točka za razumevanje potencialne seizmičnosti na področjih, kjer opazovalni inštrumenti kažejo nizko oziroma zmerno seizmičnost. V Bolgariji in Maroku zavzema kras velike površine. Spremembe na kraškem površju in v podzemlju navadno povzročijo katastrofalni trenutni dogodki ali pa ponavljajoča se premikanja zaradi potresov. Katastrofalni potresni dogodki so spremenili medsebojno povezane kraške ekosisteme in so bili vzrok za pomlajevanje, reaktiviranje ali prekinitev kraških procesov. Naravni površinski ali podzemeljski relief sta bila deloma ali v celoti uničena; nastal je nov tip reliefa; geološko okolje je bilo spremenjeno; nastale so spremembe v količini odtoka in v smeri površinskega in podzemeljskega odtekanja kraške vode; nastali so gravitacijski tipi močvirij; kraške jame, lokalni tektonski jarki, prihajalo je do podorov in zemeljskih plazov in ozemlje je bilo podvrženo grezanju in uničenju; spremenjeno je bilo ekološko ravnotežje urbaniziranih pokrajin. V pričujočem delu je govora o različnih paleoseizmičnih pojavih na krasu v Bolgariji in v Maroku. Na podlagi preučevanja tektonskih premikov so dana priporočila za varstvo teh ozemelj.During the recent years there has been a growing interest in recording and investigating the effects of paleoseismic events in surface and underground karst in almost all countries. Karst represents a reliable reference marker for understanding the potential seismicity in regions with instrumentally established low to moderate seismicity. The karst terrains in Bulgaria and Morocco occupy considerable areas. The disturbances in surface and underground karst had usually been provoked by catastrophic one-act events or by repeatedly activated movements by earthquakes. The catastrophic seismic events had disturbed the naturally interrelated karst ecosystems and were the reason for rejuvenation, reactivation or attenuation of karst processes. The natural surface and underground relief had been partially or entirely destroyed; a new type of relief had been formed; the geological environment had been disturbed; changes occurred in the flowrate and direction of surface and underground karst water; wetlands of the gravitation type had been formed; natural caves, local grabens, rock-falls and landslides collapsed partially or entirely and terrains were subjected to subsidence and destruction; the ecological balance in urbanized territories had been disturbed. The present work considers the different types of paleoseismic phenomena in the karst terrains in Bulgaria and Morocco. Recommendations are given for the protection of these areas

Contribution of Gravity Data for Structural Characterization of the Ifni Inlier, Western Anti-Atlas, Morocco: Hydrogeological Implications

The Sidi Ifni region in southwest Morocco is mainly composed of crystalline rocks with limited groundwater storage capacity. These water resources drain in particular fault zones with high fracture permeability. The main objective of this study is to describe the geological structure of the region to optimize future drilling locations. The gravity data were processed using various techniques, such as total horizontal gradient, tilt derivative, and Euler deconvolution, in conjunction with the interpretation of the geological data, to create a new structural map. This map confirms the presence of many previously identified or inferred faults and identifies significant new faults with their respective trends and depths. Analysis of this map shows that major faults are oriented NNESSW and NE-SW, while minor faults are oriented E-W, NW-SE, and NNW-SSE. The superposition of the hydrogeological data and the structural map reveals that the high groundwater flow values in the boreholes are located in the vicinity of the major faults and talwegs. The structures deduced from the filtering and interpretation of the gravity data suggest that the hydrogeological system of the Ifni Inlier is controlled by its structures. To confirm this impact, a high-resolution electrical resistivity map (7200 Hz) was used, with penetration depths ranging from 84 to 187 m. Negative boreholes, located in high resistivity ranges corresponding to sound basement formations without fault crossings, showed high resistivity values. The positive holes, located in anomalies with low linear resistivity, revealed the impact of fault crossings, which drain water and tend to decrease the resistivity values of the formations. Therefore, these new structural maps will assist in planning future hydrogeological studies in this area

Delineation of Groundwater Potential Area using an AHP, Remote Sensing, and GIS Techniques in the Ifni Basin, Western Anti-Atlas, Morocco

An assessment of potential groundwater areas in the Ifni basin, located in the western AntiAtlas range of Morocco, was conducted based on a multicriteria analytical approach that integrated a set of geomorphological and hydroclimatic factors influencing the availability of this resource. This approach involved the use of geographic information systems (GIS) and hierarchical analytical process (AHP) models. Different factors were classified and weighted according to their contribution to and impact on groundwater reserves. Their normalized weights were evaluated using a pairwise comparison matrix. Four classes of potentiality emerged: very high, high, moderate, and low, occupying 15.22%, 20.17%, 30.96%, and 33.65%, respectively, of the basin’s area. A groundwater potential map (GWPA) was validated by comparison with data from 134 existing water points using a receiver operating characteristic (ROC) curve. The AUC was calculated at 80%, indicating the good predictive accuracy of the AHP method. These results will enable water operators to select favorable sites with a high groundwater potential

Le Paleozoieque de la region de Mrirt (est du Maroc central) : evolution stratigraphique et structurale

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Analysis of Leachate and Water Resource Quality Surrounding Municipal Solid Waste Landfill of Tamellast (Agadir, Morocco)

The aim of this work was to study the physicochemical characterization and heavy metal testing results carried out for leachate generated by the landfilling of household and similar waste in the Tamellast landfill of Agadir. The surface and groundwater resource (often used as drinking source) samples collected from Tamellast and different water sources wells surrounding the landfill were used to find out the impact of leachate percolation on surface and groundwater quality. The Physico-chemical parameters analyzed were, pH, Electrical Conductivity (EC), Dissolved oxygen, Sodium, Potassium, while biological parameters tested were Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), E.Coli and Coliform tot. The contamination was investigated by measuring the concentration of heavy metals (Pb, Zn, Cr, Ni, As, and Fe). The Electrical Conductivity (EC), COD, BOD, Sodium, Potassium, in leachate were found to be 13180 µs/cm, 3150 mgO2/l, 1000 mgO2/l, 2000 mg/L, and 10700 mg/L, respectively. The concentration in the surrounding dug wells varied from 8.33 – 9.13 mg/L for Dissolved Oxygen, 9.8 – 18 mg/L for potassium, 0.22 – 0.6 mg/L for Fe, and 0.012 – 0.1 mg/L for total Mn. The concentration of Mn, Fe, and other parameters decreased with increasing distance between the landfill and wells

The geological and hydrogeological characteristics of Tamelast landfill site in Agadir, Morocco

The Grand Agadir is confronting with huge production of solid waste. Due to the fact of changes in habits of consumption, the increase of production, and demographic evolution. This production is buried in the controlled discharge of Tamelast. This landfill faces many environmental issues. Our work aims to evaluate the environmental characteristics based on the geological and hydrogeological properties of the site of the Tamelast landfill in Grand Agadir (Morocco). To evaluate the geological and hydrogeological characteristics of the Tamelast landfill, we have generated geological, hydrogeological maps, stratigraphic vertical sections, and cross-sections of the landfill area that have been prepared for further assessment of environmental geological factors. Besides, we also focused on other measures of permeability, and field data we could define the probability and importance of contamination by leachate. The Tamelast landfill is installed on the marl-limestone and carbonate ranges of the Campanian and Maastrichtian. Geologically, the site consists essentially of carbonate deposits, limestones, and Cretaceous marls. These geological outcrops that can play the role of a potential aquifer are the fractured Campanian marl-limestone formations. These soils have a permeability of 5.10-4 to 10-3m/s and transmissivity of 10-2 to 5.10-2 m2/s

Application of HEC-RAS/WMS and FHI models for extreme hydrological events under climate change in the Ifni River arid watershed from Morocco

Floods are among the most important natural disasters in the world. These phenomena are due to climate changes, which have caused natural hydrological events such as heavy rains. This study develops two methods applied to the watershed of the Ifni River, which is a hydro system located in the southwest of Morocco. The main objective of this chapter is to compare the flood risk determined using the Flood Hazard Index (FHI) method with the hydraulic model of HEC-RAS/WMS. This approach makes it possible to visualize and quantify the spatial distribution of floods in this basin. The FHI method makes it possible to map flood-prone areas throughout the basin while the HEC-RAS/WMS model allows it to map areas at risk of flooding downstream of the Ifni River basin due to the presence of a single station in this basin.ISBN för värdpublikation: 9780128221846; 9780128232651</p

Litho-structural interpretation of aeromagnetic anomalies reveals potential for mineral exploration in Tizi n'Test Region, Western High Atlas, Morocco

Abstract This study interprets aeromagnetic data from the Tizi n'Test area in the High Atlas massif of Morocco, aiming to gain insights into its litho-structural architecture and implications for mineral exploration and mining. We employed six different analytical techniques to the residual magnetic field data, including reduction to the pole (RTP), upward continuation, total horizontal derivative, Tilt angle, Centre for Exploration Targeting (CET) analysis, and Euler deconvolution. Our analyses differentiated the study area into three magnetic domains: the eastern Ouzellarh block, characterized by positive anomalies, a central domain characterized by a negative magnetic signature demarcating the transitional zone between the Anti-Atlas and the High Atlas separated by the Ouchden fault: and the western domain, represented by the Tichka massif. The application of total horizontal derivative, tilt angle, and a combination of filters in ternary image formats (Tilt angle, upward continuation 1000 + Tilt angle and upward continuation 3000 + Tilt angle) revealed both known and previously unidentified geological lineaments, mapping structural complexity across various orientations (NE–SW, NNE–SSE, E–W, NW–SE, and N–S). The CET grid analysis method unveiled the structural complexity, highlighting the geodynamic evolution of the region. Particularly, the Ouchden fault delineates a magnetic domain divide between the ancient High Atlas and the Ouzellarh block (Anti-Atlas). Furthermore, Euler deconvolution indicated magnetic source depths ranging from 52 m in the western domain of the Tichka massif to 6560 m in the Ouzellarh block. A comprehensive structural scheme, classified by C-A fractal analysis, identified zones favourable for exploration and mining, particularly along the Ouchden fault, Tizi n'Test, NE-SW trending lineaments in the northwestern domain, as well as along the Tichka granite’s margin