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"Daerah Ganda-Ganda, Morowali Utara merupakan salah satu daerah penghasil bijih nikel di Indonesia dari endapan laterit. Endapan laterit tersebut dihasilkan dari pelapukan batuan ultramafik (batuan asal). Pada area penelitian terdapat pada Komplek Ultramafik dari Jalur Ofiolit Sulawesi. Penelitian ini bertujuan untuk mengetahui komposisi endapan laterit, karakteristik batuan ultramafik, dan asosiasinya terhadap tektonik dari sampel batuan asal daerah penelitian. Metode yang digunakan yakni analisis petrografi, X-Ray diffraction (XRD), dan energy dispersive X-Ray fluorescence (EDXRF). Profil terdiri atas limonit dan saprolit hingga rocky saprolite. Komposisi mineral profil limonit didominasi goetit dan gibbsit. Saprolit didominasi antigorit, talk, lizardit, dan nakrit. Batuan asal didominasi mineral silikat. Jenis batuan ultramafiknya meliputi lherzolit terserpentinisasi, harzburgit terserpentinisasi, olivin websterit terserpentinisasi, dan serpentinit. Secara geokimia semua batuan ultramafik berkomposisi lherzolit. Semua batuan hadir mikrotekstur mesh. Banyak mineral olivin dan piroksen di batuan asal telah terubah menjadi mineral serpentin. Mikrotekstur serpentinit mencangkup tekstur mesh pada lizardit, tekstur relict pada olivin, tekstur veinlet mineral krisotil, dan tekstur decussate mineral antigorit. Komposisi batuan asal dominan tersusun atas mineral olivin, lizardit, dan piroksen. Batuan ultramafik daerah penelitian berasosiasi dengan tektonik supra-subduction zone (SSZ) yang dominan hingga mid-oceanic ridge basalt (MORB) dengan seri magma tholeiite.

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The Ganda-Ganda area, North Morowali is one of the nickel ore producing areas in Indonesia from laterite deposits. Laterite deposits are produced from the weathering of ultramafic rocks (source rocks). The research area is in the Ultramafic Complex of the Sulawesi Ophiolite Belt. This research aims to determine the composition of laterite deposits, the characteristics of ultramafic rocks, and their association with tectonics from the source rock samples from the research area. The methods used are petrographic analysis, X-ray diffraction (XRD), and energy-dispersive X-ray fluorescence (EDXRF). The profile consists of limonite and saprolite to rocky saprolite. The mineral composition of the limonite profile is dominated by goethite and gibbsite. Saprolite is dominated by antigorite, talc, lizardite, and nacrite. The source rocks are dominated by silicate minerals. Ultramafic rock types include serpentinized lherzolite, serpentinized harzburgite, serpentinized olivine websterite, and serpentinite. Geochemically, all ultramafic rocks fall in the lherzolite composition. All rocks have mesh microtexture. Many of the olivine and pyroxene minerals of the source rock have been altered into serpentine minerals. Serpentinite microtextures include the mesh texture of lizardite, the relict texture of olivine, the veinlet texture of chrysotile, and the decussate texture antigorite. The dominant composition of the source rocks consists of olivine, lizardite and pyroxene minerals. Ultramafic rocks in the study area are dominantly associated with supra-subduction zone (SSZ) tectonics to mid-oceanic ridge basalt (MORB) with a tholeiite magma series."

"Endapan bijih besi terdapat dalam satuan batuan ultramafik-mafik. Satuan batuan ini terdiri atas gabro dan peridotit yang telah mengalami serpentinisasi. Dalam bijih besi terkandung mineral bijih kromit, magnetit dan hematite. Berdasarkan pada komposisi mineralogi dan kimia, pembentukan endapan bijih besi diduga oleh proses magmatik; kemudian mengalami proses replacement dan oksidasi. Dengan kisaran nilai resistivity 42 -179 ohm.m yang mewakili endapan bijih besi kurang memperlihatkan kontras resistivity yang baik Anomali terbentuk pada nilai induced polarization (IP)-nya dengan kisaran nilai chargeability 24 -107 msec. Dari pemodelan IP 3 dimensi diperoleh model endapan bijih besi berbentuk podform dan lensa-lensa kecil.

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Iron ore deposits to be found on the mafic-ultramafic rocks units which consists of serpentinized gabbro and peridotite. The iron ore contains cromite, magnetite and hematite. Base on mineralogy and chemical composition, iron ore deposits is predicted to be formed by magmatic process and occurred a replacement and oxidation processes later. With range of 42 -179 ohm.m resistivity value that represent the ore iron deposits less show well contrast. Anomaly occurre on its induced polarization (IP) value with range of 24 -107 msec chargeability value which represent the iron ore deposit. Of the IP 3D modelling to be found the model of iron ore deposits have the form of podform and small lens."

"Daerah penelitian yaitu Pulau Sebuku merupakan bagian dari Ofiolit Meratus, sehingga pada Pulau Sebuku terdapat daerah yang memiliki geokimia unsur Sub-Oceanic Lihospheric Mantle (SOLM) dari paternosfer yaitu daerah Sungai Bali dan ada pula daerah yang terdiri dari geokimia unsur hasil subduksi Sub-Oceanic Lithospheric Mantle (SOLM) dari paternosfer terhadap Sub-Continental Lithospheric Mantle (SCLM) dari sundaland yaitu daerah Sarakaman. Penelitian ini bertujuan untuk mengetahui perbedaan karakteristik batuan dasar dan laterit pada dua daerah tersebut serta mengetahui persebaran unsur pada endapan laterit keduanya. Metode penelitian yang dilakukan adalah analisis data geokimia X-Ray Fluorescence (XRF), analisis statistik, analisis deskriptif data bor, dan menggunakan metode Inverse Distance Weighted (IDW) dalam pembuatan peta sebaran unsur di daerah penelitian. Dari hasil analisis, diketahui pada daerah Sarakaman telah mengalami pengkayaan unsur karena merupakan daerah yang lebih terpengaruh dari subduksi SOLM terhadap SCLM sebagai hasil terjadinya devolatilisasi dan dehidrasi metamorfik saat proses subduksi terjadi. Dapat disimpulkan keterdapatan perbedaan data geokimia pada batuan dasar yang mempengaruhi keterbentukan endapan laterit pada kedua daerah penelitian

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The research area namely Pulau Sebuku is part of the Meratus Ophiolite, so in Pulau Sebuku there are areas that have geochemical elements of the Sub-Oceanic Lithospheric Mantle (SOLM) from the paternosphere, namely Sungai Bali Area of the Banjar Asri Inc. and there are also areas consisting of geochemical elements resulting from the subduction of the Sub-Oceanic Lithospheric Mantle (SOLM) from the paternosphere to the Sub-Continental Lithospheric Mantle (SCLM) from sundaland, namely the Sarakaman Area of the SILO Inc. This research aims to determine the differences in the characteristics of bedrock and laterite in the two areas and to determine the element’s distribution of both laterite deposits. The research method used is the analysis of X-Ray Fluorescence (XRF) geochemical data, statistical analysis, descriptive analysis of drill data, and using the Inverse Distance Weighted (IDW) method in making the distribution map of elements in the research area. From the results of analysis, the Sarakaman Area of the SILO Inc., which is the part of Pulau Sebuku that is more affected by the subduction of SOLM to SCLM, experiences enrichment of the elements as a result of devolatilization and metamorphic dehydration that occurs when the subduction process occurs. It can be concluded that there are differences in geochemical data on bedrock that affect the formation of laterite deposits in this two research areas."