Wind forms dunes through __

Why are there mountains along the west coast of North and South America

densk [106]

On the West coast of North America, the coast ranges and the coastal plain form the margin. Most of the land is made of terranes that have been accreted onto the margin. In the north, the insular belt is an accreted terrane, forming the margin. This belt extends from the Wrangellia Terrane in Alaska to the Chilliwack group of Canada.

A rupture in Rodinia 750 million years ago formed a passive margin in the eastern Pacific Northwest. The breakup of Pangea 200 million years ago began the westward movement of the North American plate, creating an active margin on the western continent. As the continent drifted West, terranes were accreted onto the west coast. The timing of the accretion of the insular belt is uncertain, although the closure did not occur until at least 115 million years ago.Other Mesozoic terranes that accreted onto the continent include the Klamath Mountains, the Sierra Nevada, and the Guerrero super-terrane of western Mexico.80 to 90 million years ago the subducting Farallon plate split and formed the Kula Plate to the North. This formed an area in what is now Northern California, where the plates converged forming a Mélange. North of this was the Columbia Embayment, where the continental margin was east of the surrounding areas.Many of the major batholiths date from the late Cretaceous. As the Laramide Orogeny ended around 48 million years ago, the accretion of the Siletzia terrane began in the Pacific Northwest. This began the volcanic activity in the Cascadia subduction zone, forming the modern Cascade Range, and lasted into the Miocene. Events here may relate to the ignimbrite flare-up of the southern Basin and Range. As extension in the Basin and Range Province slowed by a change in North American Plate movement circa 7 to 8 Million years ago, rifting began on the Gulf of California.

7 0

2 years ago

Read 2 more answers

The distribution of earthquakes to find the boundaries of which major earth feature

Nadya [2.5K]

Tectonic Plates would be the answer

4 0

2 years ago

How many countries are there United States?

Arisa [49]

Answer:

195 countries

Explanation:

There are 195 countries in the world today. This total comprises 193 countries that are member states of the United Nations and 2 countries that are non-member observer states: the Holy See and the State of Palestine.

4 0

1 year ago

Read 2 more answers

A cylinder has a height of 12 cm and a total surface area of 172 cm 2 . What is the radius of the base of this cylinder?

Eduardwww [97]

Answer:

466.5 cm^2.

Explanation:

surface areas

base surface area : 466.5 cm^2

lateral surface area : 649.6 cm^2

total surface area : 1116.1 cm^2

radius

8.617 cm^2

8 0

2 years ago

Read 2 more answers

Which of the following nations does not possess nuclear weapons? A. China B. France C. India D. Spain

ycow [4]

Answer:

D. Spain

Explanation:

because they dont

8 0

2 years ago

Wind forms dunes through ___.