What causes continental flood basalts?
A flood basalt (or plateau basalt) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava. Many flood basalts have been attributed to the onset of a hotspot reaching the surface of the earth via a mantle plume.
What is a continental flood basalt province?
A CFBP can be defined as a series of volcanic outpourings erupted onto areas of continental crust and which are comprised predominantly of great thicknesses of basaltic lava flows.
What is a flood basalt in geology?
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.
What viscosity do flood basalts have?
Thus, basaltic magmas tend to be fairly fluid (low viscosity), but their viscosity is still 10,000 to 100,0000 times more viscous than water.
What are four types of continental provinces?
Classification
- Large rhyolitic provinces (LRPs)
- Large andesitic provinces (LAPs)
- Large basaltic provinces (LBPs): oceanic, or continental flood basalts.
- Large basaltic–rhyolitic provinces (LBRPs)
How is basalt formed?
Basalts are formed by the rapid cooling of basaltic lava, equivalent to gabbro-norite magma, from interior of the crust and exposed at or very close to the surface of Earth. These basalt flows are quite thick and extensive, in which gas cavities are almost absent.
What is an example of a flood basalt?
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).
How do flood basalt form?
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 is another name for flood basalts?
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). A flood-basalt province is popularly known as Trap (Deccan Traps in India).
Is flood basalt mafic or felsic?
mafic magma
Flood basalts are high-volume, widespread flows of mafic magma that solidify into basalt flows that in some cases cover thousands of square miles. The Columbia River Basalts comprise one of the world’s great flood basalt provinces.
What are the 4 types of boundaries?
Plate Boundaries and Hotspot Demonstration
- Divergent Plate Boundary. Volcanic eruptions and shallow earthquakes are common where plates rip apart.
- Convergent Plate Boundary.
- Transform Plate Boundary.
- Hotspot.
What are the 3 types of plate boundaries?
Divergent boundaries — where new crust is generated as the plates pull away from each other. Convergent boundaries — where crust is destroyed as one plate dives under another. Transform boundaries — where crust is neither produced nor destroyed as the plates slide horizontally past each other.
What is the chemical formula of basalt?
Basalt generally has a composition of 45–52 wt% SiO2, 2–5 wt% total alkalis, 0.5–2.0 wt% TiO2, 5–14 wt% FeO and 14 wt% or more Al2O3. Contents of CaO are commonly near 10 wt%, those of MgO commonly in the range 5 to 12 wt%.
What are 3 facts about basalt?
Basalt is a common extrusive rock found on Mars, Earth, and Venus. Basaltic rocks are also found on Earth’s surface as they erupt in the form of lava. More than half of the ocean floor is basalt. It is one of the most abundant volcanic rocks on Earth.
What are flood basalts associated with?
lava flows (called flood basalts or traps) and volcanic ash bury preexisting terrain, as exemplified by the Columbia Plateau in the northwestern United States. The volcanism involved in such situations is commonly associated with hot spots.
What are the 7 major plate boundaries?
The World Atlas names seven major plates: African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American.
What are the 3 types of continental drift?
There are three kinds of plate tectonic boundaries: divergent, convergent, and transform plate boundaries.
What are 4 plate boundaries?
There are four types of boundaries between tectonic plates that are defined by the movement of the plates: divergent and convergent boundaries, transform fault boundaries, and plate boundary zones. Microplates are smaller fragments of tectonic plates that appear in plate boundary zones.
What are characteristics of basalt?
Basalt is rich in iron and magnesium and is mainly composed of olivine, pyroxene, and plagioclase. Most specimens are compact, fine-grained, and glassy. They can also be porphyritic, with phenocrysts of olivine, augite, or plagioclase. Holes left by gas bubbles can give basalt a coarsely porous texture.
Is basalt basic or acidic?
Basic: rocks that are about 45 to 55% silica (mostly mafic minerals plus plagioclase feldspar and/or feldspathoid minerals), e.g. basalt.
What is the chemical composition of basalt?
Basalt generally has a composition of 45–52 wt% SiO2, 2–5 wt% total alkalis, 0.5–2.0 wt% TiO2, 5–14 wt% FeO and 14 wt% or more Al2O3.
What is the importance of basalt?
Basalt is used for a wide variety of purposes. It is most commonly crushed for use as an aggregate in construction projects. Crushed basalt is used for road base, concrete aggregate, asphalt pavement aggregate, railroad ballast, filter stone in drain fields, and may other purposes.
What is the smallest plate?
Answer and Explanation: The Juan de Fuca Plate is the smallest of earth’s tectonic plates. It is approximately 250,000 square kilometers.
What is the largest plate?
the Pacific Plate
The Hawaiian Islands were created by the Pacific Plate, which is the world’s largest plate at 39,768,522 square miles.