Quiz 4 Flashcards
Principle of inclusions
if inclusions (pieces of rock) are found within a rock formation, those inclusions must be older than the formation they are included within
Identify this structure
Dome
Disconformity
If the rocks above and below the erosion surface are parallel, the surface is called a disconformity
Syncline
a concave upward fold in which the layered strata dip towards the center of the fold (it resembles a “U”).
Identify this symbol
Anticline axis
Identify this structure
Plunging syncline
Geological events that can cause unconfomities
1) Deposition of sediments
2) Uplift and erosion
3) Metamorphism
4)Intrusion of magma
5) Faulting, folding, or tilting (Note the type of fault / fold and the stress that
caused it.
Strike
the line formed by the intersection of a horizontal plane and an inclined surface. This line is called a strike line, and the direction the line points in (either direction, as a line points in two opposite directions) is the strike angle.
Foot wall
the block located beneath the fault plane.
Principle of original horizontality
undeformed sedimentary rock are deposited horizontally. This means that if we see sedimentary rock that is tilted or folded it was first deposited flat, then folded or tilted afterward
Identify this structure
Reverse fault
Identify this structure
Monocline
Angular unconformity
The rocks below the erosion surface are
not parallel with those above, the surface is called an angular unconformity
Identify this symbol
Plunging anticline axis
Identify this symbol
Plunging syncline axia
Principle of faunal succession
a stratigraphic principle where geologists use fossils in the rock to help interpret the relative ages of the rock.
Identify this structure
Overturned anticline
normal fault
When extensional forces are applied to the fault blocks , the hanging wall block will move down with respect to the foot wall block.
Identify this structure
Syncline
Hanging wall
The block located above the fault plane
Dip
the angle between that horizontal plane and the inclined surface (such as a geological contact between tilted layers) measured perpendicular to the strike line down to the inclined surface.
Identify this symbol
Horizontal strata
Dome
an upwarping of Earth’s crust, which is similar to an anticline in terms of the age relationships of the rocks
anticline
fold is convex up: the layered strata dip away from the center of the fold (if you drew a line across it, the anticline would resemble a capital letter “A”