Bollons Seamount
Encyclopedia
Bollons Seamount is a seamount
(underwater volcano) just east of the international date line
, a few hundred miles off the coast of New Zealand
.
The seamount was involved in a 2002 survey and collection project defined to find the end scope of the Australian Plate. The Bollons Seamount has been shown to be a site of extensive Cretaceous
-era rifting
in the area towards the southern Chatham Rise
between 83.7 and 78.5 MYA. Magnetic anomalies from the seamount indicate that it was the site of highly irregular activity, with differences in the rifting there being up to 100 km (62 mi). A 50 km (31 mi) gap near the seamount, known as the Ballons gap, is interpreted as being due to excess volcanism is the seafloor-spreading process. A ridge just south of the seamount, the Antipodes Fracture Zone, is interpreted as having been built by a combination of compression and volcanic activity associated with the triple-junction Bellingshausen-Marie plate boundary
nearby.
Seamount
A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of depth. They are defined by oceanographers as...
(underwater volcano) just east of the international date line
International Date Line
The International Date Line is a generally north-south imaginary line on the surface of the Earth, passing through the middle of the Pacific Ocean, that designates the place where each calendar day begins...
, a few hundred miles off the coast of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
.
The seamount was involved in a 2002 survey and collection project defined to find the end scope of the Australian Plate. The Bollons Seamount has been shown to be a site of extensive Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
-era rifting
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
in the area towards the southern Chatham Rise
Chatham Rise
The Chatham Rise is an area of ocean floor to the east of New Zealand, forming part of the Zealandia continent. It stretches for some from near the South Island in the west, to the Chatham Islands in the east...
between 83.7 and 78.5 MYA. Magnetic anomalies from the seamount indicate that it was the site of highly irregular activity, with differences in the rifting there being up to 100 km (62 mi). A 50 km (31 mi) gap near the seamount, known as the Ballons gap, is interpreted as being due to excess volcanism is the seafloor-spreading process. A ridge just south of the seamount, the Antipodes Fracture Zone, is interpreted as having been built by a combination of compression and volcanic activity associated with the triple-junction Bellingshausen-Marie plate boundary
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
nearby.