Regional Geology and Stratigraphy
Regional structure Lomblen Island include of Banda arc Volcanic belt, with structure terms as folding and faulting in NE-SW and SE-NW direction. The oldest rock formation is Kiro Formation (Tmk) in lower Miocene until upper Miocene. This formation consist of lava, breccias, agglomerate implied layered tuff. Kiro formation wedge with Nangapanda formation (Tmn) that consisted of sandy tuff, breccias tuff, and implied by limestone. Those old formation above were infiltrated by granodiorite (Tmd) in upper Miocene. When Pliocen-Plistocene there was volcanic activity such as lava, agglomerate, and tuff.
Regional structure Lomblen Island include of Banda arc Volcanic belt, with structure terms as folding and faulting in NE-SW and SE-NW direction. The oldest rock formation is Kiro Formation (Tmk) in lower Miocene until upper Miocene. This formation consist of lava, breccias, agglomerate implied layered tuff. Kiro formation wedge with Nangapanda formation (Tmn) that consisted of sandy tuff, breccias tuff, and implied by limestone. Those old formation above were infiltrated by granodiorite (Tmd) in upper Miocene. When Pliocen-Plistocene there was volcanic activity such as lava, agglomerate, and tuff.
Regional Stratigraphy of Lomblen Island (Noya, Y., and Suwarno, N., 1983)
Structure Characteristics
By regional investigation in field, map of topography and interpretation photograph air there are 2 especial structure direction that is: north-south direction and northeast-southwest direction. In this area (Atedai) there are 6 big structure they are lineament, volcano, cauldron, crater, caldera, slide and fault.
Lineament
This lineament structure have the direction NW-SE. This structure is the oldest big structure estimated cut the basement. Alongside this lineament have emerged the volcano network, such as: Watulolo, Atolojo, Watukuba etc.
Cauldron (crater of Atolojo)
This cauldron structure is the result of eruption mount Atolojo, which among other things yield fallout sediment of pyroclastic skoria andesitic. Cauldron diameter 750-1000 m encircling from NE till NW and open toward north.
Caldera Watukuba
This structure is the result of eruption Watukuba yielding dusty sediment of pyroclastic. diameter of caldera Watukuba 2500 m encircle from north direction to west till easterly. In floor of caldera there are geothermal manifestation like hot ground and alteration.
Debris Avalanches/sliding of Wai Teba
This structure represent the slide which have association with the weak area, form like horse poultice that opening eastwards of Watuwawer.
Fault of Wai Kowan
Fault structure have the direction NE-SW. Alongside this structure have attended the hot water source of Wai Kowan, hot ground of Koti and area of alteration Lowo Kebingin.
Fault of Lewoderoma
This structure have the direction NE-SW. As long as this structure have emerged the hot water source of Lewoderoma And hot water of Waiketi.
Geomorfology
Regional area of research by Volcanology Department of Indonesia divided in 5 morphology region:
Set of this distinguished by circular hilly. The relief is smooth until middle. Dale instruct north-south direction. River have parallel semi pattern and sentence sharply form in high stadium erosion. Set of this reside in north formed of old rock volcanic.
· Mount Watuloko
Set of this distinguished by topography form which harsh, precipitous level of inclination and erosion river deeply. Set of this take possession of the middle until north of investigation area limited of old morphology volcanic. Set of this built by lava andesitic which is generally escaped because fault.
· Mount Watukuba and Atalojo
Set of this show the very typical topography form that is volcano crater and caldera. There are a crater with the diameter 750-1000 m ( Mount Atalojo) and a caldera with the diameter 2500 m ( Mount Watukuba). Set of this morphology is formed by fallout of sediment of pyroclastic and lava. The river have pattern radial with the narrow tight dale pattern making dominant vertical erosion.
· Debris Avalanches unit
Set of this have the wavy topography form with middle of level inclination. Generally weak river stream and a little erosion. Set of this formed by rock from landslide.
· Plain morphology unit
Set of this located in coast environment formed by rock alluvial. Set of this distinguished by smooth topography.
By regional investigation in field, map of topography and interpretation photograph air there are 2 especial structure direction that is: north-south direction and northeast-southwest direction. In this area (Atedai) there are 6 big structure they are lineament, volcano, cauldron, crater, caldera, slide and fault.
Lineament
This lineament structure have the direction NW-SE. This structure is the oldest big structure estimated cut the basement. Alongside this lineament have emerged the volcano network, such as: Watulolo, Atolojo, Watukuba etc.
Cauldron (crater of Atolojo)
This cauldron structure is the result of eruption mount Atolojo, which among other things yield fallout sediment of pyroclastic skoria andesitic. Cauldron diameter 750-1000 m encircling from NE till NW and open toward north.
Caldera Watukuba
This structure is the result of eruption Watukuba yielding dusty sediment of pyroclastic. diameter of caldera Watukuba 2500 m encircle from north direction to west till easterly. In floor of caldera there are geothermal manifestation like hot ground and alteration.
Debris Avalanches/sliding of Wai Teba
This structure represent the slide which have association with the weak area, form like horse poultice that opening eastwards of Watuwawer.
Fault of Wai Kowan
Fault structure have the direction NE-SW. Alongside this structure have attended the hot water source of Wai Kowan, hot ground of Koti and area of alteration Lowo Kebingin.
Fault of Lewoderoma
This structure have the direction NE-SW. As long as this structure have emerged the hot water source of Lewoderoma And hot water of Waiketi.
Geomorfology
Regional area of research by Volcanology Department of Indonesia divided in 5 morphology region:
- Old volcanic
- Mount Watuloko
- Mount Watukuba and Atalojo
- Debris Avalanches unit
- Plain morphology unit
Set of this distinguished by circular hilly. The relief is smooth until middle. Dale instruct north-south direction. River have parallel semi pattern and sentence sharply form in high stadium erosion. Set of this reside in north formed of old rock volcanic.
· Mount Watuloko
Set of this distinguished by topography form which harsh, precipitous level of inclination and erosion river deeply. Set of this take possession of the middle until north of investigation area limited of old morphology volcanic. Set of this built by lava andesitic which is generally escaped because fault.
· Mount Watukuba and Atalojo
Set of this show the very typical topography form that is volcano crater and caldera. There are a crater with the diameter 750-1000 m ( Mount Atalojo) and a caldera with the diameter 2500 m ( Mount Watukuba). Set of this morphology is formed by fallout of sediment of pyroclastic and lava. The river have pattern radial with the narrow tight dale pattern making dominant vertical erosion.
· Debris Avalanches unit
Set of this have the wavy topography form with middle of level inclination. Generally weak river stream and a little erosion. Set of this formed by rock from landslide.
· Plain morphology unit
Set of this located in coast environment formed by rock alluvial. Set of this distinguished by smooth topography.
0 comments:
Post a Comment