Table of Contents
What caused the Columbia River flood basalts?
The basalt columns formed when thick lava flows cooled after emplacement.
How are flood basalts plateau basalts like the Columbia River Plateau formed?
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). A flood-basalt province is popularly known as Trap (Deccan Traps in India).
Where are flood basalts found?
Many flood basalts are associated with rift valleys, are located on passive continental plate margins, or extend into aulacogens (failed arms of triple junctions where continental rifting begins.) Flood basalts on continents are often aligned with hotspot volcanism in ocean basins.
What state has the greatest extent of flood basalts?
The largest continental flood basalt province in the United States is the Columbia River flood basalt in Washington, Oregon, and Idaho. The Columbia River flood basalt province is 6-17 million years old and contains an estimated 1,250 cubic miles (4,900 km3) of basalt.
When was the Columbia River flood basalt?
The Columbia River Basalt Group (CRBG) is the youngest, smallest, and best-preserved continental flood basalt. It erupted ~210,000 km3 of lava in the Pacific Northwest, United States, between ~17 and 5 million years (Ma) ago.
Is a flood basalt a volcano?
Flood basalts are yet another strange type of “volcano.” Some parts of the world are covered by thousands of square kilometers of thick basalt lava flows – individual flows may be more than 50 meters thick, and individual flows extend for hundreds of kilometers.
Which of the following best describe how flood basalts form?
Which of the following best describe how flood basalts form? Flood basalts form as a result of an eruption above a mantle plume.
Do flood basalts erupt?
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.
Is Yellowstone A flood basalt?
“This huge flood basalt event covered an area of more than seven million squared kilometres of basaltic rock, that’s more surface area than all the countries of the European Union combined.
How thick are flood basalts commonly?
How old are the Columbia River basalts?
Volcanism began about 17.5 million years ago and ceased about 6 million years ago. Most of the volume of the Columbia River Flood Basalt Province (85%) was erupted in only 1.5 million years from 17 to 15.5 million years ago. Volume of each formation, in cubic kilometers, is given in parentheses.
What would happen if a flood basalt eruption?
In human terms, this would be like Iceland’s Laki eruption of 1773 all over again, but on a global scale; livestock would die, people would get breathing problems, structures would become corroded – and in the modern age, most flights would be grounded.
How can flood basalts cause a mass 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.
How was the Columbia Plateau related to Yellowstone?
They found that the youngest rocks were grouped around the Yellowstone plateau, with lavas increasing in age to the west. This evidence suggests that a concentrated heat source is melting rocks at the base of the lithosphere underneath the Columbia Plateau province.
What is the Columbia River flood basalt province?
The Columbia River Flood Basalt Province forms a plateau of 164,000 square kilometers between the Cascade Range and the Rocky Mountains. In all, more than 300 individual large (average volume 580 cubic km!) lava flows cover parts of the states of Idaho, Washington, and Oregon.
What is the Karoo and Ferrar large igneous province?
The Karoo and Ferrar Large Igneous Provinces (LIPs) are two large igneous provinces in Southern Africa and Antarctica respectively, collectively known as the Karoo-Ferrar, Gondwana, or Southeast African LIP, associated with the initial break-up of the Gondwana supercontinent at c. 183 Ma .
What are the characteristics of the Columbia River basalt group flows?
The Columbia River Basalt Group flows exhibit essentially uniform chemical properties through the bulk of individual flows, suggesting rapid placement.
What are flood basalts?
Flood basalts are thick successions of basalt erupted onto the continents over short periods of time, like the Columbia River Basalts in the NW United States and the Deccan Traps in India ( Figure 3.6 ).