Volcanic Hills Research Articles

GEOMORPHOLOGICAL FEATURES OF SIDAMULYA, SUKABUMI REGENCY, CILETUH PALABUHANRATU UGG

The Sidamulya region, located in the Ciracap Subdistrict of Sukabumi Regency, forms part of the Ciletuh Palabuhanratu UNESCO Global Geopark (UGG) and exhibits unique geomorphological features influenced by geological structures and surface processes. This study focuses on analyzing the area’s geomorphology through morphographic, morphometric, and morphogenetic aspects using Digital Elevation Model (DEM) data processed via ArcGIS and field verification. The research identifies five geomorphological units, including denudational and volcanic hills with varying slope gradients, drainage patterns, and lithological compositions. These units are shaped by exogenic processes such as erosion, weathering, and sedimentation, with lithologies including sandstone, breccia, and andesitic-basaltic lava. The thematic maps produced from this study provide valuable insights into the region’s landscape evolution and contribute to sustainable management within the geopark area. Keyword: Sidamulya, Morphography, Morphometric, Morphogenetic, Geomorphology

Conceptual groundwater model of the north-eastern flanks of Mount Kenya

Despite serious concerns over declining river flows and prolonged dry spells in the north-eastern region of Mount Kenya and the Ewaso Ng’iro River watershed many aspects of the groundwater system remain unexplored. In particular, the recharge-discharge dynamics of the Ewaso Ng’iro River have not been studied, and no conceptual groundwater model currently links the recharge areas in the high-elevation humid regions to the drier lowlands. This study aims to address this significant knowledge gap by assessing the recharge-discharge dynamics of the Ewaso Ng’iro River and identifying the relevant groundwater subsystems and the main flow paths within the various lava layers constituting the aquifer system. Hydrochemical and stable isotope analyses revealed three distinct subsystems with slightly different chemistries and different recharge zones, all of recent meteoric origin. Groundwater from Mt. Kenya is of the HCO3-Na-Mg-Ca type with no dominant cations, whereas groundwater from the Nyambene Range, the other surrounding volcanic hills in the area, is of the HCO3-Na type. Groundwater in the third subsystem in between is of the HCO3-Mg type and is confined or semi-confined. In this area, carbon-13 analysis showed a strong influence of mantle-derived CO2 on the groundwater chemistry (very high electrical conductivity and left-shifted oxygen-18 ratios). Finally, major ions and stable isotopes (ẟ18O and ẟ2H) confirmed that during the dry season, the river is entirely groundwater-fed, with the Mt. Kenya subsystem contributing half of the maximum river flow rate of 800 l/s.

Marine Environments in Front of the Ancient City of Pompeii (Southern Italy) at 79 CE: New Insights for the Unknown Location of the Harbour

A multidisciplinary study, including geomorphological, stratigraphic, paleontological and archaeological methods and techniques, allowed for a detailed exploration of coastal landforms and environments in front of the ancient city of Pompeii (southern Italy). The famous site of Pompeii sits on a small volcanic hill in the alluvial-coastal plain of the Sarno River, very close to the ancient paleoshoreline. When the Roman city was buried during the eruption of Vesuvius in 79 CE, pyroclastic fall and flow deposits covered the urban centres and ancient coastal landforms. In this study, 83 new boreholes were carried out up to a depth of 10 m. Some of them (15) were analysed for their sedimentological, stratigraphical and paleontological characterisation, in order to reconstruct the sedimentary environments in 79 CE. The data collected allow for new hypotheses to be formulated regarding the paleoshorelines, as well as the 79 CE coastal landforms and environments. In particular, litho-stratigraphic and fossil assemblages highlight the presence of shallow marine environments in a large back-ridge depression, named Masseria Curati, that is located just outside the city walls. This hypothesis opens new insights on the unknown location of the harbour of the Roman city.

RELIEF AND GEOLOGICAL STRUCTURE OF REGIONAL LANDSCAPE PARKS “PRYTYSIANSKYI” AND “CHERNIVETSKYI”

Eight regional landscape parks (RLP) are located on the territory of the Ukrainian Carpathians, which play an important role in relief and natural complexes protecting within the region. RLP significantly complements the nature protection functions of two nature reserves and 13 national parks in the Ukrainian Carpathians. Six RLPs are located in the mountainous part of the region, and regional landscape parks "Prytisyanskyi" and "Chernivetskyi" are within the premountain uplands, the natural complexes of which are insufficiently protected. Within the boundaries of the Precarpathian Upland there are sections of two national nature parks such as Halytskyi and Hutsulshchyna. There are no nature reserves or national nature parks within the Zakarpattia (Transcarpathian) Plain. Regional landscape parks "Prytisyanskyi" and "Chernivetskyi" due to the cluster structure of the territories significantly improve the state of protection of premountain natural complexes. In the relief of the southern section of RLP "Prytisyanskyi", the dominant position covers by the low and high floodplains, less often by the first floodplain terrace of the Tysa River. The relief of the northern part of the park is represented by low and high floodplains, fragments of the first floodplain terrace. A complex of different types of meanders is observed in the channel of Latoritsa River. RLP "Prytisyanskyi" fairly fully represents the features of the geological structure and fluvial relief of the Uzhgorod-Beregivska and Vylok-Korolevska alluvial plains of the Zakarpattia (Transcarpathian) Plain with island volcanic hills. Most of the territory of RLP "Chernivetskyi" on the west and south from Chernivtsi city covers by Chernivtsi Upland with a layered and hilly sculptural relief and Mount Tsetsyna (537 m). The park includes separate sections of low terraces along the Prut River. The northern part of the RLP is represented by the Khotyn Upland with Mount Berda (516 m) as the highest point of the Ukraine’s plain part within the East European Platform. The Khotyn Upland is an asymmetric hilly plateau. Its the highest peaks are formed by structural surfaces with steep slopes. The lower level of relief in the RLP is represented by watersheds with karst forms (karst funnels, polje). RLP "Chernivetskyi" represents the geological and geomorphological structure of the Chernivtsi-Storozhynetsky strand-hilly upland of the Pokut-Bukovinsk-Peredkarpattian stratum-denudation-accumulative Upland, as well as the Khotyn structural Upland of the Prut-Dnister stratum-wave Plain. Keywords: Regional landscape park; RLP "Prytisyanskyi"; RLP "Chernivetskyi"; Ukrainian Carpathians; relief.

Lunar Dome Detection Method Based on Few-Shot Object Detection

Lunar domes have always been one of the important windows to understand lunar volcanic activities, but traditional geological dome identification methods are costly. This study attempts to establish an automatic identification method for lunar volcanic domes through FSOD (Few-Shot Object Detection). Since our previous research has been trying to automatically identify lunar volcanic hills using traditional recognition algorithms, our team will try Few-Shot Object Detection this time. In this study, the researchers first obtained the dome coordinates from the list of known lunar domes and intercepted the data this research need from the corresponding coordinates on the DEM moon images. Subsequently, this research used the existing data to train six traditional recognition algorithms and FSOD and compared their performance to verify the feasibility of this study. This research use AP50 and AP75 to evaluate the performance of the model. Finally, this research found that the AP50 of FSOD can reach 0.76, and the AP75 can reach 0.43. However, although FSOD does perform better than other traditional identification methods, this research believe its accuracy is still far from our expectations. Admittedly, compared with YOLO v5, the performance of FSOD has not been significantly improved, but this study still verifies that it is feasible to apply FSOD to the identification of lunar volcanic domes.

ANALYSIS AND QUANTITATIVE ASSESSMENT OF GEODIVERSITY AT KARYA MURNI, GORONTALO, INDONESIA

Karya Murni is one of the areas in the northern arm of Sulawesi that has been tectonically influenced. Tectonic processes have implications for the formation of rocks and geological features that have the potential to be developed into geodiversity sites. The development of geological features as a geodiversity site in aspiring geopark Gorontalo can protect valuable geological features from frequent degradation. This research aims to analyze and conduct quantitative assessments of geological diversity in Karya Murni, Gorontalo. The research method used is field observation, laboratory analysis, and geodiversity assessment. Field observations included observing landform, collecting rock samples, and measuring geological structures. Field observations were also carried out to observe aspects of the geodiversity assessment which included science, education, tourism, and risk degradation. Laboratory analysis consists of geomorphological analysis, petrographic analysis, and geological structure data analysis. Geodiversity assessment uses the Geological Survey Center of Indonesia assessment. The results suggest that the geomorphology of the study area can be divided into four geomorphic units - the volcanic hills, denudational hills, Karst hills, and fluvial plain units. The stratigraphy of the research area is divided into four units from the age of the early Eocene to the Holocene - the andesite lava, volcanic breccia, reef limestone, and alluvial deposit units. The geological structure of the study area is a trending northeast–southwest to northwest–southeast. Active faults at the location of the study area consist of the Apitalawu normal fault. At recent states, generally geosites of the Karya Murni have moderate scientific values, the low educational and touristic values and high risk of degradation. The geodiversity potential of the research area can be utilized for further research and education.

Aplikasi Sistem Informasi Geografis Dalam Pemetaan Zonasi Rawan Banjir Kecamatan Monano Kabupaten Gorontalo Utara

Monano Subdistrict is one of the sub-districts located in Gorontalo UtaraRegency, Gorontalo Province, which does not have a flood hazard map. Thisstudy aims to determine the geological conditions and create a flood hazardmap. This study collected field data, such as lithological data, plotting dataon flood coordinates of each village, as well as validation data of the floodhazard level. The spatial analysis used in this research scores on flood-proneparameters, such as slope, rainfall, and land use that are overlayed alongwith lithological data. As a result, four geomorphological units are obtained:volcanic hills, denudational hilss, and fluvial and marine plains. From thegeological aspect, four units of lithology constituents are produced, such asandesite units, agglomerate units, sandstone units, and alluvial deposit units.The data also exposes that: slopes range from 0-45o flat to very steep, landuse is covered by settlements, rice fields, shrubs, and forests, as well asrainfall which refers to a very high intensity of rainfall, which is 2771 mmper year. The data obtained produces a flood hazard map divided into threeclasses: low, medium, and high.

Karakteristik Geomorfologi Daerah Posso Kabupaten Gorontalo Utara dan Sekitarnya

The landforms in the Gorontalo area are only limited to the physiographic division of Gorontalo. Therefore, this research aims to analyze the geomorphological characteristics of the research area to obtain detailed data that can be used as basic data for the theoretical purposes of Gorontalo geomorphology and disaster applications. The method used in this research is field observation and visual interpretation using satellite imagery, namely GeoEye (GoogleEarth) and Digital Elevation Model. Data analysis was carried out in the form of an analysis of the geomorphological condition of the research area supported by the results of image interpretation—determination of geomorphological units using the Van Zuidam classification. The results showed that the geomorphology of the study area consisted of six geomorphological units: structural hills, volcanic hills, denudational hills, denudational plains, fluvial plains, and marine plains. The morphography and morphometry of the research area are hilly, lowland, and coastal plains generally located at an altitude of 0-393 masl with slopes ranging from flat to extremely steep with a sloping pattern. The morphology of the landform units in the study area starts from the Early Miocene to the Holocene in the form of magmatism, volcanism, and exogenous processes. The presence of geological structures in the form of fractures and faults in geomorphological units and the influence of exogenous processes on landforms can be a reference in mapping the direction of mitigation in the research area, theoretically and practically.

Characteristics of volcanic rocks and associated intrusions based on petrography analysis in Jari-Krondonan Area, Bojonegoro Regency, East Java

Pandan volcano is one of the dormant Quaternary volcanoes in East Java characterized by several volcanic centers which extend to the northern part. This study is aimed to identify the volcanic rocks and intrusions of Jari - Krondonan area, Bojonegoro as well as determine their petrology and mineralogical characteristics. Geological observation was conducted to obtain primary data and to collect samples. Thin section of samples was prepared to analyze the petrographic aspects. Field observation shows several volcanic hills at Mount Jati, Mount Puru, Mount Watu, and Mount Lawang sites. Based on field mapping, lithologies of the research area are andesitic lava and intrusion with columnar joint or sheeting joint structure, surrounded by andesitic breccia. Andesite characterized by porphyritic texture with visible phenocrysts and volcanic glass groundmass. Samples from Mount Lawang and Mount Watu are composed of plagioclase and hornblende as main minerals. Samples from Mount Jati and Mount Puru are composed of plagioclase and pyroxene. Quartz, sanidine, and olivine present as accessory minerals. Plagioclase and pyroxene occasionally formed glomerocryst and poikilitic texture, which play an important role in the fractionation and crystal settling processes. Sieve and regular zoning in plagioclase suggest magma mixing. Gabbro and metamorphic xenoliths found in Mount Lawang and Mount Watu indicates an interaction with country rock during magma rising.

Hydrothermal Fluids-Rock Interactions in the Geothermal Area of the Ngebel Volcano Complex Ponorogo, East Java, Indonesia

The Ngebel geothermal area is morphologically in several volcanic cones arranged as lava domes, volcanic hills, and lake craters. Volcanic cones are composed of lava, pyroclastic falls, pyroclastic flows, volcanic cones such as Jeding Volcano, Kemlandingan Volcano, Manyutan Volcano, and Ngebel Volcano. The magmatism activity that occurs in this area is andesitic-dacitic and also forms a geothermal system. This geothermal system is estimated to produce 50 MWe. During the formation of a geothermal system, hydrothermal fluids interact with the surrounding rock. Based on the results of geological mapping, petrographic analysis, and analysis of rare earth elements. In general, the results of rock-fluid interactions show a decrease in the concentration of rare earth elements, both light and heavy REE elements, from andesite basaltic samples to cold water samples. However, an unexpected reduction from 10 times chondrite to 0.3 times chondrite from hot water to cold water. This research will contribute to the hydrothermal alteration process in the research area that previous researchers have never done and expect to provide new information about forming the geothermal system in the Ngebel Volcanic Complex area.

Soils in the Bulia micro watershed of Gorontalo province, Indonesia, and their quality assessment

Ten representative pedons from the Bulia micro watershed of Gorontalo Province, Indonesia, were characterized and classified to determine its land quality (LQ) class. Angular blocky, sticky, plastic consistencies and a hard consistency prevailed in the soil structure. In the alluvial plains the soil texture is dominated by the clay fraction, while in the hills and volcanic mountains the sand fraction is dominated. The soils in the Bulia micro watershed also have acid to neutral reaction, with the range of very low to high OC (organic carbon) levels, the reserve of exchangeable bases was dominated by Ca2+ in two series patterns, namely: Ca2+ > Mg+ > Na+ > K+ and Ca2+ > Na+ > Mg+ > K+, cation exchange capacity (CEC) ranged from low to very high, and the base saturation varied from moderate to very high. The alluvial plain is represented by Inceptisol in P1 and Typic Humustepts (P7), also by Oxic Humustepts (P3), then Mollisol on P4 (Typic Argiudolls) and Typic Haplustolls (P6), Alfisol on P5 (Typic Paleustalfs). Entisol on P2 (Typic Ustipsamments) was found in volcanic mountains and P9 (Typic Paleustolls) P8 (Ultic Paleustalfs), P10 (Inceptic Haplustalfs) are typical of volcanic hills. On the alluvial plains the land was categorized as the LQ class II, III and IV, the volcanic mountains were the LQ class IV, while the land on the volcanic hills was categorized as the LQ class VI. River bank erosion on the land river terraces can be held by the manufacture of gabions, talud, cliff reinforcement plants and terraces. The soil temperatures and high clay content can be regulated by mulching and organic materials.

How do adults of the critically endangered hermit butterfly (Chazara briseis) utilise their habitat? (Lepidoptera, Satyrinae)

Effective conservation of specialised, endangered species depends on the knowledge of all vital resources they require within species’ lifetime. The butterfly Chazara briseis is endangered throughout Europe, especially so in all states north from the Alps. It depends on large areas of open steppe grassland with short and sparse turf. To identify resource use by adult C. briseis butterflies in relation to vegetation structure within its sites. We re-analysed mark-recapture data from the last Czech metapopulation, inhabiting a chain of volcanic hills in Ceske Stredohori highlands and hosting 2000 adults in 2006. We related adult activities observed prior to captures to visually assessed vegetation structures and land cover types obtained from aerial photographs. Additionally, we used land cover types to explore the adults’ home ranges and to compare capture points with randomly selected points. The butterflies displayed clearly structured diurnal activity with nectaring from morning to noon and courtship activities and egg-laying in the afternoons. Both sexes used short-sward patches (egg laying, patrolling), but also patches with taller, flower-rich vegetation (mating, nectaring). These results were corroborated using land cover types, however, with much lower explanatory power. Lifetime utilisation of land cover types (home ranges) differed between sexes, females utilised more shrubby and longer-sward areas than males. Randomly selected points within the sites significantly differed from capture points, the latter contained more open, either short or tall grassland patches. Management of inhabited sites must provide open, short-sward patches alternating with flower-rich taller sward and shrubby patches.

СТРУКТУРА СКЛОНОВОЙ ЛОЖБИННОЙ СЕТИ КРИОЛИТОЗОНЫ В ОКРЕСТНОСТЯХ г. АНАДЫРЯ

Water runoff on the slopes of the permafrost zone passes through a network of hollows of various structures and patterns in plan. This is clearly distinguishable on aerial and satellite images, but often poorly distinguished on the ground. The study is aimed at recognizing the reasons for the difference in the structure of the drainage network, which is necessary for understanding the mechanisms of surface runoff generation and the modern relief formation in the permafrost areas. In the vicinity of Anadyr (Chukotka, Russia), three morphological types of the hollow network were identified. In the areas of distribution of each type of hollow network field observations were made, and the morphometric characteristics of the slopes to which they are associated were obtained from the digital surface model and satellite images. Each type of the hollow network corresponds to definite range of altitude, the type of relief, the slope gradient and profile, the composition of the deposits, and the depth of seasonal thawing. It has been established that although all types of troughs are used by temporary streams, they have different mechanisms of development. The hollows with a fan structure form the densest parallel network with a distance of 10–40 m apart. These are characteristic of concave slopes of interfluves with close bedding of bedrock and are the result of fluvial modeling of irregularities formed as a result of uneven sliding of the slope material (gelifluction). The intertwining troughs are confined to the slopes of the volcanic hills, the steepest of the studied ones. Fresh silty sediments have been observed at their bottoms and their formation is associated with erosional processes. Single hollows located at a considerable (200–300 m) distance from each other are formed in loose quaternary deposits with a developed network of ice-wedge-polygons. The role of thermokarst is significant in their deepening.

Geology and 2D modelling of magnetic data to evaluate surface and subsurface setting in Bongongoayu geothermal area, Gorontalo

Bongongoayu is one of the regions in Indonesia that has geothermal potential. Bongongoayu requires surface and subsurface data to support the preliminary data. This research aims to determine surface and subsurface data conducted by geology and magnetic method. The surface data, including geomorphology, lithology, hydrology and manifestation. The subsurface data have taken by the magnetic method. The result showed that the geothermal manifestation of Bongongoayu is a hot pool. The surface temperature is 43 to 59 °C. The geomorphology units is composed of volcanic hills unit and lake plains unit. The lithology of the research area is composed of granite and alluvial deposits. Based on petrographic analysis, the level of alteration in granite rocks is 65% and is classified as moderate alteration. The recharge area is in the north and southwest of the research area. Discharge area is in the central area. Based on 2D magnetic modeling, there are two subsurface layers. The first layer is alluvial and the second layer is granite. Rocks that are under the alluvial layer and have been altered are interpreted as a cap rock. 2D magnetic models show normal faults in the research area as a controlling factor for geothermal fluid.

Relationship between soil morphology and variability of upland degradation in Bogowonto Watershed, Central Java, Indonesia

Land-use change and lack of conservation in Bogowonto Watershed area have caused land degradation due to erosion and landslides. The rate of land degradation can be measured through the morphological characteristics of the soil and landscape. This study aimed to identify the relationship between the morphological characteristics of the soil and the rate of land degradation in Bogowonto Watershed area. The research framework initiated from the interpretation of thematic maps, surveys and field observations, and verification using land degradation assessment software. Sample points were determined using a stratified random sampling method. In general, land degradation is affected by slope, limited soil development, suboptimal conservation measures, and land-use change. Particularly, land degradation is affected by the type of landscape and the morphological characteristics of the soil. Volcanic hilly landscapes show a degradation rate of fine to very fine, characterized by thick soil depth (>60 cm), generous root distribution, loamy textured soil, fine soil particle size (O <0.002 mm), and good soil structure. The distribution of easily weathered volcanic ash causes volcanic hills to have thick and fertile soil characteristics. Quaternary-tertiary volcanic transition landscapes show a degradation rate of damaged to heavily damaged, characterized by thin soil depth (<60 cm), limited rooting, dominant coarse fraction (O 2–0.05 mm), and contact with fields lithological discontinuity. The data obtained provide information on the morphological characteristics of the soil and land degradation in Bogowonto Watershed area. The results of the study can also be used as a formulation for the conservation of Bogowonto Watershed area.

Environmental Together With Interspecific Interactions Determine Bryophyte Distribution in a Protected Mire of Northeast China

Question What environmental variables and plant-plant interactions affect mire bryophyte distribution and does the surrounding landscape with human disturbance play a role in the mire bryophyte distribution? Location Jinchuan mire, Northeast China. Methods We studied the spatial distribution of bryophytes in 100 1 × 1 m-quadrats in the mire. Spatial variables were simulated by analysis of the distance-based Moran’s eigenvector maps. Variation partitioning analysis was used to reveal the relative contribution of spatial and environmental variables to bryophytes. The relationship between environmental variables and bryophytes were tested by redundancy analysis. We used co-occurrence and niche overlap models to detect interactions among bryophytes. We also studied the influence of the surrounding landscape on the distribution of bryophytes in relation to water chemistry. Results The eight bryophytes occupying part of the mire had both a general distribution trend and a local spatial structure. Over 40% of the total variation in cover among bryophytes could be explained by spatial and environmental variables. In this fraction, the environmental variables explained 29.7% of the variation, of which only 4.5% was not spatially structured. Redundancy analysis showed the contribution of dwarf shrub cover, Na and P to the bryophyte distribution was relatively large. Concentration of Na and dwarf shrub cover decreased gradually from north to south, and contributed most to the variation in species composition along the first axis. The concentrations of P decreased from east to west, and contributed along the second axis. All the bryophyte species were spatially isolated but with large niche overlaps, indicating that the bryophyte community was structured by interspecific competition. Conclusions Sodium mainly originating from the volcanic hill and P from the paddy fields were the main environmental factors affecting the bryophyte distribution. Concentrations of Na and P showed spatial structure, and resulted in induced spatial dependence playing a major role in the spatial structure of the bryophyte community. Dwarf shrubs affected by nutrient distribution in the mire significantly influenced the bryophyte distribution in the mire. We conclude that the surrounding ecosystems had important influence on bryophyte distribution via nutrient influx. Furthermore, competitive interactions exacerbated the spatial separation of bryophytes.

Excavations at Metsamor, seasons 2013-2018

The archaeological site of Metsamor is situated in the southwestern part of Taronik village (formerly Zejva), 35km southwest of Yerevan, in the Ararat Valley. The coordinates of the site are 40°07′36″N 44°11′11″E. The convenient location, fertile soil and favourable climatic conditions allowed people to develop their activities in this territory from very ancient times.The site has, over time, developed around several volcanic hills. The left-bank tributaries of the Metsamor River originate at the artesian springs at the foot of those hills. The site is conventionally named after the river.

ASESMEN NILAI-NILAI PARIWISATA TERHADAP FITUR GEOLOGI DAERAH BONGO DAN SEKITARNYA SEBAGAI DASAR PENGEMBANGAN GEOWISATA DI PESISIR SELATAN GORONTALO

Geology is an important aspect in the development of tourism in an area. One of the attractions in a natural tourism location is certainly highly controlled by the geological setting in the area. The purpose of this research is to assess tourism values of geological features in the Bongo and surrounding areas as a basis for developing geotourism on the southern coast of Gorontalo. The research location is at coordinates N 00029’42” - N 00029’51” and E 12301’26” - E 12303’32”. The method used in this study is a surface geological survey, which includes field data collection in the form of lithology, geological structure and geomorphology. The standard used for assessing tourism values is the technical guide for assessing geological heritage resources by the Geological Survey Center. The results showed that the lithology unit of the study area consists of granite, volcanic breccia and reef limestone. The geological structure in the research area is shear fracture with main stress that relatively directed to northwest-southeast. The geomorphic unit of the study area consisted of two units, namely volcanic hills, and marine units. The results of the assessment of tourism values on geological features explain that the Bongo and surrounding areas are included in the medium category. Improvements are needed on low value criteria, namely vulnerability, relationships with other values, and economic level.

A dynamics condition of coastal environment in Padang City-Indonesia

Padang City is located on the West coast of Sumatra Island that borders directly with the Indian Ocean. The coastal region of the city stretches from Pasia Jambak beach, Muara Anai in the Northto Sungai Pisang in the South. The coast of South section is different from the coast of Northsection, because the Southern coastline is heterogeneous because there are many small bay, small islands and narrow beaches directly adjacent to the volcanic hills. This research aims to determine the dynamics condition of a coastal environment based on the characteristic (length, velocity, energy, and height), sediment transport value, accretion/abrasion factor value, and coastal equilibrium in Padang City.The method used in this study is the calculation of wavelength (L0), wave velocity (C), wave energy (E), run-up height (Hb), and sediment transport (Q) to determine accretion/abrasion factor and equilibrium (G0). Furthermore, it is done by Geographic Information System (GIS) approach to spatial information of research location. Research result shows that coastal region(beach)in Padang City tends to experience accretion along the beach of Pasia Sabalah, Panjalinan North, Panjalinan South, Parkit, Purus South, Purus North, Muaro Padang, Air Manis North and Pasia Putih. While the abrasion conditions occur inPasia Jambak, Parupuk Tabing, Bung Hatta University beach, Air Manis South and Sungai Beremas.

Potensi Batugamping Untuk Bahan Baku Industri Semen Daerah Biluhu Timur Dan Sekitarnya

Limestone is a sedimentary rock composed by calcium carbonate derived from the rest of marine organisms and the main materials of cement so exploration and calculation of limestone resources need to be done. The research area is administratively located at the Biluhu Timur Village and its surroundings, Batudaa Pantai District, Gorontalo Regency. The purpose of this study is to observe the geological conditions of the study area to determine distribution of limestones in the study area to be used as cement industrial materials with the geological mapping, and the analysis limestone geochemical using XRF (X-Ray Flourescence). Based on the result of this research can be concluded that the research area was devided into four geomorphological units, consisting of volcanic hills unit, denudational hills and plain unit, and the coastal plain unit. The litology arranged by granodiorit, basal, and the limestone (packstone and wackestone). Based on the result of geochemical analysis using XRF and calculation of volume using Surpac softwere can be devided into three blocks. The A block have limestones (packstone) with the content of CaO 51.79% and MgO 1.98% that meets the requirement materials of portland cement with total volume 423 107 230 tons. The B block have limestones (wackestone) with the content of CaO 4.92% and MgO 5.28% that not meets the requirement materials of portland cement with total volume 729 263 008 tons. The C block have limestones (packstone) with the content of CaO 52.85% and MgO 0.98% that meets the requirement materials of portland cement with total volume 539 883 150 tons.