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Tertiary Sequence Stratigraphy of Bird Head Area, Eastern Indonesia Alam, Syaiful; Setiadi, Djadjang Jedi
Indonesian Journal on Geoscience Vol 6, No 3 (2019)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2017.393 KB) | DOI: 10.17014/ijog.6.3.267-278

Abstract

DOI: 10.17014/ijog.6.3.267-278 A long depositional period of Papua limestone called Kais Formation, which is overlain by clastic sediments of Steenkool Formation, reflects an interesting stratigraphic architecture in the West Papua region. Using seismic stratigraphic method of five stacking patterns, forestepping, downstepping, upstepping, backstepping, and seismic facies (parallel, prograding clinoform, channel fill, mounded) have been observed. Chronostratigraphic reconstruction was completed to figure out the depositional units in space and time. This study reveals the lowstand deposit during Early to Middle Eocene (LST), transgressive-highstand carbonate deposit during Middle Eocene to Middle Oligocene, and transgressive-highstand silisiclastic (TST-HST) deposit during Middle Miocene - Late Pliocene.  
Tertiary Sequence Stratigraphy of Bird Head Area, Eastern Indonesia Alam, Syaiful; Setiadi, Djadjang Jedi
Indonesian Journal on Geoscience Vol 6, No 3 (2019)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.6.3.267-278

Abstract

DOI: 10.17014/ijog.6.3.267-278 A long depositional period of Papua limestone called Kais Formation, which is overlain by clastic sediments of Steenkool Formation, reflects an interesting stratigraphic architecture in the West Papua region. Using seismic stratigraphic method of five stacking patterns, forestepping, downstepping, upstepping, backstepping, and seismic facies (parallel, prograding clinoform, channel fill, mounded) have been observed. Chronostratigraphic reconstruction was completed to figure out the depositional units in space and time. This study reveals the lowstand deposit during Early to Middle Eocene (LST), transgressive-highstand carbonate deposit during Middle Eocene to Middle Oligocene, and transgressive-highstand silisiclastic (TST-HST) deposit during Middle Miocene - Late Pliocene.  
Tertiary Sequence Stratigraphy of Bird Head Area, Eastern Indonesia Syaiful Alam; Djadjang Jedi Setiadi
Indonesian Journal on Geoscience Vol 6, No 3 (2019)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2017.393 KB) | DOI: 10.17014/ijog.6.3.267-278

Abstract

DOI: 10.17014/ijog.6.3.267-278 A long depositional period of Papua limestone called Kais Formation, which is overlain by clastic sediments of Steenkool Formation, reflects an interesting stratigraphic architecture in the West Papua region. Using seismic stratigraphic method of five stacking patterns, forestepping, downstepping, upstepping, backstepping, and seismic facies (parallel, prograding clinoform, channel fill, mounded) have been observed. Chronostratigraphic reconstruction was completed to figure out the depositional units in space and time. This study reveals the lowstand deposit during Early to Middle Eocene (LST), transgressive-highstand carbonate deposit during Middle Eocene to Middle Oligocene, and transgressive-highstand silisiclastic (TST-HST) deposit during Middle Miocene - Late Pliocene.  
A Combination of Embedded Markov Chain and Binomial Probability As A Tool in Sedimentary Facies Analysis Djadjang Jedi Setiadi; Iyan Haryanto; Budi Muljana; Syaiful Alam
Indonesian Journal on Geoscience Vol 9, No 3 (2022)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.9.3.291-302

Abstract

DOI:10.17014/ijog.9.3.291-302The methodology of facies analysis may include statistical examination to establish a local facies model. Without such examination, it is very difficult to predict the facies succession and to interpret the changes in depositional conditions from thick or complex stratigraphic sections. Based on the survey of sedimentary geologic literature in Indonesia, it is suggested that the aforementioned statistical method has relatively seldom been used in Indonesia. Such a situation may reflect a gap in information on the methodology and, accordingly, it seems imperative that there should be a re-exposition of the method. This paper presents a concise exposition of the combination of the embedded Markov Chain and binomial probability as one of the most successful statistical methods which are used in facies analysis. The results of previous studies of The Citalang Formation are used as a case study to illustrate its applications to the real geologic world.
A Combination of Embedded Markov Chain and Binomial Probability As A Tool in Sedimentary Facies Analysis Djadjang Jedi Setiadi; Iyan Haryanto; Budi Muljana; Syaiful Alam
Indonesian Journal on Geoscience Vol. 9 No. 3 (2022)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.9.3.291-302

Abstract

DOI:10.17014/ijog.9.3.291-302The methodology of facies analysis may include statistical examination to establish a local facies model. Without such examination, it is very difficult to predict the facies succession and to interpret the changes in depositional conditions from thick or complex stratigraphic sections. Based on the survey of sedimentary geologic literature in Indonesia, it is suggested that the aforementioned statistical method has relatively seldom been used in Indonesia. Such a situation may reflect a gap in information on the methodology and, accordingly, it seems imperative that there should be a re-exposition of the method. This paper presents a concise exposition of the combination of the embedded Markov Chain and binomial probability as one of the most successful statistical methods which are used in facies analysis. The results of previous studies of The Citalang Formation are used as a case study to illustrate its applications to the real geologic world.
MOUNTAIN-FRONT SINUOSITY AND ASYMMETRICAL FACTOR OF LELES-GARUT INTRA-ARC BASIN, WEST JAVA Haryanto, Iyan; Setiadi, Djadjang Jedi; Alam, Syaiful; Ilmi, Nisa Nurul; Sunardi, Edy
Journal of Geological Sciences and Applied Geology Vol 2, No 5 (2018): Journal of Geological Sciences and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v2i5.20230

Abstract

The Leles-Garut Basin, with an elevation ranges between 650 and 725 above mean sea level, is a Quaternary topographic basin area situated in the east-trending volcanic arc of West Java. In contrast to the adjacent Bandung Basin, the nature of the basin bounding area of the Leles-Garut Basin is not clearly defined. The presence of volcanic chain and structural lineament exhibits the difference in morphological features. A quantification of morphological indices was chosen to redefine an active tectonic involvement in surrounding basin border. Mountain-front sinuosity indices range from 1.1 to 3.9 and basin asymmetrical factor suggests a wide range of the effects of active tectonic even a little tilting. The study unveil that the basin bounding is not only volcano-bounded but also fault-bounded.
Miocene Planktonic Foraminiferal Biozonation for South Sumatra Basin, Indonesia Setiadi, Djadjang Jedi; Hendarmawan, .; Sunardi, Edy; Sentani, Eddy Arus; Hutabarat, Johanes
Journal of Geological Sciences and Applied Geology Vol 2, No 3 (2017): Journal of Geological Sciences and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v2i3.15615

Abstract

Planktonic foraminifera are widely utilized for marine sediments analysis and recent developments in the geochronology of planktonic foraminifera has improved their values as a tool for sedimentary basin analysis. Assessment on the applicability of the “standard” foraminiferal biozonations (e.g., Bolli, 1966; Blow, 1969; and Postuma, 1971) to the biostratigraphy data of the South Sumatra Basin suggests that the standard zones, which are mostly interval-zones defined by first occurrence events, are hardly applicable to the biostratigraphy data derived from the examination of well-cuttings routinely and continuously used in most sedimentary basin studies in Indonesia.The proposed biozonation in this paper were constructed based on two considerations, i.e. information on the biostratigraphy events as indicated in regional- and global-scale biozonation schemes and the occurrence of foraminifera species in the South Sumatra Basin. The correlation between the proposed zonation and that of Blow’s (1969) scheme suggests that the proposed zonation is basically a Blow’s zonation and, accordingly, may be perceived as a modified Blow’s zonation for South Sumatra Basin. 
PENDEKATAN KUANTITATIF DALAM PENENTUAN ASOSIASI FASIES LAUT DALAM FORMASI HALANG PADA SUNGAI KALIGINTUNG, JAWA TENGAH SUBAGJA, MUHAMAD AGAM; Setiadi, Djadjang Jedi; Jurnaliah, Lia; Syafri, Ildrem; Alam, Syaiful; Elfitra, Dhanu
Bulletin of Scientific Contribution Vol 17, No 3 (2019): Bulletin of Scientific Contribution : GEOLOGY
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (932.863 KB) | DOI: 10.24198/bsc.v17i3.23503

Abstract

Penggunaan metode kuantitatif cukup berkembang pada tahun 1950an dalam bidang sedimentologi dan stratigrafi terutama dalam membantu menjelaskan asosiasi fasies, proses pembentukannya dan lingkungan pengendapan. Lokasi penelitian berada koordinat 07° 30' 00,0" – 07° 30’ 30.0” LS dan 109° 27' 30,0" – 109° 28’ 10,0” BT yang secara administratif berada pada Provinsi Jawa Tengah. Daerah penelitian termasuk ke dalam Formasi Halang. Tujuan dari penelitian ini adalah untuk mengetahui model asosiasi fasies lokal yang terbentuk pada daerah penelitian. Pengambilan data dilakukan dengan metode penampang stratigrafi terukur pada sebagian lintasan Sungai Kaligintung sedangkan pengolahan data dibantu oleh metode kuantitatif berupa analisis Markov Chain dan Binomial Probability untuk mengetahui hubungan antar fasies. Pada daerah penelitian terdapat 13 litofasies yaitu Diorganized gravels (A1.1), Normally-graded Pebbly Sand (A2.7), Thick-bedded disorganized sand (B1.1), Thin-bedded coarse-grained sand (B1.2), Parallel-stratified sand (B2.1), Thick-bedded sand-mud couplet (C2.1), Medium-bedded sand-mud couplet (C2.2), Thin-bedded sand-mud couplet (C2.3), Mud-dominated sand-mud couplet (C2.4), Mottled muddy sand (C1.2), Structureless silt (D1.1), Structureless mud (E1.1) dan Contorted strata (F2.1). Adapun asosiasi fasies pada daerah penelitian terdiri atas Channel fill deposit, Levee deposit, Lobe deposit dan Interchannel deposit. Kata kunci :   Binomial Probability, Formasi Halang, Litofasies, Markov Chain.
Regresi Non-Linear pada Pemodelan Dekompaksi Alam, Syaiful; Nurdradjat, .; Muljana, Budi; Setiadi, Djadjang Jedi
Bulletin of Scientific Contribution Vol 17, No 1 (2019): Bulletin of Scientific Contribution GEOLOGY
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (423.801 KB) | DOI: 10.24198/bsc.v17i1.20989

Abstract

AbstractDecompaction modeling is critical step in geohistory analysis. Decompaction modeling aims to obtain the thickness of stratigraphic unit before being compacted. Formulation of decompaction modeling requires initial porosity ( )  and coefficient of compaction (c). These two parameters are disentangled by porosity-depth relationship. Exponential model is used as the basis for knowing the relationship. Historically, exponential model often describes a more realistic porosity-depth phenomenon than other models. The exponential model yield the absence of negative porosity as the depth increases. The parameter  and c from a number of data are solved through regression method. This paper presents statistical explanation on non-linear regression to generate a simpler formulation, thus facilitating the calculation of initial porosity and coefficient of compaction. These parameters are used later in decompaction modeling.  Keywords: Decompaction modeling, non-linear regression, initial porosity, coefficient of compaction. AbstrakPemodelan dekompaksi adalah bagian yang penting dalam analisis geosejarah. Pemodelan dekompaksi bertujuan untuk mendapatkan ketebalan unit stratigrafi sebelum mengalami kompaksi. Formulasi pemodelan dekompaksi memerlukan parameter porositas awal ( ) dan koefisien kompaksi (c). Kedua parameter tersebut dapat ditentukan dari model porositas-kedalaman yang digunakan. Model eksponensial dijadikan sebagai landasan untuk mengetahui hubungan tersebut. Secara historis, model eksponensial seringkali menyajikan fenomena porositas-kedalaman yang lebih realistis dibandingkan dengan model lain. Model eksponensial memungkinkan tidak adanya nilai porositas yang negatif seiring dengan bertambahnya kedalaman. Parameter  dan c dari sejumlah data tersebut dapat dicari melalui metode regresi. Paper ini menyajikan pemaparan proses statistik regresi non-linear sehingga menghasilkan formulasi yang lebih sederhana. Formulasi ini memudahkan perhitungan penentuan parameter   dan c. Parameter tersebut digunakan nantinya dalam pemodelan dekompaksi. Kata kunci: Pemodelan dekompaksi, regresi non-linear, porositas awal, koefisien kompaksi.
BATUBARA FORMASI STEENKOOL DI DAERAH RANSIKI, PAPUA Setiadi, Djadjang Jedi; Alam, Syaiful; Nurdrajat, .; Gani, Reza Mohammad Ganjar; Firmansyah, Yusi
Bulletin of Scientific Contribution Vol 16, No 3 (2018): Bulletin of Scientific Contribution GEOLOGY
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1212.477 KB) | DOI: 10.24198/bsc.v16i3.19008

Abstract

Makalah ini menyajikan hasil penelitian terhadap salah satu endapan batubara yang belum banyak dikenal dalam literatur geologi Indonesia, yakni batubara Formasi Steenkool (akhir Miosen – Plistosen) yang ada di daerah Ransiki, Kepala Burung, Papua. Hasil penelitian lapangan menunjukkan bahwa batubara Formasi Steenkool dapat dibedakan menjadi tiga jenis, yakni bright coal, banded bright coal, dan dull coal. Batubara tersebut umumnya berwarna hitam dengan gores coklat, dan keras. Belerang kadang-kadang ditemukan mengisi bidang pecah planar hingga conchoidal yang berkembang didalamnya. Lapisan-lapisan batubara Formasi Steenkool di daerah Ransiki memiliki ketebalan yang sangat bervariasi, mulai dari beberapa centimeter hingga hampir 3 m. Sebagian diantaranya mengandung parting serpih karbonan dengan ketebalan umumnya kurang dari 20 cm. Lapisan-lapisan batubara umumnya diapit oleh lapisan serpih karbonan, meskipun ada sebagian diantaranya yang dialasi atau ditutupi oleh lapisan batupasir halus. Hasil penelitian laboratorium terhadap 13 sampel terpilih mengindikasikan bahwa batubara Formasi Steenkool umumnya memiliki kelembapan rata-rata < 3% adb, kadar abu rata-rata < 5%, kadar volatil rata-rata > 40%, kandungan karbon tertambat rata-rata > 45%, dan kadar belerang rata-rata < 1% dengan nilai kalor > 5000 kal/g. Penelitian ini mengungkapkan hasil yang berbeda dengan laporan yang selama ini diterima mengenai batubara Formasi Steenkool. Pertama, hasil penelitian ini menujukkan bahwa hampir semua batubara Formasi Steenkool di daerah penelitian merupakan high-volatile subbituminous coal, bukan lignit sebagaimana dilaporkan selama ini. Kedua, batubara Formasi Steenkool memiliki kualitas yang cukup baik. Hal itu terlihat dari bukti fisik sebagaimana terlihat di lapangan dan dari hasil penelitian laboratorium yang menunjukkan bahwa semua sampel memiliki nilai kalor lebih dari 5000 kal/g. Hasil penelitian ini mengindikasikan bahwa batubara Formasi Steenkool layak diteliti lebih lanjut dan seksama untuk mengetahui potensi endapan batubara di wilayah Kepala Burung, Papua, dan untuk mengkaji nilai ekonomis yang mungkin dimilikinya.Kata kunci: Formasi Steenkool, Batubara, Papua