1.5 Field Geology Flashcards
What is the principle of superposition?
In an undisturbed sequence of sedimentary rocks, the oldest rocks are at the bottom and the youngest are at the top.
How is stratigraphy used in field geology?
Stratigraphy is used to understand the layers of rock and their historical sequence, helping determine the relative ages of geological features.
What is the difference between strike and dip?
Strike is the direction of the line formed by the intersection of a rock layer and the horizontal plane, while dip is the angle at which the rock layer is inclined from the horizontal.
What is a fault?
A fault is a fracture in the Earth’s crust along which movement has occurred, often due to tectonic forces.
What is the significance of cross-cutting relationships?
The principle that a feature (like a fault or intrusion) that cuts across other features must be younger than the features it cuts through.
What are the four types of geologic mapping?
The four types are lithologic, stratigraphic, structural, and environmental mapping.
What are the common tools used in field geology?
Common tools include compasses, hammers, GPS, clinometers, field notebooks, and sample bags.
What is an outcrop?
An outcrop is a visible exposure of rock or soil on the surface of the Earth.
What is the purpose of a geologic profile?
A geologic profile is a vertical section of the Earth, showing the arrangement of rocks, faults, and other geological features.
What tool is commonly used to measure strike and dip in the field?
Brunton Compass
What is the purpose of a geologic map?
To show the distribution, nature, and age relationships of rock formations in a given area.
What type of geologic feature is represented by contour lines forming a V shape pointing upstream?
A river or stream valley.
What is strike and dip?
Strike is the direction of a horizontal line on a plane, and dip is the angle at which the plane inclines.
