Faculty & Staff Profiles

Relative Dating

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Relative Age Dating of Rock Strata 

Rock Strata
(Oldest to Youngest)
Rationale


White Sandstone Original horizontality, Superposition
Siltstone Superposition
Igneous Batholith Cross-cutting
Limestone Superposition
Shale Superposition
Sandstone A Superposition
Earthquake Fault Cross-cutting
Conglomerate Superposition
Dolostone Superposition
Igneous Dike B Cross-cutting
*Igneous Dike A
(*The relative order between this rock strata and the Sandstone B and Glacial Debris cannot be determined with the graph shown.  But we do know it is older than Igneous Dike B.)
Cross-cutting 
(*Just comparing it with Igneous Dike B.)
Sandstone B Superposition
Glacial Debris Superposition

Unconformities in the profile:

Type of Unconformity Unconformity Location
(Needs to be described as a boundary between rock layers.)


Angular Unconformity Limestone/Sandstone A

Shale/Sandstone A
Nonconformity Igneous Batholith/Limestone
Igneous Dike B/Sandstone B
Disconformity Dolostone/Sandstone B
(Not easily identifiable.  The existence of a nonconformity between the Igneous Dike B and Sandstone B suggests this disconformity.)