ESCI 4

Weathering, Transportation, Deposition, Lithification

Physical –deterioration of pre-existing rocks throught physical actions, frost

Chemical – chemical decomposition of pre-existing rocks (biggest cause of change)

Movement of sedimentary materials from point of weathering to point of deposition

• Fluid flow – flowing medium like water or air
• may entrain or dissolve the materials andmove them (well sorted)
• Gravity – direct reaction to force of gravity (poorly sorted)

The settling or precipitation of sedimentary materials

-Composed of redeposited terrigenous sed. particles (erosion to transport to deposition)

• the degree to which the rock is composed of similar sized grains
• Sorting is relative to method of disposition
• grain size = energy sand is higher energy than
• clay

degree of roundness/angularity

likely transported long distances

piece of un yet weathered protolith

Stalactites, cave deposits

Limetone-carbonates biologically precipitated from H20

Evaporites-residue left over after evaporation of mineral rich H20 (Halite, chert)

A rock’s composition tells us about its erodability and transportablility

is not easily eroded and not dense (last rock standing)

weathers easily, dense, not very transportable

Coquina and chalk are bioclastics

-discrete sed. grains are classified by grain size – boulders, pebbles, sand, silt, clay