Folds, Faults, and Mountains
Terms
undefined, object
copy deck
- anticline
- A convex fold in rock, the central part of which contains the oldest section of rock.
- basin
- A round or oval sepression in the Earth's surface, containing the youngest section of rock in its lowest, central part.
- brittle failure
- The rupture of cool, near-surface rocks, caused by relatively low stress.
- compression
- Stress that reduces the column or length of a rock as that produced by the conergence of plate margins.
- dome
- A round or oval bulge on the Earth's surface, containing the oldest ssection of rock in its raised, central part.
- elastic deformation
- A temporary stress-induced change in the chape or volume of a rock, after which the rock returns to its original shape and volume.
- elastic limit / yield point
- The maximum stress that a given rock can withstand without becoming permanently deformed.
- fault-block mountains
- A mountain containing tall horsts interspersed with much lower grabend and bounded on at least one side by a high-angle normal fault.
- fold and thrust mountains
- Mountains that have been created by the compression of convergent plates.
- joints
- A fracture dividing a rock into two sections that have not visibly moved relative to each other.
- marine terrace
- Formed at sea level these structures are created when surf crashes into the strata shaping its edge or terrace. Over time the land uplifts and the cycle is repeated.
- normal fault
- A dip-slip fault marked by a generally steep dip along wich the hanging wall has moved downward relative to the footwall.
- plastic deformation
- A permanent strain of rock that entails no rupture.
- reverse fault
- A dip-slip fault marked by a hanging wall that has moved upward relative to the footwall.
- shearing stress
- Stress that sliced rocks into parallel blocks that slide in opposite directions along their adjacent sides.
- strain
- The change in the shape or volume of a rock that results in stress.
- stress
- The force acting on a rock or another solid to deform it, measured in kilograms / sq cm or lbs / sq in
- strike-slip or transform faults
- A fault in which two sections of rock have moved horizontally in opposite directions, parallel to the line of the fracture that divided them. Shearing stress
- syncline
- A concave fold, the central part of which contains the youngest section of rock.
- tension
- Stress that stretched or extends rocks, so that they become thinner vertically and longer laterally. Tension may be caused by divergence or rifting.
- thrust fault
- A reverse fault marked by a 45 degree dip or less.
- upwarped mountains
- A mountain consisting of a broad area of the Earth's crust that has moved gently upward without much apparent deformation, and usually containing sedimentary, igneous, and metamorphic rocks.