earth's crust under oceanic is composed of this rock type
Oceanic crust Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium. It is thinner than continental crust, or [er it is denser, having a mean density of about 2.9 grams per cubic centimeter[1] as opposed to continental crust which has a density of about 2.7 grams per cubic centimeter.[2]
Northern Hemisphere Its surface is 60.7% water, compared with 80.9% water in the case of the Southern Hemisphere, and it contains 67.3% of Earth's land.[2]
Vein Veins are present throughout the body as tubes that carry blood back to the heart. Veins are classified in a number of ways, including superficial vs. deep, pulmonary vs. systemic, and large vs. small.
Small intestine Food from the stomach is allowed into the duodenum through the pylorus by a muscle called the pyloric sphincter.