GEO 1111 Lecture Notes - Lecture 6: Denudation, Snowball Earth, James Hutton

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Donald Cummings

Document Summary

Combination of relative dating and absolute dating. Similar of stratigraphy (looking at patterns in strata) Used to establish relative ages of rock units in earth"s crust. Vertical succession or volcanic rocks, a higher rock unit is younger than a lower one. Upon initial deposition, strata tend to extend in all directions until they pinch out or until they grade laterally into a different kind of sediment. A structure that cross cuts another is the younger of the two. Structure included in another is the older of the two. Fossils in stratigraphic succession change upwards (with time) in a predictable way. Best ones : shortest lifespans and greatest geographic extents. Physical laws of nature have remained the same since the dawn of time. To prove snowball earth, correlation needs to be global) Based on physical (rock type, grain size, colour, minerals), biological, and chemical. Involves study of large-scale patterns in the physical characteristics of strata (rock type)