The Lithosphere: Introduction to the Land Unit

Earth’s Lithosphere Lithosphere = a layer of land that forms Earth’s surface Includes the rocks, soil and sand that make up land

Earth’s Lithosphere 10-200 km thick Cool, rigid outermost part of the earth’s mantle Divided into tectonic plates Cause earthquakes/ mountain ranges

The Lithosphere 10-200 kilometers Rocks making up the lithosphere Igneous Rock Sedimentary Rock Metamorphic Rock

Igneous Rock Formed when magma (molten rock deep within the earth) cools and hardens. When lava cools very quickly: no crystals form rock looks shiny and glasslike Gas bubbles trapped in the rock during the cooling process tiny holes and spaces form

Igneous Rock Examples Pumice Obsidian Basalt Other examples include: Diabase, Diorite, Gabbro, Granite, Rhyolite, Scoria

Sedimentary Rock As rock breaks down slowly over time, the tiny pieces of rock that wear off become sediments that are carried away by wind and water. Sediments settle into layers Layers of sediment accumulate and are compressed and cemented Fossils are almost always found in sedimentary rock!!!

Sedimentary Rock Examples Shale = silt particles Sandstone = sand particles Limestone = calcium carbonate or calcite (shells of marine organisms) Other examples include: Breccia, Conglomerate

Metamorphic Rock Formed under the surface of the earth from the metamorphosis (change) that occurs due to intense heat and pressure (squeezing). Ribbon-like layers May have shiny crystals, formed by minerals growing on their surface slowly over time

Metamorphic Rock Examples Marble Slate Gneiss Other examples include: Quartzite, Schist, Serpentinite

Characteristics Used to Identify Rocks Crystals Fossils Gas Bubbles Glassy Surface Ribbon-Like Layers Sand or Pebbles

The Rock Cycle