Introduction

The Sarawak Delta which comprises the lower part of the Sarawak River basin is located in the Kuching and Bau districts. Recently, this area was proposed as the Sarawak Delta Geopark which covers most of the Sarawak River basin and its tributaries. The proposed Sarawak Delta Geopark area comprises Bako, Santubong, Sarawak River Delta, Serapi, Bau and Padawan with an approximate coverage of 1000 km2 (Fig. 1). The area is selected due to its richness in geological diversity, and also it represents a good example of interactions between geoheritage resources, communities, cultures and the environment. Furthermore, the uniqueness of delta morphology has never been used in any geopark establishment elsewhere.

Fig. 1
figure 1

The proposed Sarawak Delta Geopark boundary within the Sarawak River basin

Full size image

The sustainable development concept for the Sarawak Delta was triggered by deep concerns regarding environmental degradation, based on recommendations on broad and solid scientific evidence. Sustainable development can be defined as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’ (World Commission on Environment and Development 1987). This is a new paradigm and concept for articulating the process of development to replace a past development perspective, with one more comprehensive and integrated from various aspects, particularly through the establishment of relevant policy (Hadi et al. 2010; Wikipedia 2015). So far, this concept has successfully addressed key issues in policy pertaining to environments globally. Sustainability sciences, a related subject established to derive some impetus from the concepts of sustainable development and environmental science, provides a critical framework for sustainability as well as to guide sustainability governance (Komiyama and Takeuchi 2006; Soederbaum 2008). The concept of a geopark is to support the principles of sustainable development. It has been proven and shown by successful geoparks such as Langkawi Global Geopark in Malaysia, Unzen Volcano Geopark in Japan, Jeju Island Geopark in South Korea and other established global and national geoparks in Asia-Pacific and European countries.

Geological resources have very important roles in development, economy, social and community well-being. In Malaysia, the mineral industry has undoubtedly been a major contributor to economic, social and industrial development. In their latest annual report, the Malaysian Mining Institute forecasted that Malaysia’s mining industry would reach MYR135.2 billion by 2018, increasing at a rate of 5.0 % per annum (Malaysia Mining 2014), while in the 2012 report, they forecasted that values will reach MYR109.3 billion by 2016. An annual average growth of 1.1 % from 2011 is estimated at MYR103.7 billion (Malaysia Mining 2012). The oil, gas and energy sector has been the mainstay of Malaysia’s growth and contributes to approximately 20 % of national gross domestic product (GDP), estimated to raise total gross national income (GNI) contribution to RM241 billion by 2020 from RM110 billion in 2009 (Economic Transformation Plan (ETP) Annual Report 2012; Tse 2015).

Despite its important role in many aspects including environmental management and natural resources, geology has never been properly linked with sustainable development. Hence, there have been little discussions about geology in sustainability sciences. Nevertheless, the concept of sustainability has been emphasised in geological resource management since the eighteenth century, and until the late nineteenth century, knowledge and understanding of geology remained low and limited in this context. Geology and geological resources were only known to have important economic values and have not been viewed from other perspectives. Furthermore, Earth scientists, or geologists, are often not familiar with nature conservation theory. They have typically have had little knowledge of aspects of the development of conservation strategies and policies, particularly as they relate to geoconservation (Pemberton 2007). Only recently have a few sustainability approaches been introduced to geologists such as in the publication on quarries and quarrying: ‘Sustainable Development, Green Technology and Best Practices’ (Institute of Quarrying Malaysia 2013). Sustainability approaches with regards to the geological heritage or geoheritage and its conservation have been discussed since the early 1990s, and recently both concepts have become the focal points of extensive discussions by various agencies either internationally or nationally (Brocx and Semeniuk 2007; Reynard 2008; Gray 2008).

Geoheritage sites are derived from geodiversities in which the geological aspect is the fundamental. In tandem with the sustainable development concept, geoheritage is a defined component of geodiversity that is important to human beings (and communities) for purposes other than resource exploitation, i.e. things we would wish to retain for present and future generations (Sullivan 1997; Eberhard 1997). Various studies, including Komoo (2000), clearly indicate that ‘geoheritage value is strongly linked to scientific value in terms of scientific records for research and education; however, some of geoheritage resources, particularly mineral, fossil and unique landform features, can also be associated with aesthetic, recreational or cultural values’. The geoheritage concept involves proper identification, characterisation, assessment and ranking of significant geoheritage sites or geosites based on their scientific, aesthetic, cultural and recreational heritage value. It is the concept that comprises existing cases of geodiversity, identified as having conservation significance (Gray 2004). Geoheritage sites are flexible and not necessarily located within the conservation area; however, the effort to conserve geoheritage sites in general (either within or outside the conservation area) would need the geoconservation approach.

Most writers consider geodiversity in a similar way to that defined by Gray (2004) as follows: ‘the natural range (diversity) of geological rocks (rocks, minerals, fossils), geomorphological (landform, processes) and soil features, includes their assemblage of features, relationships, properties, interpretations and systems’. Prosser (2002) defined geological diversity as the variety of rocks, fossils and minerals and natural processes. Some additional diversity should also be included, comprising landforms, primary and secondary structures, geological processes and ex mining sites. At one stage, following the introduction of the term geoconservation for the protection of geological features for their intrinsic, ecological and geoheritage value (Sharples 1995), the term geodiversity was coined and appeared to replace the term geoheritage (Brocx and Semeniuk 2007). Some authors like Kiernan (1990) and Eberhard (1997) made geodiversity analogous with biodiversity. But the effort was strongly rejected by many others. Brocx and Semeniuk (2007) suggested that the use of the term geodiversity, which etymologically means ‘the diversity of geological features’, should be applied only to region-specific or site-specific features and it should not be used to mean ‘diversity of all things geological’ because the term geology is broad enough in scope and scale (as discussed above) to carry that implication.

The first use of the term ‘geoheritage’ by Bradbury (1993) considered geoheritage to mean those aspects of the Earth which are important to our understanding of its history—the nature of geoheritage sites, which are akin to cultural heritage sites or documents, meaning that they are non-renewable resources. Subsequently, there are many definitions of geoheritage that have been introduced by various researchers (Dixon 1995; Sullivan 1997; Semeniuk 1997, 1998, 2001; Osborne 2000; Komoo 2000; Cook et al. 1998; Anon 1999; Sharples 2002; Gray 2004; Conservation and Land Management 2005, summarized in Brocx and Semeniuk 2007). Meanwhile, the term geological heritage was used as the title of the first conference on geological conservation, the ‘First International Symposium on the Conservation of our Geological Heritage’ which took place in Digne, France (Anon 1991; JNCC 1994), and was adopted by others (Joyce 1997; Zagorchev and Nakov 1998; Gonggrijp 1999; Brilha 2002; and McBriar 1995 cited in Brocx and Semeniuk 2007). In a broader sense, geoheritage integrates all sub-disciplines in geology such as geomorphology, stratigraphy, palaeontology, mineralogy, structural geology and landscape heritage, as well as places and materials connected to geosciences and its progress. Conservation efforts for geological heritage are considered to be a sustainability approach for utilizing geological resources. Both geoconservation and geotourism are the products of geoheritage conservation.

In the proposed Sarawak Delta Geopark, various geological formations are fundamental for the geoheritage diversity. Existing geological sites which have been identified and described are considered to be significant geoheritage sites with high value and rank. The aim of this paper is to establish further understanding of the sustainable geological heritage development approach in Sarawak Delta Geopark, with emphasis on the geological sites in areas dominated by clastic and carbonate sedimentary rocks in Bako and Bau, respectively. It also aims to promote the sustainable development of geological resources through conservation of geoheritage and to implement the sustainability concept in resource utilisation.

Geology and Landscapes of Sarawak River Basin

The proposed Sarawak Delta Geopark is underlain by various geological formations (Fig. 2). They form an appropriate foundation for the occurrences of geodiversity in the proposed area. The area is underlain by Tuang Schists (Pre-Upper Carboniferous, 360 Ma), Jagoi Granodiorite (Early Jurassic, 195 Ma), Sadong Formation (Upper Triassic, 235–208 Ma), Serian Volcanic (Upper Triassic, 228–208 Ma), Sejingkat Formation (Jurassic-Cretaceous, 200–125 Ma), Bau Limestone (Upper Jurassic-Lower Cretaceous, 152–139 Ma), Pedawan Formation (Upper Jurassic-Upper Cretaceous, 150–83 Ma), Kayan Sandstone (Upper Cretaceous-Eocene, 83–47 Ma), Plateau Sandstone (Upper Eocene-Early Oligocene, 38–28 Ma), igneous intrusive (Neogene; Lower Miocene, 23–15 Ma) and Quaternary alluvium (2.5–0 Ma).

Fig. 2
figure 2

Geological map of the proposed Sarawak Delta Geopark and surrounding area (modified after Yin EH 1992; Hon 1975, 1976; Tan 1993)

Full size image

The Tuang Schists are the oldest rock formation in the area and are composed of phyllite, quartz schist, quartz-mica schist and sometimes quartz-epidote schist, quarza-actinolite schist and metasandstone. It covers areas such as Kampung Bintawa, Bako-Petrajaya road, Penrissen road, Kenyalang Park and Kota Samarahan. Two genera of foraminifera fossils (Glomospira and Gaudryina) and possibly tentaculitids extracted from the phyllite indicate a broad age ranging from pre-Upper Carboniferous to the Valanginian, Barremian and Albian stages of the Lower Cretaceous (Tan 1993). The Sadong Formation is the second oldest rock formation found in the area and is mainly represented by the Serin Arkose Member (the lower sequence of the formation) which is dominated by massive feldspathic sandstone and is sometimes interbedded with thin hard grey shale layer. In the Late Triassic (Carnian to Norian), Halobia sp. and Monotis sp. have been identified as index fossils for Sadong Formation (Pimm 1965; Wilford 1955). The Serian Volcanics are the only volcanic rocks found in the area, and their composition varies from acidic to alkaline comprising andesite, dacite, trachite, pillow basalt, pyroclast, breccia and tuff. The Semabang Member which is the upper unit of the Serian Volcanics is made up of dacite, rhyolite, tuff and breccia interbedded with shale, sandstone and chert. The Serian Volcanic area was believed to have originated from calc-alkaline and high-K calc-alkaline magma (Kirk 1968; Hon 1976). In some places, the Serian Volcanics are intruded by younger Miocene (15 Ma) tonalite stocks and microtonalite dykes and sills. The Sejingkat Formation is made up of a thick sequence of thinly bedded to massive chert and metachert in places, chaotically associated with metabasalt, metadolerite and gabbro, and small amounts of strongly contorted, sheared black phyllite, feldspathic sandstone, tuff, schists, metagreywacke, microdiorite and andesite. Radiolarian chert from Bako headland contains Archicorys, Cenosphaera, Dicolocapsa, Dictyomitra, Flustrella and Stylostaurus of the Jurassic-Cretaceous age (Wilford 1965), most of which are poorly preserved and cannot be properly assigned to any specific age (Jasin 2000). The Sejingkat Formation is considered to be part of a melange due to its highly tectonised and chaotic occurrence.

The Bau Limestone is widely distributed in the Bau-Padawan area and is generally composed of massive interbedding of pale grey pure limestone with some dark grey bedded argillaceous limestone. Its basal Krian Member occurs locally in Bau with lithologies comprising thin sandstone, shale and conglomerate sequence. The Bau Limestone has a high diversity of landscapes with impressive karstic hills and caves, rich in both fossils and geological structures. Fossil diversity includes foraminifera, calcareous algae, corals and rudist bivalves which indicate that the limestone ranges from Late Jurassic to Early Cretaceous (Wolfenden 1965; Wilford and Kho 1965; Bayliss 1966; Yanagida and Lau 1978; Beauvais and Fontaine 1990). Structural diversity within the Bau Limestone can be seen as Paku Anticline, Skiat Syncline, Tangan and Sirenggok Syncline and the various faults; Tai Parit, Krian, Tabai, Songsang Tongga, Lanyang, Totag, Saboa, Tai Ton, Johara, Pides and Gumbang fault; and Karang Bila Dome and Pangga Dome (Wolfenden 1965).

The Pedawan Formation consists of mainly shale interbedded with mudstone and sandstone, with minor occurence of thinly bedded siltstone, argillaceous radiolarian limestone lenses and conglomerate. Based on foraminiferal assemblages, the Pedawan Formation was divided into three sub-units namely lower, middle and upper sections (Wilford and Kho 1965). The occurrence of some foraminifera, ammonoid, radiolarian, algae and plant fossils indicate a Late Jurassic-Late Cretaceous age (Wilford and Kho 1965; Hashimoto and Matsumaru 1977; Muller 1968; Ishibashi 1982). The Kranji Sandstone Beds form the thinly to thickly bedded quartz arenites near the base of Pedawan Formation at Kranji hill, Batu Kitang-Bau road (Hon 1975, 1976; Yin EH 1992). The Kayan Sandstone is characterised by cross-bedded, medium to coarse-grained massive sandstone with minor amounts of conglomerate and thinly bedded black, reddish and grey mudstone. Its lower part was assigned to the palynology zone of Rugubivesiculitest, whilst the upper part is equivalent to the Proxapertites and Retitriporites variabilis zones which indicate a Late Cretaceous-Eocene age for the whole of the Kayan Sandstone (Wolfenden and Haile 1963; Muller 1968). Wood fossils are abundant within this formation particularly in the Bungo Highland area with species such as Palmoxylon cf. lacunosum (Unger), Palmoxylon sp., Ficoxylon sp. and Phyllocladoxylon sp. (Wilford 1955). These fossils are commonly found along the river bed of this area. The Plateau Sandstone which is dominated by sandstone and conglomerate, with a few shale and siltstone layers, occurs only within the Bako Peninsular. The presence of highly matured kerogen of angiosperm-derived tricolporate/tricolpate pollen indicates that the Plateau Sandstone is of Late Eocene age (Johansson 1999). Wood fossils have been found at several localities within this sandstone (Wilford 1965; Badang 2010). Primary structures such as convolute structures, cross beds, slump folds and trough cross lamination are abundant. At some localities, the Plateau Sandstone forms quartz-feldspatic and sometimes pelitic hornfels when it is in contact with intrusive rocks (Tan 1993).

Igneous rocks with ages ranging from Palaeozoic to Quaternary are represented by the Jagoi Granodiorite and Neogene igneous rocks, mainly granodiorite, diorite, tonalite, microgranodiorite, microdiorite, microtonalite and dacite, rarely rhyolite and basalt. The Jagoi Granodiorite represents the earliest igneous activity in Borneo and occurs in the Bau District. The rock is characterised by the I-type granodiorite with coarse to medium-grained leucocratic, grey to pale green in colour (Ting 1991). The granodiorite forms the Jagoi and Kisam ranges that extend southwest into West Kalimantan, Indonesia. Radiometric dating on biotite and hornblende indicates that the Jagoi Granodiorite is of Early Jurassic age (195 ± 2 Ma) (Tate 1991). The latest igneous activities, mainly post-orogenic intrusions during and after the Miocene, include dykes, sills, stocks and laccoliths, intruded into most older rock formations. These intrusives are dated as of Late Paleocene to Miocene age (58 to 16 ± 4 Ma) or most probably Pliocene (Wilford and Kho 1965; Kirk 1968). Quaternary deposits are the youngest geological units that cover almost half of the proposed Sarawak Delta Geopark area. These deposits comprise unconsolidated material of deltaic, fluvial, estuarine and coastal sediments such as residual soils, collovium, alluvium, terrace deposits, delta and river mouth sand and mud, flood plain and paludal mud and silt (Tan 1993; Lam 1998).

The distribution of different rock formations within different tectonic terrains has resulted in the formation of various significant landscapes within the Sarawak River Basin. Five main geological landscapes have been identified within the area (Fig. 3). They are isolated coastal hills and islands, flat coastal plains, low and undulating hills, limestone karsts and highlands.

Fig. 3
figure 3

Geological landscape of the proposed Sarawak Delta Geopark including Bako and Bau at Northeastern and Southern part of the area, respectively

Full size image

Geoheritage Conservations and Geosites in the Context of Delta Sarawak Geopark

The Bako, Santubong, Sarawak River Delta, Serapi and Bau areas host many geological sites with high values and ranks which can be considered as significant geological heritages or geosites (Ali et al. 2014; Badang 2010). However, only geological sites in the Bako and Bau areas represent clastic and carbonate sedimentary rocks respectively and will be highlighted further in this paper.

During inventory and preliminary general qualitative assessment, several significant geoheritage sites (geosites) have been successfully identified (Fig. 4, Table 1 and Figs. 5, 6, 7, 8, 9, 10, 11 and 12). Each significant geoheritage site consists of several important geological features. Apart from its highly significant scientific values, geoheritage sites also serve the public interest. Geoheritage needs to be promoted and interpreted to suit a wide spectrum of population. These steps are necessary for geoconservation and geotourism, which are considered the two main approaches in sustainable geoheritage research development. Many geoheritage sites have the potential to become tourist destinations, and they serve as local and regional economic engines that show the interdependency between the economic and the environmental system. Again, this is another continuous sustainable development effort to conserve part of the nature while at the same time gaining profits from the environmental resources. This is another scenario in which geoheritage concept development can contribute towards the sustainability used and conservations in the proposed Sarawak Delta Geopark.

Fig. 4
figure 4

Significant geosites indicating geodiversity, significance and heritage values in Bako and Bau within the proposed Sarawak Delta Geopark (the geosites’ number is referred to the list in Table 1)

Full size image
Table 1 Significant geosites in Bako and Bau area, part of the Sarawak Delta Geopark
Full size table
Fig. 5
figure 5

Teluk Assam geosites, Bako: a Teluk Assam cliff, showing geological strata, b Secondary structure, liesegang, c Teluk Assam cliff, viewed from North, d an erosional product resembling eagle head at Tanjung Sapi, e Mega scale tabular cross bedding, f pot holes, g Padang Batu Plateau, the horizontal sandstone surface, h sunset view from Assam River mouth

Full size image
Fig. 6
figure 6

Teluk Pandan geosites, Bako: a Teluk Pandan Kecil beach and cliff, b sea stack and remnant island at Tanjug Batu Belah, c Bako Sea stack, d a beach ridge dissected by a stream, e mushroom rock, f Batu Belah headland, g Teluk Pandan Besar beach, viewed from southwest plateau, h a cliff showing a magnificient geological strata at Teluk Pandan Besar

Full size image
Fig. 7
figure 7

Pulau Lakei geosites, Bako: a sandy beach at southern part of Pulau Lakei, b Tanjung Pak Amit viewpoint, c abrasion platform, d convolute structure of Plateau Sandstone, e thick sandstone cutting by major geological structure (fault), f sandstone pillar near coastal cliff of Pulau Lakei, g black wood fossil embedded in the lower part of pebbly sandstone at Teluk Limau, near Pulau Lakei, h engraved writing on sandstone surface (indicated by red arrow) at Salamun Pond

Full size image
Fig. 8
figure 8

Tanjung Rhu geosites, Bako: a abrasion platform on the surface of sandstone, b wood fossil at bottom part of coarse sandstone layer and tabular cross bedding, c a series of major jointed sandstone layers near Teluk Tajor, d Pasir Merah (red sand) beach, e iron concretion in sandstone, f perched boulder near Teluk Tajor, g isolated abrasion platform, h sandstone arch at Teluk Tajor

Full size image
Fig. 9
figure 9

Wind-Fairy Cave geosites, Bau: a a chamber in Fairy Cave, upper part Gunung Kapor, b brecciated limestone at the lower part of Gunung Kapor, c main passage in Fairy Cave, d limestone pinnacle field near Gunung Kapor, e one of the passage in Wind Cave, f wood fossil gallery at Gunung Kapor, g fossils in Wind Cave

Full size image
Fig. 10
figure 10

Karst morphology in Bau area: a dissected limestone hills, Gunung Tabai near Krokong, Bau, b NW-SE Tai Ton Fault divided Gunung Tai Ton and Gunung Tabai, c rockface of Gunung Staat facing Southeast, d Gunung Staat, viewed from Northeast, e erosional feature (notch), Wind Cave, f limestone pinnacles near Kampung Skiat

Full size image
Fig. 11
figure 11

Ex-mining geosites, Bau: a Bukit Young gold mine site office, b Tasik Biru, the main ex-mining site for gold, c former stibnite processing plant, d, e scattered abandoned structures, f abandoned stibnite ore

Full size image
Fig. 12
figure 12

Tai Ton geosites, Bau a–d Gunung Apin tunnel, Tai Ton (a), mineralisation zone inside the tunnel (b), central entrance of the tunnel in Gunung Apin (c), northwest end of the tunnel in Gunung Apin (d); e a boulder related to local myth, Batu Kulat Kampung Podam, f Pedawan Formation strata and a sill

Full size image

Geoheritage will bear no meaning without recognition and further development. Geoheritage research is the systematic approach to the proper identification, mapping and characterisation of geological features along with significant scientific, educational, cultural or aesthetic values (Unjah 2011). This must be followed by the development and continuous maintenance of the site as a nature geoconservation and geotourism spot.

Geoconservation

Nature protection is always easily considered and tends to become a very common trend in both planning and policy-making circles. However, it is almost exclusively focussed on the conservation of biodiversity while very little attention is given to non-living or abiotic resources such as geological resources. Various geological resources (geodiversity) such as important rock, mineral and fossil sites are non-renewable and cannot be restored once destroyed. This justifies that geological resource (abiotic) conservation should be given a priority. Geological conservation or geoconservation involves preservation and conservation of the valuable and significant geological features. It complies with the early definition of geoconservation by Legge and King (1992) as protection of significant geological and landscape features because of their scientific, educational, research, aesthetic and inspirational value to humans. Later, the integration of geoconservation with geoheritage and geodiversity is discussed by various authors such as Sullivan (1997), Semeniuk (1997, 1998 and 2001) and Sharples (2002). Gray (2005) stated that geodiversity should be conserved for two main reasons i.e. its values and threats, which leads to a simple formula: Value + Threat = Conservation Need; therefore, the first step towards the conservation of geoheritage or geoconservation is to recognize all possible threats and values though threats are not the only reason to conserve geodiversity.

Geoconservation involves the identification and conservation of geodiversity for intrinsic, ecological or heritage values (Dixon 1995). Though the term geoconservation has not been universally accepted, the basic aim of geoconservation is to conserve well-developed and well-expressed representative examples of important elements of the geodiversity found in a region. Geoconservation is defined as ‘the dynamic preservation and maintenance of geosites’ and lies more in the availability and accessibility of these sites rather than concern with damage or loss (Hose 2005). Geoconservation can then be determined as the endeavour of trying not only to conserve geodiversity and geoheritage (Sharples 2002) but also to enhance and promote geological and geomorphological features, processes, sites and specimens (Burek and Prosser 2008). Geoconservation is a proper approach for conserving geodiversity and geoheritage sites (in the form of geosites, geomorphosite, etc.) for future generations. It is appropriate with an understanding of sustainable development as defined by World Commission on Environment and Development (1987). This will reaffirm the influential contributions of the geoconservation concept in sustainability and conservation.

Most of the protected areas in Sarawak focus on biological objects rather than geological, resulting in a higher number of protected areas based on biological aspects. However, the Bako National Park and Bau area possess both geological and biological diversity. Apart from many geosites, there are also a large number of endemic and relict plant species. The geoconservation concept is applicable in all areas either within or outsite existing protected areas (National Park and Nature Reserve). In the case of the proposed Sarawak Delta Geopark, at least three areas with a different status have been identified i.e. (1) the existing protected area (existing National Park and Nature Reserve), (2) forest (permanent) reserve and road reserve and (3) private land. All geosites within these areas are subjected to the jurisdiction of existing Acts such as National Parks and Nature Reserve 1998, Sarawak Cultural Heritage Ordinance 1993 and National Heritage Act 2005. The geoconservation approach for geosites within protected areas is relatively easy. It would involve the permission and management of the existing National Parks and Nature Reserve according to existing Acts and Enactments. However, the geoconservation approach for the geosites located within forest and road reserves requires permission from the relevant state authorities such as Land and Survey Department, Public Works Department (Jabatan Kerja Raya-JKR) and local councils. Geoconservation development of any geosites located in private land would require a mutual agreement between the developer and the land owner to benefit both parties with guidance by local authority. Almost all of the significant geosites in Bako and Bau (Table 1) have a high potential to become geoconservation sites in the Sarawak Delta. Various significant geosites have also been identified in areas such as Santubong, the islands, the delta complex and Bungo Highland.

Sustainable Development of Geoheritage Resources through Geopark and Geotourism

Geopark

The geopark concept arised in the mid-1990s as a response to the needs to conserve and enhance the value of areas of geological significance in Earth history, and this initiative was successfully created in 2004 by 17 members of the European Geoparks Network (EGN) and eight Chinese Geoparks came together to form the Global Geoparks Network (GGN) with the support from UNESCO (2006). Since then, the development of geopark evolution has been tremendously accepted by many countries and continents over the world. Guidelines have been formulated by UNESCO for those countries who are interested to join the GGN. The geopark concept has also been well accepted within the Asia-Pacific countries through the establishment of the Asia-Pacific Geopark Network (APGN) to support the GGN. In many Asia-Pacific countries, the development of geoparks is endorsed by the National Geopark Committee of the respective country. The Sarawak Delta is currently a National Geopark and is being developed to be an Aspiring Global Geopark. The inventory effort to identify the geological heritage resources site within the Sarawak Delta was started in the mid-2000. Various significant geosites have been located, mapped, characterised and assessed. Possible boundaries and the size of the coverage area also have been demarcated. For the collaboration and promotion initiative, few series of discussion with the stakeholders and related agencies, public awareness programmes also have been carried out.

A geopark is composed of single, unified geographical areas where sites and landscapes of international geological significance are managed with a holistic concept of protection, education and sustainable development (UNESCO 2014). It is an interdisciplinary development approach that would address some environmental aspects such as outstanding geological, geomorphological, biological, and cultural features which could be integrated. A geopark has become a development tool or branding of an area, taking into consideration the balance between nature-culture conservation, geotourism activities and local community well-being (Komoo 2010; McKeever 2010; UNESCO 2014). In Europe, beside its main objective to cooperate on the protection of the geological heritage and the promotion of sustainable development in their territories, the establishment of the geopark initiative through the European Geopark Network (EGN) became an alternative to overcome the problems of slow economic development, unemployment and a high level of emigration in France, Germany, Spain and Greece (Zouros 2004). While in Malaysia, by referring to the success of Langkawi Geopark, Leman et al. (2007) believed that the geopark concept has paved a clearer path for the geoheritage conservation agenda in Malaysia and a model for sustainable development of geological heritage resources. It could become a catalyst for future development of geoparks in this region. The Sarawak Delta Geopark could promote integrated conservation of its natural and cultural heritage, as well as to enhance tourism for the benefit of the socio-economy through sustainable development in Kuching and its surrounding area. Only through the geopark approach can these geological heritages be conserved, benefit, boost the local economy and enhance the educational level of the local people.

However, the process to become global geopark is not an easy task. Few very common issues always become obstacles and have to be addressed collaboratively. The three issues are the existing conservation entity, complete highly scientific geological resources and natural resource management procedures. Taking Malaysia as an example, the natural resource matters in each state are managed by respective state agencies using different ordinances and enactments. In West Malaysia, the Forestry and Wildlife Department are responsible for forest resources, while in Sabah and Sarawak, the Forestry Department is responsible for the forest resources in their respective state.

The challenge in developing a geopark within the existing conservation areas (National Park, Nature Reserve, etc.) is also different compared to the new and unprotected areas. For example, Langkawi does not have single conservation entities except the permanent forest reserve. Establishment of new conservation areas by various agencies is easily accepted by the local community with less conflict. However, the scenario could be different for other proposed geoparks, particularly for Sarawak Delta where conflict of interest might arise between the earlier established national park. The proposed Sarawak Delta Geopark comprises five national parks, including one RAMSAR site and a few nature reserves, facing similar challenges. The Sarawak Delta Geopark comprises areas gazetted by a state agency. Though there are various geological heritages of high values within both areas, the conflict in terms of the rights for management might arise if there is no proper development plan being formulated. In the earlier plan, several areas such as Gunung Kinabalu, Sarawak Delta, Kinta Valley and Kenyir Lake were proposed to become geoparks. However, the processes to develop these proposed geoparks are still very slow due to some obstacles and none of them have yet achieved geopark status at the moment.

Geotourism

Geotourism’s first widely published definitions (Hose 1997; 2000) were specifically related to on-site interpretative provision for the purpose of geoconservation, but most of the following literature indicated that geotourism is related to geology and landscape (Dowling and Newsome 2010; Geological Society of Australia 2015 cited in Ng 2015). According to the latest consolidated definition by Ng (2015), geotourism is defined as responsible travel to areas with interesting geology and geomorphology for appreciation, enjoyment and learning which results in conserving the environment and improving the well-being of local people. Over the past 15 years, geotourism has invariably had a geological basis and encompassed an examination of the geological feature, interpretation and promotion of geosites and geomorphosites (Desa 1990, 1995; Desa and Badang 1999; Badang et al. 1997; Badang 1999; Komoo 2000; Allan 2011; Allan et al. 2011; Hose 2012; Dowling 2012). Komoo and Mohamad (1993) built up a definition of Tourism Geosciences as a proposed new branch of applied geosciences that deals with applications of geological knowledge in developing ecotourism through systematic characterisation of new areas and enhancing the appeal of existing tourist destinations. Tourism Geosciences has been offered as an option at the School of Environmental and Natural Resources Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, (Desa 2000a, b).

Geotourism is not just about geology; it also covers many aspects. Ever since it was developed in the UK in the late 1980s, geotourism has gain recognition from many agencies such as schools, universities and museum geologists; moreover, recently, it has become an important element recognized by the geopark authorities over the globe such as Global Geopark Network (GGN), European Geopark Network (EGN) or Asia Pacific Geopark Network (APGN) as well as national geoparks in countries such as Japan and China. Geotourism activities are an important component for the development and establishment of geoparks. In the latest development, Ng (2015) relate geotourism with four key elements: well-being of environment and people, sustainability and responsibility, enjoyment and learning and geology and landscapes. He also listed six important principles in geotourism: must be a sustainable form of tourism environmentally, economically and socio-culturally; must have geology, but not limited to geology; must promote geosciences and geoconservation; must be beneficial to local people and have their engagement; must be fun and enjoyable, providing unforgettable experiences to tourists; must involve excellent interpretation in disseminating geological knowledge in an understandable way and must be able to arouse interests of tourists.

The geotourism establishment is to encourage repeat visitors/tourists (Badang 1999; Badang et al. 1997; Komoo and Mohamad 1993, 1997). The study towards a better understanding of motivations for a geotourism experience from a Self-Determination Theory (SDT) perspective for respondents in Jordan and Australia by Allan (2011) revealed that the main intrinsic intention was for various reasons including ‘to escape from the hustle and bustle of the daily life routine’, ‘relaxation’, ‘enjoyment’, ‘a sense of wonder’ and ‘gaining knowledge’. Another results from the same study also revealed that the intrinsic motivation and identification were significant predictors of the behavioral intention (loyalty) to revisit geosites (visit geosites repeatedly).

Geotourism is the product of geoconservation by transforming geoheritage and geoconservation into profitable effort whereby particular attractions are the various selected geosites. This sustainable transformation approach is also known as unconventional utilisation of geological resources rather than conventional which has included extracting geological resources since the previous centuries. This is how the environment provides humans with goods and services through different inputs for economic activities from the geological resource aspect. Establishment of the geotourism concept clearly indicates its contribution towards conservations efforts and sustainable utilisation. Being an important component of geopark development, geotourism is highly considered as a sustainable tourism product i.e. the best tourism alternative as opposed to mass tourism which allowed large numbers of people in a short span of time to places of interest.

Most of the geosites in Bako National Park (Table 1) have a high potential for geotourism since they are located near existing trails, close to accessible beaches and along frequently used transportation (boat) routes. However, other basic infrastructures such as signage boards and descriptions (in layman terms) are urgently needed for visitors to understand the geological and landscape attractions. Establishment of the new interactive geotrail or upgraded geotrail from an existing trail that contains various types of geosites is also recommended as an appropriate alternative. In Bau, most of the geosites are located near the main road or at least accessible by gravel road. The existing pathway in Fairy and Wind caves could be upgraded as mini-geotrail with additional signages and descriptions of geological inputs. The main geotrail with various geosites in the Bau areas including Bau Town (former mining town) is another possibility and highly recommended. The transportation modes are by road and nature trails.

Discussion and Conclusions

Natural geological aspects are very diversified, and this establishes a great geodiversity. In the Sarawak River basin, both the Bako and Bau areas clearly show important geodiversities in clastic and carbornate rock formations, respectively. As commonly defined in many literatures, the natural range (diversity) of geological materials (rocks, minerals, fossils) and geomorphological (landforms, processes) and soil features contributes to the richness of the geodiversity within the proposed Sarawak Delta Geopark. It includes their assemblages of features, relationships, properties, interpretations and systems (after Gray 2004); also ‘the link between people, landscape and culture: it is the variety of geological environments, phenomena and processes that make those landscapes, rocks, minerals, fossils and soils which provide the framework for life on Earth’ (Stanley 2001); ‘the range or diversity of geological (bedrock), geomorphological (landform) and soil features, assemblages, systems and processes’ (Australian Heritage Commission 2002) and ‘geological diversity or the variety of rocks, fossils and minerals and natural processes’ (Prosser 2002). Sharples (2002) links geodiversity with geoconservation and suggested that if ‘geodiversity’ is the quality we are trying to conserve, then ‘geoconservation is the endeavour of trying to conserve it’.

Since it became an academic discipline about 200 years ago, geology has made a valuable contribution towards our understanding of the history of the Earth and the evolution of life. The geological record contained in rocks and sediments provides evidence of billions of years of Earth history and which can be used to demonstrate evidence of continental movement, climatic change, changes in sea level and the evolution of present-day natural landscapes. Geology also has great impacts upon the human evolution, civilisation and environment as shown by the establishment of Bau Town linked to mining activities and the huge delta plain as a major urbanisation in the Kuching area. Geological and geological processes influence many aspects of human life such as location and distribution of the natural resources that support our everyday life; economic development at a local, regional and national level; natural and cultural landscape, land use and biodiversity; and understanding of the dynamic nature of the environment (mountain building, climate change, extinctions and geological hazards).

Special mapping and proper identification of geodiversity are needed for geoconservation and later on for geotourism development purposes. By doing so, the relationship between environment, economic and society can be established. This is in line with the understanding of sustainability with compact environment and society that involves physical aspects (exploitation) and an ethical attitude and which is affected by our technologies and way of life (Vucetich and Nelson 2010). Hence, geology and geodiversity if properly managed and developed can contribute to the sustainable utilisation of the geological heritage resources of Sarawak Delta.

Consensual definition of sustainability science is as elusive as the definition of ‘sustainability’ or ‘sustainable development’. Sustainability science derives from environmental complexity (Komiyama and Takeuchi 2006), after redefining the environment due to issues such as human health, economy, social justice and natural security (Lubchenco 2004) to help overcome global environmental changes to reach for global sustainability. The sustainable development concept was initiated after deep concerns for environmental degradation, and it was formulated based on recommendations on broad and solid scientific evidence. The sustainable development concept integrated the three important components namely economic, society and environment. It is simply a new way of articulating the process of development in place of the past development perspectives based on feudalism, mercantilism, capitalism and contestation from fascism, socialism and marxism (Hadi et al. 2010). So far, many key issues in policies particularly regarding environment at national and international levels have been successfully established. Through understanding of its importance, sustainability science has been established as an academic discipline to obtain and develop ideas and concepts for sustainable development and environmental science and to provide a crucial framework for sustainability and to guide sustainability governance.

Geology as the main and fundamental component in the Earth systems has become a very important element for study and could become a focal scope for research and development in sustainability science as well as in other natural fields. Directly, geology plays a major part in the environment and has important roles for social and community well-being, economic growth and development. A very close relationship between geology and sustainability science is stated in its broad-based definition below:

The cultivation, integration, and application of knowledge about Earth systems gained especially from the holistic and historical sciences (such as geology, ecology, climatology, oceanography) coordinated with knowledge about human interrelationships gained from the social sciences and humanities, in order to evaluate, mitigate, and minimize the consequences, regionally and worldwide, of human impacts on planetary systems and on societies across the globe and into the future—that is, in order that humans can be knowledgeable Earth stewards (Kieffer et al. 2009).

Geoheritage, geoconservation and geotourism concepts as described in this paper are part of a sustainable geological heritage development in the proposed Sarawak Delta Geopark area. Further description on geosites in the Bako and Bau areas as two important main geosites, including the three other sites (Santubong, Delta-Islands and Serapi), has shown that there is a diversity of significant geological heritages within the proposed Sarawak Delta Geopark area. Both Bako and Bau areas are considered to have the best representative localities of diverse geological heritage covering coastal and inland geological landscapes that offer many geological features for geoconservation, geotourism and geoeducation.

The establishment of a geopark could enhance sustainable geological heritage development efforts through the integrated development of the existing vast natural resources, cultural resources and already established conservation areas (e.g. National Parks and Nature Reserves). In conclusion, a geopark would have the best approach for the sustainable development for the Sarawak Delta as it can ensure the conservation of resources, promote awareness through education and elevate socio-economic status through geotourism.