E-ISSN : 2541-5794 P-ISSN : 2503-216X Journal of Geoscience, Engineering, Environment, and Technology Vol 01 No 01 2017 THE PALEOGENE TECTONOSTRATIGRAPHY OF NORTHERN PART MASALIMA TRENCH BASIN Luhut Pardamean Siringoringo1 *, Dardji Noeradi2 1 Sumatera Institute of Technology, South Lampung, Indonesia. 2Bandung Institute of Technology, Bandung, Indonesia * Corresponding Author: [email protected] Tel.:+62-813-1120-8367 Received: Oct 1, 2016. Revised : 15 Nov 2016, Accepted: Nov 20, 2016, Published: 1 Dec 2016 DOI: doi.org/10.24273/jgeet.2016.11.2 Abstract Northern part of Masalima Trench Basin is located in the southern part of the Strait of Makassar, which includes Masalima Trough and Massalima High. The area of research is an extension of the South Makassar Basin which extends from South Makassar Basin to the Northeast part of Java Sea. Subsurface data are used such as 2D seismic sections (21 lines) and data drilling w ells (2 w ells) to understand the tectonic structure in the basin formation and understand the stratigraphic order of basin. Based on w ell data can be known that Northern part Masalima Trench Basin is aborted rift because marked by post rift phase. Northern part Masalima Trench Basin w as formed by normal faults which have trend northeast -southw est w ith pre rift, early syn rift, late syn rift, and post rift sediment geometry. Early syn rift sediment was Middle Eocene, late syn rift sediment w as Middle Eocene till Early Oligocene and post rift sediment was Early Oligocene till Early Miocene. The Depositional environment of early syn rift phase such as beach, shallow marine, and land. The Depositional environment of late syn rift phase such as beach till deep marine, and the depositional environment of post rift is deep marine. Keywords: Masalima, Tectonostratigraphy, Basin. 1. Introduction sedimentary pattern on northern part Masalima Trench Basin from syn rift to post rift. 1.1 Background of Research Research area is located in northern part Masalima Trench Basin w hich includes Masalima High, Sibaru High, and Masalima Trough. The area of research is an extension of the South Makassar Basin w hich extending from South Makassar Basin to the Northeast part of Java Sea (Kupecz dkk, 2013). As extension of south makassar Basin, the tectonic process w hich happen in research area w as estimated very close relation with the forming process of South Makassar Basin. Because of this, the writer will analyze the forming process of northern part Masalima Trench Basin and its filling. Beside that, the research area is the one of minimum research areas, it can be know n from publications of research area w hich still few . Hopefully, this research w ill add existing publications especially about the forming process of northern part Masalima Trench Basin. Fig. 1. The location of research area (red line) In Indonesia map, the research area is located on the south west of offshore south Sulawesi province The purposes of this research area are to know or southeast Kalimantan island, and located in the the forming mechanism and filling of northern part north of Lombok Island (Fig. 1). Masalima Trench Basin in Paleogene age. The topics of research including the geometry of The hypothesis of research are Masalima Trench research area especially from Middle Eocene to Basin w as estimated aborted rift and North-East Early Miocene which is estimated different from trend faults are dominantly control sedimentary South Makassar Basin pattern at Masalima Trench Basin. The basic Siringoringo P.L. et al./ JGEET Vol 1 No 1/2016 7 assumption is sedimentary thickening showing 2. Regional Geology basin configuration on sedimentation. 2.1 The Regional Tectonic of South Makassar Basin 1.2 Methods of Research Research area is located in northern part The main data that be used in this research are Masalima Trench Basin w hich includes Masalima 21 2D lines seismic and tw o w ells data (fig. 2). Tw o High, Sibaru High, and Masalima Trough. The area w ell data are Alfa w ell and Beta w ell. Alfa w ell data of research is an extension of the South Makassar including bore hole descriptions, biostratigraphy Basin w hich extending from South Makassar Basin data for determine age and bathymetry zone, and to the Northeast part of Java Sea (Kupecz et al, w ireline logging. Wireline logging data are gamma 2013). ray log, density log, resistivity log, and sonic log. South Makassar Basin w as formed in the Meanw hile, Beta w ell data are bore hole southeast of Sundaland that was influenced by descriptions, biostratigraphy data for determine age three large plates: Eurasia, India-Australia, and and bathymetry zone, and wireline logging. Pacific. It is bordered by Adang fault zone in the Wireline logging data are gamma ray log, density north and West Sulawesi fold belt in the east part. log, resistivity log, and induction log. In the south bordered by Masalima High, and in the The beginning of research w as literature study west bordered by Paternoster Platform (Hidayat et about research area. Then, continued collecting 2D al, 2012). seismics and w ells data. Well data consist of bore Masalima Basin in special term, is a part w hich hole descriptions, biostratigraphy data to tighten in the tip south west of South Makassar determine age and bathymetry zone, and w ireline Basin. It is bordered by opening to South Makassar logging. Seismic data be used for pulling Main Basin in the north, Masalima High in the east, tectonostratigraphy units boundaries and faults. north platform in the south, and Sibaru High in w est After that, continued did w ell seismic tie. After tied, (Hidayat et al, 2012) (fig. 4). continued to determine interval composition of every tectonostratigraphy unit and make isochron map to know thickening of sedimentary pattern. At the last step of research were to know forming mechanism and basin sedimentary filling (fig. 3). Fig. 2. The data including 21 2D lines seismic and tw o w ells 8 Siringoringo L.P. et al./ JGEET Vol 1 No 1/2016 Fig. 3. The Flow chart of research Fig. 4. The research location area in South East Sundaland structure skeleton map (Hidayat et al, 2012) Siringoringo L.P. et al./ JGEET Vol 1 No 1/2016 9 In the research area, the oldest sediments w ere w as deposited on Late Eocene, in this phase, the estimated from Paleocene consist of coal, supply of clastic material had been decreased. sandstone, and claystone that are interpreted from This formation was dominated by carbonates land deposit. The rifting process maybe begun from platform and bathymetry indicated Neritic Zone Middle Eocene and ended in last Eocene. Eocene with interbeds carbonates clay and limestone that sediments w ere deposited in graben and half reflecting platform area. graben at sea environment and land (Pireno et al, 3. Berai Formation. 2009). This formation was deposited when the rifting Based on regional data, the tectonic history of process had stopped on Oligocene. Berai Formation south Makassar Basin can be divided into two deposition showed lateral changing from platform phases of tectonic, they are Extensional and environment and carbonates platform to slope and Compresional Phase. basin plain. From biostratigraphy analysis, 1. Extensional Phase. carbonates platform w as developed in Neritic Zone. This phase happen at Middle Eocene till early 4. Under Part Warukin Formation. Miocene and divided in tw o period, they are: Under part Warukin Formation deposition on early - Rifting (Middle Eocene-Last Eocene) till middle Miocene as same as Berai Formation This period w as presented by graben structure, restively, show ed facies changing little by little from half graben, and horst with NW-SE and N-S platform facies to slope and basin plain. Under Part trends (Kupecs et al, 2013). This structures w ere Warukin Formation consist of clay-limestone interpreted as back arc rifting result that caused intersbeds on Neritic and Sub Neritic. by subduction in the east part of Sulaw esi 5. Upper Part Warukin Formation. - Post Rifting and Descent (Oligocene-Early This formation indicated facies changing laterally Miocene) from platform to slope and basin plain. This In this period was presented by decreasing of formation developed in Neritic and Sub Neritic fault activities frequency in rifting period (main 6. Dahor Formation. fault boundary). In this period, South Makssar This formation consist of lithology that had relation Basin experienced descent activity, manifested with compressional event. Consist of shallow by maximum transgression, thick sediment, and marine transgression sediments like limestone, post rifting sediment spreading (Kupecz et al, claystone, and shale. This formation w as deposited 2013). on late Miocene till Pliocene. 2. Compressional Phase (Middle Miocene-Last Miocene). 3. Result In Middle Miocene till Last Miocene, Button and 3.1 Lithostratigraphy Determination Banggai-Sula microcontinents collision with East Sulaw esi subduction complex. This event To know lithostratigraphy in research area, will produced thrust fault, folding, inversion refer to Alfa well data because it is the one well structure. The evidence of this event can be w hich have passed seismic line and stratigraphyly, observed in the east part of South Makassar be estimated is more complete than others because Basin and Sulaw esi land (Sengkang to Kolosi of located inside of basin. area) (Hidayat et al, 2012) This Alfa well data will be used as referring in determination interval composition every the unit 2.2 Regional Stratigraphy of South Makassar of tectonostratigraphy. Basin From Fig. 6, can be seen the cutting descriptions result of Alfa well. From this result, the writer Based on well data, the lithology type in the compared with the stratigraphy of South Makassar South Makassar Basin leaning having same type Basin.