Metamorphic Rocks - (Marble, Slate, and Schist)
Sedimentary Rocks - (Shales and Conglomerates)
Igneous Rocks - (Volcanic rocks like basalt, diabase, and granites)
Broadly speaking our earth's geological make-up can be split into 3 specific types:
Metamorphic rocks are formed when magma (molten rock) is pushed upwards from the earth's core into overlying rocks. Unlike a volcanic eruption, the magma does not erupt through the surface but cools deep within the earth. These rocks are formed by the effects of high heat and high pressure.
Rocks formed from sediment, precipitation from solution (concretion or crystalization), or the products of organisms. Examples: sandstone, rock salt, coal, and carbonates. Shales and sandstones are recycled rocks: existing rocks are eroded by rivers or the sea to form sand and mud. These deposits are then compressed to form a new rock.
Rocks formed from hot molten material which cools on the surface of the earth.
These rock are continuously forming and recycling as shown here:
(thanks to VisEarth - http://visearth.ucsd.edu/) |
For a more comprehensive description with photos of metamorphic rock
click here ==>Metamorphic Rock Identification
For a more comprehensive description with photos of minerals
click here ==>Mineral Identification
For a more comprehensive description with photos of igneous rock
click here ==>Igneous Rock Identification
For a more comprehensive description/analysis of general geology and Pennsylvania geology
click here ==>Geologic History of Central Pennsylvania
For a more comprehensive description/analysis of general geology with beautiful photos
click here ==>Univ. of California, Santa Barbara - Geology 103
For a more comprehensive description of the geology and geography of New York Bight region
click here ==>Geology And Geography Of New York Bight Beaches
For a geological map of the Newark basin (NJ)
click here ==>Geological map of NJ
For a smaller geological map of the Newark basin (NJ)
click here ==>Smaller Geological map of NJ (P.E. Olsen)
For a smaller geological map of the Newark basin (PA)
click here ==>Smaller Geologic map of Pennsylvania (from the Pennsylvania Department of Conservation and Natural Resources)