Electronic Theses and Dissertation

Daerah penelitian berada pada perbatasan dua kecamatan, yaitu blangkejeren kabupaten gayo lues provinsi aceh. secara geografis berada pada 4° 00’ 32.4” lu - 3° 58’ 22.8” lu dan 97° 24’ 36.0” bt - 97° 21’ 21.6” bt, luas area penelitian 24 km². kondisi geologi regional pada lokasi penelitian terdiri dari formasi kluet (puk) yang terdiri dari slate , phylite, metalanau, arenit metakuarsa yang berumur palaeozoik akhir, formasi rampong (tlr) yang terdiri atas batupasir interbedded, sebagian berkapur dan konglomerat, batulumpur abu-abu, vulkaniklastik dan konglomerat basal tipisyang berumur oligosen akhir dan endapan alluvium (qh) terdiri dari kerikil, pasir dan lempung dengan umur holosen, atas dasar inilah peneliti tertarik untuk melakukan penelitian, dimana lokasi penelitian ini memiliki litologi batuan sedimen dan metamorf yang cukup beragam dan juga belum pernah dilakukan penelitian mendetail mengkaji studi geologi sehingga perlu dilakukan penelitian lebih lanjut kondisi geologi permukaan dan studi petrografi. dari penelitian diperoleh 4 satuan geomorfologi mencakup satuan bentuk lahan denudasional unit d1, satuan bentuk lahan struktural unit s1, satuan bentuk lahan fluvial unit f1, dan satuan bentuk lahan fluvial unit f3. secara stratigrafi diperoleh 5 satuan batuan penyusun berdasarkan umur tertua hingga termuda meliputi satuan batuan batulanau (tlr), satuan batuan serpih (tlr), satuan batuan batupasir (tlr), satuan batuan konglomerat (tlr), dan satuan endapan alluvial (qh). struktur geologi yang mempengaruhi area penelitian berupa struktur kekar. terdapat 3 sampel batuan yang dilakukan prosedur petrografi yaitu sayatan tipis batupasir (formasi rampong), sayatan tipis batulanau (formasi rampong), dan sayatan tipis serpih (formasi rampong). berdasarkan hasil analisis petrografi batupasir pada formasi rampong diberinama quartz arenite sandstone. analisis petrografi pada batulanau formasi rampong dan serpih formasi rampong menunjukkan bahwa batuan tersebut dikategorikan sebagai mudrock. kata kunci: pemetaan geologi, analisis petrografi, geomorfologi, sayatan tipis (thin section)

The research area is located on the border of two sub-districts, namely Blangkejeren in Gayo Lues Regency, Aceh Province. Geographically, it lies between 4° 00’ 32.4” N - 3° 58’ 22.8” N and 97° 24’ 36.0” E - 97° 21’ 21.6” E, covering a total area of 24 km². The regional geological setting of the research area consists of the Kluet Formation (Puk), composed of slate, phyllite, metashale, and metaquartz arenite from the Late Paleozoic; the Rampong Formation (Tlr), which comprises interbedded sandstone (partly calcareous), conglomerate, gray mudstone, volcaniclastic rocks, and thin basal conglomerates from the Late Oligocene; and Holocene Alluvial Deposits (Qh), consisting of gravel, sand, and clay. These geological characteristics prompted the researcher to conduct a study in the area, as it contains a diverse range of sedimentary and metamorphic lithologies and has not been previously examined in detail from a geological perspective. Therefore, further research is necessary to investigate the surface geological conditions and perform petrographic studies. The study identified four geomorphological units, including: Denudational landform unit (Unit D1), Structural landform unit (Unit S1), Fluvial landform unit (Unit F1), and Fluvial landform unit (Unit F3). Stratigraphically, five rock units were identified in order from oldest to youngest: Siltstone Unit (Tlr), Shale Unit (Tlr), Sandstone Unit (Tlr), Conglomerate Unit (Tlr), and Alluvial Deposit Unit (Qh). The dominant geological structure affecting the study area is jointing. Three rock samples were analyzed petrographically through thin section procedures: sandstone thin section (Rampong Formation), siltstone thin section (Rampong Formation), and shale thin section (Rampong Formation). Based on the petrographic analysis, the sandstone from the Rampong Formation is classified as quartz arenite sandstone. The siltstone and shale samples from the same formation are classified as mudrocks. Keywords: Geological Mapping, Petrographic Analysis, Geomorphology, Thin Section