Rocks

Igneous - Hardened up magma from inside the Earth, or hardened up lava from volcanoesSedimentary - Layers of sediment compacted and cemented togetherMetamorphic - Other types of rock changed by extreme heat and/or pressurePorous Rocks - Liquid can pass throughNon-porous rocks - Liquid cannot pass throughHow are Sedimentary rocks formed? 1. SedimentationBits of rock are broken off, transferred by the river to the river bed.2. CompactionThe weight of the layer on top squeezes out water and squashes the sediment together.3. CementationSalt crystals "glue" cement pieces or sediment together.How are Igneous rocks formed?If the magma cools quickly -> Small crystals form in the rockIf the magma cools slowly -> Large crystals form in the rockNo fossils form because the magma/lava melts itWeathering3 types-Physical weathering-Chemical weathering-Biological weatheringPhysical weathering:When it is extremely hot -> Rock expandsWhen it is extremely cold -> Rock contractsWind, Rain and WaveWind blows tiny grains of rock awayRain and waves -> liquid gets into small cracksFreeze - Thaw-Water inside rock freezes-This forces the rock open and makes a big crack in the rock-When the ice thaws, water seeps further down the rock-Repeat