A quantitative approach to geosites assessment of the Talassemtane National Park (NW of Morocco)

Un enfoque cuantitativo para la evaluación de geositios del Parque Nacional de Talassemtane (NO de Marruecos)

A. Aoulad-Sidi-Mhend¹, A. Maaté², R. Hlila², M. Martín-Martín^3,*, S. Chakiri¹, S. Maaté²

¹ Université Ibn Tofail, Laboratoire de Géosciences des Ressources Naturelles, Département de Géologie, Faculté des Sciences de Kenitra, Morocco. Email: alimhend@yahoo.fr, sdchakiri@gmail.com. ORCID ID: http://orcid.org/0000-0002-5609-227X, http://orcid.org/0000-0001-7781-1192

² Université Abdelmalek Essaâdi, Laboratoire de Géologie de l’Environnement et Ressources Naturelles, Département de Géologie, Faculté des Sciences de Tétouan, Morocco. Email: alimaate58@gmail.com, rhlila@yahoo.com. ORCID ID: http://orcid.org/0000-0003-2340-1141, http://orcid.org/0000-0002-3086-1077, http://orcid.org/0000-0001-6655-2930

³ Departamento de Ciencias de la Tierra y Medio Ambiente, University of Alicante (Alicante, Spain). Email: manuel.martin.m3@gmail.com; ORCID ID: http://orcid.org/0000-0002-5797-9892

* Corresponding author

IntroductionTOP

The project aims to protect natural and cultural assets and tries to provide more visibility to geotourism, as well as education, following the works developed by the European Geopark Network and other individual geoparks in the the world, the UNESCO defined the Global Geoparks in 2015 (although started to work with Geoparks in 2001) as a tool to promote sustainable growth of zones with geological heritage (McKeever et al., 2010). Geoparks are well-delimited regions with a growth program, which seek to integrate the geoconservation of areas of geological interest with the conservation of cultural roots of the peoples and nations (Eder & Patzak, 2004; Zouros, 2004; McKeever et al., 2010). To achieve the conservation of a sector with a certain number of suitable geosites, the measures of conservation, education and sustainability recommended by UNESCO in the Global Network of National Geoparks must be followed, because the parks of this network are forced to introduce standard facilities and services of high quality. UNESCO promotes sharing of best practices and similar strategies for growth and preservation of geotourism, providing support to areas with geosites, which leads to exchange of knowledge in the entire world.

The inventory and quantitative approach of geological heritage assessment in the conservation of geoheritage must be the first step, continued by the preservation, study, advancement, and surveillance of sites of geological interest (Brilha, 2016). In relation to the sites of geological interest in recent years a few concepts have come out, but the term used for designating sites with geologic and scientific value is “geosite”.

The Talassemtane National Park (TNP), situated in NW Morocco, was designed by UNESCO (October, 2006) as a part of the Mediterranean Intercontinental Biosphere Reserve (El Merzguioui, 2006). The park is situated south of Tetouan and its geographic coordinates are 35°13’31” N / 5°08’26” W (Fig. 1A). Chaouen, Talambote, Akchour, Oued Laou, Bab Taza, Chrafate, Ametrasse and Khmis M’diq are the most renowned towns and cities inside the TNP (Fig. 1B). The communication roads more important are the P4111 and P4105 (provincial roads), the R412 (regional) and the N2 (national road). The main rivers and valleys are the Oued Laou, Oued Tassikeste, Oued Talambote, Oued Farda, Oued El Kelaa and Oued Kanar (Fig. 1B). The main mountains are the Jbel Kelti (1926 m), Jbel Tazaoute (1725 m), Jbel El Kelaa (1616m), Jbel Tissouka (2122m), Jbel Lakraa (2159m) and the Jbel Taloussisse (2005m). It covers an area of about 60.000 hectares being a natural area with a very important biodiversity and geodiversity at Moroccan and Mediterranean scale.

The TNP shows hot-dry summers and warm (sometimes cold) winters. The average annual temperature varies from 14°C to 20°C. January shows lowest temperatures and August the highest. The rainfalls are abundant (some years exceed 1000 mm, and sometimes 1800 mm in the higher area) in the TNP area (Agence du Bassin Hydraulique du Loukkos -ABHL-, 2006). There is a shocking change between the very rainy mountain areas (1939 mm) and the dry bottom ones of the TNP (464 mm in the Talambote weather station). In the high mountains, the rain is measured in a weather station of the Fir plantation. This station is situated between 1250 and 2050 m in the forest of the TNP (2000 ha) and between 1050 and 1893 m in that of Tazaout (1000 ha). This variation is explained by the fact that the humid winds come from the Mediterranean (east) causing precipitations in the steep eastern zone. In the case of the bottom areas of the coast, precipitations increase from S to N (361 mm in Jebha, 464 mm in Oued Laou).

An important contrast between the white and red rock walls (without vegetal cover) and the great variety of greenish colors in the hollow valleys is evident. In the high mountains around Chaouen (usually over calcareous rocks) the endemic tree of Morocco can be found: firs (Abies maroccana and A. tazaotana), wild olive trees, cork oaks and green oaks (Aafi et al., 1997). Traditional agriculture is developed in terraces on the slopes as fruit trees: pear, olive, pomegranate, fig, walnut, etc. (Bayed & Ater, 2008). Birds of prey such as the golden eagle can also be found (Gensbol, 1984). In some cases, in the upper areas, families of maggot monkeys, gazelles and mountain goats can be spotted (Mehlman & Parkhill, 1988).

The park is a mountain chain from a landscaping point of view. The TNP is mainly made of a calcareous massif where karstic typologies and phenomena are very developed and diffuse (El Gharbaoui, 1980). The more characteristics are the caves, gorges and natural bridges (El Gharbaoui, 1980). Some of these sites have been inventoried as Geosites in this work.

The geoheritage of the TNP has never been addressed by the authorities of the park, despite its great importance. Moreover, the park is a naturally very rich in sites of geological interest (Geosites), several of which are of national relevance (Aoulad-Sidi-Mhend et al., 2019). The above mentioned Geosites could be considered, in a near future, as main part of the touristic, educational and economic offer of the TNP. The geological heritage presented in the park is, in a great part, the response to the climate, as well as the geological evolution from the Primary Era to the present day (including the Variscan and Alpine orogenic phases).

Therefore, the main goal is to preserve this geodiversity that is threatened by anthropic activities. In order to achieve this goal, concrete measures for conservation must be approved by local and regional authorities based on accurate knowledge of this topic. This paper tries to evidence and highlight the importance and variety of the sites of geological interest located in this park. In addition, this work intends to go further beyond the classical vision perceived about the geological heritage as an inanimate entity in which the human activities take place without care on preservation. The best way to ensure adequate protection measures for significant geological features in the TNP is to adhere to the measures for sustainable development, education and conservation dictated by UNESCO in the Global Net of Geoparks. For that reason, the aim of this paper is to consider the Geosites of the TNP with the aim of promoting the bases for tourism, preservation and education in a sustainable management plan, following the UNESCO basis from the Global Geopark Network.

Geological setting of the TNPTOP

The TNP is situated in the Moroccan Rif (Fig. 1A) which makes part of the western portion of the Peri-Mediterranean Chain (Guerrera & Martín-Martín, 2014). This chain is the response to the plate evolution, subductions and collisions during the Miocene of the Mesomediterranean Microplate that was located in the westernmost Tethys from Jurassic times on (Guerrera et al., 2005 and 2012). In the Moroccan Rif three main tectonic complexes of units are classically defined (Fig. 1B): Internal Zones, Maghrebian Flyschs and External Zones (Guerrera & Martín-Martín, 2014). The Internal Zones show a Variscan paleozoic succession, affected by a nappe tectonic and, in most of the cases, by Alpine metamorphism. These units also show Mesozoic-Tertiary successions, overinposed to the Maghrebian Flyschs Units. The Internal Zones in the Moroccan Rif (Fig. 1B) consist of the Sebtide Complex, in lower position, the Ghomaride Complex, in upper position and, some authors also mentioned the “Dorsal”, in uppermost position and frontal tectonic position over the Maghrebian Flyschs Units (Chalouan, 1986; Maate, 1996).

The TNP is located on the “Dorsal” of the Internal Zone (Fig. 1B). In this area this unit is made of thrusting tectonic sheets SW oriented. The successions of the “Dorsal” are made of calcareous and pelitic rocks (Middle Triassic to Lower Miocene in age), being the Late Triassic-Early Liassic calcareous successions the more characteristic (Nold et al., 1981; El Kadiri, 1991; Maaté, 1996; Hlila, 2005). With minor representation, terrains assignable to the Ghomaride Complex appear, usually interpreted as klippes over the “Dorsal” (as it is the case of Talambote area). The upper Ghomaride complex in a great part consist of Silurian to Devonian slates, inmature sandstones and limestone (Chalouan, 1986). Paleogene sediments can be also found in a few of cases. Those consists of limestones with larger foraminifera (alveolines and nummulites) according to Hlila et al. (2007). Also, minor outcroppings of Sebtide klippes can be found in tectonic contact over the “Dorsal”. These klippes are made of shales and pelites (Permian to Triassic in age) showing a low metamorphism (Kornprobst, 1974). The succession is ended with Plio-Quaternary materials made of marls, pelites and conglomerates that crops out in the Tirinesse Basin. This is an intramontane basin situated at the East side of the TNP (Hlila et al., 2014 a & b).

MethodologyTOP

The research methodology applied to select and classify the Geosites and also to decide on the degree of protection needed to apply is the following:

The applied evaluation is based on a combination of the works (Grandgirard, 1999; Reynald et al., 2007; Pralong, 2006; Weber et al., 2006; Reynard et al., 2016; and Brilha, 2016) concerning this topic. The evaluation consists of four parts (Table 1): Scientific Value (SV), Additional Values (AV), synthesis and result of the Global Value (GV) and, separately, the Degradation Risk (DR).

For the quantitative approach of the Geosites assessment two modules are involved: Scientific Value (SV) and Additional Value (AV). Each module is composed, in turn, of several criteria. Values between 0 and 1 (with an interval of 0.25) have been used for each criterion. The SV module of the inventoried Geosites has been calculated with the following formula (Pralong, 2006) involving the Location and Preservation (LP), Representativeness (R), Frequency (F), Paleogeographic Value (PV) and the Educational Value (EV) criteria:

SV = (LP + R + F + PV + EV) / 5

The AV module takes into account the Ecological Value (ECV), Aesthetical Value (AEV), Cultural Value (CV) and Turistic Value (TV) criteria. In turn, the ECV considers the ecologic diversity (ed) and whether the Geosite belongs or not to a protected area (pa) criteria, while the AEV considers the visibility (v) and contrast (c) criteria of the Geosites. The CV evaluation considers the possibility of religious (ri), historical (hi), literary (li) and geo-historical (gh) importance criteria, but in this case, only the value of the highest criterion of the former will be considered (and not the mean of these values) since it is very rare to find a Geosite with both religious, historical, literary and geo-historical values. Finally, the TV value is based on the accessibility (a), existence of public infrastructures (i), density of Geosites in the area (d) and the geotouristic risk (gr). The criterion of the accessibility (a) has been prioritized and only values equal to 1 for (a) has been considered. Possible sites with difficulties of access (values minor to 1 for accessibility) have been discarded.

So, the AV module of the inventoried Geosites has been calculated with the following formula (Pralong, 2006):

AV = (ECV+AEV+CV+TV) /4 = {[(ed + pa) / 2] + [(v + c) /2] + [CV]+ [(gi + a + i+ d + gr) /4]} / 4].

The Global Value (GV) results of the following formula involving the SV and the AV modules (Pralong, 2006):

GV = [(SV + AV/2) / 150] x 100

The Degradation Risk (DR) has also been separately valorized (Table 1) following the procedures by Brilha (2016). For the evaluation of the deterioration, five criteria are used: alteration of the outcropping (Dge), closeness to degrading activities (Ppa), measures of protection taken by the administration (Lgp), access facilities (Acc) and population density (Dop). The former criteria take values between 0 and 1 (with an interval of 0.25) and later weighted as in the following formula. The DR is obtained after the addition of the five criteria.

DR = [(Dge x 0.35) + (Ppa x 0.20) + (Lgp x 0.20) + (Acc x 0.15) + (Dop x 0.10)]

The thresholds for the SV, AV, GV and DR values are: 0-0.25 low, 0.26-0.50 moderate, 0.51-0.75 high, 0.76-1 very high.

ResultsTOP

Geosites and results of the evaluationTOP

An important number of sites of geological interest have been recognized and inventoried in the TNP (Aoulad-Sidi-Mhend et al., 2019). Among these, 34 have provided a GV upper to 0.75 (very high), these latest being considered as geological heritage of the park (Table 2; Fig. 2). The SV (Table 2; Fig. 2) is very high in 32 cases and high in the others two, meanwhile the AV (Table 2; Fig. 2) is very high in 14 cases, high in 18 cases and moderate in only 2 cases. On the other hand, the DR (Table 2; Fig. 2) is very high in 2 cases, high in 19 cases and moderate in 13 cases. The Geosites can be referred, according to their typology (Table 2), in structural geology (SG), stratigraphy (S), petrography (PT), paleontololy (PL), geomorphology (G), hydrogeology-hydraulics (H) and geomaterials (GM).

Details and valorization of five Geosites chosen as referenceTOP

Five sites of geological interest from the case studies regarding different geological typologies have been selected as reference of the abundant wealth in geosites (not much is known about the possible visitors) in the park area (Tables 3 and 4). The description, situation, figures, photographs and scoring of these sites of reference are shown in the following text.

The Rueda Eocene limestones successionTOP

This Geosite is the number 3 (Fig. 1B) and is one of the few example of the paleontological typology (PL). A Ghomaride Complex tertiary succession made of limestones and calcarenites with several types of larger foraminifera (unicellular microfossils) are visible close to the provincial road P4105 very near the Rueda village (Fig. 3A, B). These rocks, dated as Cuisian to Early Lutetian by Hlila et al. (2007), are made of diverse micropaleontological facies (Alveolina, Nummulites, Assilina, red algae, Solenomeris and Miniacina) and is visible to the naked eye. The scoring of this Geosite (Table 3) reveals a scientific value classifiable as very high (SV = 0.90). A moderate-high value is obtained for the additional value (AV = 0.53) mainly due to the lack of cultural value and importance. The final scoring for the global value is very high (GV = 0.78) and the presence of fossils visible to the naked eye, moreover as these are microfossils, make this Geosite essential. The Degradation Risk (Table 4) is high (DR = 0.7).

The Tirinesse BasinTOP

This is the Geosite 7 and consists of a rectangular tectonic graben of reduced dimensions (about 4 km long x 1 km wide) and with a NE-SW orientation (Fig. 1B) filled with Pliocene marine sediments. It is, indeed, a good example of stratigraphic geosite (S). Two NE-SW oriented normal faults are identified as delimiting the SE and NW borders. The infilling of the basin is from lower Pliocene age with marine characteristics and related to a post-orogenic sedimentary cycle. It is a scarce example of an intermontane basin located in the Internal Zone eliminar la “d” final of the Moroccan Rif (Fig. 3C). Four members form the filling sedimentary succession of Tirinesse basin have been described (Hlila et al., 2014 a & b): (i) 30m of fluvial conglomerates resting unconformably over the basement; (ii) 200m of pelites and grey marls with planktonic foraminifera and gypsum in the upper part of the level; (iii) 20m of yellow sandy pelites and marly levels; and (iv) 30m of chaotic and poorly stratified alluvial conglomerates. A relict marine abrasion platform gives the area a geomorphologic important feature. This abrasion platform is sculpted at approximately 580 m altitude in the SE border of the basin. The geosite, when scored, (Table 3) reveals a Global Value of a very high value (GV = 0.97) derived from very high values of the Scientific Value (SV = 1) and the Additional Value (AV = 0.91) making this Geosite essential in stratigraphic and sedimentological aspects. The Degradation Risk (Table 4) is moderate (DR = 0.47)

The Talambote thrustingTOP

This is the Geosite number 10 (Fig. 1B) classified as structural geological typology (SG). This site of geological interest shows a thrusting in the Ghomaride Complex (Fig. 3D). The thrusting of Paleozoic rocks over Triassic ones is located to the right side of the Talambote River just before the intersection with the route to Talambote village. The structure, affecting the Koudiat Tizian Unit, is visible from the route P4100 from Rueda to Talambote. The Paleozoic is made of grayish pelites, grawackes and conglomerates (usually Culm facies); meanwhile the Triassic consists of reddish clays, sandstones and conglomerates (continental red beds “verrucano”). Some meters to the East the normal succession, it can be seen where the Paleozoic is followed upwards by the Triassic. The scoring of this Geosite (Table 3) reveal a high Global Value (GV = 0.75) derived from the very high value of the Scientific Value (SV = 0.95) and the high Additional Value (AV = 0.55) making this Geosite essential for its structural geology aspects. The Degradation Risk (Table 4) is high (DR = 0.56).

The Ras el Ma spring TOP

This is the Geosite number 15 and it is located in the Chaouen city (Fig. 1B), and it is classified as hydrogeological-hydrological typology (H). This spring is a very active source (Agence du Bassin Hydraulique du Loukkos -ABHL-, 2008), with a stable flow of about 470 l/s (Fig. 3E) rising to 1200 l/s in the humid period. Nowadays this source appears to be enclosed in a “room” from which the water is captured and transported for the local water supply system. Accessible by a footpath, this source is of a cultural interest to the local population. Additionally, close to the source, washing of clothes by the washerwomen takes place. Hence, this Geosite is also a tourist attraction point for visitors to the city. The source is located in the western boundary of the Calcareous “Dorsal” (a carbonate massif belonging to the Internal Zone) in contact with the clayish and marly sediments of the External Zone. In detail, this contact is a thrusting of the External “Dorsal” (Jbel Tissouka sheet) over the External Zones (Tanger Unit). The scoring (Table 3) reveal a scientific value (SV = 0.90) classified as very high and an additional value very high (AV = 1) for the Geosite. The Global Value results are also very high (GV = 0.93) making this Geosite a very recommendable for its hydrogeological aspects. The Degradation Risk (Table 4) is high (DR = 0.58).

The Ametrasse fallen blocks TOP

It is the Geosite number 21 (Fig. 1B) belonging to the geomorphological typology (G). An impressive process of fallen blocks can be seen in this Geosite (Fig. 3F). The blocks descend from the cliff of the Jebel Akroud onto the village of Ametrasse forming a rock avalanche, which affected and destroyed some households in the past. This is a zone affected by instability, with a rapid but not instantaneous downstream land movement of high dimension blocks over a long distance. The last episodes of this progress which affected the Amettrasse Village took place in the 1970s. This is a typical phenomenon of gravitational instability leads to the falling of these blocks down the slopes. The fallen blocks belong to calcareous rocks from Jebel Akroud (a tectonic klippe of the Internal “Dorsal”) overimposed upon the Ametrasse unit (External “Dorsal”) made of marls and sandstones of Tertiary age. The zone is also affected by an important tectonic accident (Ametrasse fault) and many other faults of minor entity and jointing that fracture are the massive calcareous rocks in a very intense way. The consistency of this fragmentation favored the individualization and dislocation of the blocks downwards. The scoring of this Geosite (Table 3) shows a scientific value of a very high value (SV = 0.95). The additional value is only high (AV = 0.66) mainly due to the lack of cultural value and importance. The final scoring for the global is very high (GV = 0.85) and the essential importance of this Geosite is, without a doubt, for its landscaping and geomorphologic value. The Degradation Risk (Table 4) is high (DR = 0.62).

Discussion and ConclusionsTOP

The adherence to the rules of preservation, sustainable growth and education recommended by UNESCO are a good way to adequately protect a zone with a huge number of sites of geological interest. UNESCO (following previous works by the European Geopark Network and others individual geoparks in the whole World) started working on Geoparks in 2001 and approved the Global Geoparks program from 2015. 140 Geoparks located in 38 countries have been registered up to this date (Fig. 4). Most of them are situated in “First World” countries from Western Europe (12 Spain, 10 Italy, 7 France, 6 United Kingdom, 5 Germany, 5 Greece, 4 Portugal). It is worth noting the rising of registered parks from emerging countries such as China (with 37 Geoparks). In Asia, Japan shows a high interest with 9 Geoparks. In contrast, in North America, only Canada (3 Geoparks) and Mexico (2 Geoparks) have shown interest in the Geoparks network. Brazil and Uruguay (1 Geopark each one) have also recently incorporated to this program in South America. Morocco (the M’Goun Geopark, located in the Atlas) and Tanzania have registered one Geopark each in the African continent. The Tichoukt Massif is another zone from Morocco with a certain interest in the conservation of sites of geological interest. In this area, an itinerary with geological heritage sites has been recently released (Oukassou et al., 2017).

The examples presented earlier make the studied park a natural space of great geodiversity, with sites of geological interest with diverse typologies provide an additional value to its richness and memorable biodiversity (Aoulad-Sidi-Mhend et al., 2019). The evaluation has allowed inventorying 34 Geosites as geological heritage in the TNP (Table 2; Fig 3). In all cases, very high global values (greater to 0.75) have been found, 12 of them reaching values greater than 0.85 (Geosites 4, 5, 7, 8, 14, 15, 18, 22, 27, 28, 29 and 32). Nevertheless, this geodiversity is being threatened by anthropic interventions, making the protection and evaluation of these Geosites a priority. In fact, the evaluation of the Degradation Risk of the 34 Geosites has revealed than the DR is very high in 2 cases, high in 19 cases and moderate in 13 cases.

The quantification performed in the Geosites makes it possible to reduce subjectivity. The information gathered about the site can be easily improved and updated later when the site changes over time due to the measures taken by the authorities of the country. Even though the concrete area of the TNP has been analyzed and the richness of geosites of the area is evident once the park is compared with other parks in Morocco, the values obtained for the DR for the geosites indicate that some measures should be taken to protect the park. For all of these reason, it is imperative that all the actors involved (local-regional authorities, local population, schools and middle schools, universities and scientific institutes, NGOs, etc.) should face their responsibilities in order to make the necessary efforts (Aoulad-Sidi-Mhend, 2014) to implement the protection of the geological heritage of the TNP.

We recommend following the rules and concept of preservation, sustainable growth and education proposed by UNESCO for Global Geoparks. Hence, in a perspective of preservation and valorization of the Geosites proposed as geological heritage of the TNP, some axes of actions can be mentioned in the following passages to establish the basis for a sustainable growth and the inclusion of the TNP in the Global Geoparks network:

The above proposed initiatives will contribute to Education and promote Tourism. In the case of Education, the TNP could contribute towards organizing activities and providing logistical support to the local and regional schools and universities. In the case of Tourism, the promotion of the geological heritage of the park can help the activation of the economic activity and sustainable growth in the northern Morocco. Consequently, the numbers of local and foreign visitors could be increased over time, leading to favorable conditions for the creation of local enterprises and cottage industries aimed at geotourism and geoproducts.

AKNOWLEDGEMENTS TOP

Two anonymous reviewers and Research Project CGL2016-75679-P (Spanish Ministry of Education and Science), Research Groups of the Alicante University (CTMA-IGA) are acknowledged.

ReferencesTOP