Q. What is a crosscutting relationship? A. An igneous rock, fault, or other geologic feature must be younger than any rock across which it cuts.

Q. What is relative age? A. is the “age” of a rock or strata compared to the ages of other rocks or strata.

Q. Which law states this, as sedimentary rocks form, they are deposited on older rock layers. A. Law of Superposition

Q. What is the difference between an extrusion and an intrusion? A. Intrusion stay inside of the rock layers and never make it to the surface, which makes it just magma, while extrusions are only on the surface and are lava.

Q. What is an intrusion? A. are igneous rocks that form when magma pushes up into rock layers.

Q. What are igneous rocks layers that form on the surface when lava hardens? A. Extrusion

Q. The law of horizontality states what? A. The law states that layers of sediment were originally deposited horizontally under the action of gravity. 

Q. Are intrusions, extrusion, faults, and folds younger or older than the rocks that they invade? A. Younger

Q. According to what theory, is the Earth 4.6 billion years old A. Uniformitarianism

A. Law of Fossil Succession Q. What is the law of faunal succession also known as? A. Law of Fossil Succession

Q. What is a fault? A. are breaks in the earth’s crust. A fault is always younger than the rock it cuts through.

Q. What is a fold? A. occur when rock layers are compressed together and bend or curve.

Q. What is an unconformity? A. are gaps in the rock sequence (caused by the erosion of rock layers).

Q. What are angular unconformities? A. occur when rock layers are tilted or uplifted, and then worn down by erosion and weathering.

Q. What is the Law of Faunal Succession? A. is based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances.

Q. What are disconformities? A. are gaps created when erosion occurs on an overlying rock layer.

Q. What are nonconformities? A. are formed when sedimentary rock overlays igneous or metamorphic rocks.

Write a Geologic Cross-section for this picture Write a Geologic Cross-section for this picture. Name all the cross-cutting relationships and any Unconformities.

1 Sedimentary layer of D was created. 1 Sedimentary layer of H was created 1 Sedimentary layer of A was created Layers D, H, and A are compressed and bent to form folds. An intrusion C cuts through layers D,H and A but not to the surface. A fault G cuts through layers D, H, A and the Intrusion C. 1 Sedimentary Layer F was created 1 Sedimentary layer I was created 1 Sedimentary layer B was created Layers F, I, B are uplifted and titled. 1 Sedimentary layer of E was created. Cross Cuts- C Intrusion, G is a Fault Unconformities- Nonconformities between lines D and C, F and C Disconformities between lines D and H, H and A Angular Unconformities between lines F and E, I and E, and B and E unconformity at the top of E