Textbook Notes (368,800)
Canada (162,168)
EESA06H3 (234)
Nick Eyles (205)
Chapter 19

Chapter 19 notes

4 Pages
Unlock Document

Environmental Science
Nick Eyles

Chapter 19 Time and Geology James Hutton is regarded as the father of modern geology He has a theory called uniformitarianism states that geologic processes operating at present are the same processes that operated in the past o the present is the key to the past o this term is a bit unfortunate, because it suggests that changes take place at a uniform rate o in some countries, actualism is used instead of uniformitarianism this term comes closer to conveying Huttons principle that the same processes and natural laws that operated in the past are those that we can actually observe or infer from observation as operating at present it is based on the assumption that physical laws are independent of time and location dating based on radioactivity allows us to determine a rocks numerical age, also called absolute age relative time is the sequence in which events took place Principles Used to Determine Relative Age contacts are the surfaces separating two different rock types or rocks of different ages formations are bodies of rocks of considerable thickness with recognizable characteristics that make each distinguishable from adjacent rock units o named after local geographic features to determine the relationship of geologic events to one another, four principles are applied: o original horizontality states that beds of sediment deposited in water formed as horizontal or nearly horizontal layers o superposition states that within a sequence of undisturbed sedimentary or volcanic rocks the layers get younger going from bottom to top if sedimentary rock is formed by sediment settling onto the sea floor, then the first layer must be there before the next layer can be deposited on top of it o lateral continuity states that an original sedimentary layer extends laterally until it tapers or thins at its edges this is what we expect that the edges of a depositional environment, or where one type of sediment interfingers laterally with another type of sediment as environments change o cross-cutting relationships states that a disrupted pattern is older than the cause of disruption The Grand Canyon regional metamorphism took place resulting in the schists of the lower part of the canyon erosion followed and levelled the land surface sedimentation followed these sedimentary layers were subsequently tilted once again, erosion took place the lowermost of the currently horizontal layers of sedimentary rock was deposited each of the layers progressively higher up the sequence formed finally, the stream eroded its way through the rock, carving the Grand Canyon www.notesolution.com
More Less

Related notes for EESA06H3

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.