EESA06H3 Study Guide - Final Guide: East African Rift, Ore, With Folded Hands
Document Summary
Relative( i am older than you) vs. absolute ( i am 37 and you are 20) age. Unconformities ( missing pages in the geologic book of time) Most rocks are not considered to be mineral deposits, even though they are indeed composed of minerals. Instead, the term mineral deposit means the rock is especially rich in some commodity that might be valuable, and such rocks are said to be mineralized. If a mineral deposit contains enough of a commodity to be mined at a profit, it is an ore deposit, and the valuable rocks or other materials in that deposit are ore. Many geologic processes can concentrate minerals or chemical elements, but it takes special circumstances to form a mineral deposit, especially one rich enough to become ore. Some ore-forming environments involve hot or deep processes and others involve low-temperature processes typical of near-surface environments.
