THE LANGUAGE OF THE EARTH – PART VII
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Geochronology Methods for Determining the Relative and Absolute Age of Rocks THE LANGUAGE OF THE THE LANGUAGE OF THE EARTH – PART VII EARTH – PART VII
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THE LANGUAGE OF THE EARTH – PART VII. Geochronology Methods for Determining the Relative and Absolute Age of Rocks. Relative Age Dating - Superposition. Principles of Faunal Succession and Faunal Assemblage. Index Fossils - Widespread distribution - Restricted, known time of existence - PowerPoint PPT Presentation
Transcript of THE LANGUAGE OF THE EARTH – PART VII
GeochronologyMethods for Determining the Relative and Absolute Age of
Rocks
THE LANGUAGE OF THE THE LANGUAGE OF THE EARTH – PART VIIEARTH – PART VII
Relative Age Dating - SuperpositionRelative Age Dating - Superposition
Principles of Faunal Successionand Faunal Assemblage
Index Fossils - Widespread distribution- Restricted, known time of
existence- Common to many environments
Principle of Cross-cutting Relationships
Global Time MarkersGlobal Time MarkersVolcanic Ash Eruptions
Global Time MarkersGlobal Time MarkersMagnetic Reversals
Global Time MarkersGlobal Time MarkersMeteor Impacts
K-T impact site
K-T Boundary
coal
mudstone-impact layer
Global Time Global Time MarkersMarkers
Climate Change
Gaps in the Geological RecordGaps in the Geological RecordUnconformities
Creating Creating UnconformitiesUnconformities
Gaps in the Minnesota TimescaleGaps in the Minnesota Timescale
Regional Correlation of UnitsRegional Correlation of UnitsPiecing the Rock Record Together
Absolute Age DeterminationsAbsolute Age DeterminationsRadiometric Dating
Radioactive Isotopes
Radioactive Decay
Radioactive Decay Radioactive Decay Half-life Half-life
ZirconZrSiO4
U substitutes for Zr, but Pb does not.
87Rb 87Sr; 86Sr is stableRb – chemically substitutes for KSr – chemically substitutes for Ca
87Rb/86Sr
87Sr/86Sr
Ca-plagioclaseGranite whole rockK-feldsparBiotite (K-rich)
t=087Sr/86Sr°
t=1
Metamorphismat t=1
t=2Isochron
87Sr/86Sr°(m)
Rb-Sr Dating of a GraniteRb-Sr Dating of a Granite
GEOPUZZLE 1
GEOPUZZLE 2
GEOPUZZLE 3
