how well the flu vaccine is matched to flu viruses that are causing illness. Over a period of 31 seasons between 1976 and 2007, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people.
metamorphic rocks form from heat and pressure changing the original or parent rock into a completely new rock the parent rock can be either sedimentary igneous or even another metamorphic rock the word metamorphic comes from greek and means to change form the diagram above shows you how the rocks on earth have been changed continually over time from one rock type to another
Metamorphic rocks that form because they are exposed to heat from magma form at the same plate boundaries igneous rocks form: divergent, oceanâocean convergent and oceanâcontinent convergent. These types of metamorphic rocks can also form at hot spots. Metamorphic rocks formed when rocks are buried to depths with high temperature and pressure are found where rocks are squeezed and crumpled into mountains, that is, at convergent plate boundaries. The hot fluids mostly form when water flows near magma.