Answer:
4 billion years
Explanation:
Scientists have found the oldest known rocks on Earth. They are 4.28 billion years old, making them 250 million years more ancient than any previously discovered rocks. Earth formed about 4.6 billion years ago from a disk of gas and dust circling the sun.
The answers that apply are;
- striped pattern
- provide evidence to seafloor spreading
Ocean ridges can be found at divergent boundaries where two plates are moving away from each other. As the magma rises to fill the void, it cools into rock and forms new crust. The iron minerals in the rocks align with the earth’s magnetic field before the rock cools. This causes the rocks in these areas of seafloor spreading to have band-like patterns. The irons align differently each number of years in relation to the flipping of the earth’s magnetic field. This phenomenon has been used to determine the ages of these rock layers.
Answer:
A biome is an enormous ecosystem, spreading over a broad geographic range.
Explanation:
Biomes are classified here in such a form as to get into account their corresponding ranges and similar weather. All climate zones, though, come into one of three essential classifications: tropical and subtropical, temperate, and polar and subpolar.
The first of specific categories is a term covering the area along the equator, spreading north and south by approximately 30 degrees in either direction. In North U.S, this would involve southerly Florida, Texas, and Louisiana. Temperate areas spread from about 30 to 60 degrees on each side of the equator, thus leading in most of America. Ultimately, subpolar and polar regions lie among 60 degrees and the poles, which occur at 90 degrees.
Answer:
Rivers provide water, and a transportation route (before roads and railroads). They can also form a natural boundary or barrier to protect or defend people. Rivers can provide fish and can also make the lands around them very fertile. if they overflow their banks occasionally.
Explanation:
