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Geological Heritage Values of the Yongcheon Cave (Lava Tube Cave), Jeju Island, Korea
Abstract
Yongcheon Cave is a typical lava tube cave, which formed by multiple flows of lava during the Late Quaternary. However, it is also a lime-decorated cave with numerous splendid carbonate speleothems along two parts of the passage. This paper deals with these special unique features of the cave together with their formation processes and the geoheritage significance based on detailed investigation of overlying carbonate sand dunes and speleothems. The cave is about 3360 m long, composed of 2590-m-long main passage and about 370-m-long branch passages. Because the cave contains unexplored passages at the downstream end, it is estimated that the total length can be at least about 400 m longer. The cave contains various microtopographic characteristics such as multiple and various forms of lava coatings on the surface as well as dented features by thermal erosion. They include pahoehoe and aa lavas, rockfalls, lava falls, lava benches, gutters with overflowed lava levees, tube-in-tubes, and lava benches on the floor. Lava flowlines are prominent on the wall, and also, anastomosing branches, lava bridges, and multiple leveled floors are other distinctive morphological features. Carbonate sand dunes were formed by transportation of beach sands nearby and partially overlie two parts of the cave passage. Carbonate sediments are medium sand-sized and are mostly composed of mollusk and coralline red algae fragments up to 60~70% with a minor contribution of benthic foraminifers, echinoderms, bryozoans, and volcanic rock fragments, which may well represent typical temperate carbonate constituents elsewhere. Beach sediments, the source of carbonate dune sands, also show the similar texture and composition. This suggests that the dune sands were transported onto the area by wind along the valleys. Previous age dating results of four carbonate sand dunes including several paleosol layers imply the formation ages of the dunes at each site since the deposition of carbonate sands in shallow seas between 4700 and 6000 years BP due to full deglaciation after Last Glacial Maximum. Carbonate speleothems began to grow in the cave after the deposition of dunes. Detailed mapping of the cave and dune fields strongly suggest that the dune distributions are directly related to the formation of carbonate speleothems. A variety of carbonate speleothems are found in Yongcheon Cave such as soda straws, stalactites, stalagmites, columns, rimstones, flowstones, cave corals, draperies (curtains and bacon sheets), cave pearls, shelfstones, and moonmilks. However, many carbonate speleothems show erratic morphologies that cannot be seen in any limestone caves elsewhere. It is because the formation of erratic speleothems is directly influenced by distribution of plant roots which helped to transport rainwater into the cave and to precipitate calcite mineral. Their unique abundance of carbonate speleothems providing splendid scenic values as well as Jeju’s special geological conditions for their formation is considered to be the outstanding universal value for the World Heritage site.
... Globally, an increasing number of regions have this type of geoheritage and have achieved international recognition for protection (Gioncada et al., 2019). For example, the volcanic island of Jeju in South Korea (Woo et al., 2019) is the only site in the world listed as Biosphere Reserve (UNESCO, 2002), Natural World Heritage (UNESCO, 2007a), UNESCO Global Geopark (UNESCO, 2015) and has five Ramsar sites declared in 2006, 2008, 2009, 2010(IUCN, 2015. Jeju is renowned for its lava tunnels and overlying speleothems, which provide valuable insights into volcanic processes and landform evolution (Woo et al., 2019). ...
... For example, the volcanic island of Jeju in South Korea (Woo et al., 2019) is the only site in the world listed as Biosphere Reserve (UNESCO, 2002), Natural World Heritage (UNESCO, 2007a), UNESCO Global Geopark (UNESCO, 2015) and has five Ramsar sites declared in 2006, 2008, 2009, 2010(IUCN, 2015. Jeju is renowned for its lava tunnels and overlying speleothems, which provide valuable insights into volcanic processes and landform evolution (Woo et al., 2019). Another example is the Island of Tenerife (Canary Islands) in Teide National Park, declared by UNESCO as a World Heritage Site (UNESCO, 2007b) by hosts singular volcanic elements like the complex of calderas, stratovolcanoes, and intra-and extra-caldera volcanic vents related to the active rift systems of the Dorsal and Santiago del Teide (Martí-Molist, Dorado-García, & López-Saavedra, 2022). ...
... Research on Jeju Island's volcanic processes progressed significantly from 1970 as groundwater drilling projects began to obtain subterranean rock cores. In addition to this, there has been significant research on hydromagmatic volcanoes and lava flows (Chough and Sohn, 1990;Tamanyu, 1990;Koh, 1997;Park et al., 1999;Sohn and Park, 2004;Sohn and Park, 2008;Sohn et al., 2012;Koh et al., 2013;Go and Sohn, 2021;Jeon et al., 2022) in addition to the island's UNESCO World Heritage sites (Hwang et al., 2005;Ahn and Hwang, 2009;Woo et al., 2013;Woo et al, 2019). ...
... Generally, the combination of local geology and anthropogenic factors can lead to the formation of sinkholes, geologic features often originating from dissolution and deep piping processes (Waltham 2008;Esposito et al. 2021), which can evolve toward collapse of the ground surface. At the same time, underground cavities, such as caves, caverns, and lava tubes, can also be designated as natural or cultural heritage sites known for their unique geological features and archeological value (Nehme et al. 2013;Woo et al. 2019;Bentivenga et al. 2019). The UNESCO World Heritage List currently includes more than 100 natural and anthropic cavern sites worldwide famous for their natural and historical significance. ...
... As Harrat Khaybar hosts large lava tubes, they are the proof that ponding and massive artery-like tube development took place in the evolution of the lava fields of Khaybar. This is very similar to those recorded from Jeju Island, South Korea, where large tubes effectively transported melts over long distances, and these sites currently form the bases of the Jeju Island UNESCO World Heritage Site [97]. Harrat Khaybar also shows similar facies architecture to other large lava-dominated intracontinental volcanic provinces such as those in southern Australia in the Newer Volcanics [98]. ...
Harrat Khaybar is an active monogenetic volcanic field in western Saudi Arabia that hosts spectacular monogenetic volcanoes and a Holocene volcanic cone with extensive lava fields. The volcanic region is a subject of intensive land use development, especially along tourism ventures, where the volcanic features are the key elements to utilize for increasing visitation rates to the region. The youngest eruption is suspected to be Holocene and occurred fewer than 5000 years ago based on the cross-cutting relationship between the youngest lava flows and archaeological sites. Lava flows are typical, from pāhoehoe to ‘a‘ā types with great diversity of transitional textural forms. Here, we recorded typical transitional lava flow surface textures from the youngest flows identified by digital-elevation-model-based terrain analysis, satellite imagery, and direct field observations. We performed lava flow simulations using the Q-LavHA plug-in within the QGIS environment. Lava flow simulations yielded satisfactory results if we applied eruptions along fissures, long simulation distances, and ~5 m lava flow thickness. In these simulations, the upper flow regimes were reconstructed well, but long individual lava flows were not possible to simulate, suggesting that morphological steps likely promoted lava ponding, inflation, and sudden deflation by releasing melts further along shallow syneruptive valley networks.
... In this line, there are many examples of caves which conform the natural heritage of the places where they are located. Thus, they contain cultural treasures that attract the attention of tourists (Woo et al. 2019). ...
Rull Cave is a karstic cavity located in Vall d’Ebo (Alicante, Southeast of Spain) developed in massive Miocene conglomerates and Cretaceous limestones which consists of a single room with a rounded shape. It is a tourist cave with an average of 15,091 visitors per year. The environmental conditions in the cave’s interior and exterior, as well as the physical properties above the cave, were measured from 2012 to 2021 to understand the gaseous dynamics and their relationships in this three-component system (soil-cave-atmosphere). Besides the presence of visitors, Rull Cave maintains stable values of mean temperature (16.1 °C) and relative humidity (97.6%). The cave presents two different gaseous stages in an annual cycle. In the study period, maximum average values of CO2 and 222Rn were reached in the hottest months (3966 ppm of CO2 and 4185 Bq/m3, respectively), while coldest months are related to the lowest gaseous concentrations (478 ppm of CO2 and 368 Bq/m3, respectively). Discrete sampling of δ13C of CO2 in cave, outdoor atmosphere and soil allows to characterize the spatial distribution and temporal variations of the gaseous concentration in background atmosphere, cave and soil air as well as the relationship between them. Results show that the dynamics of 222Rn and CO2 in the cave air follow different patterns defined by the complex relationships between external and internal factors. Findings permit lately to preserve the quality of the cave indoors and to understand the possible risk derived from the presence of indoors hazardous substances.
... Bella and Gaál 2013;Margielewski and Urban 2017;Wray and Sauro 2017;Woo et al. 2019). The cultural values are usually represented by archaeological artefacts of Paleolithic cultures; however, cave dwelling has been continued ...
The definition of geoheritage recognizes scientific features that allow us to understand the history of the Earth and the processes forming and changing it. Some definitions also include intrinsic values as well as aesthetic and cultural importance of the geosites. Nevertheless, there is still a crucial aspect of human-geoscience (human-Earth) interrelations not clearly expressed in these definitions, which can justify the promotion of geoheritage and geoconservation, namely, the importance of the Earth, its structures, and processes in the development of human civilization and the importance of geosciences in the interpretation of human history and the present-day situation. In this paper, several examples of such geosites and categories of geosites are given: geological structures that conditioned human history, caves as a birthplace of human culture, springs as symbolic and real sources of water necessary for life and economy, mass movements as both destructive and constructive phenomena, and exploitation of mineral resources as a factor that has boosted the progress of civilization. Consequently, we postulate the inclusion in the meaning (definition) of geoheritage, sites, and categories of sites, that convince public and policy makers, that Earth’s elements and processes are ecosystem services of crucial importance. They are important not only for geoscientists, but in the development of human civilization, history, and the present state of human affairs.
... Jeju Island, located on the southern coast of the Korean Peninsula, provides a valuable testbed for the geological/geomorphic studies of lava tubes due to their high spatial density, the unique diversity of cave morphology [14], and easy accessibility [15]. ...
Lava tubes, a major geomorphic element over volcanic terrain, have recently been highlighted as testbeds of the habitable environments and natural threats to unpredictable collapse. In our case study, we detected and monitored the risk of lava tube collapse on Jeju, an island off the Korean peninsula’s southern tip with more than 200 lava tubes, by conducting Interferometric Synthetic Aperture Radar (InSAR) time series analysis and a synthesized analysis of its outputs fused with spatial clues. We identified deformations up to 10 mm/year over InSAR Persistent Scatterers (PSs) obtained with Sentinel-1 time series processing in 3-year periods along with a specific geological unit. Using machine learning algorithms trained on time series deformations of samples along with clues from the spatial background, we classified candidates of potential lava tube networks primarily over coastal lava flows. What we detected in our analyses was validated via comparison with geophysical and ground surveys. Given that cavities in the lava tubes could pose serious risks, a detailed physical exploration and threat assessment of potential cave groups are required before the planned intensive construction of infrastructure on Jeju Island. We also recommend using the approach established in our study to detect undiscovered potential risks of collapse in the cavities, especially over lava tube networks, and to explore lava tubes on planetary surfaces using proposed terrestrial and planetary InSAR sensors.
... The groundwater monitoring wells (JRGJ1 and JRGJ3) and the meteorological station (WJS) are also shown reaching the sea. Within this lava tube cave system, which is one of three properties nominated by UNESCO for the World Heritage List in 2007 due to its outstanding geoheritage value, various types of lava tube caves are present, which contain impressive secondary carbonate speleothems (Woo et al., 2019). This lava tube cave system includes several lava tube caves formed from lava that had erupted from Geomunoreum as well as collapsed trenches that are genetically related to the lava tube caves (Ahn & Hwang, 2009). ...
Volcanic aquifers supply a substantial portion of water resources in many parts of the world, including islands, and their productivity depends strongly on volcanic stratigraphy, which exhibits considerable heterogeneity. We investigated water inflow to lava tube caves formed from numerous basaltic lava flows in the northeastern coastal area of Jeju Island after storm events and monitored relative inflow rates monthly over 1 year to characterize groundwater flow processes in the upper parts of volcanic aquifers, and to evaluate the applicability of the previous hydrogeological models proposed for the island. Considerable water inflow arose shortly after storms from exposed palaeosol layers on the walls of the caves. The monthly monitoring results showed that wall inflow associated with these palaeosol layers is substantial. In both cases, discharge from ceiling drips was much less and more temporally variable compared to wall inflow discharge. Water flowing into the caves was rapidly drained through the floor at all monitoring sites. The lateral extent of the palaeosol layers was identified using drill core logs near the cave and outcrops in the coastal area. Based on these results, we inferred that multiple perched aquifers are formed by low-permeability palaeosol layers between lava flows, which are connected by vertical flows at discontinuities in the palaeosol layer, eventually reaching the basal aquifer. This study revealed the water inflow processes observed in lava tube caves constrained by palaeosol layers, and established a hydrogeological conceptual model incorporating multiple perched aquifers in both coastal and mountainous areas associated with extensive palaeosol layers formed during volcanic hiatuses. This finding would help elucidate recharge, groundwater flow, and contaminant transport processes in many volcanic aquifers that are not adequately represented by the previous models, and contribute to better management of groundwater in those areas.
... The above evaluation shows that the DNFP has a strong TECC, and offers a rare and valuable tourism resource in Changchun: ice and karst caves. Besides attracting tourists through internal improvement, the scenic spot should fully integrate to the planned Changchun Economic Circle, and prepare a development strategy for scenic spot-driven rural tourism, which promotes the mutual growths of the scenic spot and the nearby villages [30]. ...
In recent years, rural tourism has become a hot topic in the academia. Many researchers have proposed to alleviate the poverty of farmers and revitalize rural areas through rural tourism. This paper fully quantifies the tourism environmental carrying capacity (TECC) of Diaoshuihu National Forest Park (DNFP), and evaluates the current status of rural tourism near the scenic spot. Four criteria were selected according to the actual situation of the scenic spot. The TECC of the DNFP was evaluated by Pascal's Principle and then through analytic hierarchy process (AHP). Based on the evaluation results, several suggestions were put forward to promote the scenic spot-based rural tourism in and around the DNFP. The results show that the TECC of the DNFP was 6,160 persons, the annual TECC was 985,600 person/year, indicating that the scenic spot is under weak load. The local government is advised to optimize the design and implementation of DNFP-based rural tourism from four aspects: enhancing the integration between scenic spot and nearby villages, rationalizing the income distribution system, training talents for scenic spot-based rural tourism, and stepping up government guidance on rural tourism. The research results provide a reference for similar cases of scenic spot-driven rural tourism.
Arxan-Chaihe Volcanic Field is located southwest of the Great Xing'an Range in Inner Mongolia, NE, China. This monogenetic volcanic field formed in the Pleistocene, with its latest activity a fissure eruption about 2000 years ago. Here we present the first geodiversity estimate of the region, applying a method combining the geomorphological and geological elements into a grading system, weighting their rarity, significance, and uniqueness. To outline the geomorphological diversities, the geomorphon concept was used alongside watershed analysis of the theoretical fluvial network of the region. In addition volcanic geomorphological elements were provided. Available geological maps, field surveys, and volcano geology classification were utilised for the geological diversity estimates. Geology and geomorphology are the core parameters of the qualitative-quantitative assessment of geodiversity. Geographical Information Systems (GIS) have been used for calculations of geomorphological and geological parameters to provide geodiversity estimates for the region of ACVF. The variables used to estimate geodiversity include geology (rock rareness from global perspective) and geomorphology (slope variations). In addition we used channel systems, and terrain characterization (geomorphon) to describe the morphodiversity of the study area. Our study assessed recent volcanic features and concluded they have high geodiversity and elevated geoheritage values. However, the uplifted and structurally complicated old terrains with mature fluvial networks provide high geomorphological diversity to the region, therefore keeping the overall geodiversity score high.
Caves are rare in northeast Africa and, thus, deserve attention as potential geoheritage objects (geosites). Assessment
of Djara Cave and its vicinity (Western Desert, Egypt) has permitted to document unique features, such as the cave
itself as a peculiar subsurface landform, speleothems providing data for palaeoenvironmental reconstructions, rock art
demonstrating elements of past landscapes, siliceous nodules weathered from Eocene limestones and a network of dry
drainage channels indicative of wetter palaeoenvironments. These features are assigned to geomorphological, sedimentological
and palaeogeographical types of geoheritage. Djara Cave and its vicinity are proposed as a geosite of national
rank; it is vulnerable to anthropogenic stress and needs geoconservation measures and instalment of interpretative
signs. This geosite is already popular among tourists, and can be used for further tourism development. More generally,
the presence of caves in Egyptian desert areas makes possible the recognition of national speleological heritage that
requires special country-level strategies of management.
Jeju Island, located in the southern sea of the Korean Peninsula, is a volcanic island created by the tertiary and quaternary volcanic eruptions. A group of lava tubes formed between quaternary lava flows constitutes one of the most predominant geological contexts owing to its unique and complex network, for which a total of 178 lava tubes is estimated. As a significant portion of lava caves have not been discovered, the threat caused by lava cave collapse has become one of the major concerns in connection with the recent infrastructure construction in Jeju Island. Considering the risk potential, the overall distribution and collapsing risk of the Jeju lava tube network were investigated in this study. Through spatial analysis, we firstly found that the lava tubes distribution is not correlated with specific geological units. Secondly, the risk of collapse is high especially when there are ongoing artificial constructions around the undisclosed lava tube network. We therefore introduced Interferometric Synthetic Aperture Radar (InSAR) techniques to measure the deformation of the ground surface where lava tube networks distributed underground. InSAR results and the proposed machine learning applications identified that the populations of ground deformations was up to 1–2 mm/year and was inferred to be caused by the instability of the shallow lava cavity. Given that underground cavities could pose serious risks, a detailed physical exploration and threat assessment of potential cave groups is required before intensive anthropogenic construction is developed.
The drivers behind the inception of, and the variable, pulsatory eruption rates at distributed intraplate volcanic fields are not well understood. Such broad areas of monogenetic volcanism cover vast areas of the world and are often heavily populated. Reliable models to unravel their behaviour require robust spatio-temporal frameworks within the fields, but an analysis of the potential proximal and distal regional volcano-tectonic processes is also needed. Jeju Island (Republic of Korea) is a volcanic field that has been extensively drilled and dated. It is also located near one of the world’s best-studied tectonic plate boundaries: the subduction zone in southwestern Japan, which generates the Ryukyu and SW Japan arcs. A new set of 40Ar/39Ar ages collected from cores penetrating the entire Jeju eruptive pile, along with geochemical information, is used to construct a temporal and volumetric model for the volcano’s growth. The overall pattern indicates inception of volcanism at ~1.7 Ma, with an initial 1.2 Myr of low-rate activity, followed by over an order of magnitude rise over the last 0.5 Myr. The magma flux at Jeju correlates well with increased extension rates in the arc/backarc region. In particular, we infer that the increased trenchward mantle flow, caused by the greater rollback of the Philippine Sea Plate, activated pre-existing shear weaknesses in the mantle beneath Jeju, resulting in mantle upwelling and decompression melting that caused a change in compositions and an increase in eruption rates at Jeju. Thus, the volcanic activity of an intraplate field system can be modulated by regional subduction processes occurring more than 650 km away. This model may explain the frequent observation of pulsatory behaviour seen in many monogenetic volcanic fields worldwide that lie within 1,000 km of subduction zones.
This study presents petrochemistry and absolute ages of subsurface volcanic rock cores from twenty(20) boreholes in the eastern lowland (altitude loom below) of Jeju Island, Handeong-Jongdal-Udo-Susan-Samdal-Hacheon areas, and discusses topography and volcanism in the area. The subsurface volcanic rock cores are mainly basalts in composition with minor tholeiitic andesites and basaltic trachyandesites. Sequences of intercalated tholeiitic, transitional and alkalic lavas suggest that tholeiitic and transitional to alkalic lavas must have erupted contemporaneously. Especially, occurrences of trachybasalts and basaltic trachyandesites at the bases in the area imply that the volcanism in the area was initiated with slightly differentiated alkaline magma activity. The absolute ages of the subsurface volcanic rock cores range from . The lava-forming Hawaiian volcanic activities of the eastern lowland can be divided into five sequences on the basis of sediment distribution, whole rock geochemistry and absolute ages of the subsurface volcanic rock cores; stage I-U, stage II and stage III during syn-depositional stage of Seoguipo Formation, and stage IV and stage V(younger than 100Ka) during post-depositional stage. In the eastern lowland of Jeju Island, compositional variations and local occurrences of the subsurface volcanic rocks as well as existences of various intercalated sediment layers (including hydrovolcanogenic clasts) suggest that the volcanism must have continued for long time intermittently and that the land has been progressively glowed from inland to coast by volcanic activities and sedimentation. It reveals that the subsurface volcanic rocks in the eastern lowland of Jeju Island must have erupted during relatively younger than 200Ka of stages IV and V. The results of this study are partly in contrast with those of previous studies. This study stresses the need that previous reported volcanic activities in Jeju Island based on K-Ar ages of volcanic rocks should be carefully reviewed, and that stratigraphic correlation from boreholes should be conducted by quantitative criteria combined with petrography and petrochemstry as well as radiometric studies of volcanic rock cores.
Jeju Island, the largest Quaternary volcanic island in Korea, has formed mostly since the early Pleistocene, but its latest chronology of volcanism and sedimentation is still poorly constrained. Here we report optically stimulated luminescence (OSL) ages for two hydromagmatic volcanoes on the southwestern coast of Jeju Island, i.e., the Songaksan and Suwolbong tuff rings. The basaltic tuffs of these volcanoes contain abundant quartz sands from underlying marine sedimentary sequences. Two samples collected from the middle part of the Songaksan Tuff yielded highly reproducible quartz single-aliquot regenerative-dose (SAR) OSL ages of 7.0±0.3ka, providing the first direct age estimate of Holocene volcanism in Jeju Island. The quartz OSL age estimate of 5.1±0.3ka for the younger reworked basaltic tuff (the Hamori Formation) is comparable with previous radiocarbon and U-series disequilibrium dating of fossil mollusk shells. Two samples from the Suwolbong Tuff show quartz OSL age estimates of 18.3±0.7 and 18.6±0.9ka, which are identical within error ranges and younger than the quartz OSL age estimate of 23.2±1.0ka for the underlying Gosan Formation. This study confirms that volcanism and attendant sedimentation were active in Jeju Island until very recently.
High-resolution, stratigraphically ordered samples of the Udo tuff cone and lava shield offshore of Jeju Island, South Korea,
show complex geochemical variation in the basaltic magmas that fed the eruption sequence. The eruption began explosively,
producing phreatomagmatic deposits with relatively evolved alkali magma. The magma became more primitive over the course of
the eruption, but the last magma to be explosively erupted had shifted back to a relatively evolved composition. A separate
sub-alkali magma batch was subsequently effusively erupted to form a lava shield. Absence of weathering and only minor reworking
between the tuff and overlying lava implies that there was no significant time break between the eruptions of the two magma
batches. Modelling of the alkali magma suggests that it was generated from a parent melt in garnet peridotite at c. 3 to 3.5GPa
and underwent mainly clinopyroxene+olivine±spinel fractionation at c. 1.5 to 2GPa. The sub-alkali magma was, by contrast,
generated from a chemically different peridotite with residual garnet at c. 2.5GPa and evolved through olivine fractionation
at a shallower level compared to its alkali contemporary. The continuous chemostratigraphic trend in the tuff cone, from relatively
evolved to primitive and back to evolved, is interpreted to have resulted from a magma batch having risen through a single
dyke and erupted the batch’s head, core and margins, respectively. The alkali magma acted as a path-opener for the sub-alkali
magma. The occurrence of the two distinct batches suggests that different magmatic systems in the Jeju Island Volcanic Field
have interacted throughout its history. The polymagmatic nature of this monogenetic eruption has important implications for
hazard forecasting and for our understanding of basaltic field volcanism.
KeywordsMonogenetic volcanism-Basalt geochemistry-Jeju Island-Plumbing system-Alkali basalt
The230Th/234U ages of fossil mollusk shells collected from the Sinyangri and Hamori Formations, the youngest stratigraphic units on Jeju
Island, Korea, were estimated using multiple collectors inductively coupled plasma mass spectrometry. Seven aragonite shells
yielded230Th/234U ages ranging from 3434±40 yr to 4980±33 yr (2σm), in concordance with radiocarbon ages for samples containing little232Th. Our data suggest that the230Th/234U method can be a potentially useful tool for dating Holocene mollusks, provided that there is no evidence for severe recrystallization,
cementation, and considerable amount of common thorium. An early uptake of uranium immediately after burial and subsequent
maintenance of closed system for uranium and thorium can be assumed for our mollusk samples. This study, together with previous
radiocarbon and optical dating results, demonstrates that the Hamori Formation where human footprints were recently discovered
deposited during the middle Holocene.
A morphodynamic classification of surfzones, beaches and dunes of the microtidal, low- to high-energy southeast Australian coast is presented.The first section (A: Waves and beaches) briefly deals with the transformation of deep-water wave energy as it crosses the shelf, nearshore and surfzone. Depending on the deep-water wave characteristics and shelf and inshore morphology, resultant breaker wave energy may be high, moderate or low, and the accompanying beach surfzone morphodynamic state in fine to medium sand beaches either dissipative, intermediate or reflective. Dissipative beaches have wide surfzones with shore parallel bar(s) and channel(s) and predominantly shore-normal circulation; intermediate beaches are characterised by rip circulation, crescentic-transverse bars and megacusps; and reflective beaches by a barless surfzone and steep, cusped or bermed beach. Each beach form has a characteristic level of beach stability, zone of sediment storage and mode of beach and dune erosion.Landward aeolian sediment transport of swash-deposited sand (Section B) is dependent on the subaerial beach topography and the aerodynamic flow regime across that topography. Characteristic profile shapes are ascribed to each beach type (dissipative, intermediate and reflective). Aeolian sand transport rates are potentially highest on dissipative beaches, moderate on intermediate beaches and lowest on reflective beaches. These rates determine the potential size of foredunes which are correspondingly largest on dissipative beaches and smallest on reflective beaches. The combination of mode and frequency of beach/dune erosion, rates of aeolian sand transport, and foredune volume and morphology provide an explanation of the nature and morphology of landward-occurring, large-scale dune systems. Dissipative beaches are frequently characterised by large-scale transgressive dune sheets; intermediate, by a trend from large-scale parabolic dune systems (high-wave energy) to small-scale blowouts (low-wave energy); and reflective beaches by minimal dune development.
Paleoclimatic changes over the past 400 years were investigated based on textural and geochemical characteristics of the YC-2 stalagmite which grew in Yongcheon Cave (lava tube cave) on Jeju Island, Korea. The stalagmite is about 68 mm long and annual growth laminae are distinctively identified. The age of the stalagmite was mainly determined by counting annual growth laminae supplemented by other radiometric dating methods, and it is estimated that the stalagmite grew at least for ca. 242 years including the hiatus. This hiatus is located at about 15 mm from the base and is present in the form of one thick brown growth lamina which was formed when the stalagmite stopped to grow. Texturally, the stalagmite can be divided into two phases: Fluid inclusion-poor, compact columnar calcite (Phase A) and fluid inclusion-rich, sparse columnar calcite (Phase B). This textural division is intimately related to the spacing of growth laminae, that is, Phase A is characterized by narrower spacing of growth laminae. Phase A with narrow-spaced growth laminae indicates the slower growth rate due to lower amount of rainfall when Northeast Asian summer monsoon intensity was relatively lower. Based on high resolution carbon isotope trend, the stalagmite can be divided into three stages (Stages I, II and III). The relatively more positive carbon isotopic compositions of the Stage I (δ13C = −3.3–0.4‰, PDB) in the lower part indicate that it grew during the Little Ice Age (LIA) under cold and dry climate with less vegetation. The Stage II is a transitional period from cold and dry to warm and wet climate with a continuous decrease in carbon isotope values (from 0.6 to −9.6‰ in δ13C). This stage shows the gradual weakening of the LIA climate. Carbon isotope trend also suggests that the LIA interval was terminated near middle 1870's around Korean peninsula. Relatively low carbon isotopic compositions during Stage III (δ13C = −11.0 ∼ −8.0‰) in the upper part should indicate that climate was changed to the warm and wet Current Warm Period. Warming since 1960 can also be recognized. Complete coincidence between textural data (internal calcite texture and growth laminae spacing) and high resolution carbon isotope compositions strongly suggests that past climate changes such as monsoonal variations in Northeast Asia have been clearly recorded in the stalagmite in Yongcheon Cave.
Volcanic caves have been considered of little mineralogic interest until recent years. As a consequence, very few papers have been printed on this topic in the past. In reality volcanic cavities are a very favorable environment for the development of different minerogenetic processes. Cave minerals actually present in volcanic environments constitute up to 40% of secondary chemical deposits found in all the caves of the world, and 35 of them (corresponding to ~10% of the actually known cave minerals) are restricted to such a environment. In the present paper, the six minerogenetic mechanisms active in the volcanic caves (degassing, solubilization, alteration, karst process, biogenic activity, phase change) are described following the decrease of cave temperature. The genesis of some of the most important secondary chemical deposits is discussed and a tentative list of the most interesting volcanic caves for hosted speleothems is given.
Jeju Island is a Quaternary shield volcano in which about 120 lava tubes have been found within the lavas. We made a lava flow field map from lithofacies, features and latitude of lava surfaces in the northeastern part of Jeju Island, and then examined closely the distribution and mutual relation of lava tubes in each lava flow field. As result, the Geomunoreum lava tube system is divided into a series of master tubes(Utsanjeun-gul, Bukoreum-gul, Daerim-donggul, Manjang-gul, Gimnyeong-gul, Yongcheon-donggul, Namjimi-donggul and Dangcheomul-donggul lava tube), a complicated networks of small tubes(Bengdwigul lava tube), and a series of unitary tubes(Bilemot-gul, Gaeusaem-gul lava tube) in Geomunoreum lava flows. Particularly a canyon, 2 km in length to NNE direction from the Geomunoreum scoria cone, is interpreted to be collapse trench of lava tube roof that belongs to an upflow part of the master tube in the Geomunoreum lava tube system, according to the location and direction. Accordingly, the source of lava flows forming above lava tubes, is the Geomunoreum scoria cone. The Manjang-gul lava tube is part of the Geomunoreun lava tube system. We can explain the formation and growth processes of the Manjang-gul lava tube, as follows. Firstly, the initial lava tube was formed, and then subsequently lava flow passes through the initial tube. Then, the surface of the following lava became solidified to form the floor of the upper level tube. Afterwards, the liquid lava was drained to form the lower level tube, which constructed a multi-level lava tube. The later lavas continually flowed through the lower level tube, caused deeper erosion of the tube's floor and thicker lava accretions of the tube's ceilings. Finally, a new lava poured down from the ground surface into the lower level tube to form a lava column whtin the tube. The Yongcheon-donggul, Namjimi-donggul and Dangcheomul-donggul lava tube is lime-decorated lava tubes which contains numerous speleothems. Location map of the Geomunoreum lava tube system, Jeju Island, Korea.
Long lava flows are traditionally considered to form when low-viscosity lava is erupted at high effusion rates. However, this view has recently been challenged. Detailed field measurements on active lava flows on Kilauea have shown that inflation of lava flows after emplacement can result in reactivation and continued lengthening of flows. Inflated sheets can thus act a insulated conduits (lava tubes) that permit the transport of lava over great distances at near isothermal conditions. Detailed observations of long lava flows in the Columbia River Basalt Group and in the Cenozoic Volcanic Provinces in northern Queensland confirm that this mechanism is not restricted to recent flows on Hawaii. These findings have led to a search for evidence of inflation in flows in other parts of the world and have stimulated theoretical and laboratory research on the emplacement and cooling of lava in flows and in tubes. Understanding the formation of long submarine and planetary lava flows presents an additional challenge. Current evidence supports high effusion rates for some, possibly all, long planetary lava flows, and improved resolution from the Mars Global Surveyor will undoubtedly lead to either a confirmation or a rejection of this view. In this review, we discuss the geological importance and distribution of long lava flows, we investigate diametrically opposed views on the formation of long lava flows, and we stress the need for an interdisciplinary approach to improve our understanding of these enigmatic geological features.
Dangcheomul Cave in Jeju Island, Korea, is a lava tube about 110m long. The cave is located only a few meters below the surface under alkali basalt, and contains numerous and various calcite speleothems such as soda straws, stalactites, stalagmites, columns, cave corals, curtains, flowstones, rimstones, carbonate powders, and shelfstones. Carbonate sand dunes overlying the lava tube are responsible for the formation of calcite speleothems. The sand dunes were formed from the carbonate sediments transported from adjacent shallow seas and beaches, and are composed of mollusks, echinoderms, coralline algae, benthic foraminifers, bryozoans, etc. Oxygen isotopic compositions of some speleothems and cave water indicate that the spelothems have grown mostly by evaporation of cave water. Also, carbon isotopic compositions suggest that the majority of carbon was derived from overlying carbonates with a minor contribution of organic carbon from the overlying soil.Most speleothems in Dangcheomul Cave do not show typical morphology as can be commonly seen in limestone caves. These erratic forms imply a different mode of speleothem formation. High density of soda straws, stalactites, and columns as well as erratic morphology may also provide the evidence that the plant roots are responsible for their growth.
This contribution summarizes and brings up to date the recommendations made by the IUGS Subcommission on the Systematics of
Igneous Rocks for the classification of volcanic rocks when modal analyses are lacking. The classification is on a non-genetic
basis using the total alkali-silica (TAS) diagram, and is as nearly consistent as possible with the QAPF modal classification.
The diagram is divided into 15 fields, two of which contain two root names which are separated according to other chemical
criteria, giving the following 17 root names: basalt, basaltic andesite, andesite, dacite, rhyolite, trachybasalt, basaltic
trachyandesite, trachyandesite, trachyte, trachydacite, picrobasalt, basanite, tephrite, phonotephrite, tephriphonolite, phonolite
and foidite. Using Na-K criteria, trachybasalt may be further divided into the sub-root names hawaiite and potassic trachybasalt,
basaltic trachyandesite into the sub-root names mugearite and shoshonite, and trachyandesite into the sub-root names benmoreite
and latite.
13 C and 14 C analyses were performed on a series of modern Jamaican land snails in order to quantitatively determine the sources of shell carbon. A model of these carbon sources, the pathways by which carbon reaches the shell, and the fractionation processes involved are presented. The contribution of limestone to shell carbonate is variable but may comprise up to 33% of the shell. About 25–40% of shell carbonate is derived from plants and about 30–60% from atmospheric CO 2 . Variation among populations and species with respect to 13 C and 14 C is attributed to the effects of limestone incorporation, snail size (as it affects CO 2 exchange rate), physiological characteristics (presence of urease, respiration rate), and activity patterns of the snails. A formula for correction for isotopic fractionation of 14 C of shell carbonate, based on 13 C measurements, is derived. Bicarbonate-aragonite fractionation is apparently very minimal. Shell organic carbon appears to be derived largely from plants but also to a lesser extent from inorganic hemolymph carbon. This introduces the possibility of a small age anomaly of shell organic 14 C due to limestone incorporation.
Tubular lava stalactites are found in many lava tubes. Field observations, sample analysis, and comparative studies indicate that these are segregations extruded during cooling from partially crystallized lava at about 1,070°to 1,000°C. Retrograde boiling within the lava creates a vuggy fabric and provides a mechanism to expel the interstitial liquid. In addition to tubular lava stalactites, a variety of other lava formations can also result.
Kazumura Cave is a lava tube located in Puna District on the Island of Hawaii. A brief description and history of the cave is included. Compass and tape surveys in 1994 and 1995 extended the system significantly. This provided an excellent opportunity to study a long master lava tube. Lava deposition and thermal erosion are primary factors affecting the cave morphology. This is demonstrated by passage configuration, multiple levels, invasion of extraneous tubes, and the development of lava falls. Other tube features such as windows, balconies, and rafted breakdown are also discussed. Some features in Kazumura Cave are similar to those associated with carbonate caves and surface water streams.
Cited By (since 1996): 3, Export Date: 4 January 2013, Source: Scopus, doi: 10.1016/j.jvolgeores.2009.06.010, Language of Original Document: English, Correspondence Address: Németh, K.; Volcanic Risk Solutions, Institute of Natural Resources, Massey University, Private Bag 11222, Palmerston North, New Zealand; email: k.nemeth@massey.ac.nz, References: Alvarado, G.E., Soto, G.J., Volcanoes in the pre-Columbian life, legend, and archaeology of Costa Rica (Central America) (2008) J. Volcanol. Geotherm. Res., 176, pp. 356-362. , Volcanoes and Human History, Special Issue. Cashman K.V., and Giordano G. (Eds);
Variation in13C/12C and18O/16O ratios in the shell carbonate of several species of land snails was studied along a climatic gradient in semi-arid to arid areas in the southern Levant.13C was found to be enriched in snails from communities having plants with a C4 photosynthetic pathway. Depleted δ13C values were found in areas with high mean annual rainfall, apparently due to higher input of metabolic CO2 as a result of greater snail activity. Shell carbonate δ18O values show a weak relation to the δ18O values of rainwater. The shell δ18O values are enriched by 2–8‰ relative to isotopic equilibrium with environmental waters. Enrichment is suggested to result from metabolic effects on body water (with lower activity producing greater enrichment) but evaporation could also be a factor. Consistent differences in both13C and18O were found among species and may relate to the time when shell deposition occurs. As with most paleoenvironmental indicators, the application of shell isotopes is complicated by the multiplicity of controls of isotopic composition.
This paper describes the nature and environmental significance of variations in textural parameters within a large coastal dunefield in tropical northern Australia. Grain-size parameters of modern beaches and foredunes are very similar but are distinct from those of parabolic dune and sandplain environments. On average, beach and foredune sands have a normal grain-size distribution, but parabolic dune sands are predominantly negatively skewed. Negative skewness is interpreted as primarily reflecting sorting of dune sediments by winnowing at dune crests and by avalanching on slip faces. A general relationship between mean size and skewness is supported, with finer sediments showing increased negative skewness. Positive skewness can therefore not be used as a diagnostic property of aeolian sediments.
The age and origin of carbonate sand dunes in Gimnyeong area, Jeju Island
- H S Ji
- K S Woo
- R Kim
- D W Choi
- D Y Yang
- B K Park
- HS Ji
The study on geology and volcanism in Jeju Island (I): petrochemistry and
- G W Koh
- J B Park
- Y S Park
Study on source of lava flows forming the Manjanggul lava tube
- U S Ahn
- S K Hwang
- US Ahn
Oxygen and carbon isotopic compositions of recent land snail shells in Korea: implications for climate
- J K Kim
- K S Woo
- J S Lee
- JK Kim
Dune forming factors in a geographical context
- J A Klijn
Oreum (adventive volcano) in the Jeju Island
- M S Yang
- J H Moon
- S S Kang
- K S Hyeon
- Y J Jang
The age and constituents of the carbonate sand dunes in Hyeopjae area, Jeju Island: implication for late Holocene sea level change
- K S Woo
- J K Kim
- KS Woo
Geographical variation in coastal development
- J A Davies
- JA Davies