Download Mechanical weathering - occurs when physical forces break rock

Weathering and Erosion
Mechanical weathering - occurs when physical forces break rock into smaller
and smaller pieces without changing the rock’s mineral composition.
Frost wedging - the mechanical breakup of rock caused by the expansion of
freezing water in cracks and crevices
Talus large piles of sediment which typically form a cone shaped deposit at the
base of steep, rocky cliffs.
Unloading - Reduced pressure on igneous rock allowing the rock to expand
caused by the removal of large amounts of over burden rock.
Exfoliation - a process where slabs of the outer edge of an expanding igneous
rock break off in layers or sheets.
Biological activity - the activity of organisms, including plants, burrowing
animals, and humans, that cause mechanical weathering.
Chemical weathering - the transformation of rock into one or more new
compounds.
Spheroidal Weathering – the process which causes the corners and edges of
rock to be more rounded.
Differential Weathering - caused by variations in mineral composition, rock
weathers unevenly to create unusual and spectacular rock formations and
landforms.
Soil - part of the regolith that supports the growth of plants. It has four major
components: mineral matter, or broken-down rock; humus, which is the
decayed remains of organisms; water; and air
Regolith - the layer of rock and mineral fragments that covers most of Earth’s
land surface.
Loam - a mixture of all three soil sizes. Best suited for plant life.
Parent material – the sediments that soil formed in place.
Residual soil - parent material for that soil is the bedrock directly below it.
Transported soil - parent material for that soil has been carried from
elsewhere and deposited
Soil horizons are zones or layers of soil.
Soil profile is a vertical section through all the soil horizons.
Pedalfer - common type of soil developed under forest vegetation with iron
oxides and aluminum-rich clays in the B horizon.
Pedocal - common type of soil developed with drier grasslands with abundant
calcium carbonate.
Laterite - common type of soil developed in hot, wet, tropical climates with
intense chemical weathering.
Mass movement - the transfer of rock and soil down slope due to gravity.
Rockfall - occurs when rocks or rocks fragments fall freely through the air.
Rockslides - segments of bedrock moves suddenly along a flat, inclined
surface.
Slump - the downward movement of a block of material along a curved
surface.
Mudflows – rapid movement of a mixture of soil, rock, and water that has a
consistency of wet concrete.
Earthflows - relatively slow down hill movements of material containing a
large amount of water and clay-rich sediment.
Creep - is the very slow, downhill movement of soil and regolith.