|Morphology The Threshold Mountain is formed by small cones forming a row of mountains extending north and south from the Mount Threshold complex, which is a cone of young volcano (kwarter), and its activity develops through the remains of the caldera body. This volcanic cone grows on the body of a previously formed lava volcano.
Morphology The Mount Threshold complex is formed by tertiary hills in the form of a ridge extending from west to east, patterned by streams of parallel rivers, while in the north-west and south-west a dendritic drainage pattern. The younger morphology consists of the Ambang mountains and the volcanic cones and the plains.
Volcanic rock in Mount Threshold Complex is the result of magmatic eruption which is estimated to occur 240,000 years ago, it is known from the date of 40 Ar (Electrik Consalt, Italy 1983).
Based on the lithology, the stratigraphic position and the source of eruption, the complex rock of Mount Ambang can be divided into 6 (six) groups from old to young are: sedimentary rock, old volcanic rock, erupted rocks Gunung Pinupulan complex, rocks of eruption mountain group Ambang, eruption of Mount Tayot and Molibut group, lava and Aluvial sediment. Alluvial sediment is the youngest sediment composed consisting of loose sludge in the form of sand, gravel, kerakal and lava lava.
Based on the analysis of aerial photography and field data, the geological structure that developed in the area of Mount Ambang from is normal faults, straightness and structure of volcano (crater).
Normal fault trending north-east – southwest with a relatively descending northwest. In general, normal faults are cutting old volcanic rocks.
In the normal faults in Tuduaog village there are 2 (two) lava domes of Mount Ilantat and Mount Kayumanis whose appearance appears to be triggered by the normal faults that cut the cesareous fault of the southeast – northwest that happened before. Indications of this normal southeast-northwest fault can be identified from the straightness on the slopes of Mount Ilantat and Mount Kayumanis. The structure of the crater is found at the summit of Mount Mooat which is estimated to remain the eruption point of the dome of Mount Mooat…