Citation: Jeddi, E.M.; Ntarmouchant, A.; Carvalho, M.d.R.; Bento dos Santos, T.M.; Ferreira da Silva, E.A.; Elabouyi, M.; Driouch, Y.; Mali, B.; Ntarmouchant, N.; Smaili, M.H.; et al. Interdisciplinary Approach and Geodynamic Implications of the Goutitir Geothermal System (Eastern Meseta, Morocco). Water 2023, 15, 1109. https://doi.org/10.3390 /w15061109 Academic Editor: Paolo Madonia Received: 21 January 2023 Revised: 3 March 2023 Accepted: 8 March 2023 Published: 14 March 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). water Article Interdisciplinary Approach and Geodynamic Implications of the Goutitir Geothermal System (Eastern Meseta, Morocco) El Mehdi Jeddi 1 , Ahmed Ntarmouchant 1 , Maria do Rosário Carvalho 2,3, * , Telmo M. Bento dos Santos 2,3 , Eduardo Anselmo Ferreira da Silva 4 , Mustapha Elabouyi 5 , Youssef Driouch 1 , Brahim Mali 1 , Nahla Ntarmouchant 6 , My Hachem Smaili 1 , Beatriz Cotrim 2 and Mohamed Dahire 1 1 GERA—Laboratory of Geosciences, Environment and Associated Resources, Faculty of Sciences, University Sidi Mohammed Ben Abdellah, Dhar El Mehraz, Fez 30050, Morocco 2 Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal 3 DG-FCUL—Departamento de Geologia, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Edifício C6, 1749-016 Lisboa, Portugal 4 GeoBioTec Research Unit, Department of Geosciences, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal 5 Faculty of Sciences, Moulay Ismail University, Meknes 50000, Morocco 6 DLGR Laboratory, URAC 43, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech 40000, Morocco * Correspondence: mdrcarvalho@fc.ul.pt Abstract: Morocco has an important geothermal potential materialized by its several thermal springs which constitute an essential surface geothermal indicator. These springs are dispersed throughout the country and present in every major structural domain. However, a significant amount is concentrated in the northern and northeastern areas. Associated with the great hydrothermal system of eastern Morocco, the thermal spring of Goutitir emerges in the Meso-Cenozoic sedimentary formations located east of the Guercif Basin, composed of a mixture of clays, carbonates, and marls, covered in unconformity by Quaternary tabular molasses. The upflow of the thermal water is dependent of Alpine faults systems with N30 and N100 directions, which are probable reactivated Hercynian structures that facilitate its circulation to the surface. The Goutitir spring has been studied by an interdisciplinary approach to identify the origin of the thermal water, the rock–water interactions, and the reservoir temperatures, contributing to the establishment of the conceptual model of the associated hydrothermal system. This thermal water is of chloride-sodium type with a hyperthermal character (43–47 ◦ C). The isotopic composition (δ 18 O= −8.7 to −8.35‰; δ 2 H= −58.6 to −54.3‰) indicates a meteoric origin and a recharging zone located at around 2000 m of altitude. The chemical composition allows to classify the water as chloride-sodium hydrochemical facies, stabilized at ~100 ◦ C in crystalline basement rocks, which, according to seismic data, are located at ~3 km depth. The concentrations, patterns, and correlations of trace elements point out water–rock interaction processes between the deep water and basic magmatic rocks. The integration of the chemical and isotopic data and the surface geological context shows that the Goutitir water flows within a hydrothermal zone were basic to ultrabasic lamprophyres rich in gabbroic xenoliths outcrop, witnessing the existence, at depth, of basic plutons. Moreover, near the source, these veins are strongly altered and hydrothermalized, showing late recrystallization of centimetric-sized biotites. The chloride-sodium composition of this water may also be a testimony to the presence and reaction with the overlying Triassic saline and gypsiferous and Meso-Cenozoic mainly carbonated formations. Keywords: Eastern Meseta; Goutitir thermal spring; geothermal system; chemical composition; stable isotopes 1. Introduction In recent years, the concern for the use of green energies has led to an increase in geothermal resources exploration, which has been a new area of research in countries that Water 2023, 15, 1109. https://doi.org/10.3390/w15061109 https://www.mdpi.com/journal/water