By Marissa Welch EDU 290 Central Michigan University Rocks
A Rockis a grouping of one or more minerals Three types Igneous Sedimentary Metamorphic What is a rock?
Rocks are very useful in the environment for things such as: cement, gravel, building materials, countertops, tiles, and statues as well as other things like containing ground water and oils/gas Helps to discover the history of the Earth’s atmosphere and life on Earth Why study Rocks?
Igneous rocks are formed by cooling and crystallization of magma (below the Earth’s surface) or Lava (above the Earth’s surface) There are two types of Igneous rocks Intrusivewhich form from magma coming up from the mantle into the crust and cooling Extrusivewhich form from volcanic eruptions Igneous Rocks
Examples of Igneous Rocks Granite is an example of an Intrusive Igneous Rock It forms under the Earths surface from the cooling of magma leaking up from the mantle of Earth Intrusive igneous rocks have noticeably large crystals and are usually rough to the touch unless they are polished Examples: Kitchen Counters The Continental Crust of the Earth is primarily made of Granite
Other examples of Intrusive Igneous Rocks: Gabbro Andesite Diorite
Examples of Extrusive Igneous Rocks Basalt is an example of an Extrusive Igneous Rock The Oceanic Crust is made primarily of Basalt Basalt is formed from lava on the crust of the Earth. Because it is formed on the surface, the crystals are very fine-grained
Obsidian Rhyolite Scoria Other examples of Extrusive Igneous Rocks
Sedimentary Rocks Sedimentary rocks are formed by the accumulation of sediments. Sediments include materials from sand grain size to boulder size There are three basic types of sedimentary rocks: Clastic (physical weathering) Chemical Organic
Clastic Sedimentary Rocks Clastic Sedimentary Rocksare formed from mechanical weathering debris Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks breccia, conglomerate, sandstone and shale are some examples Breccia Conglomerate Sandstone Shale
Chemical Sedimentary Rocks Chemical Sedimentary Rocks form when dissolved materials precipitate from solution Example : Halite that forms from dried up saltwater lakes rock salt (Halite) and some limestone are examples of Chemical Sed. Rocks Halite Limestone
Organic Sedimentary Rocks Organic Sedimentary Rocksform from the dead plants and animals and their debris. Coal and fossiliferous limestone are examples of organic sed. rock An example of fossiliferous limestone has sea shells in it Organic material comes from anything living or has lived before Fossiliferous Limestone Coal
Metamorphic Rocks Metamorphic rocks have been modified by heat, pressure and chemical process usually while buried deep below Earth's surface. Exposure to these extreme conditions has altered the minerals, texture and chemical composition of the rocks. There are two basic types of metamorphic rocks: Non-foliated Foliated
Foliated Metamorphic Rocks Foliated metamorphic rocks: have a layered or banded appearanceknown as a foliation Examples are gneiss, phyllite, schist and slate produced by exposure to heat and directed pressure Gneiss Slate Schist
Non-Foliated Metamorphic Rock Non-foliated metamorphic rockssuch as marble and quartzite do not have a layered or banded appearance Quartzite Marble
All pictures came from www.gelogy.com Information on definitions came from the book used in Gel 100 at Central Michigan University Information from slides 9-15 came from www.gelogy.com Sedimentary information came from http://geology.com/rocks/sedimentary-rocks.shtml Metamorphic information came from http://geology.com/rocks/metamorphic-rocks.shtml Work Sited Page