Answer:
Deserts
Explanation:
A desert is a region on the earth surface with little to no rainfall all year round. Deserts also experience a wide range of temperatures daily. During the day, temperature is very high, at night, temperature falls rapidly and it is cold.
These extremes of conditions coupled with some other factors makes deserts badlands for plant growth. The soil is very lose here and contains little to no nutrients. Organic matter is non-existent due to low biodiversity.
Plants that grow in such conditions are called xerophytes. An example is cactus. They have evolved to survive and adapt to such extremes of conditions.
Examples of such deserts around the world are Sahara desert, Namib desert, Atacama desert, Kalahari desert etc.
Magma. Magma can be made of many different materials, and once it breaches the earth surface it is called lava. Lava is what comes out of volcanoes, magma is what is still underground
Answer:
potassium-argon dating
Explanation:
Potassium-argon (K-Ar) dating technique is the most appropriate dating method for establishing the age of a volcanic ash. It is most applicable for dating minerals and rocks more than 100,000 years old. It is based on measuring the product of the radioactive decay of an isotope of potassium (k) into argon (Ar). Since potassium is a common element found in many volcanic ash layer, the time since re-crystallization is calculated by measuring the ratio of the amount of argon 40 (Ar-40) accumulated to the amount of potassium 40 (K-40) remaining in these volcanic ashes.
They form in the ocean where undersea volcanoes are errupting. The magma turning into lava piles up on top of itself over lots of time to form land.