GEODA

GEOLOGI DAN POROSITAS SATUAN BATUPASIR KARBONATAN HALANG SEBAGAI AKUIFER DAERAH KARANGMOJO DAN SEKITARNYA KECAMATAN KARANGGAYAM, KABUPATEN KEBUMEN, PROVINSI JAWA TENGAH

Eko Galeh Wahyu Prayetno — 2025-03-18

The research area is located in Karangmojo Village and its surroundings, Karanggayam District, Kebumen Regency, Central Java Province. The research area is physiographically included in the southern Serayu mountain zone (van Bemmelen, 1949). Stratigraphically, the research area is divided into six units, namely the Chert unit, the Karangsambung carbonate mudstone rock unit, the Totogan polemic breccia rock unit, the Waturanda andesite breccia rock unit, the Penosogan carbonate sandstone rock unit and the Halang carbonate sandstone rock unit. The ages of the oldest to youngest rocks are Paleocene to Late Miocene. The research area is divided into three geomorphological units, namely the denudational hills and medium-steep slopes unit (D1), the denudational mountains and hillsides unit (D2) and the structural anticline and syncline hills unit (S9). The research area has the potential for sandstone as a rock that can store and channel water (aquifer), so that it can be used by local communities to support subsurface water needs.

Keywords: Geology, Stratigraphy, Geomorphology, Aquifer.

STUDI ZONA ALTERASI DAERAH X, KECAMATAN LOLAYAN, KABUPATEN BOLAANG MONGONDOW, PROVINSI SULAWESI UTARA BERDASARKAN ANALYTICAL SPECTRAL DEVICES (ASD)

Greaty Julivelyn Moniung — 2025-03-18

Administratively, the study site is located in Motandoi Village, East Pinolosian District, South Bolaang Mongondow Regency, North Sulawesi Province. The study area is located in the central part of the northern arm of Sulawesi, which is composed by a magmatic arc of Neogene age. The geological conditions are complex enough to produce potential mineral resources that are economical and have the potential to be the seat of mineralization. The purpose of the research is to determine the geological conditions and identify alteration zones in the research area in order to determine the heat source of the hydrothermal system. The study area is composed of dacite tuff, tuff breccia and quartz diorite. The alteration type of the study area is divided into several types, namely sillica vuggy (SV), sillica massive (SM), sillica advanced argilic (SAA), clay advanced argilic (CAA), and argilic (AR). Then correlated with the set of minerals obtained from the analytical spectral device (ASD) results, thus obtained: vuggy quartz - alunite alteration zone, massive quartz - alunite ± dickite ± Kaolinite alteration zone, alunite ± Kaolinite ± phyropylite alteration zone, phyropylite ± dickite ± Kaolinite alteration zone, dickite ± alunite ± phyropylite alteration zone, Kaoliniteite ± white mica alteration zone, montmorillonite ± white mica ± Kaolinite alteration zone. where the heat source of the study area is in the vuggy quartz - alunite alteration zone and the massive quartz - alunite ± dickite ± Kaol alteration zone.

Keywords: ASD, alteration, Motandoi Village, dacite tuff, tuff breccia

EVOLUSI MAGMA BERDASARKAN ANALISIS GEOKIMIA DAN MIKRO TEKSTUR PLAGIOKLAS PADA INTRUSI ANDESIT GUNUNG JULANG DAERAH DESA CINANGSI DAN SEKITARNYA, KECAMATAN CISITU, KABUPATEN SUMEDANG, PROVINSI JAWA BARAT

Suriawan — 2025-03-18

Java Island is part of a volcanic arc archipelago resulting from the subduction of the Indo-Australian plate which moved north under the Eurasian plate. The process of freezing magma into rock can reveal many stories behind it. The distance from subduction to rock formation will also influence what chemical elements accompany it. Andesite intrusions in the research area are part of the magmatism activity which is unique in that it has a different color at each observation location. This makes researchers interested in studying changes in the composition of andesite intrusions, considering that there has been no specific study regarding the genesis of andesite intrusions in the research area by previous researchers. The method used in the research consists of micro-texture analysis and geochemical analysis of rocks using the XRF (X-ray Fluorescence) method. Based on the results of geochemical and microtextural analysis of plagioclase, magmatism activity in the study area has experienced an evolution, this can be seen from the formation of repeated textures in one phenocryst, indicating that there is an increase in high temperatures and interactions with primitive magma and melts rich in Ca caused by the mixing of magma. large scale. because this can happen when magma mixes (magma mixing). In shallow magma chambers, turbulence is also experienced by magma rotation which causes physical and chemical changes as well as recrystallization or the growth of certain micro-textures. This is then supported by geochemical data which shows that the magma differentiation stage occurred at the last stage with a high magma affinity calc-alkaline series.

Keywords: intrusion, magma evolution, geochemistry, micro-texture

GEOLOGI DAN ZONASI KERENTANAN GERAKAN TANAH DAERAH CIPORAS DAN SEKITARNYA KECAMATAN KARANGPUCUNG, KABUPATEN CILACAP PROVINSI JAWA TENGAH

Eza Nurfadli — 2025-03-18

The research area is very interesting to study in terms of lithology, stratigraphy, geological structure and morphology that develop in the research area, so researchers are interested in researching the Ciporas area and its surroundings, Karangpucung District, Cilacap Regency, Central Java Province. Regarding the specific problems raised in the research, it includes the Land Movement Vulnerability Zoning of the research area, where the Ciporas area and its surroundings have many landslide points which are very prone to landslides, so that is the reason for researchers to analyze the research area based on rainfall, slope, land use, rock type, and soil type and factors controlling ground movement.

Keywords: lithology, stratigraphy, geological structure and ground movement.

ANALISIS KUALITAS AIR TAMBANG NIKEL BERDASARKAN NILAI TOTAL SUSPENDED SOLIDS (TSS) DAN DEWATERING DI BLOK X PADA PT. STARGATE PASIFIC RESOURCES, KABUPATEN KONAWE UTARA, PROVINSI SULAWESI TENGGARA

Meta Dwiarsiana — 2025-03-18

The research area is in block X PT. Stargate Pacific Resources, North Konawe Regency, Southeast Sulawesi, which is part of the Sulawesi ophiolite route with complex geological conditions and still active tectonics. The research location in the East Arm of Sulawesi still has quite large potential for laterite nickel deposits. The abundance of potential for later nickel is certainly important enough to be balanced with systematic exploration activities, which also have an impact on the quality of mine water. Based on this, observations are needed in terms of water quality and how it is processed. The characteristics that influence TSS are interpreted to be due to the main factors in the form of morphological conditions and zone conditions and the environment around the air quality sampling in the research area. Water treatment in nickel mines also uses the dewatering method. Analysis of runoff water discharge from Cathment area to Sediment block X is known. The runoff water discharge at the highest rainfall is 9,230 (m3/hour) with an actual erosion value of 1,851, a particle deposition rate of 0.00694 m/second, so compartments are needed with dimensions of each compartment 5.1 meters wide and 10.2 meters long and an area area of 561.07 m2 includes sediment ponds and embankments. With an estimated suspended solid load entering the sediment pond of 8 mg/l sediment pond volume and a processing efficiency of 78%, the sediment pond maintenance schedule is a maximum of every 10 months.

Keywords: Laterite nickel deposits, Dewatering, TSS, Modeling, Water Quality.

GEOLOGI DAN ANALISIS KORELASI SIFAT FISIK TERHADAP NILAI UJI KUAT TEKAN BATU ANDESIT PADA DAERAH SIDOHARJO DAN SEKITARNYA KECAMATAN DORO KABUPATEN PEKALONGAN PROVINSI JAWA TENGAH

Eny Khairunnisa — 2025-03-18

Andesite is a type of volcanic igneous rock, extrusive, of medium composition, with an aphanitic to porphyritic texture that is widely distributed on the island of Java. Andesite research was carried out to determine the influence of rock physical properties on the uniaxial compressive strength of andesite lava rock by testing the physical properties and mechanical properties. Analysis of the physical properties of rocks is carried out to identify dimensions, bulk weight, air content, porosity and degree of saturation. Analysis of the mechanical properties of andesite rock obtains UCS values. The physical properties test and the mechanical properties test on andesite rock tested 4 andesite rocks where the rocks came from 2 different sources, namely Khuluk Perbata and Khuluk Kendeng. The andesite rock samples at Khuluk Perbata obtained an average unit weight of 2.6985 gr/cm3, the andesite rock at Khuluk Kendeng resulted in an average unit weight of 2.6615 gr/cm3, the porosity of the Khuluk Perbata andesite rock averaged 17.045% of the rock. andesite in Khuluk Kendeng has an average porosity of 21.595%, the compressive strength value of andesite rock in Khuluk Perbata averages 187.385 MPa, while the compressive strength value of andesite rock in Khuluk Kendeng averages 163.3 MPa.

Keywords: Andesite, Physical Properties, Compressive Strength, Khuluk Perbata, Khuluk Kendeng.

KARAKTERISTIK PEMBENTUKAN LAVA SUNGAI PARAGA DAERAH SALOPA DAN SEKITARNYA, KABUPATEN TASIKMALAYA, PROVINSI JAWA BARAT

Alifian Syahreza Lasawedi — 2025-03-18

Salopa area, Tasikmalaya Regency, West Java Province is regionally located in the Jampang formation which is dominated by volcanic material. Seen from its positive potential, it is one of the areas that has the potential as a location for the formation of non-biological natural resources such as minerals and minerals. The lava of the research area is part of volcanism activity which has a unique shape. This makes researchers interested in studying the rock genesis of the Paraga River lava, considering that there has been no special study of the genesis of the lava of the research area by previous researchers. The method used in the research consists of petrographic analysis and geochemical analysis of rocks using the XRF (X-ray Flourescence) method to determine the main elements in rocks. Based on the results of the research, the characteristics of Basalt Lava rocks in the research area petrographically include a type of volcanic rock with the name basalt (Streckeisen, 1976) and geochemically has a basic magma composition with the name Basalt rock according to the classification (Le Maitre et al, 1989), with a temperature of ±1000oC. Magma in the study area belongs to the calk-alkaline series group with a depth of ± 165.69 Km, the last stage of magma differentiation.
Keywords: Salopa, Lava, XRF, Petrography, Geochemistry

UJI KEKUATAN SPT BATUGAMPING GOLOK DAN KALKARENIT GOLOK DAERAH PULAU MIANG, KECAMATAN SANGKULIRANG, KABUPATEN KUTAI TIMUR, PROVINSI KALIMANTAN TIMUR

Jeovano Greynaldo Kanine — 2025-03-18

This research was conducted on Miang Island, Sangkulirang District, East Kutai Regency, which took place from 22 October to 22 December 2022. The aim of this research was to determine the SPT Strength Value with drilling carried out on Miang Island, to determine the characteristics and strength of the rocks, and explains the comparison between regional points where the SPT test is carried out.

In accordance with the stages in the construction process of a civil building construction, a complete and detailed planning of the building plan (drawing design) is always required. For this reason, planning data is first needed, including location surveys, topography, geology, and complete soil investigations before construction is built. The foundation is one of the building elements that has a very important role in transmitting forces from the upper construction elements to the subgrade. Therefore, the strength of the foundation must consider the suitability between the load from the construction and the bearing capacity of the soil. Bowles (1997) states that there are two general requirements that must be met in planning foundations. Firstly, the subgrade must be able to support the construction load without experiencing shear failure, and secondly, the foundation settlement that will occur must be within permitted limits. The results of foundation planning in the form of type, depth and dimensions of the foundation based on SPT value data can be compared with the results obtained based on physical and mechanical property data from laboratory tests.

Keywords: Geology of the research area, SPT, Golok

KARAKTERISTIK GEOKIMIA ENDAPAN NIKEL LATERIT PADA BLOK X DI KABUPATEN MOROWALI UTARA PROVINSI SULAWESI TENGAH

Muh Gilang Tri Irawan — 2025-03-18

The research area is in block X PT. Paku Bumi Inti Mineral, North Morowali Regency, Central Sulawesi Province which is part of the Sulawesi ophiolite route with complex geological conditions and still active tectonics. The research location is in the East Arm of Sulawesi which has quite large potential for laterite nickel deposits. The abundance of nickel laterite potential is certainly important enough to be balanced with systematic exploration activities. The aim of this research is to determine the geological conditions and also the geochemical characteristics of laterite nickel deposits in the research area, so that we can find out the Ni content from each drill point and then what controlling factors are the causes of high and low Ni levels from each drill point in the research area. The characteristics of the top soil are brownish red, contain lots of plant roots, and have a Ni content of 0.76-0.87%. The Limonite zone is reddish brown and has a Ni content of 0.75-1.62%. The Saprolite zone is yellowish brown and has a Ni value of 0.47-2.13%. The brownish black Bedrock zone has a Ni content of 0.25-0.80%. The dominant controlling factors in the research area are topography and ruggedness.

Keywords: Laterite, characteristics, controlling factors.

ANALISIS PENGARUH POROSITAS PADA UJI KUAT TEKAN UNIAKSIAL TERHADAP KUALITAS BATUGAMPING KLITIK DAN BATUPASIR KARBONATAN KEREK DENGAN PENDEKATAN REGRESI NON LINIER EKSPONENSIAL DAERAH PANDEAN, KECAMATAN MANTINGAN, KABUPATEN NGAWI, PROVINSI JAWA TIMUR

Brandon Marcelo Michael Potu — 2025-03-18

The utilization of rock mining resources is very taken into account in development. The potential of mining material resources in Karanganyar Village, Karanganyar Subdistrict, Ngawi Regency, East Java Province is quite calculated. To determine the quality, research needs to be done on the determining factors of the quality of the rocks used, among others; porosity, permeability, and UCS. To determine how much influence the strong press test is performed using exponential non linear regression analysis. Porosity is classified as negligible – fair, permeability is relatively good – very good; the resources in the research area are classified as directed resources with rock strength classified as very weak - moderate; low – medium quality. The results of the analysis of porosity influence on the value of press strong test results showed significantly up to 81,8% with conclusives that implicated each other and declared valid.

Keywords: Regression, Porosity and compression test.