Chapter 8 Flashcards
What is Uniformitarianism
The principle that geologic processes operating at present are the same processes that operated in the past.
What is actualism?
The principle that geologic processes operating at present are the same processes that operated in the past. This term emphasises the present is the key to the past.
What is a rocks numerical age?
Age given in years or some other unit of time.
What is relative time when it comes to rocks?
The sequence in which events took place. AKA the rock cycle.
What is superposition in rock layering?
The principle that the oldest rock is at the bottom and the youngest rock is on the top.
What is lateral continuity in sedimentary layers?
The principle that states than an original sedimentary layer extends laterally until it tapers or thins at its edges.
What is a cross-cutting relationship?
A disrupted pattern or layer is older than whatever disrupted that pattern or layer.
What is does the word inclusion mean in the context of the age of rocks?
rocks that are inside of magma are older than the magma.
What is unconformity when dealing with the dating of rocks?
When two contacts have a significant jump in geological history that is not recorded.
What type of unconformity is disconformity?
When horizontal layers are parallel to each other and a couple of layers are eroded then more layers are layered on top of the younger layers creating a gap in the geological timeline.
What type of unconformity is Angular unconformity?
When the younger layers are parallel, but the older layers are tilted or folded. Usually the upper layers of folded rock were weathered flat creating a gap in the geological timeline.
What type of unconformity is nonconformity?
A contact in which an erosion surface on plutonic or metamorphic rock has been covered by younger sedimentary or volcanic rock. Their is usually lots of erosion that occurs.
What is correlation when dating rocks?
Comparing how old a rock is in a certain area compared to another area.
What is physical continuity?
When you can see the same rock layer in different places. Like the top layer in the grand canyon.
What is faunal succession when dealing with how old rocks are?
The principle that younger fossils will form over younger fossils.
