Struktur Geologi Pada Batuan Sedimen Silisiklastik Mesozoikum Formasi Meluhu Lengan Tenggara Sulawesi

Abstrak

This research was conducted on sedimentary rocks of the Meluhu Formation of the Toronipa Member with the aim of determining the type and mechanism of the geological structures formed. The methods used were field data collection and structural analysis using stereography. The results showed that the rocks in the study area were coarse sandstone and medium sandstone with shale inserts of Triassic - Jurassic age. The geological structures formed were folds, joints and faults. The folds formed were inclined planes with an axial plane orientation of N352°E/29° and a hinge line of N252°E/27°. The joints found were scour joints with the direction of maximum main stress in the southwest-northeast and southeast-northwest directions. The direction of stress of the joints had the same correlation with the direction of fold formation and rock position. Based on the presentation of dominant data on the direction of rock position, the initial orientation of the rocks in the study area was southwest-northeast. While the second orientation direction of Southeast-northwest is thought to be the result of rotation when a Cenozoic shear fault occurred. Based on this, the main direction of maximum geological structure in the study area is southeast-northwest. The types of faults formed are reverse faults (fractures and shifts of sandstone blocks intercalated with shale) and normal faults (the presence of fractures, quartz veins, and waterfalls). Folds and reverse faults are formed when the continental and ophiolite zones collide, while reverse faults are thought to form when the continental zones expand.

Kata kunci

• Fm Meluhu
• Structure
• sedimentary rock
• silisiclastic