Earth Sciences 2240F/G Lecture Notes - Lecture 2: James Ussher, Cenozoic, Geochronology
20 Jan 2018
School
Department
Course
Professor
Document Summary
Archbishop james ussher: placed earth"s creation in the year 4004. 4. 5 billion years ago the building of the earth was well under way. No way to tell for sure how long it took but that was the start. We know this from the primitive asteroids which are the oldest matter found in meteorites. These are used because earth formed from the same matter that started the solar system. Principle of superposition: (steno) argued, if sedimentary rock layers are deposited on top of each other, then in any vertical sequence the oldest layers will be at the bottom, youngest at the top. Principle of original horizontality: sedimentary strata would have lain flat when they were first deposited and would have been originally horizontal. Principle of original lateral continuity: the flat lying sedimentary strata would have initially been extended in all directions: however we acknowledge now that there is unconformity.
