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Journal : Indonesian Journal on Geoscience

Estimated Emplacement Temperatures for a Pyroclastic Deposits from the Sundoro Volcano, Indonesia, using Charcoal Reflectance Analyses Harijoko, Agung; Ayu Safira Mariska, Nanda; Anggara, Ferian
Indonesian Journal on Geoscience Vol 5, No 1 (2018)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.5.1.1-11

Abstract

DOI: 10.17014/ijog.5.1.1-11This study applies the charcoalification measurement method to infer the emplacement temperature of pyroclastic flow deposits erupted from the Sundoro Volcano, Indonesia. This pyroclastic flow partially covered the Liyangan archeological site, a site where Hindu temples were constructed approximately 1,000 years ago. Five samples of charcoal collected from this area were analyzed for reflectance and elemental composition. Charcoalification temperatures were determined based on mean random optical reflectance values (Ro) plotted on published Ro-Temperature curves. Charcoalification temperatures were also estimated using a published formula based on the charcoal’s hydrogen to carbon (H/C) ratio. These two methods for determining pyroclastic flow deposition temperatures indicated that the pyroclastic deposits that entombed the Liyangan archeological site ranged from 295° to 487°C when they were deposited. This study used very simple, rapid, precise, and low-cost methods of charcoalification temperature measurement to infer the emplacement temperature of a pyroclastic deposit. This estimation procedure could be applied widely to predict emplacement temperatures in volcanic area in Indonesia to enhance volcanic hazard mitigation.
Syn-sedimentary Mafic Volcanics in the Eocene Coal-bearing Tanjung Formation, Senakin Peninsula, South Kalimantan (Borneo), Indonesia Moore, Tim Allen; Friederich, Mike C.; Trofimovs, Jessica; Anggara, Ferian; Amijaya, D. Hendra
Indonesian Journal on Geoscience Vol 7, No 1 (2020)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.7.1.65-85

Abstract

DOI:10.17014/ijog.7.1.65-85Syn-sedimentary mafic volcanism has been identified within a rift setting (Eocene Tanjung Formation) in the Senakin Peninsula, southeast Kalimantan. Fine-grained, dark-grey basalt lava occurs and has prominent vertically oriented columnar jointing. Petrographically, the basalt is composed of small euhedral pyroxene, olivine, and lath-shaped plagioclase phenocrysts within a very fine-grained dark coloured groundmass. A volcaniclastic unit also occurs and in outcrop has sharp contacts with underlying and overlying sedimentary mudstone. The unit is composed of cm-scale clasts of fine-grained to glassy textured basalt with vesicles of varying size and abundance. Euhedral pyroxene phenocrysts are observed within the clasts, although some with overprinting alteration. Palagonite alteration on the margins of some clasts is noted and is indicative of mafic composition volcanic material that has come into contact with sea water. Presence of bivalve and coral fragments in sandstone and mudstone underlying the volcaniclastic unit indicates emplacement into a marine environment. Core description from 33 locations over an 18 km transect length show that both the basalt and volcaniclastic sediments are extensive throughout the east Senakin area. Lithological relationships and compositional similarities between the basalt and volcaniclastic sediment suggest they are related and were contemporaneous with sedimentation within the Tanjung Formation. It is proposed that the basalt unit is designated the Tanah Rata Basalt Member of the Tanjung Formation. If a wider distribution occurs for the volcaniclastic unit it is proposed that it is termed the Gumbil Volcaniclastic Member of the Tanjung Formation.
Preliminary Study of Rare Earth Element and Yttrium (REY) Content of Coal In Sangatta Coalfield, East Kalimantan, Indonesia Anggara, Ferian; T.B.M. Petrus, Himawan; Patria, Aulia Agus; Bangun, Aya Shika
Indonesian Journal on Geoscience Vol 7, No 3 (2020)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.7.3.305-314

Abstract

DOI:10.17014/ijog.7.3.305-314Kutai Basin is known as one of the most prolific sedimentary coal basins in Indonesia. Coal-bearing sequence in Kutai Basin is mainly Miocene to Eocene in age in which the coal seams are mostly in Miocene strata. Researchers have found that REY concentration in some coals and coal ashes are equal to or higher than that of the conventional deposit, as such coal deposit has become an important source for REY. Moreover, REY recovery as by-product from coal deposits could alleviate the “dirty” into “clean” coal energy. Referring to this shifted paradigm, a study on REY in Indonesian coal has put interest not only for researchers, but also for all stakeholders in this country. In this particular study, Sangatta coalfield in East Kalimantan was chosen as the area to observe the REY concentration. This area has been set due to its interesting geological setting, especially Pinang Dome that might have coal deposit with enriched REY. For the analyzed samples, drill cores were collected and then observed closely using polished section, inductively coupled plasma atomic emission spectroscopy (ICP-AES), and inductively coupled plasma mass spectrometry (ICP-MS). Based on the collected data, the highest REY concentration in coal deposit is located in the nearest part of the Pinang Dome. The REY content in coal deposit is associated with hydrothermal fluids and sediment source. These data suggest that there is a significant effect on Pinang Dome in the REY content in the coal deposit.
Spatial Variability in Macro- and Microtextures of A Tropical Intermontane Peatland: Preliminary Investigation into The Kutai Lake Peat System, East Kalimantan, Indonesia Anggara, Ferian; Muchitawati, Guritno Safitri; Moore, Tim. A.; Septantia, Afrina
Indonesian Journal on Geoscience Vol 8, No 2 (2021)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.8.2.275-296

Abstract

DOI:10.17014/ijog.8.2.275-296Peat deposits of the Muara Siran, East Kalimantan area, were investigated for their vertical and lateral succession, to examine the characteristic variability, particularly its macro- and microtextures. The deposits are situated in the Kutai Basin, in the vicinity of several Cenozoic coal deposits. Peat samples were taken from twenty-seven coring sites in the area, using a MacCaulay peat corer. The Muara Siran peatlands lie between the Kedang Kepala and Belayan Rivers. Siran Lake lies between these rivers and within the peat system. The peat thickness varied from 0.5 m to 12 m. Decomposed sapric peat formed the basal and margins of the deposit, overlain by moderately decomposed hemic peat in the central part of the peatlands, though both sapric and hemic peat types are interbedded at the margins of the mire. The fibric peat types were found mostly at the top of the mire and only distal from any active streams. Twenty-four samples of peat were freeze-dried for petrographic analyses of both plant part and maceral analyses using a reflected microscope. On the average, the dominant plant parts were stems and wood (i.e. secondary xylem). Maceral composition was mostly from the huminite group (on the average 89%), particularly the macerals humodetrinite and textinite. Macroscopic peat type and microscopic composition are linked. Fibric peat was found to be rich in wood and textinite. Hemic was mostly composed of stems and wood with textinite and humodetrinite as the most abundant macerals. Sapric peat has near equal proportions of stems, wood, and macerated tissue. Humodetrinite is the most abundant maceral in sapric. The average ash and sulfur content were low, 1.29 wt.% and 0.11 wt.%, respectively. Understanding the physical characteristics of inland peat as in Muara Siran peatland is essential to build knowledge of how inland peat is formed and what makes it different from coastal peat. Muara Siran is a unique, relatively small peatland in the central eastern Kalimantan which is still considerably pristine, hence may serve the aim of this study well.  
Co-Authors Addintamma, Fajri Zakka Afrina Septantia Agung Harijoko Agung Rizki Perdana Agus Prasetya Amaranggana, Adzani Nareswari Andre Nouval Anggun Purnama Edra Arifudin Idrus Arsha Maulana Aulia Agus Patria Aviliana, Aviliana Aya Shika Bangun Ayu Safira Mariska, Nanda Ayu Safira Mariska, Nanda Bangun, Aya Shika Beny Wiranata Beny Wiranata Brilian R. Sadewo Cikasimi, Mutiara Dagus Resmana Djuanda Dea Anisa Ayu Besari Deddy Tanggara Dinar Hananto Kurniawan Diyan Pamungkas Donatus Hendra Amijaya Fahrialam, Aldian Febry Yulindra Abdi Saputra Fenny Tamba Friederich, Mike C. Giwangkara, Atifa Maritza Guritno Safitri Muchitawati Gussyak, Selasian Handika M. Prabu Haryo Edi Wibowo Hendra A, Donatus Hidayat, Tantan Himawan T.B.M. Petrus Himawan T.B.M. Petrus Himawan Tri Bayu Murti Petrus Hotden Manurung Hotden Manurung I Made Bendiyasa Isnadiyati, Oyinta Fatma Isyqi Janna Azizah Wijayanti Jarot Setyowiyoto Jessica Trofimovs Jyalita, Jasmin Kezia Kartika Windya Kezia Kartika Windya Kusuma, Anindya Ayu Kyuro Sasaki Laksono Trisnantoro Lucas Donny Setijadji Mardhani Riasetiawan Mike C. Friederich Moore, Tim Allen Moore, Tim. A. Muchitawati, Guritno Safitri Nanda Ayu Safira Mariska Nugroho Imam Setiawan Oyinta Fatma Isnadiyati Pamungkas, Diyan Patria, Aulia Agus Patria, Aulia Agus Perdana, Agung Rizki Petrus, Himawan Tri Bayu Prakoso, Wildan Guntur Purnama Edra, Anggun Putra, Agik Dwika Putra, Ilham Satria Raditya Sarju Winardi Sasaki, Kyuro Septantia, Afrina Shelia F. Hunarko Sinabang, Paul Vito Parluhutan Slamet Sumardi, Slamet Solikh, Mochammad Wildanun Sugai, Yuichi Sujoto, Vincent Sutresno Hadi Supardin Nompo Susilawati, Rita Tamba, Fenny Tangkas, I Wayan Christ Widhi Herman Tim Allen Moore Tim. A. Moore Trofimovs, Jessica Vanisa Syahra Wahyu Wilopo Wibisono, Sigit Arso Widi Astuti Widi Astuti Widya Rosita Wildan Guntur Prakoso Winda Putri Anggraeni Wiranata, Beny Yuichi Sugai Yusup Iskandar