What earth boundaries are constructive (making new crust)?

A constructive plate boundary, sometimes called a divergent plate margin, occurs when plates move apart. Volcanoes are formed as magma wells up to fill the gap, and eventually new crust is formed. An example of a constructive plate boundary is the mid-Atlantic Ridge.

Explanation:

gold discovery in california, and pioneer settlers were sometimes pulled west because they wanted to make a better living. others received letters from friends or family members who had moved west. these letters often told about a good life on the frontier. the biggest factor that pulled pioneers west was the opportunity to buy land.

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answer; protectionism fosters competition and keeps price regulated;