AP Environmental Science Trotter

ROCKSMINERALS  Heterozygous  Can be organic or non- organic  Follow the rock cycle  Three types: sedimentary, igneous, metamorphic  Homozygous  Organic  Must follow rules of minerals

 Intrusive igneous rocks are formed from magma that cools and solidifies within the crust of a planet  Granite and Pumice

 Extrusive igneous rocks form when magma makes its way to Earth's surface. The molten rock erupts or flows above the surface as lava, and then cools forming rock. The lava comes from the upper mantle layer, between 50 km and 150 km below the Earth's surface.  When lava erupts onto the Earth's surface, it cools quickly. If the lava cools in less than a day or two, there is no time for elements to form minerals. Instead, elements are frozen in place within volcanic glass. Often, lava cools over a few days to weeks and minerals have enough time to form but not time to grow into large crystals.  Basalt is the most common type of extrusive igneous rock and the most common rock type at the Earth's surface.

 Sedimentary rocks are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water.  Weathering and erosion are vital pieces needed in order to form sedimentary rock.

GRAND CANYONSANDSTONE

 Metamorphic rocks make up a large part of the Earth's crust and are classified by texture and by chemical and mineral assemblage  They may be formed simply by being deep beneath the Earth's surface, subjected to high temperatures and the great pressure of the rock layers above it.  They can form from tectonic processes such as continental collisions, which cause horizontal pressure, friction and distortion.  They are also formed when rock is heated up by the intrusion of hot molten rock called magma from the Earth's interior.

 Weathering: break down of rocks on or near Earth’s surface.  Erosion: the removal and transport of weathered material  Erosion has been occuting since the formation of the crust.

 The break down of rock caused by the climate. Some things that add to mechanical weathering is Temperature: frost wedging, which is the repeated freezing and thawing of water in cracks.

 Pressure Bedrock is under lots of pressure from all of the rock which lies on top. Once the top rock is removed, pressure is reduced. Eventually this will be uncovered and it will be exposed. The peeling of the layers over time is called exfoliation. Exfoliation= dome shaped formations

 The process by which rocks and minerals undergo changes in their composition as the result of chemical reactions.  The composition of a rock will determine what effects of chemical weathering will have. Lichens Acid Rain Water- hydrolysis Oxygen + other substances= oxidation CO2: dissolves calcite and limestone

 Climate: the amount of precipitation, temperature, and evaporation. The interaction between temperature and precipitation is the most important. Chemical weather occurs primarily in warm weather.  Occurs with abundant rainfall, warm temperatures and lush vegetation.  Mechanical weathering occurs more in colder climates. Another affect would be rock type: some are more resistant than others.

 O Horizon: leaf litter/detritus  A: Topsoil: dark decomposed organic materials  B: consists of mineral layers which may contain concentrations of clay or minerals such as iron or aluminum oxides or organic material moved there by leaching  C: bedrock

 Polar: Good drainage but no horizons, permafrost  Temperate soils: lots of humus, Al and FeO2 rich soils, rainfall consistent  Desert Soils: high level of salts ( less precipitation). Thin A horizon.  Tropical Soils: intense weather, little hummus, few nutrients. Soils rich in Fe and Al.

 1977: Soil & Water Conservation Act- continued evaluations for soil and water  1985: Food Security Act: “ Swampbuster” Discouraged drying out wetlands 1990 funds were denied to farmers who dried out their lands