scholarly journals Geochemistry Acidic Water of Banyupait River Effect Seepage of Crater Water Ijen Volcano, Asembagus, Situbondo, East Java, Indonesia

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.

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.


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.


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.


2020 ◽  

Introduction: Given the crisis of water shortage and the industrial development in Iran, comprehensive water-resource management, planning, and serious handling of water quality of the rivers in Iran are the critical issues to tackle with. The concentration of river pollutants is a function of both the quantity and quality of the river flow regime. In this regard, the construction of large dams leads to quantitative and qualitative changes in downstream rivers. These changes are effective in the health of the river environment for such uses as drinking, agriculture, and industry. Accordingly, it is essential to consider the quality of river water in addition to the amount of river water needs. Materials and Methods: This study examined a 22-km long section of the river at the riffle of Taleghan Dam in Alborz Province (103 km from Karaj), Iran. The average annual and monthly discharges of the river in four 6-km-apart stations were estimated. The statistics of eight hydrometric stations and a discharge-surface method were used to calculate the average annual discharge of each sub-basin downstream of Taleghan Dam. Moreover, the discharge non-dimensionalization method, along with the observational statistics of the index station, was used to calculate the average monthly discharge in the examined stations. The Hydrologic Engineering Centers River Analysis System (RAS-HEC) software was then utilized to determine the values ​​of river flow rates hydraulically. Additionally, water quality parameters were compared with the standard concentrations proposed by the World Health Organization (WHO) for drinking-water quality to examine possible changes in pollutant concentrations during the study. Correlation and regression statistical tests in SPSS software (version 24) were then used to analyze the relationship between discharge and pollutant concentration. Results: The experimental equation of Q = 0.0372A0.8641 was obtained to estimate the discharge based on the sub-basins area using the discharge-surface method. The average annual discharge at stations 2, 3, and 4 (B, C, and D) were estimated at 1.39, 2.11, and 3.39 m3/s, respectively, using this equation. Subsequently, the average monthly discharges in the studied stations in September were calculated at 0.21, 0.29, and 0.46 m3/s, respectively. Afterward, the discharge was measured using HEC-RAS software in the same month at 0.34, 0.44, 0, and 0.62 m3/s, respectively. The examination of water quality values from ​​among the 17 water quality parameters revealed that physicochemical elements, pH concentration, lead (Pb), and electrical conductivity were higher than the standard concentration of drinking water proposed by the WHO. Conclusion: A model was presented to estimate sanitary water flow by performing correlation tests and linear regression calculations between the river discharge at the dam downstream and the concentration of water quality parameters. According to the proposed model, the minimum flow of sanitary water was estimated at 1.82 m3/s to be considered to release from the dam in the driest month of the year. Therefore, the release of water as the minimum flow of sanitary water less than 1.82 m3/s was not allowed in any other month of the year.


1996 ◽  
Vol 34 (12) ◽  
pp. 33-40 ◽  
Author(s):  
Y. Hosoi ◽  
Y. Kido ◽  
H. Nagira ◽  
H. Yoshida ◽  
Y. Bouda

The inflow of pollutant load from urban areas and the stagnation of water due to sea water intrusion cause the deterioration of river water quality in tidal zone. In order to improve water quality, various measures such as the reduction of pollutant load by sewage systems, discharge control from sewage treatment plants considering river flow, nutrient removal by aquatic plants, and the dredging of bottom sediments have been examined. The choice of these measures depends on the situation of the river environment and finances. In this study, a field survey was carried out in a typical urban river basin, first. Secondly, on the basis of this survey, a mathematical model was formed to simulate flow and water quality. Several purification alternatives designed for the investigated river basin were comparatively evaluated from the viewpoint of the effect of water quality improvement and their cost. Finally, they were prioritized. Through this case study, a planning process of river water quality management was shown.


2020 ◽  
Vol 6 (1) ◽  
pp. 28-32
Author(s):  
Novi Komariah ◽  
Saimul Laili ◽  
Hari Santoso

Water is a natural resource that is needed for the life of human being, even for all the creatures. Therefore, these water resources must be protected so that humans and other living things can be utilized properly. The macrofauna community defines whether the water quality is good or not. The study of the effect of river water quality on the diversity of macrofauna in the Metro river flow of Lowokwaru Subdistrict, Malang City aims to determine the effect of river water quality and to compare the diversity of macrofauna in several Metro river locations in Lowokwaru District, Malang. The method used is quantitative descriptive by calculating the Shanon Winner diversity index. The results obtained for station I amounted to 1.95 classified as lightly polluted, at station II the results were 1,007 which were classified as moderately polluted, and at station III the results were 0.69 which were classified as heavily polluted. Key Words: water quality, macro fauna, Metro river ABSTRAK Air merupakan sumber daya alam yang diperlukan untuk kebutuhan hidup orang banyak, bahkan oleh semua makhluk hidup. Oleh karena itu, sumber daya air tersebut harus di lindungi agar tetap dapat di manfaatkan dengan baik oleh manusia dan makhluk hidup lainnya. Komunitas makrofauna menentukan kualitas air baik atau tidak. Penelitian tentang pengaruh kualitas air sungai terhadap keragaman makrofauna di aliran sungai Metro Kecamatan Lowokwaru kota Malang bertujuan untuk mengetahui pengaruh kualitas air sungai dan untuk membandingkan keanekaragaman makrofauna di beberapa lokasi aliran sungai  Metro Kecamatan Lowokwaru kota Malang. Metode yang di gunakan yaitu deskriptif kuantitatif dengan melakukan perhitungan indeks keanekaragaman Shanon Winner. Indeks keanekaragaman yang di hasilkan pada stasiun I sebesar 1,95 yang tergolong tercemar ringan, pada stasiun II indeks keanekaragaman yang di hasilkan sebesar 1,007 yang tergolong tercemar sedang, dan pada stasiun III di dapat hasil indeks keanekaragaman 0,69 yang tergolong tercemar berat. Kata kunci: Kualitas air, makrofauna, sungai metro.


2006 ◽  
Vol 10 ◽  
pp. 41-44 ◽  
Author(s):  
Agnete Steenfelt ◽  
Julie A. Hollis ◽  
Karsten Secher

Ultrabasic alkaline magmatic rocks are products of melts generated deep within or at the base of the lithospheric mantle. The magmas may reach the surface to form lavas and pyroclastic deposits; alternatively they crystallise at depth to form dykes or central complexes. The rocks are chemically distinct and may contain high concentrations of economically interesting minerals and chemical elements, such as diamonds, niobium, tantalum, rare earth elements, phosphorus, iron, uranium, thorium, and zirconium. Ultrabasic alkaline rocks are known from several provinces in Greenland, but extrusive facies have only been preserved at a few places; e.g. at Qassiarsuk in South Greenland where pyroclastic rocks occur, and in the Maniitsoq region, where a small volcanic breccia (‘Fossilik’) contains fragments of Palaeozoic limestone. Ultramafic lamprophyre and kimberlite are mainly emplaced as dykes, whereas carbonatite forms large intrusive bodies as well as dykes. The ultrabasic alkaline magmas that have been emplaced at certain times during the geological evolution of Greenland can be related to major episodes of continental break-up (Larsen & Rex 1992). The oldest are Archaean and the youngest dated so far are Palaeogene. Figure 1 shows the distribution of known ultrabasic alkaline rocks in West Greenland. The large and well-exposed bodies of alkaline rocks and carbonatites in the Gardar Province were discovered already in the early 1800s (Ussing 1912), while less conspicuous bodies were discovered much later during geological mapping and mineral exploration. Many alkaline rock bodies, particularly dykes, are difficult to identify in the field because they weather more extensively than the country rock gneisses and form vegetated depressions in the landscape. However, their distinct chemistry and mineralogy render alkaline rocks identifiable in geochemical and geophysical survey data. Thus, the Sarfartôq carbonatite complex was discovered during regional airborne gamma-spectrometric surveying owing to its elevated uranium and thorium contents (Secher 1986). The use of kimberlite indicator minerals has led to the discovery of alkaline rocks such as kimberlites and ultramafic lamprophyres that carry fragments of deep lithospheric mantle. Such rocks may also contain diamonds. Kimberlite indicator minerals are high-pressure varieties of minerals, such as garnet, clinopyroxene, chromite and ilmenite that were formed in the lithospheric mantle. Exploration companies have processed thousands of till samples from southern West Greenland for kimberlite indicator minerals and found many new dykes.


2020 ◽  
Vol 5 (1) ◽  
pp. 40
Author(s):  
Irien Akinina Fatkhiandari ◽  
I Gde Budi Indrawan, Dr.

Geometries of excavated tunnel portal slopes at Bagong Dam site was initially designed without taking into account earthquake load. The excavated slope designs also assumed the rocks consisting the slopes were homogenous. The purpose of this research was to evaluate stability of the excavated tunnel inlet and outlet slopes at the Bagong Dam site under static and earthquake loads using finite element method. Stability of the natural slopes was also analyzed for comparison. The numerical static and pseudostatic analyses of slope stability were carried out using RS2 software (Rocscience, Inc.). Input data used in the numerical analyses were obtained from engineering geological mapping, rock core analyses, and laboratory tests. Seismic coefficient applied in the pseudostatic slope stability analyses was determined following guideline described in Indonesian National Standard. The engineering geological mapping and evaluation of rock cores indicated that the inlet tunnel slope consisted of four types of materials, namely residual soil, poor quality of volcanic breccia, very poor quality of volcanic breccia, and good quality of volcanic breccia. The outlet portal slope consisted of six types of materials, namely residual soil, very poor quality of limestone, poor quality of limestone, very poor quality of volcanic breccia, poor quality breccia, and good quality breccia. Based on the secondary elastic wave velocity (Vs) values, the rock masses in the research area were classified as hard rock (SA). Seismic analyses based on the earthquake hazard source map with 10% probability of exceedance in 50 years provided by the National Earthquake Center (2017) indicated that the PGA and the corresponding amplification factor FPGA in the research area were 0.3 and 0.8, respectively. The calculated seismic coefficient for the pseudostatic slope stability analyses was 0.12. The numerical analysis results showed that, in general, earthquake load reduced critical Strength Reduction Factor (SRF) values of the slopes. However, the natural and excavated tunnel portal slopes were relatively stable under static and earthquake loads. The natural slope at the tunnel inlet with a 40° inclination had critical SRF value of 4.0, while that of at the tunnel outlet with a 51° inclination had critical SRF value of 2.6. Under static load, the excavated slopes at the tunnel inlet and outlet having a 45° inclination had critical SRF values of 2.4 and 5.0, respectively. Under earthquake load, the excavated slopes at the tunnel inlet and outlet had critical SRF values of 2.3 and 3.5, respectively.


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