Geomorphological Analysis and Heritage Value of Dobreștilor–Brusturet Cave: A Significant Geomorphosite in the Bran–Dragoslavele Corridor, Romania

Abstract

This study examines the morphology and development of Dobreștilor–Brusturet Cave, located in the Brusturet gorge at the western edge of the Bran–Dragoslavele Corridor, an important tourist route in the Romanian Carpathians. The research aims to analyze the geomorphological characteristics and establish the heritage value of the Dobreştilor Cave geomorphosite, supporting protection efforts for invertebrate species that led to the cave’s designation as a natural monument. The inventory of physical features prompted the Piatra Craiului National Park Scientific Council to consider including this speleological site in a thematic geotourism circuit called “The Road of Gorges and Caves in the Upper Basin of the Dâmbovițean”, integrated within protected areas. This represents the first geomorphological study of the cave. Given its ecological significance within the national park’s strict protection zone, recreational tourism is prohibited. The cave should only be used as a geotourism resource for scientific research and education. Morphogenetic analysis reveals that the cave has evolved in a vadose hydrological regime since the Pleistocene, with cavity expansion influenced by free-flowing water alternating with that under pressure during torrential episodes, concomitant with the precipitation of calcium carbonate that formed various speleothems. This research supports documentation for promotional materials and could assist local authorities in the Dâmbovicioara commune with geotourism development decisions, potentially integrating the site into a proposed “Moieciu–Fundata–Dâmbovicioara–Rucăr Geological and Geomorphological Complex”.

1. Introduction

Geotourism, practiced anywhere on Earth, is a human activity that involves not only visiting tourist attractions offered by the landscape (geosites of geological interest, geomorphosites, and geoparks), but also deciphering meaning from an educational and scientific geological–geomorphological perspective [1]. This creates qualitative information related to understanding the role of geological support, the manifestation of geological processes including those generated by morphogenetic agents, and the result of their action, materialized in systematically hierarchical landforms together with their related deposits [2]. Therefore, geotourism is clearly an emulation of human intelligence, a cardinal and select form of cultural tourism that supports and stimulates the understanding of the genesis, evolution, and role of relief in the landscape as well as its function as a support for other components of the environment. In particular, the relief associated with the limestone of mountain areas (mountain peaks and ridges, cliffs, gorges, defiles, caves, limestone plateaus with diverse minor forms, etc.) constitutes an attractive tourist resource due to the richness, diversity, and complexity of the forms it offers both individually and in combination with the landscape. At the same time, tourists are particularly fascinated by limestone and karst landforms for their panoramic views, uniqueness, novelty, structural complexity, typological diversity, vertical display, depth, and physiognomy or through the manifestation of attractive, objective, and subjective phenomena [3].

Due to the original (and sometimes unique) characteristics of geographical regions from a geological and geomorphological point of view, for which specific criteria are required, there is no generally accepted methodology for selecting, inventorying, and evaluating geomorphosites. At the same time, the ultimate goals of applying these methodological approaches do not coincide in all situations. Internationally, some of the best-known methods for inventorying and evaluating geomorphosites have been developed by members of the Working Group on Geomorphological Sites of the International Association of Geomorphologists (IAG). Among them, representatives of the University of Modena and Reggio Emilia [4,5], the University of Lausanne [6], the University of Valladolid [7], the University of Cantabria [8], the University of Minho [9], and others have distinguished themselves. The evaluation methods proposed in the above-mentioned works are used to pursue different goals, but all of them include the following evaluation criteria: rarity, integrity, and scientific representativeness of geomorphosites. Emmanuel Reynard [6] described, synthesized, and extracted the common characteristics of the geomorphosite inventory and assessment methods proposed in the IAG working group. One of the conclusions is that a scientific evaluation should always be carried out, which is the aspect that outlines the geomorphosite quality of a landform. Added to this is the assessment of additional values (protection of geomorphologic heritage, tourism promotion, or use of the site for educational purposes), assessment of potential use, and the need for protection. Viola M. Bruschi and Antonio Cendrero [8] have developed an inventory method that examines the intrinsic qualities (rarity, scientific knowledge, exemplarity, constitution in a typical location, diversity of elements of interest, integrity, and age), the potential for use of geomorphosites, and their possible threats and the need for protection. Assigning much less importance to additional qualities, which will only participate in the quantification of intrinsic value, will have little influence on the result regarding the value of the geomorphosite. This aspect makes this method less suitable for the study of geomorphological sites in relation to tourism [3].

Professor Jean-Pierre Pralong [10] also proposed a frequently used evaluation method that focuses primarily on the tourist value of geomorphological sites. This value is considered to be the average of landscape or aesthetic (Vsce), scientific (Vsci), cultural–historical (Vcult), and social–economic (Veco) values. The author points out that all four values account for the same proportion of the total value, and posits that this is justified by the lack of a real reason for the greater or lesser importance of one of the values. The Pralong method, often utilized and preferred by Romanian geomorphologists, seems to cover the essential points in the evaluation of a tourist objective, but it does not cover certain geomorphological characteristics (dynamics of landforms, complexity or diversity of the elements of interest, geological structure, vertical development/cavern development), nor aspects related to the promotion of the geomorphosite or anthropogenic activities that could affect its value. Romanian contributions to studies on geomorphosites inventoried and evaluated in limestone mountain areas have been made by representatives of geographical schools in Oradea [11], Timișoara [12], Cluj-Napoca [13,14,15,16], and Bucharest [17,18,19].

In the present study, the evaluation of geomorphosites, preceded by rigorous selection and followed by their value ranking, was achieved using 38 criteria (partially taken from previous literature, modified, and adapted to the morphological characteristics of the Bran–Dragoslavele Corridor) inspired by the methodology designed and proposed by Cocean G. and Surdeanu [13], who used the method in the analysis of geomorphosites in the Trascău Mountains [3], a division of the Apuseni Mountains in the Romanian Carpathians. The use of this evaluation method is justified due to the relative similarity between the relief that has developed on Mesozoic limestones in the two Carpathian geographical areas and numerous key valley sectors and caves that have developed on their slopes.

Viewed as a geomorphosite, the Dobreștilor Cave proves to be a remarkable geotourism resource for its geomorphological, aesthetic, and ecological value, which is superior to most of the caves explored and researched in the geographical area of the Bran–Dragoslavele depression corridor. At the same time, its functional value in terms of scientific potential for fields such as physical speleology, ecology, and zoospeology increases its attractiveness. The first-rank importance of the analyzed cave, at least in the Podu Dâmboviței–Dâmbovicioara geographical area (together with the Dâmbovicioara caves of Cheia Peșterii; of Urșilor in Cheia Mica, Dâmboviței; and Miresii in Cheia Mare, Dâmboviței), is also underlined by its educational importance as a training resource with strong relevance to the mentioned fields of interest, as well as by its didactic relevance, as the cave has the attributes of a model with exemplifying value. Its location in the strict protection zone of the PNPC and the ecological relevance of the cavity as a significant biotope for 28 species of invertebrates [20] require the exclusion of any form of recreational tourism. Declared a natural monument in 2000, the Dobreștilor Cave can be exploited as a geotouristic resource only for scientific research and educational purposes, with restricted access controlled by the administration of the national park to which it belongs. Therefore, we propose that the geomorphologic speleological cave Peștera Dobreștilor–Brusturet, one of the sites with remarkable geotourism value within the geographical area located at the boundary between Piatra Craiului Massif and the Bran–Dragoslavele Corridor, should be included in the thematic geotouristic circuit proposed by us under the name “The Road of Gorges and Caves in the Upper Dâmbovicioara Basin” (the axis of the Dâmbovicioara–Brusturet–Valea Seaca a Pietrelor valleys) to be included in several nationally and EU-protected natural areas. There are a number of caves in the upper basin of the Dâmbovița river that are of various scientific and/or educational significance, and there are some important valley sections along the river’s course and tributaries (Dâmbovicioara, Orăți Valley, Cheia–Rudărița and Ghimbav Valley), which inspired us to propose the idea of this spectacular geotouristic circuit. As shown in the geographical area on the map in Figure 1, the circuit includes the following geotouristic objectives: 18 morphological sectors of a gorge-type valley, a limestone torrential valley (Hornul Orății), 12 speleological sites, and a flooded sinkhole (the “Bottomless Lake” swallet/doline). The 18 gorges [21] (numbered from 1 to 18 in black, Figure 1) are the Great Gorge and Small Gorge of Dâmbovița (1, 2), Dâmbovicioara Gorge and Cheița Dâmbovicioarei Gorge (3, 4), Cave Gorge (5), Hammer Gorge (6), Brusturetului Gorges (7, 8), Gorge of the Dry Valley (9), Orății Gorge (10), “Cheița” Gorge (11), “În Pereți” Gorge (12), Rudăriței Gorge (13), Crovului Gorge (14), Prepeleacului Gorge (15), Urdăriții Gorge (16), Ghimbavului Gorge (17), and Izvorului Gorge (18). Morphographic and morphometric characteristics (length/depth, slope, elevation, relative altitude, etc.) and other attributes of the mapped speosites can be found in the relevant research data presented in the bibliographical sources [22,23,24,25]. The geomorphologic objectives listed above, ideally integrated into the proposed thematic geotouristic circuit, can be used with other sites of geomorphological relevance, among which the most well known are the “Babele Orății” morphosculpture (from the village of Podu Dâmboviței) and several geosites with paleontological relevance for the marine invertebrate fauna of Lower Jurassic–Upper Cretaceous age [26]. The geotouristic goals listed in the region corresponding to the “Karst area Cheile Dâmbovița–Dâmbovicioara–Brusturet” geological and geomorphological nature reserve are merely a portion of all of the geotouristic goals in the Bran–Dragoslavele depression.

For the whole area of the Bran–Dragoslavele Corridor, in addition to the above-mentioned geotouristic circuit (integrated into the RNGG1 of the strict protection area of the Piatra Craiului National Park, category Ib of the International Union for the Conservation of Nature), the development of geotourism will be able to take into account the following three thematic geotouristic circuits:

- “The Road of Gorges and Caves in the Upper Basin of Prăpăstiilor Valley”, with the existence of one of the most spectacular and frequently visited successions of gorges in Romania, which makes up the geomorphosed complex of the Prăpăstiile Zărneștilor Gorges, integrated into the natural reserve of the Zărneștilor Gorges (village Măgura, commune Moieciu) established in 2000. This area is included in the strict protection zone of the Piatra Craiului National Park (IUCN category Ib) and the Piatra Craiului Natura 2000 site. The Zărneștilor precipices include six key-type valley sectors that evolved through speleology [23,27]. The complex geomorphosite also includes the biospeciologically (faunistically) relevant caves Peștera Mare de la Prepeleac and Peștera Mica de la Prepeleac, both closed to the public in order to protect the rare local non-troglobiont endemite Nesticus constantinescui [20].

- “The fossil nests of the Tethys Sea in the Moieciu–Dâmbovicioara–Rucăr area”, a circuit that can be organized in loops and valleys in the Rucăr–Dâmbovicioara geographical area as well as on the somital surfaces of Sasului Hill and the Măgurii Ridge. The 13 geosites inventoried [26,28] are of particular paleontological relevance and show species of marine invertebrates characteristic of the Middle and Upper Jurassic–Lower Cretaceous stratigraphic interval.

- “The Road of the Caves of the Ancestors of the Paleolithic”, a circuit that could include the Paleolithic archeospeosites Gooseberry Cave and Small Cave in the village of Cave, which will be joined by the geoarcheospeosite of the Big Cave in the village of Cave with remains of the Middle and Upper Paleolithic belonging to the Musterian and Aurignacian material cultures [29].

The final three envisaged geotouristic circuits, which form part of the larger Bran–Rucăr–Dragoslavele Corridor, are situated on the administrative grounds of the communes of Moieciu, Fundata, Dâmbovicioara, and Rucăr. We suggest creating a new geological and geomorphological nature reserve called “Moieciu–Fundata–Dâmbovicioara–Rucăr” (RNGG2), category IV IUCN, which might include these circuits. This new protected natural area will be established in accordance with GEO No. 57 of 20 June 2007 on the regime of protected natural areas and conservation of natural habitats and wild flora and fauna [30], supplemented with the clarifications of Law No. 49 of 7 April 2011 [31]. Tourists who arrive in the future protected area (RNGG2) will be able to collect information from the Tourist Information and Promotion Center in Dâmbovicioara, Podu Dâmboviței, where current information will be made available related to recreational, cultural, and rural tourism. The proposed nature reserve will bring together speleological and gorge geomorphosites, geosites of particular paleontological relevance, three paleolithic archaeosites, and three thematic somite belvederes for geomorphological and ornithological observations (birdwatching). From a didactic and practical point of view, the development of geotourism in the area of the Bran–Dragoslavele Corridor requires the design of thematic geotouristic circuits similar to the international trends in geotourism. In addition, geosites/geomorphosites should be integrated into them and adequately promoted through brochures and tourist information panels created with respect to rule “6 F”: fascination, familiarization, loyalty, functionality, fusion, and training [32].

In the current context of economic development in the Bran–Dragoslavele Corridor, the concept of geotourism is virtually non-existent in approaches to promoting tourism in the region. Under these circumstances, the importance of re-evaluating the resource potential of the landscape, taking into account components with exceptional potential such as geomorphosites, is also pragmatically linked to the diversification of the tourism on offer in the region. This naturally continues with the promotion and valorization of geomorphosites, with the ultimate goal of increasing the number of tourists and income from economic activities dependent on tourism.

2. Study Area

The Dobreștilor–Brusturet Cave [33] in Ciocanu village, Dâmbovicioara commune (Argeș county, Romania), is a speleological geomorphosite with speophysical and zoospeological relevance (especially for invertebrate fauna). It is integrated into several protected natural regions in the Southern Carpathians’ relief subunits, the Bran–Dragoslavele Corridor and the Piatra Craiului Mountains [34], a branch of the Romanian Carpathians. The cavity is located in a calcareous erosion marker called Colții Pietrei Galbene, situated on the left slope of the upper Brusturet Gorge (Cheia Strâmtă), with an accessible entrance at an absolute altitude of 1160 m. It is positioned 193 m from the bed of the Brusturet–Dâmbovicioara Valley (Figure 2).

The erosion marker corresponds to a narrow secondary interfluvium, delimited by two steeply sloping torrential valleys, developed on faults, which converge downstream and become tributaries to Brusturet Valley.

The Brusturetului–Dâmbovicioara Valley, in the Brusturetului Gorges sector, is deep in Jurassic limestones to the east of the Piatra Craiului syncline axis. This valley delimits the Piatra Craiului Massif to the west (western flank of the homonymous syncline) from the Bran–Dragoslavele Corridor to the east, with the latter being represented by the predominantly limestone ridge of Mount Coja (eastern flank of the same syncline). The Brusturet Gorges became part of the geological and geomorphological nature reserve “Karst area Cheile Dâmbovița–Dâmbovicioara–Brusturet” (RNGG1) prior to the incorporation of the area into the Piatra Craiului National Park (PNPC) in a 1972 resolution of the Argeș County People’s Council, in compliance with Law No. 4/1972 on the management of forests under the direct administration of villages [35]. Law No. 5/2000 on the adoption of the National Spatial Plan—Section III—Protected Areas [36] later extended the national park’s original surface area, incorporating the nature reserve within the PNPC’s stringent protection zone.

A significant portion of the PNPC territory was incorporated into the network’s structure in 2007 in compliance with Ministerial Order No. 1964, which established the protected natural area regime of sites of community importance as an essential component of Romania’s Natura 2000 European ecological network [37]. Thus, the Brusturetului Gorges (two sectors), together with nine other key-type valley sectors of RNGG1 (Figure 1) and some caves found in their slopes (natural habitats of community and national interest with code number 8310—caves closed to public access) were also included in the protection area of the Site of Community Importance ROSCI 0194 Piatra Craiului [38,39,40].

3. Materials and Methods

The karst research expeditions undertaken in Dobreștilor Cave during the spring of 2022 provided a favorable context for complex scientific activity (Figure 3), including detailed photographic documentation and a large set of speophysical measurements. These investigations were conceived and implemented with the fundamental objective of elucidating the morphological particularities of the karst formation and building a rigorous theoretical framework on the morphogenetic processes that determined the genesis and evolution of this underground cavity.

A high-precision surveying procedure was performed on 1 May 2022, using advanced laser surveying technologies including the Leica Disto X310 (Leica Geosystems AG, Heerbrugg, Switzerland) specialized instrument, a professional multi-functional rangefinder. The acquired numerical data were subsequently digitally processed using the open-source software application TopoDroid 6.3.6–35 (Figure 4a), deployed on a mobile device. The cartographic representation of the cavern floor planimetry required an additional stage of computer graphic modeling, performed using the professional software Adobe Photoshop CC 2020, accurately integrating the laser measurements obtained previously.

The longitudinal spatial configuration of the subterranean system was mapped through the central axis of the cave, which is the reference element for multiple visualization modalities: planimetric projection (Figure 4b), longitudinal section, and three-dimensional modeling implemented in TopoDroid and Google Earth Pro software systems. The fundamental topological components—nodal points and linear segments (views)—were recorded in a three-dimensional system using the Disto X310 device, which facilitated the simultaneous acquisition of three essential categories of data: distance measurements, automatic slope calculation, and azimuth determination.

This information was spatially contextualized by incorporating the precise geographic coordinates of the GPS reference point established at the cave entrance (45°28′06″ N, 25°13′54″ E, absolute altitude 1160 m). The Google Earth Pro platform provided advanced functionalities for the representation of the central line of the karst formation, allowing both the visualization of its projection on the external topographic surface and the generation of a three-dimensional longitudinal profile (visualizable in the two-dimensional plane), realistically positioned at the appropriate depth below the topographic surface and precisely oriented with respect to the cardinal points.

This integrated methodological approach facilitated the comprehensive reconstruction of the hydrodynamic trajectory within the karst system, starting with the surface receiving atmospheric precipitation, continuing with the temporary runoff on epigeous talvegic slopes and infiltration processes through the sinkhole-type formations corresponding to the Piatra Galbenă Bridge, and culminating with the complex hypogeous drainage system specific to the Dobreștilor Cave.

The altimetric model used (DEM) was developed respecting spatial accuracy criteria, being configured with a spatial resolution of 10 m and incorporating a discretization error correction coefficient calibrated at 0.5. The main cartographic base that provided the essential altimetric data for generating the model was a second-edition topographic map at a scale of 1:25,000 produced through the scientific and technical effort of the Military Topographic Directorate of the Ministry of National Defense during the period 1974–1986 [41]. The mentioned cartographic material was the information source for the systematic extraction of the level metric elements, represented by the network of contour lines with a standardized equidistance of 10 m, as well as for the acquisition of the spatial configuration of the hydrographic drainage network.

The methodological procedure of the spatial interpolation of topographic data was implemented in the ArcGIS/ArcMap geoinformatic environment by means of the specialized Topo to Raster tool, which incorporates advanced mathematical algorithms for relief modeling. The theoretical and computational foundation of this method is represented by the AUDEM program, a remarkable scientific development by researcher Michael Hutchinson, which underwent successive refinements and methodological adaptations between 1988 and 2011 [42]. The conceptual essence of this algorithm lies in its ability to generate coherent topographic hydrologic surfaces that respect the physical laws of runoff and faithfully reflect the actual terrain morphology, including morphologic peculiarities specific to karst relief.

The main analytical foundation for the morphotectonic observations was the geological map of the Socialist Republic of Romania presented at a scale of 1:50,000 [43], an essential cartographic tool that enabled the identification and spatial delimitation of the lithostratigraphic units and highlighting of the structural elements determining the morphogenetic evolution of the karst system. The primary cartographic information was supplemented, nuanced, and contextualized by the critical exploitation of a substantial corpus of specialized geological literature, which provided the theoretical and interpretative framework necessary for a comprehensive synthesis of the morphotectonic characteristics of the studied region.

The integration of digital topographic information with structural geological data facilitated the construction of a transversal geological profile, which allows the positioning of the Dobreştilor Cave within the Piatra Craiului syncline to be visualized. This integrated methodological approach, based on the convergence of advanced geomatic techniques and classical geological interpretation, constitutes a valuable analytical tool for understanding the overall geomorphological structure and evolutionary dynamics of the karst relief.

The method used to inventory and evaluate geomorphosites took into account the intrinsic or structural values (geomorphological, aesthetic, and ecological) of the geomorphosites, as well as the functional values derived from the former and attributed by humans (cultural, scientific, and economic). The formula used to calculate the total value of each proposed geomorphosite was as follows: VT (total value of the geomorphosite) = VS (structural value) + VF (functional value) − AR (restrictive attributes); VS = VS1 (geomorphological value) + VS2 (aesthetic value) + VS3 (ecological value); VF = VF1 (cultural value) + VF2 (scientific value) + VF3 (economic value); and AR = AR1 (vulnerability to natural phenomena and processes) + AR2 (presence of economic activities with a negative impact or that could affect tourism and/or the geomorphosite) + AR3 (unsightly elements).

4. Results

4.1. Geological Features

The geologic map of the R.S.R., scale 1:50,000, sheet 110 c Rucăr L-35-87-C, suggests that certain geological/geomorphological phenomena that manifested along the Dâmbovicioara–Brusturet–Valea Seacă a Pietrelor hydrographic axis created, among others, the Brusturet Gorges (Cheia Lungă and Cheia Strâmtă). This occurred through erosion and complex karst processes (speleoepigenesis) along longitudinal faults [23] in the Upper Jurassic–Lower Cretaceous limestones of the Kimmeridgian (149.2 ± 0.7–154.8 ± 0.8 million years before present), Upper Tithonian (about 145–147 m. y. BP), and Berriasian (139.8–145 m. y. BP) [44]. They are Štramberk-type limestones [45], which are part of the sedimentary package at the boundary between the Piatra Craiului Massif (2238 m), located to the west, and the limestone ridge of Mount Coja (1546 m) in the Bran–Dragoslavele corridor, located to the east. These two morphological units make up a huge limestone geological structure—the Piatra Craiului syncline (with Cretaceous conglomerates in the syncline axis)—whose eastern flank is the Coja Mountain (Figure 5). According to the same geological map, both of the Brusturetului gorges are cut into the eastern flank of the syncline, not on its axis, which suggests that the course of the waters in the Brusturetului Valley was conditioned by a longitudinal fault.

Strictly locally, the calcareous erosion marker hosting the Dobreștilor–Brusturet Cave is composed of reef carbonate deposits of Upper Tithonian–Berriasian age, represented as a whole by a massive structure in which thin strata of bioclastic–intraclastic rudstone, grainstone (calcarenite), and micritic–phenestral limestone are distinguished. Stratigraphically, the mentioned limestone accumulation belongs to the Cheile Dâmbovicioarei Formation [46,47] and is at least 300 m thick, measured from the bed of the Brusturet River (Cheia Strâmtă) to the highest altitudes on the limestone surface of the vertical fault-tilted block, called Piatra Galbenă.

The R.S.R.’s 1:50,000 scale geologic map offered enough hints to unravel the morphotectonics of the Piatra Craiului syncline’s eastern edge. The fracture of the carbonate plate of the Piatra Craiului syncline and the entrainment of sedimentary blocks on the fault system were caused by the generalized uplift of the sedimentary cover caused by the pushing of the crystalline bedrock of the Leaota Mountains (Leaota Series, Călușu–Tămășel Complex). These ruptural effects have been progressively described as a result of Middle Cretaceous (Austric diastrophism), Ante-Paleogene, and Post-Paleogene orogenetic expressions, including the Old Styric phase, the Wallachian phase’s block uplift, and the Pasadene neotectonic motions [48]. Several structural compartments observable on the map base along the ridge of Mount Coja, separated by vertical transverse faults or offset by transverse decropping, occurred. At the same time, in the southern part of the ridge, as consequence of the local tectonics (probably manifesting during the Wallachian movements), the ruptured structural element in which Dobreștilor Cave is framed was generated. Thus, the Piatra Galbenă tilted block appears well delimited by vertical faults that are inscribed in the cartographic plane, triangular in shape with one of the peaks facing east (Figure 6).

The tilting of the structure was accomplished by the altitudinal descent (subsidence) of the calcareous sedimentary package on the vertical faults that designate the sides of the east-facing peak, concomitant with the tectonic uplift generated on the opposite side of the eastern peak of the triangle. As a morphologic consequence, a gently sloping topographic surface with potential for karstification occurred, named Piatra Galbenă Bridge (Figure 7), which constitutes the area of water catchment, drainage, and infiltration to the Dobreștilor Cave.

Post-Austric transgression [50], subsequent to the Middle Cretaceous orogeny, covered landforms modeled on Jurassic limestones. These could be found under the Upper Albian–Cenomanian overburden composed of calcareous conglomerates, breccias, and megabreccias, so the existence of buried (fossil) relief paleoforms, represented by the existence of the five sinkholes on the surface of the Yellow Stone Bridge, likely molded by the Upper Cretaceous overburden (Figure 8), is hypothesized. We refute this hypothesis, since the quasilinear arrangement of the sinkholes in the same geographical direction (northeast–southwest) as that of the Dobreștilor Cave and in the upstream extension of the latter indicates that the diaclase along which karstification was realized crosses the entire Upper Jurassic and Upper Cretaceous sedimentary package, so the age of this rupture line can only be younger than the age of the strata it intersects [51].

4.2. Geomorphology

Morphometric features. The inventory [22] for the Brusturetului Gorges shows four caves on the right slope of the Brusturetului Valley and six on the left slope. The Dobreștilor–Brusturet cave clearly distinguishes itself from all nine of the other karst voids by its length of 210.3 m, its length in plan of 195 m, and the average height of the cavity (obtained by averaging the values measured with the rangefinder, evenly distributed along its length) of 6.71 m. For comparison, the average value of the lengths of the four caves discovered in the right slope is 11.25 m, and the average length of the other five caves on the left slope is 12.1 m. In fact, among all of the caves found inside the Bran–Dragoslavele Corridor, according to the cave’s length specification, the Dobreștilor Cave occupies the fourth position, after the Uluce Cave of 236.3 m [52] and before the Posada Cave of 212.6 m [53].

In situ measurements and observations were the primary source of the Dobreștilor Cave’s primary morphometric (Figure 9, Figure 10 and Figure 11) and morphologic features. The entrance’s absolute altitude measurement (0 m elevation, downstream end) is 1160 m, and the relative altitude in relation to the bed of the Brusturetului–Dâmbovicioara Valley measures 193 m. The slope of the cave floor from downstream to upstream is +37.3 m (maximum +34 m and minimum −3.3 m).

Speleothems. The typology of speleothems helps to disclose the inner morphology of the cave under study. With a hall developed at the junction of three and four lithoclades, the cave’s general morphological background (The Chamber of the Slender Ankles of Enișoara), preceded and succeeded by a meander-shaped gallery but with a general quasilinear layout (developed on a tectonic diaclase), its inner microrelief’s genetic typology reveals common forms and deposits that can be seen in other Romanian Carpathian caves [54,55].

As a form resulting from erosion, at a height of about 0.5–1 m from the floor, an erosion level is well encrusted, evidenced by lateral bench-work [56] observable in cross-sections of the gallery upstream of the Sala Gleznelor Zvelte. It constitutes a testimony resulting from the change in the level at which the water flowed during the torrential modeling episodes and highlights the transition from a predominantly pressurized flow regime (in some sections) to a free-flowing regime (Figure 11h and Figure 12a). Lateral (meandering) niches are better emphasized in the downstream half of the speosite.

The access portal to the cave (Figure 11a), a fossil morphological element with a quasi-giogival aspect (extended by a vestibule with a height of 5–8 m), was formed by lateral tectonic traction and mixed processes related to episodic torrential erosion (prior to fossilization) in conjunction with the disaggregation of limestone by gelivation followed by the manifestation of the phenomenon of detachment and gravitational collapse of rock blocks of variable size.

The chemical deposits are represented by increasingly rich and diversified types of calcitic accumulations in the middle and towards the upstream end of the cavity. Drip forms are represented predominantly by conical stalactites (Figure 12a–c). These are associated with tubular stalactites (macaroni) and pre-drainage stalactites, some of which are anemolites (Figure 13a–c). Candle stalagmites (Figure 11c and Figure 12b), conical stalagmites, and stalagmo-stalactites (Figure 11f, Figure 12c, Figure 14 and Figure 15c) complete the palette of drip forms.

Gravitational leakage forms are also well represented within and upstream of The Chamber of the Slender Ankles of Enișoara by precession stalactites, crusts, and parietal veils (draperies) (Figure 11b,g and Figure 14a–c). The floor of the single hall is partially covered by a stalagmitic floor, on the surface of which the presence of gours is also noticeable (Figure 11d). Microgours are present less frequently, formed on gently sloping surfaces of the cave walls (Figure 15b).

Calcitic eccentric-type crystalline microforms (Figure 15a), resulting from the capillary displacement of water in an apparently antigravitational direction [54], have formed on a short montmilch-film stalagmite on a narrow, beveled sill on the parietal surface. Some particular types of chemical deposits are represented by montmilch deposits on the surface of some stalagmites. Other types resulted from the formation of residual (decalcification) clays, spread both on certain parietal surfaces (“leopard skin”) on stalactites (Figure 12b) and especially on the cave floor. In conditions of the slow and relatively continuous flow of pellicular water, clay surfaces deposited on the floor at the base of a sidewall can sometimes generate floor basins (gours).

Deposits of clastic origin are represented by sand accumulations in the gallery, but also by collapsed and interlocked blocks (Figure 15). The latter are scattered mainly along the gallery (disaggregation by gravitational collapse) and in the cave vestibule (disaggregation by gelivation and gravitational collapse).

5. Discussion

5.1. Geomorphologic Features of the Dobreștilor–Brusturet Cave

Drainage network. Topographed on the karstified surface of the Piatra Galbenă Bridge (an area of catchment, drainage, and infiltration of water in the karst system analyzed) were six sinkholes, with the five upstream appearing as forms resulting from clastokarst processes directed along a lithoclase, as indicated by the quasilinear arrangement of microdepressions. The clastocarstification was manifested by the dissolution of calcareous material of the post paroxysmal sedimentary [50] cover of the Upper Cretaceous (Upper Albian + Cenomanian). Of the mapped concave microforms, the upstream sinkhole has the largest diameter, about 20 m (Figure 8). The downstream one was modeled on limestone and has an irregular shape, resulting from the twinning of three swallets (Figure 9c) that capture the entire network of epigean talvegages (Figure 9b) that drain temporary waters from the surface of the karstified bridge extended up to about 30 m above the level of the receiving sinkhole–ponor (semi-fossil sinkhole).

Although the water flow path has not yet been tested by means of a brightly colored substance (sodium fluorescein), we admit a priori that the sinkhole–ponor (with three swallets), belonging to the upper seepage zone, drains the water collected from the Piatra Galbenă Bridge towards the karst system of the Dobreștilor–Brusturet cave, whose upstream terminus (point B at 1194 m absolute altitude) is located about 20 m, measured on the topographic surface, from swallet d1 (1226 m alt. abs.) and about 41 m from swallet d3 (1227 m alt. abs.).

The underground flow of water towards the cave, along the alignment of the sinkholes (the valley of sinkholes) but also through its cavity, is realized in a north-east–south-west geographic direction, being facilitated and imposed along the way by the diaclase developed quasi-parallel to the vertical fault positioned to the south and to the fault that conditioned the formation of the deep limestone torrential valley to the north (Figure 6 and Figure 7).

Morphographic features. In the interior of the limestone mass, the above-mentioned lithoclase is clearly visible for almost the entire length of the Dobreștilor Cave. The corresponding diaclase of the cave can also be observed in the upstream extension of its gallery, in a north-easterly direction, on the surface of the karstified bridge, which is suggested by the quasilinear arrangement of topographed sinkholes along the epigean talvegus collector (Figure 7). The transverse profile of the diaclase at the location of the access portal (elevation 0 m, downstream end) and the observations made along the cave gallery indicate that the fracture flared towards the base, which suggests that the lateral traction of its flanks had tectonic causes related to the evolution of the Piatra Galbenă block, which sank on vertical faults towards its eastern corner. The morphology of the cave gallery provides numerous examples showing quasi-vertical lithoclasts deepened towards the base by free-flowing water (Figure 14a,c). In the upstream third of the cave, sectors of a pressure flow tunnel are distinguished [54,57], formed by lateral erosion highlighted in the lithoclastic walls and subsequently deepened by flowing waters (Figure 11h, Figure 12a and Figure 14a).

The −3.3 m slope of the Dobreștilor Cave (existing at about 17 m from point A, elevation 0 m) is the minimum elevation of the sector of infiltration (loss) of the temporary hypogeous course in the depth of the limestone mass (Figure 10), on a hidden path of the cave diaclase. Observations made at a difference in level of about 20–25 m, below the access portal, on the surface of the slope in a small limestone area allowed for the identification of the lithoclasts (corresponding to the cave) reappearing in a new opening of a clogged cavity, impenetrable by man.

Morphogenetic aspects. The morphogenesis of the Dobreștilor Cave is closely linked to the evolution of the Brusturetului Gorges. The erosion on which the cave has been modeled has the shape of an interfluvial calcareous ridge (Colții Pietrei Galben), evidenced on the left slope of the Brusturetului Valley, at about 190 m relative altitude, above the upper limit of the walls of the narrow gorge in the middle of the forest floor. The interfluvium was detached by the regressive deepening of two limestone streams delimiting it to the north (tributary) and to the south (collector), whose evolution was conditioned by pre-existing faults (Figure 6, Figure 7, and Figure 9a).

The topography and mapping of the cave (Figure 11), in conjunction with the observations made during the three field research campaigns, allowed us to accept the hypothesis that the karst has developed in a vadose karst regime, probably since the Pleistocene, as determined by the general free-flowing water (temporarily alternating with the pressurized flow regime) and the deepening and widening of the cavity towards the base during torrential episodes. This occurred concurrently with the precipitation of calcium carbonate in the form of gravitational seepage and dripping. Arguments in support of this hypothesis are related to the cave’s oval shape and the dimensions of the access portal (4.8 m high and 3 m wide at the base); the generalized cross-section profile of the cave, with the sidewalls flared towards the base; the floor slope in the sense of increasing the elevation from downstream to upstream by 37.3 m over a length of 210.3 m; and the quasi-circular shape (±1.5 m in diameter) of the gallery in transverse profile, evident in the upstream half of the cave at a height of about 1–2 m from the present talveg.

In the Holocene, the predominant geomorphological processes remained those specific to the karstification phenomenon in the vadose regime, characterized by the deposition by dripping and gravitational penetration of calcium carbonate precipitated from the saturated solution originating from the infiltration zone (Piatra Galbenă Bridge) and percolation. The increasingly numerous and sophisticated drip formations are present in the upper third of the cave. The morphodynamics with a complementary role were characterized by episodes of torrential runoff causing deep and lateral erosion, allowing the shaping of the present slope to be well calibrated between +21.8 m and −3.3 m. At the same time, the process of gravitational collapse has generated the existing landforms and deposits.

In conclusion, the generation of forms of torrential erosion (and corrosion), chemical precipitation, and clastic accumulation was realized along the path of an upstream degraded diaclase, likely opened during the tectonic movements of the Wallachian phase or the non-tectonic movements of the Pasadena phase of the Carpathian orogeny. The vertical evolution of the cave was conditioned by the dimensions of the diaclase that directed the water into the system, corroborated by the permanent lowering of the local base level, imposed by the continuous deepening of the Brusturet–Dâmbovicioara river in the Jurassic limestone package along the fault line. It should be noted that the deepening of the river valley was caused by the lowering of the regional base level at Podu Dâmboviței, a graben-type tectonic depression [23].

5.2. The Heritage Value of the Dobreștilor–Brusturet Cave Within the Thematic Geotourism Circuit “The Road of Gorges and Caves in the Upper Dâmbovița Basin”

In order to evaluate the most representative geomorphosites proposed for inclusion in the thematic geotourism circuit “The Road of Gorges and Caves in the Upper Dâmbovița Basin”, 38 inventory criteria were designed and applied. Based on these criteria, the most appropriate score was awarded as objectively as possible from the five point fractions (0 p, 0.25 p, 0.50 p, 0.75 p, and 1 p). The 11 most representative geomorphological sites were evaluated from a total of 30 geomorphological objectives of a calcareous and karst nature with morphotouristic value (18 key valley sectors, 10 caves, and two hydrokarst systems). Following the application of the criteria, diagnostic sheets were drawn up for the selected and proposed geomorphosites. The geomorphosites were ranked according to their value hierarchy (

Table 1. Value hierarchy of the proposed geomorphosites belonging to the thematic geotourism circuit “The Road of Gorges and Caves in the Upper Dâmbovița Basin”.

Crt. No.	Geomorphosite (G—Indicative)	Structural Value			Functional Value			Restrictive attribute	Total
		VS1	VS2	VS3	VF1	VF2	VF3
1	G1 Dâmbovicioarei Gorges and Brusturetului Gorges	5.00	3.25	3.00	2.75	5.00	8.25	0.75	26.50
2	G2 Great Gorge of Dâmbovița, Ghimbavului Gorge, and “Cheița” Gorge	5.00	3.25	3.00	1.25	4.75	5.75	0.50	22.50
3	G3 Orăți Valley, upper sector with Orății Gorge (“Orății Canyon”)	4.25	2.50	2.00	2.50	4.00	5.75	1.25	19.75
4	G4 Miresii Cave	5.25	2.50	2.25	1.25	4.00	4.50	0.25	19.50
5	G5 The karst hydro system “Fundățica swallet and Rudărița Valley–Uluce resurgence”	5.50	1.75	2.00	1.25	3.50	5.50	1.50	18.00
6	G6 Dâmbovicioara Cave	3.00	1.50	1.75	1.75	3.25	7.25	1.25	17.25
7	G7 Bears Cave or Colțul Surpat Cave	3.75	1.75	2.00	2.00	3.50	5.25	1.25	17.00
8	G8 Dobreștilor–Brusturet Cave	4.75	2.00	2.00	0.75	3.25	3.75	1.00	15.50
9	G9 The karst hydro system “Waterfall and Caves from Plai”	3.50	1.75	1.50	0.25	3.25	5.50	1.25	14.50
10	G10 Posada Cave	4.00	1.50	1.50	1.25	2.50	5.00	1.50	14.25
11	G11 Pleașa Cave	4.00	1.50	0.25	0.25	1.50	4.50	0.75	11.25

) and geographically located (Figure 16). The inventory criteria were successfully used to establish the value hierarchy and place each geomorphosite in its rightful position. We posit that the 11 proposed geomorphosites are currently the most valuable morphotouristic objectives (until new discoveries are made through research) within the proposed thematic geotourism circuit. The measures for promotion and geotourism development could also start from the documentation in their geomorphosite files.

The diagnostic sheet for the speleological geomorphosite Dobreștilor–Brusturet Cave (

Table 2. Diagnostic sheet for the Dobreștilor–Brusturet Cave geomorphosite.

Name		DOBREȘTILOR–BRUSTURET CAVE
Call sign		G8
Geographical location access (elevation 0 m)		In the calcareous marker Colții Pietrei Galbene on the left slope of the upper Brusturetului Gorge (Cheia Strâmtă), at the absolute altitude of 1160 m
Administrative territorial unit		Ciocanu village (Dâmbovicioara commune)
Types		Speleological geomorphosite
Extension		Linear
Total value		15.50 p
Structural value		8.75 p
Functional value		7.75 p
Restrictive attribute		1.00 p
Geomorphologic Value (VS1)	4.75 p	- Genesis (SV 1a): complex speogenesis, involving four morphogenetic factors: tectono-gravitational processes (tectonic tensile diaclase, deposits, and incision forms), chemical corrosion (in some sections), torrential erosion, and chemical precipitation (gravitational dripping and prelingering forms) (1.00 p). - Dynamics (VS 1b): landforms with slow, inferred dynamics (0.50 p). - Complexity (VS 1c): Five elements of geomorphological interest—fossiliferous gallery sections with a quasi-circular cross-section (pressure flow), diversified drip forms (including anemolites), gravity seepage forms, calcitic eccentrites, stalagmitic basement floors (gours), and microgours on gently sloping surfaces of limestone sidewalls (1.00 p). - Integrity or conservation status (VS 1d): geomorphosite slightly affected (0.75 p). - Rarity (VS 1e): regionally unique speleological geomorphosite (Bucegi Mountains–Leaota) due to the diversity and richness of the drip forms (including anemolites), gravitational prelingering and microforms resulting from capillary prelingering (calcitic eccentrites) (0.50 p). - Geological structure (VS 1f): the cave was formed along a tectonic diaclase (developed quasi-parallel to the vertical fault to the south), open in massive carbonate deposits (with fine stratification), monoclinically arranged within the tilted block of Piatra Galbenă (0.75 p). - Cave development (VS 1g): total cave length is 210.3 m (0.25 p).
Aesthetic Value (AV2)	2.00 p	- Physiognomy or physiognomy (VS 2a): geomorphosite with a unique physiognomy due to the diversity and richness of speleothems (0.75 p). - Chromaticity (VS 2b): chromatic gradation characteristic of karst voids (0.25 p). - Maximum exposure (VS 2c): selectively received speleological geomorphosite from observation points on the trail (0.50 p). - Landscape Attractiveness (VS 2d): the geomorphosite (with the embedded portal of the Yellow Stone Hills on the left slope of the Narrow Brusturet Gorge) is a component with local landscape attractiveness, but is also protected due to its landscape content. It belongs to RNGG1 (IUCN category IV) and is a nature monument (IUCN category III) included in the SPA (IUCN category Ib) of the PNPC (0.50 p).
Ecological Value (EV3)	2.00 p	- Vegetation (SV 3a): bare biotope. - Fauna (VS 3b): 28 invertebrate species were inventoried, including the coleoptera Duvalius duebelianus (local endemic, rare troglobiont/edaphobiont) and Dermestes latissima (endemic to the Southern Carpathians). Chiroptera Myotis myotis and Rhinolophus ferrumequinum were identified (1.00 p). - Degree of protection as part of a protected natural area (SV 3c): fully protected geomorphosite, declared as a natural monument (IUCN category III) (1.00 p).
FUNCTIONAL VALUE (VF) = VF1 + VF2 + VF3
TYPE	SCORE	JUSTIFICATION
Cultural (VF1)	0.75 p	- Symbolism (VF 1a): the name “Dobreștilor” attributed to the cave is due to its discoverer, Ioan Dobrescu, who named it after his family name [1], an aspect with symbolic significance, in discrete association with geomorphosite (0.50 p). - Artistic and as graphic, cartographic, and photographic representations (VF 1b): the cave has less than 10 graphic representations (sketch—longitudinal profile, map) and photographs in tourist information/popularization works and one scientific paper (0.25 p).
Scientific (VF2)	3.25 p	- Scientific references in publications (VF 2a): scientific references in occasional publications, scientific articles in national and one international journal (1.00 p). - Formative scientific resource/economic resource (tourism, etc.) (VF 2b): scientific resource with medium addressability, due to the interest in caving: physical caving and zoospeology—invertebrates (28 species) and chiroptera (0.50 p). - Function as a didactic model of morphogenetic and evolutionary landforms and/or geomorphologic processes (VF 2c): model with illustrative value (0.75 p). - Scientific representativity (relevance) (VF 2d): speleological geomorphosite with regional representativity (0.50 p). - Paleogeographic interest (VF 2e): geomorphosite of moderate paleogeographic interest, useful for deciphering the genesis and evolution of the cave in local and regional contexts (0.50 p).
Economic (VF3)	3.75 p	- Number of possible activities (VF 3a): activities related to scientific research (mainly zoospeological), and geotourism may be practiced only on the basis of a permit issued by the PNPC administration (0.50 p). - Tourism potential (VF 3b): geomorphosite that does not arouse interest in tourism as the cavity is fully protected and is intended for scientific research (0 p). - Accessibility (VF 3c): car access up to 500 m from the geomorphosite, from DC 22 (0.75 p). - Related tourist infrastructure (VF 3d): Brusturet chalet (village Dâmbovicioara) about 1 km away (0.75 p). - Facilities and services (VF 3e): shared accommodation and catering services at the Brusturet Hut (0.25 p). - Distance to nearby localities with complex services (VF 3f): the distance to Rucăr and Zărnești is between 10 and 15 km (0.50 p). - Urban centers in the neighboring region (VF 3g): the nearest urban centers are the cities of Câmpulung (27,574 inhabitants/2021), 35 km away; and Zărnești (21,624 inhabitants/2021), 36 km away (0.50 p). - Tourism exploitation during the year (VF 3h): simple, occasional exploitation (0 p). - Tourism promotion of geomorphosite (VF 3i): brief, incomplete, unprofessional tourism promotion (under the name “Cave of the Foxes”) on a single website page, very rarely accessed. The targeting of the promotion reaches a regional level, at most (0.50 p).
RESTRICTIVE ATTRIBUTE (AR) = AR1 + AR2 + AR3
SCORE	JUSTIFICATION
1.00 p	- Vulnerability to natural phenomena and processes (AR1): this speleological geomorphosite may be affected due to its vulnerability to seismic movements and other processes that may generate landslides (incachogenic deposits), but not affected as a whole (0.25 p). - Presence of economic activities with negative impacts or that could affect tourism and/or the geomorphosite (AR2): irrational pastoral activities in the area of drainage and water infiltration on the surface of the Piatra Galbenă karst plateau could affect the habitat of the speleological geomorphosite (0.50 p). - Unsightly elements (AR3): the iron fittings of a former metal grating that closed the upstream access about 90 m from the entrance (0.25 p) are visible.

) faithfully follows the inventory criteria proposed in the evaluation methodology, with 33 of these being applicable. Although it ranked eighth in the hierarchy, following three speleological geomorphosites and a karst hydrosystem, the Dobreștilor Cave obtained the second highest score (8.75 p) in the structural value section (geomorphological, aesthetic, and ecological) in the speosite evaluation hierarchy, being surpassed in this section only by Miresii Cave [25] (10 points). This aspect argues for the high intrinsic value of the analyzed geomorphosite. The position in the value hierarchy according to the structural value criterion further strengthens the justification for initiating and submitting the proposal in 2000 to designate the Dobreștilor–Brusturet Cave as a monument of nature.

5.3. Ecological and Zoospeological Value of Dobreștilor–Brusturet Cave

The heritage value of Dobreștilor Cave is also highlighted by its ecological and zoospeological value. Since 1972, the scientific community has recommended that the cave be included in a geological and geomorphological reserve, and later in the strict protection zone of the Piatra Craiului National Park, due to the cave’s significant biotop for 28 species of invertebrates [20] and its particularly attractive speleothem landscape. For these reasons, the Dobreștilor–Brusturet Cave was declared a monument of nature, according to Law no. 5/2000. The number of invertebrate species inventoried places this cave in the second position among all caves where such studies have been carried out in the whole area of Piatra Craiului National Park and the Bran–Dragoslavele Corridor, after the Big Cave of the Village of Peștera (Cave with Bats) where 41 species have been inventoried and before the Bear Cave (Cave of the Surpat Corner) with 20 species discovered.

Remarkable are two endemic species, both belonging to the order Coleoptera (beetles): Dermestes (Montandonia) latissima (Bieltz, 1852) [20], a very rare troglophilous species, cited as endemism for the Southern Carpathians; and Duvalius (Duvalidius) deubelianus (Csiki, 1903) [20], a rare edaphobiont (probably troglobiont), endemic to the Piatra Craiului Massif [20].

The Dobreștilor–Brusturet Cave is also known as the Fox’s Cave, due to the presence of a Vulpes vulpes skull inside the cave and the sufficient evidence of the presence and activity of this mammal (Figure 16 and Figure 17b).

Cave exploration in the three campaigns led to the identification of several individuals belonging to two chiropteran species: Rhinolophus ferrumequinum—Schreber, 1774 [38], or the large horseshoe-nosed bat; and Myotis miotis—Borkhausen, 1797 [38], or the large mouse-eared bat (Figure 11i). It also facilitated the possibility of identifying a geophilomorph species of myriapod of the class Chilopoda (24 October 2024), as well as a coleopteran, Catops fuscus (Panzer, 1794) [20]. The ecosystem favorable to the species of the last mentioned invertebrate [58] resulted from the biological decomposition of organic matter of animal origin, most likely originating as a residue of food brought by foxes, on which fungal hyphae developed. Catops fuscus (Figure 17c) is known as a species of the family Leiodidae (mycelial beetles), both saprophagous and mycophagous [59].

The natural isolation of the entrance to the Dobreștilor Cave, positioned at a difference of 193 m in level from the bed of the Brusturetului–Dâmbovicioara Valley towards the upper part of a steep slope, in the middle of the forest floor, as well as the stable topoclimate due to its length are favorable factors of the biotop of the cave for the protection and perpetuation of the existing invertebrate and vertebrate communities.

6. Conclusions

Until now, the Dobreștilor–Brusturet Cave has not been studied from a speophysical, morphological, or morphodynamic point of view. In this context, the geomorphological analysis carried out using classical investigation methods (overall and detailed observations, measurement and cartographic representations, the interpretation of morphology in order to decipher morphodynamics, and comparisons with other caves in the study area) highlighted the following new aspects: the morphology of the rainwater catchment area (the karstifiable Piatra Galbenă bridge) and the elementary exokarst forms represented by six sinkholes strung along the epigean drainage path (the valley of sinkholes); the direction of epigean drainage, including the receiving sinkhole–ponor and the water (morphodynamic agent) route within the karst system that it shaped; the tectonic origin of the lithoclase(s) that captured and directed the shaping agent (water); the endokarstic forms of erosion (and dissolution) of the cave gallery which, through observations in cross-sections of the upstream third, highlighted the change of the flow regime over time (from pressure flow to free flow); and the typological inventory of speleothems, especially dripstone formations.

The morphogenetic interpretation was consistent with aspects related to the karstification phenomenon manifested in an intensely tectonized geological–geomorphological setting (synclines, anticlines, grabens, horsts, faults, and detachments) specific to the central compartment of the Bran–Dragoslavele Corridor, and characterized overall by the presence of Jurassic deposits overlain by a discontinuous cover of heterogeneous Cretaceous sediments. Following the associated analysis of local and regional morphotectonic and morphostructural landmarks, together with the morphographic and morphometric data determined during the observation and measurement campaigns carried out in the field, it was concluded that Dobreștilor Cave evolved in a single morphogenetic stage in which the phenomenon of karstification occurred. The processes and forms characteristic of this stage only manifested themselves in a vadose regime, through the deepening and widening of the cavity towards the base, conditioned by the free flow of water during torrential episodes (alternating temporarily with the pressure flow regime evident in the upper half) concurrently with the precipitation of calcium carbonate in the form of dripping and gravitational dripping. The generation of the torrential erosion forms, dissolution forms, chemical precipitation formations, and clastic accumulation deposits took place along a lithoclastic track, probably opened during the Carpathian neotectonic movements of the Pasadena phase (middle Pleistocene), or, at the earliest, in the Wallachian orogenic phase (lower Pleistocene). The permanent deepening of the Brusturet–Dâmbovicioara river, imposed by the lowering of the base level at Podu Dâmboviței (graben), conditioned the vertical evolution of the cave. The permanent deepening of the Brusturet–Dâmbovicioara river, imposed by the lowering of the regional base level and by the sinking of the Podu Dâmboviței tectonic depression fault system, conditioned the vertical evolution of the cave.

In terms of its function as a protected natural area, Dobreștilor Cave is part of a geological and geomorphological nature reserve. It has also been included in the strictly protected area of Piatra Craiului National Park. It functions as a habitat of national and community interest and has been declared a “cave closed to the public”. Dobreştilor Cave was placed in protection class B of caves with sectors of national importance, primarily because of its ecological significance demonstrated by the study of invertebrate fauna, in accordance with Law No. 49 of 7 April 2011 for the approval of Government Emergency Ordinance No. 57/2007 on the regime of protected natural areas and the conservation of natural habitats and wild flora and fauna; and Article I, point 64, on the classification of caves or some of their sectors according to the criteria of scientific and cultural–educational value. At the same time, in accordance with Article I, paragraph 68, on the classification of caves or some of their sectors according to the purpose and management regime of protected natural areas, the cave was established as a monument of nature, entering the IUCN category III, based on the following considerations:

a. The importance of ecological significance, due to the existence of an isolated biotope, favorable for the life and perpetuation of the 28 species of invertebrates identified so far, of which two species are endemic. The possibility of discovering new invertebrate species is driving research activity among the specialists of the Emil Racoviță Institute of Speleology in Bucharest. The subterranean cavity is also of ecological importance due to the ideal shelter conditions offered to some vertebrate species (chiroptera, foxes, etc.).

b. The intrinsic value of the Dobreștilor–Brusturet Cave geomorphosite, particularly affirmed by the richness, diversity, and aesthetics of the dripping and gravitational seepage forms. This intrinsic value, in comparison with the same value of the known and explored speleological geomorphosites along the axes of the proposed thematic geotouristic circuit called “The Road of Gorges and Caves in the Upper Dâmboviet Basin”, was highlighted by applying specific criteria within a coherent methodology of geomorphosite inventory and evaluation. Following the ranking of the geomorphosites, the score obtained by the Dobreștilor Cave (8.75 p) in the “structural value (geomorphological, aesthetic, and ecological)” section was highlighted, which propelled the cave to the second position in the hierarchy, behind Miresii Cave (10 p). The position in the value hierarchy according to the structural value criterion further strengthens and substantiates the justification for initiating and actioning the proposal to designate the Dobreștilor–Brusturet Cave as a monument of nature.

The Transcarpathian depression under analysis is a well-known area for the harmonious coexistence of traditional human pursuits and the natural world, providing a variety of recreational tourism opportunities. At the same time, this low mountainous area is also known for the scientific, educational, didactic, and cultural value of the geomorphologic and geological sites in the “Cheile Dâmbovița–Dâmbovicioara–Brusturet karst area” nature reserve. The area is included in the strict protection area of the related national park, which led us to propose the inclusion of the speleological geomorphosite Peștera Dobreștilor–Brusturet (with speophysical, zoospeological, and ecological relevance) in the geotouristic resources of which it is part. This geomorphologic region can only be used for scientific research and educational purposes, with accessibility from the thematic geotouristic circuit called “The Road of Gorges and Caves in the Upper Dâmbovicioara Basin” (the axis of the Dâmbovicioara–Brusturet–Dry Valley of Stones valleys), alongside two other geotouristic circuits proposed by us in the central area of the Bran–Rucăr–Dragoslavele Corridor in the Transylvanian Alps.