GEODA

GEOLOGI DAERAH CIMENTENG DAN SEKITARNYA, KECAMATAN CIJAMBE, KABUPATEN SUBANG, PROVINSI JAWA BARAT

2025-09-04T11:40:01+07:00

The research area is in the Cimenteng and surrounding areas, Cijambe District, Subang Regency, West Java Province. Physiographically, it is included in the Physiography of the Alluvial Plain Zone of the North Coast of Java and has been mapped by several previous geologists, however this research is still regional in nature and uses the concept of lithostratigraphic units, making it an interest for researchers to be able to carry out mapping and grouping rock units. Based on this research, it is known that the geomorphological units that make up the research area include the strongly undulating geomorphological unit (D2), the denudational slope and hill geomorphological unit (D3). The drainage pattern that develops is in the form of a dendritic flow pattern with mature to old river stages. Stratigraphically, the research area is composed of 4 units, namely the Subang claystone unit, the Kaliwangu sandstone-claystone unit, the Citalng sandstone unit.

Keywords: Cimenteng, Flow pattern, Stratigraphy of research area.

GEOLOGI DAERAH AMBARAWA DAN SEKITARNYA, KECAMATAN AMBARAWA, KABUPATEN SEMARANG PROVINSI JAWA TENGAH

2025-09-04T09:09:12+07:00

The geology of the Ambarawa region and its surroundings was chosen as the geological
mapping area because the research area is a natural geological laboratory which is quite
interesting for research. This is because the area is included in the physiography of the Central
Zone/Volcanic Depression Zone, which is genetically formed due to endogenic activities in the
form of tectonics, magmatism, volcanism and exogenic processes are caused by the fact that in
the area there is the Ungaran volcano which is of Quaternary age. On the other hand, much
research has been carried out regarding morphology, lithology, stratigraphy and geological
structure, but is generally based on regional problems. This research was conducted in the
Ambarawa area and its surroundings, Ambarawa District, Semarang Regency, Central Java
Province. This mapping was carried out using a surface mapping method by looking at rock
outcrop data, rock distribution, geomorphology and physical characteristics of rocks. This
concept is called the lithostratigraphic concept. Based on the results of the Geology of the
Research Area, namely: The geomorphology formed in the research area is the volcanic
morphological unit of volcanic slopes, the morphological unit of denudational mountains and
hills, and the fluvial terrace geomorphological unit. Meanwhile, in Regional Geology, the
researcher found 3 rock formations and 1 breakthrough rock and 1 deposit, from the order of

old to young, namely: breccia-andesite lithic arenite rock unit of calliget formation, intrusive-
andesite rock unit, porphyroophanitic andesite rock unit of Gajah mungkur formation, andesite

rock unit Ungaran faneric, and alluvial deposit units. The environmental geology of the
research area which is the source studied is divided into two, namely: positive sources. All land
in the research area is used as agricultural land, livestock and geotourism. A negative source
that was formed in the study area was landslides and some denudational mountainous and hilly
areas, including areas where clean water is difficult.

Keywords : Geomorphology, Geology and Environmental Geology

GEOLOGI DAERAH CIPAJANG, KECAMATAN BANJARHARJO KABUPATEN BREBES, PROVINSI JAWA TENGAH

2025-09-04T14:58:14+07:00

This research was conducted in the Cipajang Village area and its surroundings, Banjarharjo District, Brebes Regency, Central Java Province. This mapping was carried out using a surface mapping method by looking at rock outcrop data, rock distribution, geomorphology and physical characteristics of rocks. This concept is called the lithostratigraphic concept. In this type 1 thesis activity, the researcher obtained 3 types of rock from old to young, namely: the Kumbang Andesite Breccia Unit which is not in harmony with the Pamali Carbonate Claystone Unit and which is in line with the Halang Carbonate Sandstone Unit. The geomorphology formed in the research area is: Denudasional Mountains & Hills Geomorphology Unit (D3), Denudasional Slope Hills Unit (D2), Alluvial Plain Unit (F3) Alluvial deposits (F1). The geological structures that develop in the research area are synclines and downturned faults in barrier formations. The environmental geology of the research area which is the source is divided into two: positive sources: all land in the research area can be used as agricultural land, livestock and fish cultivation. A negative source that formed in the research area was a landslide.

Keywords: Rocks, Geomorphology, Geological Structure and Environmental Geology.

GEOLOGI DAERAH BANYUSARI DAN SEKITARNYA, KECAMATAN MALAUSMA, KABUPATEN MAJALENGKA, PROVINSI JAWA BARAT

2025-09-08T10:41:19+07:00

The research area is in the Banyusari and surrounding areas, Malausma District, Majalengka Regency, West Java Province. Geographically, based on UTM (Universal Transfer Mercator) WGS 1984 coordinates, Zone 49S, the research area is at coordinates 195250 – 9215300 mT, 201250 – 9224399 mU. Physiographically, the research area is included in the Quaternary volcanic zone physiography with the stratigraphy of the research area composed of the oldest to youngest rocks from the Early Pliocene to Pleistocene. The differences in the rocks that make up each formation are an interesting thing to study further regarding aspects of geomorphology, statigraphy, geological structure, source potential and depositional environment in the research area. This research was carried out using geological surface mapping and analysis of laboratory data in the form of petrography and micropaleontology. The geomorphology of the research area is divided into three geomorphological units, namely the strongly undulating geomorphological unit - denudational hills (D2) and the hilly geomorphological unit - strongly denudational cuts (D3). The research area has dendritic, sub-denritic and parallel river flow patterns, with mature geomorphic stages. The stratigraphy of the study area is divided into three unofficial rock units of Pliocene - Pleistocene age. The rock units in the study area were deposited in a middle neritic environment. The rock units from old to young are the Kaliwangu carbonate sandstone unit, the old volcanic andesite breccia unit, and the andesite intrusion. The geological structure that develops in the research area is the horizontal fault to the right of the Cimuncang right slip fault. These structures were formed by a compressional tectonic phase trending west - east. The geology of the environmental system in the research area is divided into two, namely natural resources, rice fields and tea gardens, while natural disaster include landslides.

Keywords: Banyusari, Surface Geological Mapping, Stratigraphy, Geological History.

Karakteristik Alterasi Dan Mineralisasi Sulfidasi Tinggi Pada Pit “X” PT. J Resources Bolaang Mongondow

2025-09-04T09:38:15+07:00

One of the areas that has gold deposits is Bakan village, sub-district. East Pinolosian, Bolaang
Mongondow district. The research location itself is included in the work contract area of PT. J
Resources is precisely located in Motandoi village, Kec. East Pinolosian, South Bolaang Mongondow
Regency, North Sulawesi. The method used in this research is collecting surface geological data,
especially through geological, alteration and mineralization mapping which is integrated with
laboratory analysis (Petrography, analytical spectral device and fire assay). There are 4 alteration
zones in the research area, namely the quartz – alunite zone with a vuggy texture, the quartz – alunite
zone with a massive texture, the quartz – alunite – kaolinite – small zone, and the kaolinite – illite ±
quartz zone. The mineralization that develops in the research area is divided into 2, namely the
oxidation mineral association (hematite – geotite – jarosite), and the energetic mineral association –
pyrite. The mineralization that dominates the research area is the oxidation mineral association.
Mineral deposits in the research area are of the high sulfidation epithermal deposit type.
Keywords: Bakan, Geology, alteration, mineralization, epithermal, characteristic

GEOLOGI DAERAH PASAWAHAN DAN SEKITARNYA, KECAMATAN BANJARANYAR, KABUPATEN CIAMIS, PROVINSI JAWA BARAT

2025-09-04T10:30:54+07:00

The research was carried out in Pasawahan Village and its surroundings, Banjaranyar District,Ciamis Regency, West Java Province. This mapping was carried out using a surface mapping method by looking at rock outcrop data, rock distribution, geomorphology and physical rock characteristics. This concept is called the lithostratigraphic concept. In this thesis activity, the researcher obtained 5 types of rock units from old to young, namely: Jampang andesite breccia unit, Jampang Tuffan Sandstone unit, Pamutuan Napalan Tuff Member sandstone unit, Halang Sandstone Unit. The geomorphology formed in the study area is: Geomorphological Unit of Strong Wavy Topography - Denudational Hills D2, Geomorphological Unit of Topography of Denudational Medium-Sharp Mountains D3, Strong Wavy Topography D1, Weakly Wavy Topography D5, and Fluvial Plain Topography F1. The geological structures that develop in the study area are joints, anticlines, synclines and thrust faults of the Jampang Formation. The environmental geology of the study area which is the source is divided into two: positive sources: all land in the study area is used as agricultural land and livestock. A negative source formed in the study area is landslides and some hilly areas are landslide-prone areas.

Keywords: Rocks, Geomorphology, Geological Structure and Environmental Geology

HUBUNGAN MORFOLOGI TERHADAP KETEBALAN NIKEL LATERIT BLOK X PT. PAKUBUMI INTI MINERAL (PIM) DI KABUPATEN MOROWALI UTARA, PROVINSI SULAWESI TENGAH.

2025-09-04T10:44:46+07:00

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 in the East Arm of Sulawesi still has quite large potential for laterite nickel deposits. Laterite nickel deposits in an area are not

homogeneous, but their presence is controlled by several factors. In general, the distribution of nickel depends on the direction of water flow which is greatly influenced by the shape of the slope (topography). Local topographic conditions will greatly influence the circulation of water and other reagents. Accumulations of laterite nickel deposits are generally found in sloping to sloping areas, this shows that the thickness of weathering follows the shape of the

topography. In steep areas, in general the amount of water that slides (run off) is greater than the water that seeps in, this can cause less intensive weathering. This causes the layer thickness to be relatively thin. Through topographic control, the thickness of nickel laterite will be different in each condition. When processing data from 9 drilling points, each drilling point has a strong wavy topographic slope - hills with a slope of >15.9° and hilly topography -

strongly cut with a slope of >31.8°, which can be seen from the incision map. attached slope.

In the results of the drilling data, it was found that there was an appearance of differences in

laterite thickness due to differences in morphology and slope slope, for example at drill points DH-BBI-309, DH-BBI-310, DH-BBI-312 which were relatively steep points with relatively thin laterite thickness. ranges from 7-9 meters, while drill points DH-BBI-120, DH-BBI-121, DH-BBI-124, DH-BBI-130, DH-BBI-131, DH-BBI-133 have a laterite thickness of 18-26 meters with slopes that are not too steep.

Keywords— Nickel Laterite, Laterite Profile.

GEOLOGI DAERAH PASURUAN DAN SEKITARNYA,KECAMATAN PASREPAN, KABUPATEN PASURUAN, PROVINSI JAWA TIMUR

2025-09-04T11:24:44+07:00

This research was conducted in Pasuruan and surrounding areas, Pasrepan District, Pasuruan Regency, East Java Province. The research was carried out based on the author's curiosity to know the geological conditions of the research area. Geologically, the research area is quite interesting to study in terms of geomorphology, stratigraphy, geological structure, geological history, environmental geology and other geological aspects. The aim of this research is to provide an overview of the geological conditions in the research area and to find out the types of rocks exposed in the research area which was carried out using surface geological mapping methods with the help of petrographic analysis of rock samples in the research area. Based on this research, it is known that the geomorphological units that make up the research area include the Hill geomorphological unit with gently to moderately wavy topography, denudational (D1), the Hill geomorphological unit with gently to strongly wavy topography, denudational (D2), the nearly flat alluvial plain geomorphological unit with Fluvial low elevation sloping topography (F3). The flow patterns in this research area are divided into 2 types, namely parallel flow patterns and subdenritic flow patterns. Stratigraphically, the research area is composed of 3 rock units and mixed deposits above them, including the Arjuna-Welirang Volcano andesite breccia unit, the Arjuna-Welirang Volcano andesite lava unit, the Tengger Volcano tuff unit, and mixed deposits.

Keywords : Rocks, Geomorphology, Geological Structure, and Environmental Geology

GEOLOGI DAERAH KERSAGALIH DAN SEKITARNYA KECAMATAN SALOPA, KABUPATEN TASIKMALAYA, PROVINSI JAWA BARAT

2025-09-04T13:57:26+07:00

The research area is located in the Kersagalih area and its surroundings, Salopa District, Tasikmalaya Regency, West Java Province. Physiographically, it is included in the southern mountainous zone and has been mapped by several previous geologists. This study aims to provide an overview of geological conditions in the research area. The research method is surface geological mapping with the help of petrographic analysis.

Based on the results of the research, the geomorphological units include the Weak Wavy Geomorphology Unit – Denudational Strong (D2), the Strong Undulating Geomorphology Unit – Denudationional Hills (D3), the Flood Plains Geomorphology Unit (F3), There are two flow patterns, namely dendritic and parallel with the stadia of young to adult rivers. Stratigraphy consists of units, namely the Jampang Andesite Breccia Unit, the Jampang Tuff Unit, the Kalipucang Calkarenite Unit, and the Sand – Gravel Deposition Unit. The geological structure is in the form of a straightness pattern that is relatively northeast – southwest. Natural resources in the form of land and water resources that are used as rice fields, plantations, and settlements and have the potential for geological disasters in the form of landslides.

Keywords: Kersagalih, Geology, Stratigraphy, Geomorphology

GEOLOGI DAERAH GUMELAR DAN SEKITARNYA KECAMATAN GUMELAR, KABUPATEN BANYUMAS PROVINSI JAWA TENGAH

2025-09-04T14:13:14+07:00

The mapping area is in Banyumas, specifically Gumelar Village and its surroundings, with an area of ±54 km². Mapping includes aspects of geomorphology, stratigraphy, geological structure, geological history and environmental geology. The geomorphological units of the mapping area are based on morphometry and morphogenesis, namely the Fluvial plain geomorphological unit, and the weakly undulating geomorphological unit - Structural hills. Based on the lithotratigraphic division, the research area is divided into two units, namely the Halang carbonate sandstone unit and the Halang carbonate mudstone unit. Rock formation in the mapping area began in the middle Miocene - Pliocene. The structures that develop are antyclinic and synclinic fold structures, the left slip faults and joints. Sources for the research area are geotourism and agricultural land in pine forests, and land movement.

Keywords: Gumelar, Halang, Geomorphology, Stratigraphy, geological structure.