Class Notes (836,380)
Canada (509,761)
Langara College (1,809)
Geology (204)
GEOL 2207 (204)
J.Finnis (74)


6 Pages
Unlock Document

GEOL 2207

Extinctions 1. Concept of a biosphere • Understand the concept of a biosphere and Earth System Science and that the biosphere has evolved over time  Thin layer of life on the Earth‟s surface, composed of Ecosystems  Earth System Science: biosphere, hydrosphere, lithosphere, atmosphere 2. Principles of Stratigraphy (study of the manner in which strata are laid down) • Distinguish between the oldest and youngest portion of a geological section using principles of superposition, original horizontality and cross cutting relationships  Study of the layers of rock (stratigraphy) o Strata: layers of sedimentary rocks or lava flows)  Superposition: in layered strata (sedimentary rocks or lava flows)  What‟s on top is the youngest  Original horizontality: if it is tilted or folded, it was originally flat  Cross cutting relationships: unconformity = a period of non deposition or active erosion  What is oldest? Sediments or dike? Dikes are always younger than surrounding rock layers (always younger than the object that it is intruding) 3. Biostratigraphy (correlation of rocks using fossils) • Describe the concept of faunal succession and the use of fossils in correlation and in the subdivision of Earth history  Nicholas Steno  Strata of like age can be dated and correlated by the fossils they contain  Only works because species have changed through time; evolution  Amount of time a species exist: a fossil range • Recognize the qualities that make fossils useful in biostratigraphy  Short range = higher resolution  Common  Lived in environments where fossilization is likely to occur  Present in many different environments  Mesozoic = ammonites  Strata of like age can be dated and correlated by the fossils they contain, only works because species have changed through time o Fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances o Faunal succession  Fossil range = the amount of time a species exists (from evolution to extinction)  Extinction events: end of cretaceous, late Triassic, Permo/Triassic, late Devonian, late Ordovician 4. Historical Figures • Identify important historical figures in the development of stratigraphy and biostratigraphy  Nicholas Steno (Late 1600s): principles of stratigraphy  James Hutton (Late 1700s): cross cutting relationships  William Smith (1799): principle of faunal succession  Geologists in the late 170ss started to get the impression that the earth was very old  James Usher (1581-1665): adds up all dates in bible, earth is 6000 years old  George Cuvier (1800s): mammoth remains in Europe, concludes mammoths were once living species that have become extinct  Geologists conclude: earth is ancient, earth has changed a lot through time 5. The concept of deep time • Appreciate the scale of changes that can occur over geological time scales  Geological time scale: dividing the 4.6 billion years of Earth‟s history into time periods  Many of these divisions based
More Less

Related notes for GEOL 2207

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.