Post #10-Rock Metamorphism and Life

When a rock is subjected to intense heat and pressure, it transforms into a metamorphic rock. Increasing intensities of metamorphism (metamorphic grade) may render a rock such as shale entirely unrecognizable. Different combinations of heat and pressure produce different facies of metamorphic rock. Zeolite-grade metamorphism includes the lowest heat and pressure. Granulite-grade metamorphism includes the highest heat and pressure and is the last refuge before partial melting of the rock.
When a small innocent piece of sediment falls to the ocean floor, it doesn't expect anything more than the calm deep ocean surrounding it. But as this piece of sediment nears the oceanic trench, it begins to anticipate the probable inferno of heat and pressure. Once this piece of sediment hits the trench, it is rammed against the accretionary wedge of the volcanic arc and is subjected to a low-temperature, high-pressure metamorphism. If this piece of oceanic sediment rides out the subducting plate, the temperature increases along with pressure. This piece of sediment is squeezed with many others into a crystalline, foliated rock called schist. If the piece of sediment survives is still in a recognizable form, it may melt along the subducting plate and eventually emerge as part of an andesite in a volcanic eruption. If this sediment survives all of these scenarios, it is eventually plunged deep into the hot, dense mantle to assimilate into oblivion.
When we are all plopped onto the conveyor belt of life, initially we are at peace because of the relative inaction of our surroundings. As we ride out the conveyor belt, we begin to see dangers to our peace coming. However, we are powerless to slow down or stop this conveyor belt, so we are dragged to our anticipated nightmares. Once we enter the phase that we have all feared, we are subject to a maelstrom of fear and regret. After the phases are over, we say, "Heck, I'm glad I got that over with," after we wipe the seventy gallons of perspiration off of our foreheads.