Metamorphic rock the foliation is called "gneissosity"), granoblastic (includes granulite, some marbles and quartzite), and hornfelsic (includes hornfels and skarn). Metamorphic rock Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure ( or more), causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by
What Is History? form of elitism—the product of elite social groups whose security and whose privileges have been most conspicuously eroded by the crisis, and of elite countries whose once undisputed domination over the rest of the world has been shattered". Carr's opinions about the nature of historical work in "What Is History?" were controversial. In his 1967 book "The Practice of History", Sir Geoffrey Elton criticized Carr for his "whimsical" distinction between the "historical facts" and the "facts of the past", saying that it reflected "an extraordinarily arrogant attitude both to the past and to the place of the historian studying it".