Quiz 5 – Geologic Time and Seafloor

1) Two types of dating for geologic materials:
1. a) _________ relative dating ____________________________
2. b) _________ absolute dating ____________________________
2) The Law of _______ superposition ___________________________ states that in any undisturbed sequence of strata the oldest rock layer is on the bottom and the youngest is on top.
3) The Principle of _________ fossil succession ____________________ says that fossils succeed each other in a definite and determinable order.
4) _______ inclusions _____________________________ are pieces of one rock unit that are contained within another unit. These pieces are older than the rock unit they are within.
5) The principle of cross-cutting relationships states that whenever a fault or intrusive igneous rock cuts through an existing feature, it is ______ younger ______________________ than the structure it cuts.
6) The principle of ___________ original horizontality __________________________ says that sediment forms layers and if those layers are folded or inclined that occurred ______ after ______________________ (after or before) deposition.
7) What are the three types of unconformities?
1. a) _______ disconformities ________________________________
2. b) _______ nonconformities ________________________________
3. c) _______ angular unconformities ________________________________
8) The amount of time it takes for half of a radioactive nuclei (___ radioactive ___________________ isotope) in a sample to change to their stable end product (_____ stable ________________ product) is known as the __________ half life ________________________ of the isotope.
10) Isotopes of an element have the same number of ______ protons _______________________, but a different number of ______ neutrons _______________________________.

continental slope – steepest part of the ocean floor
continental shelf – broad and flat, adjacent to th
continental rise – a sloping wedge of sediment
abyssal plain – flat and in deep water, seamo
trenches – deep, narrow, depressions a
mid-oceanic ridge – large undersea mountain ran
guyots – rise from the seafloor and are
There are two types of continental margins. The Atlantic Ocean is a/an __ passive __ continental margin and the Pacific Ocean is a/an __ active __ continental margin.