Site investigation for ground models: Interpretation and mapping II Flashcards
What is a geological map?
A geological map is the representation, about a topographic map, of the different types of rocks that outcrop in the terrestrial area and the types of contacts among them.
What do closely spaced contours represent?
Steep slopes
What do contour lines represent?
Different elevations
What do thick black lines on map represent?
The geological boundary
What are dips and strikes?
The strike is the direction of intersection of an inclined surface with any horizontal plane. The dip angle is always in a vertical plane and is measured downward from the horizontal plane.
What are faults?
A fault is a fracture or zone of fractures between two blocks of rock.
What are folds?
A stack of originally planar surfaces, such as sedimentary strata, that are bent or curved during permanent deformation.
What can cause folds?
Low-angle thrust faults
What is disconformity?
A disconformity is an unconformity between parallel layers of sedimentary rocks which represents a period of erosion or non-deposition.
What is angular unconformity?
Horizontal parallel strata of sedimentary rock are deposited on tilted and eroded layers.
Why are geological maps useful?
- useful in determining geological features.
- used to interpret the cross-sectional profile of the site.
What is anticline?
An anticline is a structural trap created through the folding of rock strata into an arch-like shape
What is syncline?
A syncline is the downward arc or curve of a fold
