scholarly journals Stratigraphy of Kendeng Zone in Miyono Village and Surrounding, Sekar District, Bojonegoro Regency, East Java, Indonesia

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mutawif Ilmi Muwaffiqih ◽  
Wahyu Ardiansyah Nugraha ◽  
Irvan Fatarwin Lubis ◽  
Mochammad Indra Novian

This paper will comprehensively discuss the stratigraphy of the Kendeng Zone by using geological field mapping and laboratory analysis. The research area located in the Miyono Village and surrounding areas, Sekar District, Bojonegoro Regency, East Java with an area of 4x5 km2. Based on the geological mapping results obtained 160 points station with a variety of results in the form of tracking map of the research area. Laboratory analysis uses Embry and Klovan classification (1971), Pettijohn et al. (1987), and Mount (1985) for petrographic analysis, while paleontological analysis using Manual of Planktonic Foraminifera (Postuma, 1971) and Atlas of Benthic Foraminifera (Holbourn et al., 2013). This paper will show the differences between regional stratigraphy and the result, depositional environment, and its mechanism. Lithology units found grouping into nine units. The research area epoch ranged between N18-N23 (early Pliocene - Holocene) and the depositional environment from the lower bathyal to the terrestrial. The geological structures of the research area must be considered in the stratigraphic arrangement determination. Based on the analysis, the Kendeng Zone stratigraphic column was obtained and expected to provide accurate data of Kendeng Zone specifically around Miyono area.

Author(s):  
D., S. Reka

The following research took place in the Jamprong area, Tuban Regency, East Java Province within a study area of 2 km2. Physiographically, the study area is situated in the anticlinorium of the Rembang Zone. This research aims to define the reservoir potential of outcrop samples from the Ngrayong Formation as an analogue for the subsurface. In addition, the depositional environment and the age of the rock in the research area was determined. The Ngrayong Formation is regarded as a potential reservoir in the North East Java Basin. The accumulated data consists of stratigraphy, petrographic analysisand paleontological analysis of rock samples, and geological mapping has been carried out to determine the distribution of rocks. Facies were determined based on outcrop observations and comprise predominantly arkose sandstone facies with fine – coarse grained, moderately sorted and with cross-bedding, herringbone, and lamination, and another facies namely massive carbonate grainstone. Based on these facies, the interpreted depositional environment is the transition of tidal flat to shallow marine carbonate platform with relative biostratigraphic age of Middle Miocene, Langhian to Serravallian (M6-M8 planktonic foraminiferal biozones). Rocks in the study area have porosity >20% or very good and permeability >130 or fair based on petrographic observations, and this supports the interpretation of the Ngrayong Formations as a potential reservoir of hydrocarbons.


Author(s):  
Dwi Fitri Yudiantoro ◽  
Ramonada Taruna Perwira ◽  
Muchamad Ocky Bayu Nugroho

Lamongan volcano is one of the unique volcanoes in the Sunda Volcano. This volcano has side eruption centers or on the slopes of the volcano. The morphology of parasitic eruptions in this volcanoes complex includes maars and boccas. There are about 64 parasitic eruption centers consisting of 37 volcanic cones (bocca) and 27 ranu (maar). The purpose of this research is to study the characteristics of lithology and petrogenesis of this volcano complex, especially in Ranu Pakis and surrounding areas. The analytical method used is to do geological mapping and petrographic analysis. The lithology found in this research area consists of magmatic and phreatomagmatic eruption deposits. Genetically this lithology includes pyroclastic flow, pyroclastic fall (scoria fall and phreatomagmatic scoria fall/accretionary lapili), tuff (phreatic) and basaltic lava. In some pyroclastic deposits, especially in maar there are fragments of accretionary lapilli, while in bocca there are basaltic lavas. Other fragments present in pyroclastic deposits are basalt scoria blocks and bombs embedded in the groundmass of volcanic ash. The results of petrographic analysis indicate that the volcanic rocks in the study area are calc alkaline affinity consisting of pyroxene andesite, basalt and pyroxene basalt lava. The pyroxene basalt lava is composed by plagioclase, clinopyroxene and little olivine embedded in the volcanic glass. Lavas are structured scoria and textured porphyritic, intersertal, trachytic, aphyric and pilotaxitic. Trachytic texture is found in the basalt fragments of pyroxene from the pyroclastic fall deposits in Ranu Pakis and Ranu Wurung. While pyroxene andesite lavas composed by plagioclase, clinopyroxene embedded in the volcanic glass. Lavas are structured scoria and textured porphyritic, intergranular, pilotaxitic and aphyric.


1989 ◽  
Vol 63 (2) ◽  
pp. 146-157 ◽  
Author(s):  
David T. Cassell ◽  
Barun K. Sen Gupta

The sandstone facies of the Pliocene Rio Banano Formation of eastern Costa Rica contains benthic foraminifera indicative of an open marine, current-swept, neritic depositional environment. These sandstones and associated siltstones are placed in Zone N18 on the basis of overlapping ranges of planktonic foraminifera, particularly Globigerinoides obliquus extremus and G. ruber, and a short-ranging ostracode species, Radimella ovata. One hundred and eight species of benthic foraminifera have been identified from the formation. A multiple-group-component factor analysis of abundance distributions of several dominant or common species (Amphistegina gibbosa, Articulina mayori, Cassidulina laevigata, C. subglobosa, Cibicidoides floridanus, Elphidium discoidale, Hanzawaia concentrica, Pararotalia sarmientoi, Pseudononion basispinata, Quinqueloculina lamarckiana, Rosalina globularis, and Trifarina angulosa) in the type section aided in the recognition of three benthic foraminiferal assemblages related to environmental parameters. An open marine, shallow, sandy continental shelf environment is suggested by the first assemblage. This is considered the typical depositional environment of the unit. The second and the third assemblages, suggesting an inner littoral environment and the proximity to a reef, respectively, also indicate introduction of significant amount of transported material into the thanatotopes.


Author(s):  
Dwi Fitri Yudiantoro ◽  
Bambang Agus Irawan ◽  
Intan Paramita Haty ◽  
Dewi Sri Sayudi ◽  
Arum Suproboriniaru ◽  
...  

The Ijen volcano has Pleistocene age (294.00 ± 0.03 Ma), and this stratovolcano was very acidic crater water with a pH of 0-1. The acidic crater water seeps into the Banyupait river flow. Asembagus is a research area located on the northern slope of the Ijen volcano, and the Banyupait River drains this. The acidic river water flows from the Ijen Crater Lake, so the pH of the water river was very acidic. This study used several different analytic methodologies with some previous researchers, namely using the method of geological mapping, pH measurement, spectrophotometry, IRMS (Isotope Ratio Mass Spectrometer), and the technique of Induced Coupled Mass Spectrometry (ICP-MS). Besides, the petrographic analysis is used to determine the composition of rock minerals due to rocks interacting with acidic water. Banyupait River water in the Asembagus area has a pH of river water around 3-7.3, SO4 (220-683 ppm), and the type of water is meteoric water. Also, concentrations of Ca, K, Mg in the west Banyupait river irrigation water flow showed higher levels when compared to the eastern Banyupait River water flow. Likewise, REE elements from the Asembagus region showed lower concentrations compared to Ijen Crater water. This change in the level of chemical elements is caused by the acidity of the Banyupait River being diluted or mixed with water from other water. However, the spring was not affected by acidic water. The process of acidic water interaction with rocks can also be observed from rocks traversed by the Banyupait River flow. Chalcedony and hematite replace the primary minerals of basaltic rocks. This research is expected to improve the quality of water needed by the Asembagus community so that people can live healthily.


2021 ◽  
Vol 6 (3) ◽  
pp. 216
Author(s):  
Al Hussein Flowers Rizqi ◽  
Oky Sugarbo

The presence of surface water is always being a primary issue in Gunung Kidul regency. An aquifer investigation would support groundwater exploration. The research area is located in Tambakromo village, Ponjong subdistrict, Gunung Kidul Regency, Daerah Istimewa Yogyakarta Province. The aim of this research is about geological and subsurface conditions based on geological data and geoelectrical resistivity methods. By resistivity value interpretation, the position, depth, and thickness of aquifer could be determined. The purpose of this research is to identification of geological conditions that supported being aquifer rock. The method in this research is used geological mapping combined with petrographic analysis. The geophysics method is used to identification of aquifer in research area. Three locations were selected to acquisition geoelectrical resistivity survey. In Grogol village, there is no aquifer based on resistivity values of more than 10000 ohmmeters (andesitic breccia). An akuifuge is interpreted there in andesitic breccia instead of the presence of aquifer. The tuffaceous is interpreted as lapillistone that contained the glass with resistivity value of 43.63 and 340.11 ohmmeters. The Garon and Sumberejo village have aquifer at depth of 50 to 80 meters with a thickness of 13 to 70 meters. The type of aquifer in both area is included an unconfined aquifer, specifically located in between the limestone rock layer and andesitic breccia. By regional stratigraphic correlation, tuffaceous lapillistone is interpreted as derived from Semilir Formation. In addition, the presence of aquifer in research area could recommend for local people and government to reduce the drought disaster.


2021 ◽  
Vol 317 ◽  
pp. 01031
Author(s):  
Mohamad Fajril Falah ◽  
Jenian Marin ◽  
Tri Winarno

Ngempon Temple is one of the historical sites around the Mount Ungaran area. Ngempon Temple is the result of Hindu civilization in Indonesia which was built in the VIII-IX century. This research was conducted in the Ngempon area because it is necessary to conserve historical sites associated with geological sites in the study area. This study aims to determine the geological aspects that have the potential to become geotourism sites in the research area. The methods used are geological mapping for field data collection and petrographic analysis to determine rock characteristics. There are several sites including historical sites and geological sites in the vicinity of Ngempon Temple, namely Ngempon Temple, Diwak Waterfall, and Derekan Hot Springs. The lithologies found in the research area are claystone, tuff sandstone, basaltic andesite breccia, and andesite breccia. The volcanic rock in the research area is formed by Mount Ungaran activity during Lower Pleistocene until Holocene.


Author(s):  
Catur Cahyaningsih ◽  
Anjas Latif Ritonga ◽  
Shaury Aldila ◽  
Zulhikmah Zulhikmah

Research areas were located in the west of Kolok Nan Tuo Village. Geographically this area is located at coordinates 00 ° 36'57,85 '' - 00 ° 37'56,89 '' latitude and 100 ° 42'10,08 '' 100 ° 43'47,28 " BT. The methods used in research is geological mapping. Based on the results of stratigraphic research area is divided into three units consist of: Crystalline Limestone Unit (SBGK) consisting Crystalline Limestone of and mudstone lithofacies, Conglomerate Units (SK) consists of polymic conglomerate and sandstones greywacke lithofacies while claystone Unit (SBL) lithofacies  consists of claystone with sedimentary structures is flake. Result of research can interpreted Depositional environment based on type of lithofacies include of grain size, sedimentary structures and content of fossils. SBGK interpretated  depositional environment is a basement of basin, SK depositional environment debris unit limestones can be seen from fragments of conglomerates that many there are crystalline limestones and mudstone that make up the alluvial fan (deposition surface) and lithologies clay from sedimentary structures where rock mudstone generally in doposition the current flow that quiet can form sedimentary structures flake and properties of claystone which carbonated an identifier depositional environments sea so can be determined that the environment in the form of neritic environment.


2020 ◽  
Vol 9 (3) ◽  
pp. 72-77
Author(s):  
Fahri Adrian ◽  
Ariadi Putra ◽  
Akmal Muhni ◽  
Marwan Marwan

Kecamatan Montasik terdiri dari 2 formasi yaitu Formasi Gunungapi Lam Teuba berumur Pliosen Akhir sampai Plistosen Akhir dan Formasi Anggota Padangtiji berumur Pliosen Awal sampai Pliosen Tengah. Litologi Formasi Anggota Padangtiji terdiri dari konglomerat, batulanau, batupasir gampingan dan batu gamping. Lingkup penelitian ini meliputi kajian tentang kondisi geologi permukaan dan analisis lingkungan pengendapan sedimen karbonat pada lokasi penelitian. Metode yang digunakan dalam penelitian ini yaitu pengambilan data langsung di lapangan dan menganalisis petrologi dan petrografi pada sampel batuan. Litologi pada lokasi penelitian terdiri dari 7 satuan yaitu guguran lava, lava andesit, lapili jatuhan piroklastik, tuf jatuhan piroklastik, konglomerat, batugamping terumbu dan batupasir gampingan. Lingkungan pengendapan sedimen karbonat yang terdapat pada lokasi penelitian terbentuk di laut dangkal (reef) pada kedalaman 0 m - 200 m di bawah permukaan laut. Zona fasies pengendapan batugamping pada lokasi penelitian terendapkan pada zona platform margin sands  dan organic buildups. Sedangkan zona fasies terumbu pada lokasi penelitian terdapat pada zona reef front. Montasik district consists of two formations, Gunungapi Lam Teuba Formation aged Late Pliocene – Late Pleistocene and Padangtiji Member aged Early Pliocene – Middle Pliocene. Lithology of Padangtiji Member consists of conglomerate, siltstone, carbonate sandstone, and limestone.  The scope of this research includes a study of surface geological conditions and depositional environmental analysis of carbonate sediment. The method used in this study is direct data collection in the field and analyzing petrology and petrography in rock samples. Lithology of the research area consists of lava drop, andesit, lapili pyroclastic, tuff pyroclastic, conglomerate, fosilliferous limestone, and carbonate sandstone. Depositional environment in the research area formed at shallow marine (reef) on 0m-200m depth under sea level. Depositional facies zone in the research area is on the margin sands platform zone and organic buildups, while Reef facies zone contained in reef front zone.Keywords: Geological Mapping, Depositional Environment, Carbonate Rocks, Petrography, Montasik


Author(s):  
B. Andika

The Kutai Basin contains prolific reserves of oil and gas. The study of depositional environments is one of the goals of oil and gas exploration. The location of this research is situated in the Tanah Merah area, Samarinda. The objective of this research was to analyse outcrops of the Pulau Balang Formation exposed in the Tanah Merah area to determine the depositional environment. Site specific studies were conducted at 3 localities in this area; TM1, TM2 and TM3. This study combines geological mapping, measured sections, facies analysis, petrography, ichnofacies analysis and microfossil analysis. Geological mapping was carried out to determine the distribution of rock units and geological structures. Measured sections were used for facies analysis and the identification of sedimentary structures and ichnofacies. Petrography was carried out to determine the mineral content of rocks and microfossil analysis for palaeobathymetric environmental analysis. The geological structure of the study area comprises a NE-SW trending anticline and syncline and a left lateral strike-slip fault with E-W direction. The study area is entirely within the Middle Miocene age Pulau Balang Formation and can be divided into three facies associations. The TM1 facies association comprises strata interpreted to be deposited in a supratidal marsh and intertidal flat environment. The TM2 facies association comprises strata interpreted to be deposited in a subtidal, intertidal, and supratidal environment. The TM3 facies association comprises strata interpreted to be deposited in a shoreface environment. The petrography of the study area indicates that rock units predominantly comprise quartz wacke and lithic wacke. Two ichnofacies were identified in the research area 2, namely the Skolithos ichnofacies and the Skolithos-Cruziana ichnofacies and contain ichnogenera namely Ophiomorpha, Skolithos, Planolites, Thalassinoides, Paaleophycus. Microfossil analysis found benthonic foraminifera species including Nodosaria lamellala, N. radicula, Vaginulinopsis tricarinata, Lagena costata, Striatissima vaginulina, Bulimina lappa, Planularia auris, Quinqueloculina seminulum, Bolivina punctata and Lahena laevis. Based on the presence of these microfossils and ichnofacies, it is interpreted that the research area was deposited in a neritic-bathyal environment.


Author(s):  
Fajar Rizki Widiatmoko ◽  
Mochammad Aziz ◽  
Irwan Firmansyah

Mapping is the activity of collecting data from an area to be mapped, in the context of geology mapping means collecting data that includes descriptions of rocks, rock structures, rock positions, structure measurements (plunge/trend, pitch, microfold), rock thickness measurements, rock sampling and sketches. landscape, covering an area to be mapped. Research in the area of Gunungbatu and its surroundings, Bodeh District, Pemalang Regency, Central Java Province with the aim of knowing and knowing that it is in the research area by reconstructing the history of formation or geomorphological history, merely tectonic history in space and time, reconstructing geological history based on micropaleontological analysis. Based on the analysis carried out, it was found that the geomorphological units of the study area were divided into 5, namely the Gunungbatu Syncline Hills Unit, the Kali Bodas Anticline Valley Unit, the Girimulya Syncline Hills Unit, the Cenggiri Homocline Hills Unit and the Kebubung Homocline Valley Unit. The geology of the study area consists of two unofficial rock units in order from oldest to youngest, namely the claystone-sandstone unit and the sandstone-claystone unit. The geological structures of the pinpoint folds and faults are Mount Ketos Syncline, Kali Bodas Anticline, Gapura Syncline, Pertapan Igir Syncline, Cenggiri River Rising Fault, Kebubung Dextral Fault, and Girimulya Dextral Fault. The geological history of the research area begins with the book Unit of Claystone in the Middle Miocene Environment in Upper Bathyal. Furthermore, after the claystone-sandstone units were deposited, during the Middle Miocene – Late Miocene in the Deep Neritic Environment, the sandstone-claystone units were deposited with a turbidite mechanism. As well as the geological resource potential of the research area in the form of river utilization in the form of chunks of igneous rock, river sand deposits and gold seepage. Meanwhile, the potential for geological disasters in the form of landslides.


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