Geomorphosites of nui chua national park

Geomorphosites of Nui Chua National Park, Ninh Thuan Province, Vietnam Abstract Nui Chua National Park, Ninh Thuan province, is a semi arid climate while locating right next to a tropical forest clima.

Geomorphosites of Nui Chua National Park, Ninh Thuan Province, Vietnam Abstract Nui Chua National Park, Ninh Thuan province, is a semi-arid climate while locating right next to a tropical forest climate, therefore, it has a rich biodiversity ecosystem, where the coastal dry forest ecosystem is rarely seen in Vietnam This area contains many valuable geomorphological features in denuded – lithological – tectonic terrain, among them, three features can be considered as national treasures: 1) Nui Chua dome – block mountains; 2) Rai Cave tectonic – abrasive coastline and 3) Lang Choi Stone Park Nui Chua dome – block mountains are the unique geomorphosite of Vietnam which has the right conditions for the dry ecosystem to develop The tectonic – abrasive coastline of Rai Cave and Lang Choi Rock Park is home to unique and precious geoheritages such as two-stage development of boulders or balanced rocks, karren sculpturing, caves, notches on ancient coral reefs terrace or spheroidal weathering, tafoni on intrusive rocks, to name a few To archive the goal of sustainable development, it is important to link the conservation activities of the biodiversity at Nui Chua National Park to the preservation efforts of geodiversity (geology, geomorphology, etc.) in the area Providing scientific explanations at each geomorphosites together with safe sightseeing guides will help increase the quality of tourism, attract more visitors to explore and learn about this mysterious, wonderful, and diverse ecosystem Introduction The term “geomorphosites”, often used to refer to geomorphological heritage, is the abbreviation of “geomorphological sites” (Panizza, 2001; Pralong, 2005) Compared with geological heritages, geomorphological heritage has three specific main characteristics: aesthetics, dynamics, and overlap in scale (Reynard, 2009) The above three characteristics mean these geoheritages are beautiful, active landforms, and vary in area from small to large These features make the geomorphological heritage unique and attract visitors to admire and explore Over the past three decades, scientific studies have been carried out in many parts of the world, focusing on the scientific and complementary values of the geological and geomorphological heritages (Brilha, 2016; Fuertes-Gutiérrez & Fernández-Martínez, 2012; Ielenicz, 2009; Zouros, 2007) Like other geological heritages, geomorphological heritages deserve to be protected and preserved to pass on to future generations Nui Chua National Park area has the driest climate in Vietnam and has rich biodiversity both in mountainous and coastal areas Major tourist attractions within the Nui Chua National Park such as Vinh Hy Bay, Rai Cave, Nui Chua Mountains, and so on, can be considered as geomorphosites (Fig 1) 1 Download : Download high-res image (820KB) Download : Download full-size image Fig Geological map of Nui Chua National Park (modified from Vietnam Department of Geology and Minerals., 1998) Although Nui Chua National Park has been open for visitors for a long time, these tourist attractions have not been extensively studied in terms of scientific and complementary values As a consequence, these geomorphosites still face problems with attracting a variety of visitors as well as long term solutions for protection and conservation Within this work, the scientific and additional values of geomorphosites in Nui Chua National Park are investigated and presented This valuable information of these heritages would help to attract not only more visitors but also students and scientists to perform more thorough investigation about this National Park Methods The research is conducted based on the inventory of geomorphosites, followed the guideline of Reynard, Perret, Bussard, Grangier, and Martin (2016); Reynard, Fontana, Kozlik, and Scapozza (2007) as steps below: (1) Literature review about geology and geomorphology in journals, books, and the Vietnam geological – mineral map, Da Lat – Cam Ranh, 1:200,000 scale (Vietnam Department of Geology and Minerals., 1998) (2) Potential sites were chosen to fieldwork for the detailed descriptions of each site included: location, information on geology and geomorphology, accessibility, present uses and infrastructure, protection, condition of the outcrop (visibility), other information (ecological, cultural, historical, economic values) and photographic documentation (3) The preliminary assessment was conducted to pick out sites that have scientific and additional values following the criteria proposed by Reynard The scientific values consist of four criteria: representativeness, unique/rareness, integrity and palaeogeographical value (detailed explanation and references of these criteria are shown in Table 1) Table The scientific value of geomorphosite Criterion Scientific value Example in research area A selected geomorphosite should represent the most complete and expressive manifestation of a geomorphological phenomenon or a spatial –genetic pattern Da Chong inselberg is 86 m high mountain It has many large, rounded granite boulders which precariously balanced on top of another This site is representative for the balanced rocks in the study area and the South-Central Coast of Vietnam also Concerns the rarity of the site with respect to a reference space This criterion of a site can depend Rareness/Uniqueness on different indicators: on quantitative parameters, or on qualitative parameters; on spatial –temporal indicators Thit Beach is quite different from other beaches in this region because of its good conditions for sea turtles spawning The rareness of the sandy beach is the highest value of this site Integrity State of conservation of the site Most of the sites in this area belong to national park, therefore, they are protected by management boards Palaeogeographical value Importance of the site for the Hon Do Cape has an ancient Earth or climate history coral reef terrace The 4–5 m Representativeness Criterion Scientific value Example in research area high marine terrace represented the Quaternary tectonics and Bien Dong level changing activities The additional values include three main criteria: ecology, aesthetics (viewpoints, contrasts, vertical development, and space structuration), and culture (religious, historical, artistic, literary, geohistorical, and economic importance) In this step, we chose 12 sites that have values to be geomorphosites in this study area (Brilha, 2016; Zouros, 2007; Pereira & Pereira, 2010; Pralong, 2005; Reynard et al., 2016, Reynard et al., 2007; Wimbledon et al., 2000) (4) The heritages are classified according to three levels: local (Ninh Thuan province), regional (South Central coast of Vietnam), and national (Vietnam): based on the representativeness or/and rareness of site in each scale Besides that, we consider other scientific and additional values to suggest the level of geomorphosites Research area Nui Chua National Park locates in the north-eastern part of Ninh Thuan province The national park borders the Cam Ranh Bay – Khanh Hoa in the north, Bien Dong in the east, Ninh Hai district in the south, and the highway 1A in the southeast Nui Chua National Park includes Ninh Hai district, about a quarter of Thuan Bac district in Ninh Thuan province with an area of 29,856 ha, of which 22,513 is land, 7352 is the sea Two roads with easy access to the geomorphological features are the national highway 1A and the provincial road 702 Besides, the North-South railway, which runs parallel to the national highway 1A and the sea, is another convenient transportation method to visit the national park 3.1 Geology and geomorphology The Cretaceous Deo Ca intrusive complex occupies most of the study area (Fig 1) and belongs to the Da Lat Late Mesozoic active continental margin structure (Tran & Vu, 2009) The main intrusive rocks are granite, granosyenite, and granodiorite (Nguyen, 1999) Nui Chua Mountains are composed of intrusive rocks with six peaks Among those, the highest is Co Tuy peak (1039 m), also known as Chua Anh Mountain (means older brother) The other peaks are named Chua Chong Mountain (means husband), Chua Vo Mountain (means wife), Chua Em Mountain (means younger brother), Chua Chau Mountain (means grandchild), and Chua Chat Mountain (means great-grandchild) Holocene marine sediments occupy only a small area in the south and include sand, gravel, coral debris, and coral reefs These sediments form a 4–5 m high marine terrace, which is equivalent to the Ca Na terrace that was formed in the Flandrian transgression stage (Le & Uong, 2012) Orthogonal joint systems included two vertical systems dominantly in the direction 1) NE-SW, NW-SE and 2) sub-longitude, sub-latitude, and horizontal system The processes of denudation were developed according to the joint systems that cut into the intrusive rock bed, which were the basis for forming the typical boulder of the area 3.2 Climate and hydrography According to “Köppen-Geiger Climate Classification” the study area belongs to the tropical savanna climate entirely (Kottek, Grieser, Beck, Rudolf, & Rubel, 2006) Ninh Thuan province has two distinct seasons: the rainy season from September to December and the dry season from January to August The average temperature ranges from 24.6 to 27.2 °C There is a distinct dry season, where there will be no rain for months Then a short rainy season brings heavy rains mostly in the afternoons, with hot, humid conditions throughout the rest of the day Even with the rainy season, the annual rainfall is the lowest rainfall in South-Central Vietnam (430–940 mm), while the evaporation is quite high (1295.8– 2210.1 mm), twice as much as the rainfall (Tu, Pham, & Bui, 2018) The streams and springs in the national park are narrow, seasonal flow from the Nui Chua Mountains into the sea Most of the streams dry up during the dry season The tidal patterns that occur along the Ninh Hai district coastline are irregular diurnal tides The average amplitude of tides is about 0.8–1.2 m, with the highest is over 1.5 m (Pham, Do, & Do, 2011) From January to April, the prevailing winds blow southwest, the average wave height is 1.0–1.1 m with the maximum is about 2.0 m From October to December, winds prevail from the Northeast, the average wave height is about 1.2 m and the maximum is about 2.5 m The studyarea is in Ninh Thuan – north Binh Thuan upwelling zone, which occurs from June to September Upwelling brings nutrients into the surface water of the ocean, results in some of the most productive marine ecosystems (Nguyen, 2007) 3.3 Ecology Nui Chua National Park is located in the driest part of Vietnam therefore it has the typical and unique dry forest ecosystems rarely seen in Vietnam and Southeast Asia According to Duc, Baxter, & Page, 2009, the only primary forest that remains is evergreen forest at elevations >700 m above sea level in the north of the park Below 700 m above sea level, on the east side of the mountains there are large areas of four types of secondary forest such as sclerophyll evergreen forests, dry deciduous forest and tropical savanna woodland, dry thorny scrub and thorny woodland; thorny scrubland (Duc, Baxter, & Page, 2009) Nui Chua National Park has 1504 vascular plant species In terms of fauna, it currently has 306 species of animal, of which 64 are rare and conserved species (Tran & Dang, 2014) There are several species such as Red-shanked Douc Langur (P nemaeus) was listed in the Red List of IUCN as Endangered Asian colobine monkey (Craig Hilton-Taylor (Compiler), 2000) The coastal reefs are in relatively good condition, including 310 species (Si Tuan Vo, DeVantier, Tuyen, & Hoang, 2014) In addition, Nui Chua National Park is one of the rare inland spawning beaches for sea turtles (Tran & Dang, 2014) Results and discussion 4.1 Geomorphosites Conducting inventories and field surveys, we identified 12 geomorphosites which can be classified into five types: (1) mountains, (2) bays and lagoons, (3) marine terraces, (4) rocky coastline, and (5) beaches The scientific and additional values are shown in Fig and summarized in Table 1 Download : Download high-res image (1MB) Download : Download full-size image Fig Geomorphosites of Nui Chua National Park – Ninh Thuan Province Table Summary of scientific value and additional value of geomorphosites in Nui Chua National Park, Ninh Thuan Province Geomorphosites Symbol Scientific Values Additional Value Heritage name Level Nui Chua dome – G.3 block mountains + Geomorphology: - Five blocks of different altitudes: central block 800–1039 m high, two adjacent blocks: 800– 400 m, two outmost blocks: 400–100 m - Erosive – denudate terrain on intrusive rocks: the two-stage development of boulders, rock water stream, hanging lake, waterfall, bay etc - Neotectonic uplift + The most important criteria: Integrity, Rareness and Representativeness: All + Ecological value: National three distinct ecosystems with rich biodiversity, including: marine, dry forest and evergreen forest + Aesthetic value: Spectacular landscape spanning from hill to mountain to ocean Geomorphosites name Symbol Scientific Values Additional Value Heritage Level the landforms are in good conservation in national park + Aesthetic value: - Ca Du inselberg G.8 Ca Du – a turtle shaped mountain (in Cham language is Chơk Du’) + Geomorphology: - Inselberg on Phan Rang plain, 318 m high - Large, rounded granite boulders precariously balanced on top of another + The most important criterion: Integrity: good conservation Panoramic viewpoint: Phan Local Rang – Thap Cham town, Ninh Chu coast, Phuong Cuu salt field, Dam Vua lagoon, Ninh Hai rice field and Da Chong Mountain + Cultural value: Revolutionary historical sites of Ninh Thuan province (1999) Da inselberg Chong G.10 + Geomorphology: - Inselberg on Phan Rang plain, 86 m high - Large, rounded granite boulders which precariously balanced on top of another + The most important criterion: This site is representative for the + Aesthetic value: Regional viewpoint of Ninh Chu beach, Ninh Hai rice field + Cultural value: The historical monument of Ninh Thuan Geomorphosites name Symbol Scientific Values Additional Value Heritage Level province - balanced rocks in the South-Central Coast of Vietnam Vinh Hy erosion G.4 tectonic bay Nai lagoon G.9 The system of pagodas has unique architecture such as Trung Son pagoda, Trung Quang pagoda, Temple of Confucius, Truc Lam Vien Ngo monastery + Geomorphology: - Vinh Hy Bay was formed by the wave – destruction on the NWSE joint system This happened before the Flandrian transgression - The bay deeply penetrates in the mainland and is a connection point for the mountainous and marine ecosystem + The most important criterion: This site is representative for the erosion tectonic bay in the South-Central Coast of Vietnam + Aesthetic value: provincial level landscapes + Ecological value: Regional coral is diverse and well preserved + Cultural value: tourism; lobster farming + Geomorphology: - Nai lagoon is shallow bodies of water separated from the ocean by sandbars + Aesthetic value: Local impressive sunset landscape + Ecological value: rich biodiversity, 300 of Geomorphosites name Symbol Scientific Values Lang Choi abrasion marine G.7 terrace, abrasive effect of sediments Ninh Hai marine G.11 terrace, sediment accumulation Additional Value Heritage Level - Function of regulating flood flow, balancing groundwater and cleaning the environment + The most important criterion: This site is representative for the lagoon in Ninh Thuan province mangrove forest + Cultural value: aquaculture, potential for tourism development + Geomorphology: - Cliffs are oriented in sub-longitude fault The two-stage development of boulders or balanced rocks are common The height is 80–100 m - The largest granite boulders precariously balanced on top of another is the symbol of Nui Chua National Park - Tafoni on granite + The most important criteria: Unique, Rareness, Representativeness: This site is the only occurrence of 80–100 m high marine terrace in the the South-Central Coast of Vietnam + Aesthetic value: the dry forest landscape together with balanced boulders National + Ecological value: typical xeric plants, thick leaves, rough, and spiky stems + Geomorphology: + - Marine accumulation terrace in Flandrian transgression, 4–5 m high Cultural value: Local Sea salt farms, Geomorphosites name Symbol Scientific Values - Urban infrastructure foundations, residential areas, salt fields + The most important criterion: This site is representative for the marine terrace in Ninh Thuan province Da Vach tectonic G.2 cliff Rai Cave abrasion G.5 tectonic cliff Additional Value Heritage Level rice fields, specialty crops: grapes, garlics, chilies, spring onions The Nam Hai Mausoleum Festival which prays for good weather and good harvest + Geomorphology: - Steep cliffs 20–50 m in height and km in length is oriented in longitude fault Wave-cut cliffs resulted in carved terrain + Aesthetic value: The with many unique landscape of majestic Regional shapes cliffs + The most important criterion: This site is representative for the tectonic cliff in the South-Central Coast of Vietnam + Geomorphology: - Cliffs are oriented in sub-longitude fault Diverse coastal terrains: cliffs, marine terraces, balanced boulders, cave, wave-cut notch, razor-sharp and jagged coral rock, karren terrain + Aesthetic value: the National provincial natural landscape monuments of Ninh Thuan province (2018) + Ecological value: rich biodiversity, especially the coral reefs + Cultural value: potential for sustainable Geomorphosites name Symbol Scientific Values Additional Value Heritage Level - Ancient coral reef terrace, 4–5 m in height + The most important criteria: Unique and palaeogeographical tourism development value: This site is the only occurrence of tectonic cliff coast and ancient coral reef terrace in Vietnam Hon Do cape, G.12 ancient coral reef + Aesthetic value: beautiful coastal landscapes + Ecological value: rich + Geomorphology: biodiversity, especially - Red sand overlay on the coral reefs coral rock + Cultural value: - Wave-cut notch, razorsharp and jagged coral rock, karren terrain Regional + The most important The Temple of criterion: Lady Do belongs Palaeogeographical to Cham culture value of ancient coral reef terrace Archeology in Cham cultural relics Nuoc Ngot beach G.1 + Geomorphology: + Aesthetic value: the Regional - Pocket beach with beauty of pristine beach coarse sediment - Fresh water springs from Nui Chua Mountain + The most important criterion: Rareness of the landscape: the unique Geomorphosites name Symbol Scientific Values Additional Value Heritage Level spring meets the sea in this province Thit beach G.6 + Geomorphology: pocket sandy beach + The most important criterion: Rareness of the sandy beach: The beach has good conditions for sea turtles spawning + Ecological value: - sea turtle conservation - ecosystem of coastal Regional coral reefs has a diversity of species The common geomorphosites are balanced rocks (which are composed of two or more boulders, perched one on the other (Twidale & Vidal Romaní, 2005)) in denuded products of which dominant factors are orthogonal joints system and homogeneous material of intrusive rock bodies These can be called denuded – lithological – tectonic terrain in mountainous areas and abrasive – lithological – tectonic terrain in lower coastal areas In addition, the system of fractures is oriented to extend the coastline, currents, bays, and lagoons 4.2 National level geomorphosites proposal The most criterion for the selection of these national-level heritages is their rarity or/and representativeness Besides that, we consider other scientific and additional values to suggest the level of geomorphosites Proposing three national-level geomorphosites including 1) Nui Chua dome – block mountains, 2) Tectonic – abrasive coastline Rai Cave and 3) Lang Choi abrasive marine terrace 4.2.1 Nui Chua dome – block mountains After ALOS PALPAR data interpretating (Dataset, 2008) and topogogical analysing, the study area has four main fault systems inland: NE-SW, sub-longitudinal, NW-SE and sub-latitudinal faults These fault scarps are shown in Fig The NE-SW faults FI, FII, FIII, and FIV (Figs 3, 4) are the boundaries of the main central block The Nui Chua dome – block mountains were uplifted in the Quaternary tectonic period to form the central block 800–1039 m high (the top of Nui Chua Mount.), and lower to both sides are the 400–800 m and 100–400 m high The sub-longitudinal faults are clearly shown, which are the boundaries of small blocks and orient many sections of the coast, in which faults F2, F3, and F4 were confirmed by field survey (Nguyen-Van et al., 2020; Trinh et al., 2015) The NW-SE faults are oriented to stretch the bays such as Cam Ranh bay, Vinh Hy bay, and Dam Nai lagoon The sub-latitudinal faults are the least obvious 1 Download : Download high-res image (716KB) Download : Download full-size image Fig The fault systems in Nui Chua National Park Download : Download high-res image (262KB) Download : Download full-size image Fig A part of Nui Chua Mountains is graded by the fault boundary Source: Nui Chua National Park Dome – block mountains are common landforms on the Vietnamese mainland (Le & Uong, 2012) Another outstanding scientific value of this geomorphosite is the processes of denudation on the intrusive rock along with fault systems These fissures created specific terrains such as two-stage development of boulders, cliffs, rock-hanging lakes (Fig 5), rock water streams (Fig 6), bay, and waterfall The Nui Chua Mountains ecosystem is diverse with six ecosystems ranging from land to sea It has a dry forest ecosystem, which is typical of Vietnam and Southeast Asia (Le & Nguyen, 2012) The spectacular trekking route through Nui Chua that passes through the geomorphological landscapes from mountains to coastlines with these ecosystems has been carried out by many groups of adventurous tourists (Fig 7) One of the most popular trekking routes is the one from the National Park headquarters to the top of Nui Chua Mountains in days and nights with a total length of about 19.5 km The trekking route is designed to go through the geomorphosites from the coast of Rai Cave, Lo O stream, O Lim valley, through the topographic steps of Mount Chua such as grassland, rockhanging lake, to the top of Mount Chua Anh (Co Tuy) where a panoramic view from the highest peak of the park can be observed The landscape and ecology are additional values of Nui Chua National Park Download : Download high-res image (249KB) Download : Download full-size image Fig Hanging lake Source: Nui Chua National Park Download : Download high-res image (419KB) Download : Download full-size image Fig Lo O rock water spring Source: H.T.P.Chi Download : Download high-res image (408KB) Download : Download full-size image Fig Trekking in Nui Chua National Park Source: Nui Chua National Park 4.2.2 Tectonic – abrasive coastline Rai Cave Rai Cave is a famous tourist destination of Nui Chua National Park Two geomorphosites that attract tourists the most are the intrusive rocky coast and ancient coral reef The rocky coast is a fault stretching in the sub-longitudinal direction (Fig 8), including many types of landforms such as sea cliffs, balanced rocks, falling rocks, caves The seawall profile shows the balanced rocks pattern, a typical landform developed in intrusive rock corresponding to the second phase (Point A in Fig 8) and third phase (Point B in Fig 8) according to Geikie's classification (Twidale & Vidal Romaní, 2005) The activities of denudation in the Rai Cave coastline are strongly underway with the formation of steep cliffs and large residual boulders The space between falling rocks often forms caves These caves were once inhabited by otters, and therefore, this place had the name “Rai Cave” – which means Otters' cave Download : Download high-res image (532KB) Download : Download full-size image Fig Sub-longitudinal rocky coast, A – Orthogonal fissures (vertical and horizonal) on a vertical wall); B – Expansion crack, falling rock blocks leaving balanced rocks; C – Rock falls accumulating at the bottom; D – Ancient coral terrace Source: Ha Quang Hai The ancient coral terrace is located at the cliff base (Fig 9), has an area of about 2000 m2, the platform is quite flat, 4–5 m high above sea level Noteworthy, the ancient coral reef contains various limestone micro-landforms which attract tourists such as razor-sharp; jagged coral rock (Fig 10); bio-abrasive pits (Fig 11); pot holes and heart pits which were formed due to salt weathering There is no data on the age of the terrace, but by comparing the elevation, this terrace is equivalent to Ca Na 2nd terrace, where the corals have an absolute age of 4500 ± 250 years (Le & Uong, 2012) and were formed in the maximum Flandrian marine transgression Aesthetics are the outstanding additional value of Rai Cave geomorphosite The great seascape at dawn and dusk Especially during the -wavy days, visitors can admire the waterfalls when the seawater overflows the ancient coral terrace (Fig 12) Scientific and aesthetic value shows that Rai Cave is the only rare and unique geomorphological heritage of Vietnam Rai Cave was chosen to be the Nui Chua National Park Management Board headquarter, where visitors can learn about the National Park and its forest and marine conservation efforts 1 Download : Download high-res image (257KB) Download : Download full-size image Fig Ancient coral rock terrace Source: Ha Quang Hai Download : Download high-res image (247KB) Download : Download full-size image Fig 10 Razor-sharp, jagged coral rock Source: H.T.P.Chi Download : Download high-res image (204KB) Download : Download full-size image Fig 11 Wave-cut notch in ancient coral terrace Source: Ha Quang Hai Download : Download high-res image (145KB) Download : Download full-size image Fig 12 Waterfall into sea Source: Thien Thach (Hang Rai - Ninh Thuan once and forever | TTC Resort - Ninh Thuan [WWW Document], 2020) 4.2.3 Lang Choi abrasive marine terrace The abrasive marine terrace is known as Lang Choi Stone Park and is located in Vinh Hai commune, Ninh Hai district Lang Choi Stone Park has a total area of about 90 ha, 80–100 m above sea level The cliffs in the stone park are steep 70–80 degrees, and oriented in a longitudinal direction as fault F4 in Fig 3, Fig 13 The fissure system is dominated by fault F4 direction, which can be seen clearly in the topography (Fig 14) On the roof of the terrace, there are various sizes and shapes of granite boulders The most popular tourist attraction is ‘Da Trung’ (means egg stone, Fig 15), ‘Dau Nguoi’ (means head), ‘Con Vit’ (means duck), and ‘Cu Hanh’ (means onion), which were named based on the shapes of boulders The biggest balanced rock is called ‘Than Quyen’ (means theocracy, Fig 16), and it is chosen as the symbol of Nui Chua National Park The ‘Than Quyen’ rock is the slightly less wellrounded boulder, nearly 6,0 m in diameter This rock was finely balanced, and therefore, the ‘Than Quyen’ rock is a visual model that explains the formation of denuded – lithological – tectonic terrain and balanced rock, the typical landform of this area If in Rai Cave, we can observe the formation of boulders in the 2nd and 3rd stage (Fig 8, Fig 17 ii, iii), in Lang Choi Stone Park, this process belongs to the 3rd stage (Fig 17 iv) due to differential erosion of the differentiated mass, leaving the core stones as boulders (Fig 18) (Geikie's (1894) sketch in Twidale & Vidal Romaní, 2005) The physical and chemical weathering process resulted in the very impressive formation of the tafoni on granite (See Fig 19, Fig 20.) Fig 13 Sub-longitudinal direction cliffs as F4 fault Source: Le Tu Thanh Download : Download high-res image (292KB) Download : Download full-size image Fig 14 Sub-longitudinal joint Source: Ha Quang Hai Download : Download high-res image (212KB) Download : Download full-size image Fig 15 Balanced well-rounded boulder in Lang Choi Stone Park Source: Ha Quang Hai Download : Download high-res image (234KB) Download : Download full-size image Fig 16 Orthogonal fissures on ‘Than Quyen’ boulder (vertical and horizontal) – Symbol of Nui Chua National Park  ... Fig Geomorphosites of Nui Chua National Park – Ninh Thuan Province Table Summary of scientific value and additional value of geomorphosites in Nui Chua National Park, Ninh Thuan Province Geomorphosites. .. Trekking in Nui Chua National Park Source: Nui Chua National Park 4.2.2 Tectonic – abrasive coastline Rai Cave Rai Cave is a famous tourist destination of Nui Chua National Park Two geomorphosites. .. in Nui Chua National Park Download : Download high-res image (262KB) Download : Download full-size image Fig A part of Nui Chua Mountains is graded by the fault boundary Source: Nui Chua National