Transcript The History of Life

SEDIMENTARY ARCHIVES
Sedimentary Structures
Sole marks
SEDIMENTARY ARCHIVES
Sedimentary Structures
Flute casts
SEDIMENTARY ARCHIVES
Sedimentary Structures
Tool marks
SEDIMENTARY ARCHIVES
Sedimentary Structures
Flame Structures
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Load structures
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Mudcracks
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Planar Cross-beds
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Trough Cross-beds
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Oscillation ripples
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Tool marks
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Fossils
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Fossils
SEDIMENTARY ARCHIVES
Sedimentary Structures
Geopetal Structures or Which Way is UP?
Raindrop Impressions
SEDIMENTARY ARCHIVES
Interpretation of Sedimentary Rocks
Provide information about conditions in and near the
site of deposition
Such as:
source area from composition
amount of transport erosion
Qtz vs. Feldspar (clay and iron
compounds) vs Ferromagnesians
Immature vs mature
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
"Systems of classification are not hatracks, objectively presented to us by nature.
They are dynamic theories developed to express particular views..."
Stephen Jay Gould
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
TEXTURE
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
 >90%
Quartz
 Cement: silica
calcite
Quartz Arenite
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
 >25% Feldspar
 Granitic source
 Remainder is quartz
 Cement: clay
calcite
iron oxides
Feldspathic Arenite
Arkose
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
 >33% rock fragments
 Immature sandstone
 Poorly sorted, angular
 Remainder is quartz,
feldspar
 Cement: very little
mostly clays
Lithic Arenite
Greywacke
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
Carbonates
Composition
Carbonate rocks consist of limestone and dolostone.
The minerals present in each are:
Limestone
Calcite
Aragonite
Dolostone
Dolomite
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
Carbonates
Most of marine origin
Directly or indirectly related to biological processes
Skeletal remains may be visible
Can be evaporites
Changes in water temp., alkalinity, CO2 conc.
Clear, shallow tropical waters
SEDIMENTARY ARCHIVES
Classification of Sedimentary Rocks
Carbonates
Characteristics of most marine carbonate environments:
Warm water
Tropical climate (30 ° N - 30 ° S of equator)
Shallow water (less than 200 m deep)
Clear water (low to no terrigenous input)
Sunlight required for photosynthesis by algae