Slate is a metamorphic rock. Metamorphic rocks are formed when sedimentary or igneous rocks are exposed to conditions of very high pressure or temperature, or are exposed to large amounts of very hot water.Slate is formed when fine-grained sedimentary rock (shale) is buried and exposed to high pressure deep beneath the Earth's surface.gneous rocks are formed from melted rock that has cooled and solidified. When rocks are buried deep within the Earth, they melt because of the high pressure and temperature; the molten rock (called magma) can then flow upward or even be erupted from a volcano onto the Earth's surface.
As a patient with COPD, your health care provider may determine your oxygen levels at rest, while sleeping, or during exercise to see if oxygen may help you. If your oxygen levels are low, oxygen therapy will help reduce the strain on your heart, brain, and muscles, and using oxygen as directed may help you feel better.
Without more details, I'm going to treat this case as arising from chronic obstructive pulmonary disease (COPD) which is the most common cause of hypoxia. In that context, 85-90% spans very important numbers. 85% absolutely requires supplemental oxygen, whereas 90% does not. Generally oxygen is not covered by insurance and not prescribed unless the saturation is <89% (and we inpatient doctors need a result from the day of discharge and not before).