Flood Basalts are high volume eruptions that flood vast areas of the Earth, covering broad regions with flat lying lava surfaces. … Continental flood basalt eruptions, which degas to the atmosphere when erupted, are associated with
ecosystem mass extinctions
.
What extinction events are associated with flood basalts?
Two other major mass extinctions have been correlated with flood basalt episodes:
the end-Cretaceous event
(65 Mya) with the Deccan basalts of India and the end-Permian event (251 Mya) with the Siberian basalts.
What type of plate boundary is most associated with flood basalts?
On the continental plates at areas away from active convergence, the magmatism is confined to rift valleys and local hot spots. The volume of magma produced is minor in comparison to that generated at oceanic rises and at
convergent plate boundaries
. Flood basalts are the most common form of occurrence.
What is the source for most flood basalts?
9.2.
Flood basalt is formed by
an eruption or series of eruptions of large volcanic episodes
that cover vast stretches of land or ocean floor with flows of mafic igneous rocks (basalt lava flows).
What are the effects of flood basalts?
Environmental Effects of Flood Basalt Eruptions
Indirect environmental effects include
changes in ocean chemistry, circulation, and oxygenation
, especially from basaltic volcanism associated with large submarine oceanic plateaus that may represent flood basalt eruptions in an oceanic environment.
What kind of boundary is Mount Fuji?
It is locted on a
convergent plate boundary
(the Eurasian, North American (Okhotsk) and Philippine plates converge.)
Why are the flood basalts so fluid?
Flood Basalts are high volume eruptions that flood vast areas of the Earth, covering broad regions with flat lying lava surfaces. They are said to be the
result of mantle convection through hot spots
, which occur sporadically in time and place.
How long do flood basalts last?
Continental flood basalt provinces typically form on a timescale of
1 to 3 million years
.
Can Floods cause extinction?
Flood basalts, the largest volcanic events in Earth history, triggered dramatic environmental changes on land and in the oceans. Rapid volcanic carbon emissions led to ocean warming, acidification, and deoxygenation that often caused widespread animal extinctions.
Where can flood basalts be found in the US?
The most famous US example of a flood basalt province is
the Columbia River Basalt province
, covering most of SE Washington State and extending all the way to the Pacific and into Oregon. The Deccan Traps of NW India are much larger and the Siberian Traps are even larger than that (but poorly understood).
Are flood basalts Polygenetic?
A flood basalt province, built from different eruptive fissures dispersed over wide areas, can be considered a
polygenetic volcano
without any dominant vent. … This recognition helps in understanding the volcanological, stratigraphic, and geochemical complexity of flood basalts.
Do flood basalts have high viscosity?
Plateau or Flood basalts are extremely large volume outpourings of
low viscosity basaltic
magma from fissure vents. The basalts spread huge areas of relatively low slope and build up plateaus.
Are flood basalts effusive?
The largest known
effusive
eruptions on Earth have paved hundreds to thousands of square kilometers of its surface with basaltic lava. Erupting hundreds of lava flows over a period of a few million years, scientists refer to the resulting deposits as flood basalt and the areas covered as plateau basalt.
Do flood basalts cause global cooling?
It has been postulated that
the rapid volcanism and degassing released enough sulfur dioxide to cause a rapid global cooling
, inducing a short ice age with associated rapid fall of sea level. Soon after the ice age took hold, the effects of the carbon dioxide took over and the atmosphere heated to cause global warming.
What is short flooding?
A flood is
an overflow of water that submerges land that is usually dry
. … Floods can also occur in rivers when the flow rate exceeds the capacity of the river channel, particularly at bends or meanders in the waterway. Floods often cause damage to homes and businesses if they are in the natural flood plains of rivers.
What makes a shield volcano A shield volcano?
Shield volcanoes
Where a volcano produces
low viscosity, runny lava
, it spreads far from the source and forms a volcano with gentle slopes: a shield volcano. Most shield volcanoes are formed from fluid, basaltic lava flows. Mauna Kea and Mauna Loa are shield volcanoes.
