Papers by Salahuddin Husein
Rekaman gaya tektonik terekam pada batuan dalam bentuk kekar-kekar ekstensi maupun gerus. Secara ... more Rekaman gaya tektonik terekam pada batuan dalam bentuk kekar-kekar ekstensi maupun gerus. Secara kuantitatif, respon batuan terhadap deformasi dapat didekati dari aspek densitas kekar, yang dikontrol oleh sifat kompetensi batuan. Kompetensi batuan dipengaruhi oleh ukuran butir, komposisi, dan tingkat sementasi batuan. Penelitian ini bermaksud menyajikan hubungan antara densitas kekar dan faktor-faktor geologi yang mempengaruhi kompetensi suatu batuan, dengan studi kasus pada batuan volkaniklastik Formasi Semilir yang tersingkap di Piyungan, Bantul, D.I. Yogyakarta. Area kajian berupa singkapan tebing setinggi 7 meter dan lebar 30 meter. Pada singkapan tersebut, Formasi Semilir yang berumur Miosen Tengah tersusun atas perselingan batupasir bergradasi normal dan batulanau. Ketebalan masing-masing lapisan bervariasi dari 5 cm hingga 400 centimeter. Struktur kekar dijumpai hampir di setiap lapisan dengan kerapatan yang berbeda-beda. Metode yang dilakukan dalam penelitian ini adalah pengukuran distribusi kekar secara kuantitatif pada setiap lapisan dengan lebar singkapan 5 meter. Data diolah secara statistik dan diplot ke dalam grafik versus antar aspek yang mempengaruhi kompetensi batuan. Batuan yang memiliki ukuran butir kasar dan tebal mempunyai tingkat kompetensi tinggi sehingga hanya sedikit merekam kekar. Batuan yang memiliki ukuran butir halus dan tipis mempunyai tingkat kompetensi rendah sehingga dapat merekam kekar dengan rapat. Komposisi volkanik pada Formasi Semilir mempunyai peran dalam tingkat pengelasan antar fragmen (welded structure) yang dapat menambah tingkat kompetensi batuan. Kata kunci:Densitas Kekar, Formasi Semilir, Kompetensi Batuan
Peran geomorfologi secara kuantitatif dalam menentukan proses geologi yang paling dominan pada Da... more Peran geomorfologi secara kuantitatif dalam menentukan proses geologi yang paling dominan pada Daerah Aliran Sungai (DAS) Ngalang, Kecamatan Gedangsari, Kabupaten Gunungkidul, Propinsi Daerah Istimewa Yogyakarta sangat penting mengingat kompleksitas geologi daerah tersebut, tetapi sampai saat ini belum ada kajian yang membahas hal ini. Penelitian ini bertujuan untuk mengidentifikasi proses geologi dan membuat delineasi zona kontak litologi dan struktur geologi pada bagian-bagian dari DAS Ngalang berdasarkan karakteristik dari tiga indeks geomorfik, yaitu hypsometric curve, stream-length gradient index (SL), dan transverse topographic symmetry factor (T-index). Dari ketiga indeks geomorfik tersebut, didapatkan bahwa secara umum DAS Ngalang sangat dipengaruhi oleh tektonik dengan tingkat erosi lebih besar di bagian selatan. Kombinasi data SL dan data T-index dapat menunjukkan zona kontak litologi dan zona sesar.
Way Panas is part of Ulubelu geothermal field, which is situated at the southern end of Sumatera ... more Way Panas is part of Ulubelu geothermal field, which is situated at the southern end of Sumatera Island, Indonesia. This geothermal field is built along the active Sumatera Fault Zone, which also had acted as the main control on the development of geothermal system on the area. Abundant surface thermal manifestation were observed in the Way Panas, such as hot springs, fumaroles, gas discharges, mud pots, steaming grounds, and altered rocks. Several geologic and geophysic studies have been conducted, and some geothermal system model were proposed. However, since this area were strongly controlled by tectonic processes, it is noticed that the role of geologic structures have never been put in considerable study. This paper presents recent findings on tectonic and structural geology based on geologic mapping and remote sensing interpretation. A number of 1938 lineaments were extracted from digital elevation model, which were analyzed according to their respective rock ages. A number of 220 tectonic joints and fault kinematic were analyzed from field data. It is observed that those surface manifestations were associated with major NW-SE normal fault, which acting as boundary fault of Early Pliocene structural graben that filled by Plio-Pleistocene volcanic complex. This NW-SE structural trend was part of the Sumatran Fault system, and its reactivation produced extensional faults and joints controlled the outflow of geothermal system. Another significance finding was arcuate geologic structures produced by volcanic load that influenced the existing geothermal system.
Cekungan Serayu Utara merupakan salah satu dari dua cekungan yang menyusun Jawa Tengah.Di Cekunga... more Cekungan Serayu Utara merupakan salah satu dari dua cekungan yang menyusun Jawa Tengah.Di Cekungan ini, banyak dijumpai rembesan hidrokarbon (minyak dan gas bumi) di permukaan, sebagai salah satu tanda aktifnya sistem petroleum.Meski demikian, kompleksitas geologi yang dimiliki cekungan ini membuatnya dikenal sebagai “terra incognita” dalam dunia eksplorasi migas di Pulau Jawa.Sebagai salah satu manifestasi permukaan, rembesan hidrokarbon dapat menjadi jendela dan titik tolak pendekatan dalam mempelajari kondisi geologi bawah permukaan bagi unsur-unsur penting dalam sistem petroleum.Berlandaskan pemahaman tersebut, penelitian ini bermaksud untuk mempelajari faktor-faktor geologi yang pernah bekerja di Cekungan Serayu Utara yang mengontrol terjadinya rembesan hidrokarbon di Desa Sijenggung, Kecamatan Banjarmangu, Kabupaten Banjarnegara, Jawa Tengah.Di permukaan, rembesan tersebut terjadi pada singkapan Formasi Rambatan yang berumur Miosen Awal - Miosen Tengah.Pendekatan yang dipergunakan adalah pengumpulan data-data geologi permukaan, berupa data stratigrafi dan struktur geologi. Penurunan Cekungan Serayu Utara sebagai cekungan belakang busur (back-arc basin) di Miosen Awalmempengaruhi pengendapan Formasi Rambatan, yang diisi oleh perselingan serpih, napal, dan tuff.Kandungan material volkaniklastik halus diduga berasal dari volkanisme Waturanda di Busur Volkanik Serayu Selatan.Mekanisme pengendapan litologi Rambatan tersebut terpengaruh kondisi cekungan yang terus menurun, menghasilkan gangguan-gangguan sedimentasi (soft sediment deformation) akibat luncuran gravitasi di lereng cekungan. Memasuki Miosen Akhir, busur volkanik Jawa Tengah berpindah ke cekungan belakang busur, menghasilkan endapan-endapan vulkaniklastika kasar yang berselingan dengan klastika halus laut pada formasi-formasi Halang, Tapak, dan Pemali. Deformasi yang dominan pada Formasi Rambatan adalah luncuran gravitasi (gravity sliding) ke arah utara-timurlaut dalam rejim ekstensional, yang secara lokal menghasilkan sesar anjak pada bagian ujung luncuran (toe-thrusting). Selanjutnya, saat aktifitas volkanisme menjadi dominan di Cekungan Serayu Utara, pembebanan tubuh gunungapi (volcanic load) juga menghasilkan deformasi luncuran gravitasi ke arah lateral, terutama bergerak ke arah selatan-baratdaya, yang tidak hanya bekerja pada dormasi-formasi Neogen Akhir tetapi juga mempengaruhi Formasi Rambatan yang lebih tua. Rembesan hidrokarbon di Desa Sijenggung pada Formasi Rambatan yang memiliki potensi sebagai batuan penyimpan (reservoar) dan batuan penyekat (seal) sekaligus, diduga melalui mekanisme pecahnya batuan penyekat (seal failure). Hal ini terjadi karena rendahnya kualitasnya litologi penyekat yang rendah akibat deformasi luncuran gravitasi, sehingga hidrokarbon dapat mencapai permukaan. Kata kunci: rembesan hidrokarbon, Formasi Rambatan, struktur luncuran gravitasi, Sijenggung, Serayu Utara.
Berdasarkan analisis kandungan zirkon pada batuan volkanik berumur Miosen, Pegunungan Selatan Jaw... more Berdasarkan analisis kandungan zirkon pada batuan volkanik berumur Miosen, Pegunungan Selatan Jawa Timur (PSJT) dianggap sebuah fragmen Gondwana yang terpisah dari mikrokontinen Jawa Timur – Sulawesi Barat. Kajian tomografi seismik juga berhasil menunjukkan sebaran mikrokontinen PSJT tersebut. Model rekonstruksi tektonik yang ada selama ini menempatkan kolisi dan amalgamasi Pegunungan Selatan terhadap Sundaland terjadi pada akhir Kapur. Meski demikian, studi paleomagnetisme mengindikasikan posisi paleolatitude PSJT pada umur Eosen masih berada pada jarak sekitar 16 o selatan dari posisinya saat ini. Dengan asumsi posisi Sundaland tidak banyak berubah semenjak akhir Kapur, hal ini memunculkan pertanyaan kapan sebenarnya kolisi PSJT terhadap tepian tenggara Sundaland. Makalah ini mengusulkan kolisi tersebut terjadi secara menyerong di akhir Oligosen dan berlangsung hingga Miosen Tengah, yang diakomodir oleh subduksi ganda dan patahan transform yang kelak menjadi Patahan Progo-Muria, serta memerangkapkan kerak samudera di bawah Cekungan Kendeng
Formasi Lahat atau Formasi Kikim yang merupakan salah satu formasi pengisi di Cekungan Sumatra Se... more Formasi Lahat atau Formasi Kikim yang merupakan salah satu formasi pengisi di Cekungan Sumatra Selatan, mempunyai peranan yang penting di dalam petroleum system cekungan tersebut. Formasi Kikim sendiri mempunyai Anggota Cawang yang litologinya tersusun secara dominan oleh kandungan kuarsa. Penelitian ini bertujuan untuk menentukan lingkungan pengendapan daerah penelitian melalui analisis fasies. Hal tersebut menarik dilakukan karena terkait dengan potensi reservoir pada formasi tersebut. Analisis fasies dilakukan pada suksesi stratigrafi yang memiliki ketebalan mencapai 500 meter pada jalur pengukuran Sungai Menghalus, Sumatra Selatan. Analisis tersebut mengarah kepada pembagian fasies dengan melalui dua pendekatan, yaitu: (1) pendekatan secara deskriptif di lapangan dan (2) pembagian fasies yang mengacu pada klasifikasi Miall (1978). Pembagian fasies berdasarkan deskriptif lapangan menghasilkan 11 fasies, yaitu: fasies batupasir kerikilan-batupasir (GSS), fasies batupasir (S), fasi...
The Sumatran Fault has been subjected of scientific researches for decades. Katili (1967) is rega... more The Sumatran Fault has been subjected of scientific researches for decades. Katili (1967) is regarded as the earliest work for defining The Sumatran Fault having transcurrent deformation in the light of plate tectonics. Following the work of Katili (1967), Bellier and Sebrier (1994) proposed structural interpretation of Sumatran Fault pull-apart basins using SPOT images. In 2000, Sieh and Natawidjaja published their work concerning neotectonics of Sumatran Fault. Previous works emphasizes on intensive segmentation of Sumatran Fault as distinctive feature. To address the segmentation of Sumatran Fault, concerns should be paid to tectonic evolution of the area. Sumatra was built based upon continental collisions from Late Paleozoic to Late Mesozoic. The collisions generated NW-SE trending basement structure (Barber et al., 2005). Counterclockwise rotation of Sundaland on Middle Miocene triggered the activation of Sumatran Fault in right-handed kinematics. Pre-existing basement structu...
Daerah Watu Gajah, Kecamatan Gedang Sari, Kabupaten Gunung Kidul, Provinsi Daerah Istimewa Yogyak... more Daerah Watu Gajah, Kecamatan Gedang Sari, Kabupaten Gunung Kidul, Provinsi Daerah Istimewa Yogyakarta secara umum tersusun oleh sekuen batuan vulkaniklastik Formasi Kebo Butak. Adanya stuktur kekar tiang pada intrusi di daerah ini menarik untuk diteliti karena dapat memberikan informasi mengenai karakteristik kekar tiang serta intrusi. Analisis yang digunakan pada penelitian ini adalah analisis data lapangan dan analisis data sampel batuan dengan metode petrografi dan geokimia. Intrusi pada daerah penelitian berupa sill dan termasuk dalam intrusi dangkal. Terdapat baked dan chilled margin yang menunjukkan intrusi dangkal. Berdasarkan analisis data petrografi dan geokimia, jenis batuan beku termasuk dalam mikrogabro dengan komposisi mineral utama berupa plagioklas dan piroksen. Intrusi mikrogabro daerah Watu Gajah memiliki satu baris kolom kekar tiang. Sistem pendinginan magma tidak sempurna dan didominasi kekar tiang dengan kolom segi lima. Korelasi antara jumlah titik poligon denga...
Penelitian dilakukan pada Formasi Cibulakan Atas, Cekungan Jawa Barat Utara dan Formasi Gumai, Su... more Penelitian dilakukan pada Formasi Cibulakan Atas, Cekungan Jawa Barat Utara dan Formasi Gumai, Sub-Cekungan Jambi. Secara geologi, umur kedua formasi relatif sama, yaitu terbentuk pada Miosen Awal - Miosen Tengah. Litologi penyusun kedua formasi juga sama, yakni disusun oleh batupasir, batulempung, serpih serta sisipan batugamping yang diendapkan pada laut dangkal - shelf. Kedua formasi terbentuk pada cekungan saat post-rift dan petroleum system pada kedua cekungan telah terbukti bekerja. Tujuan penelitian ini adalah mengevaluasi dan membandingkan fasies pengendapan, faktor penyebab low-resistivity serta petrofisika pada reservoar low-resisitivity di kedua formasi tersebut. Penelitian menggunakan data log, mud log, drill stem test, side wall core yang meliputi petrografi, XRD dan SEM, serta didukung data biostratigrafi. Fasies reservoar low-resistivity Formasi Cibulakan Atas adalah shelf transition dan middle shelf di lingkungan shelf, sedangkan fasies Formasi Gumai adalah lower sho...
High-pressure low-temperature metamorphic rocks are considered as fossil subduction zones from th... more High-pressure low-temperature metamorphic rocks are considered as fossil subduction zones from the interpretation of progressive and retrogressive metamorphism, metamorphic facies series, protolith, role of fluid, geochronology of the various stages of metamorphism, P-T-t path, and exhumation model during regional metamorphism. Worldwide discovery of these rock types (e.g., Kokchetav, Dabie Shan, Indonesia, Franciscan, and Sanbagawa) have received much attention from earth scientists to demonstrate the exhumation of the rocks that have been metamorphosed at great depths in subduction zones that are exhumed at the surface.High-pressure metamorphic rocks expose in the South Sulawesi, Central Java, and South Kalimantan, which considered as central part of Indonesia. Northwesterly-directed Cretaceous subduction was suggested responsible to build these formations. Most of the metamorphic rocks occur in limited areas and are bounded by thrust fault with other units such as dismembered oph...
E3S Web of Conferences, 2021
Tunnel 3 of the Sigli Banda Aceh Toll Road has been designed based on several site investigations... more Tunnel 3 of the Sigli Banda Aceh Toll Road has been designed based on several site investigations. The site investigations have not included surface geological investigations. Subsurface geological investigations have been carried out but with less detailed drill core evaluation. This will cause less accuracy on the assessed tunnel stand-up time. This research aims to evaluate the engineering geological conditions at the tunnel construction site by conducting geological mapping with 1:5,000 scale and re-evaluating drill core using RMR89 method more thoroughly so that it can produce more accurate assessment of the tunnel stand-up time. The geological mapping result shows that the research area has three rock units, namely lapili, tuffaceous sandstones, and interbedded sandstone-siltstones, with moderate to fresh weathering degree. The drill core evaluation shows that research area has poor to good rock mass classes (34 – 67). The drill core evaluation results also indicate possible g...
Proc. Indon Petrol. Assoc., 34th Ann. Conv.
Newly acquired seismic data in the Arafura Sea to the south of Aru Islands, Eastern Indonesia rev... more Newly acquired seismic data in the Arafura Sea to the south of Aru Islands, Eastern Indonesia reveal the presence of very thick Pre-Cambrian to Paleozoic beds. Regional correlation with the Paleozoic and Pre-Cambrian proven sections in offshore and onshore areas of Australia indicate that the Arafura Sea may also have these proven sections. One of the potential sections in the Arafura Sea come from dolomitic carbonates correlatable to Cambrian-Ordovician Goulburn Group and Pre- Cambrian (Middle Proterozoic) McArthur Group in Australian areas. The carbonates are considered to be composed of blue-green algae (cyanobacteria) binding calcareous sediments forming microbial mats commonly known as stromatolites. Stromatolites were the dominant reef-building organisms during the Pre-Cambrian to the Lower Paleozoic. Exploring stromatolites for petroleum is something new in Indonesia. We need a modern analogue of these deposits to study sedimentation model and reservoir characteristics. Fortunately, although there are no many places on modern Earth for development of stromatolites due to requirements of extreme environment (isolated body of water, high alkalinity-salinity, soda ocean), there is a place in Indonesia where modern stromatolites grow. It is the Satonda Island, a small remnant volcanic island located to the north of Sumbawa at the Flores Sea. The island has a crater lake filled with seawater. Because the lake has lost all direct connections with the surrounding sea due to tectono-volcanic events, the lake environment has changed to be extreme. Stromatolites grow within the lake. Our recent field work there found calcareous reeflike structures composed dominantly of blue-green algae forming mats of in-situ calcifying microbe of cyanobacteria. We studied the geology of the lake and sedimentation as well as reservoir characteristics of living and dead stromatolites. The data we acquired, analyzed, and interpreted on stromatolites of the Satonda Island may significant for exploring their ancient counterparts beneath the Arafura Sea.
Proc. Indon Petrol. Assoc., 35th Ann. Conv.
Proc. Indonesian petrol. Assoc., 38th Ann. Conv.
The North Serayu Basin is one of two basins in Central Java. In this basin, a number of hydrocarb... more The North Serayu Basin is one of two basins in Central Java. In this basin, a number of hydrocarbon seepages have been reported, suggesting a petroleum system exists (Satyana, 2007). However, tectonic intricacy makes this area a relative “terraincognita” in terms of Java exploration. As a surface manifestation, hydrocarbon seepage is a window to study subsurface geological conditions and the petroleum system. Therefore, this research focused on the geological factors that cause the hydrocarbon seepages at Sijenggung, Banjarmangu District, Banjarnegara Regency, Central Java. In the study area, gas seepage was found in the Rambatan Formation. The methods used in this study consist of surface geological data collecting, including geological structures and measured stratigraphic data. The study area is located in Pekacangan River. Tectonic events constructing the study area started with the subsidence of the North Serayu Basin as a back-arc basin in the Middle Miocene, changed into a volcanic arc in the Late Miocene, and then returned to back-arc setting, and experienced massive foldings in the Pliocene. Finally, reactivation of volcanism occurred in the Pleistocene. These tectonic events affected the deposition of the Rambatan Formation that consists of shale, marl, and tuff. From nannofossil analysis, it is known that this formation was deposited until Early Pliocene. The massive initial thickness (due to the long term of deposition) was then multiplied by extreme recumbent folding as the result of the north-south compression created by Pleistocene volcanic loading. The large initial thickness added to by the recumbent folding drove the Rambatan Formation to maturity and reached the gas window in the Pleistocene. Thrust faults divided the whole recumbent fold into smaller compartments, also allowed the hydrocarbon to dissipate directly from the source rock to the surface.
Proc. Indonesian petrol. Assoc., 38th Ann. Conv.
Luwuk at the eastern end of Sulawesi’s East Arm has been recognized to be formed under obductiona... more Luwuk at the eastern end of Sulawesi’s East Arm has been recognized to be formed under obductional tectonic where the East Sulawesi Ophiolite Complex thrusted southward over the Banggai-Sula microcontinent during Late Neogene event. At the southern section, a gas field of Tomori has been developed with reservoirs distributed in the precollisional Miocene carbonates. To date, explorational work over the area has been incorporating collisional structures such as thrusts and wrench faults into the petroleum systems, e.g. hydrocarbon maturation and trap formation. Most of the structural concept based on the existing model of southeastward vergeance thick-skinned (ophiolitic basement involved) thrust-fold belt. A geologic field work has been conducted transecting north-south section and east-west section of Luwuk. Satellite imagery interpretation and field observation suggest the existance of three structural compartments, i.e.: (i) the northern extensional, block-faulting, tectonic regime on the ophiolite complex, (ii) the central compressional, northwestward vergeance thrust-fold belt, tectonic regime on the Tertiary carbonates, and (iii) the southern, locally gravitational sliding, tectonic regime on the Pliocene molasse. Each compartment exhibits distinct structural style and diverse tectonic control. The northern extensional compartment were controlled by rifting of Siuna Bay along the Late-Miocene right-lateral movement of Balantak Fault. The central compressional compartment were developed by the Late Pliocene northwestward shortening due to activation of Sorong Fault. The southern gravitational Molasse sliding were induced by the Late Pliocene uplift along the existing weak zone of north-south transtensional strike-slip fault. Implication of this research to petroleum exploration is a revision of Luwuk thrust-fold belt model, which is proposed to be thin-skinned (basement uninvolved) northwestward vergeance.
Journal of Applied Geology, 2015
Paleostress analysis on the landslide boundary faults is able to explain the sliding mechanism. T... more Paleostress analysis on the landslide boundary faults is able to explain the sliding mechanism. This method is particularly useful to study a paleolandslide. About 30 striated fault planes from the Parangtritis paleo-landslide, located in the Yogyakarta coastline, were analyzed to define their principle stress axes. The eastern boundary fault, named as the Girijati Fault, was the main fault responsible for the mass movement and leaving a considerable steep cliff. It moved normal in a left lateral sense with ENE – WSW extension and dragged the rockmass southward, creating a NNW – SSW extension along the Parangtritis Fault and turn it into the western boundary fault. The rockmass slided along the stratigraphic contact between the underlying Nglanggran Formation and the overlying Wonosari Formation, created a semi-circular crown cliff as the northern boundary and produced some isolated topographic highs of the thrust block near the toe. Keywords: Paleostress, landslide boundary, fault,...
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Papers by Salahuddin Husein