Corregidor Caldera
Encyclopedia
Corregidor is an extinct volcanic caldera
located at the entrance to Manila Bay
in the Republic of the Philippines. The caldera is composed of the islands of Corregidor
and Caballo
in the province
of Cavite
, which are believed to be the exposed rim of the volcano
.
with a rim elevation of 173 metres (567.6 ft) and a base diameter of 4 kilometres (2.5 mi).
Predominant rock type is dacite
with a 72.68% silica dioxide content.
based on the age of deposits.
(PHIVOLCS) lists the volcano
as potentially active. The reason for this listing rather than inactive, is not disclosed on the PHIVOLCS website listing.
Corregidor is not listed with the Smithsonian Institution
's Global Volcanism Program
as it has no known eruptions in the Holocene
epoch
(around 10,000 years ago).
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
located at the entrance to Manila Bay
Manila Bay
Manila Bay is a natural harbor which serves the Port of Manila , in the Philippines.The bay is considered to be one of the best natural harbors in Southeast Asia and one of the finest in the world...
in the Republic of the Philippines. The caldera is composed of the islands of Corregidor
Corregidor
Corregidor Island, locally called Isla ng Corregidor, is a lofty island located at the entrance of Manila Bay in southwestern part of Luzon Island in the Philippines. Due to this location, Corregidor was fortified with several coastal artillery and ammunition magazines to defend the entrance of...
and Caballo
Caballo Island
Caballo Island is a bluff, rocky island located at the entrance to Manila Bay in the Philippines. It is about 3/4 mile long with the highest elevation at 381 feet high...
in the province
Provinces of the Philippines
The Provinces of the Philippines are the primary political and administrative divisions of the Philippines. There are 80 provinces at present, further subdivided into component cities and municipalities. The National Capital Region, as well as independent cities, are autonomous from any provincial...
of Cavite
Cavite
Cavite is a province of the Philippines located on the southern shores of Manila Bay in the CALABARZON region in Luzon, just 30 kilometers south of Manila. Cavite is surrounded by Laguna to the east, Metro Manila to the northeast, and Batangas to the south...
, which are believed to be the exposed rim of the volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
.
Physical Features
Corregidor is classified by Philippine volcanologists as a potentially-active calderaCaldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
with a rim elevation of 173 metres (567.6 ft) and a base diameter of 4 kilometres (2.5 mi).
Predominant rock type is dacite
Dacite
Dacite is an igneous, volcanic rock. It has an aphanitic to porphyritic texture and is intermediate in composition between andesite and rhyolite. The relative proportions of feldspars and quartz in dacite, and in many other volcanic rocks, are illustrated in the QAPF diagram...
with a 72.68% silica dioxide content.
Eruption
Last eruption was about 1 million years (1.10 +/-0.09 Ma) BPBefore Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...
based on the age of deposits.
Listings
The Philippine Institute of Volcanology and SeismologyPhilippine Institute of Volcanology and Seismology
The Philippine Institute of Volcanology and Seismology is a Philippine national institution dedicated to provide information on the activities of volcanoes, earthquakes and tsunamis, as well as other specialized information and services primarily for the protection of life and property and in...
(PHIVOLCS) lists the volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
as potentially active. The reason for this listing rather than inactive, is not disclosed on the PHIVOLCS website listing.
Corregidor is not listed with the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
's Global Volcanism Program
Global Volcanism Program
The Smithsonian Institution's Global Volcanism Program documents Earth's volcanoes and their eruptive history over the past 10,000 years. The GVP reports on current eruptions from around the world as well as maintaining a database repository on active volcanoes and their eruptions. In this way, a...
as it has no known eruptions in the Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
(around 10,000 years ago).