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”
Basin
an area where the rocks have been warped downwards towards the center, with age relationships being similar to a syncline. Oldest strata at the outer layer
Identify this structure
Anticline
Identify this symbol
Syncline axis
Principle of cross-
cutting relationship
hen two geologic
features intersect, the one
that cuts across the other is
younger
dip-slip faults
the movement along the fault is either up or down.
Nonconformity
is an unconformity where the rock type is different above and below the unconformity. For example, if
uplifted intrusive igneous rocks are
exposed at the surface and then covered with sedimentary rock, the boundary between the two rock types is a nonconformity
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Normal fault
Identify this symbol
Strike and Dip
Identify this structure
Basin
Law of superposition
in an undeformed sequence
of sedimentary rocks the oldest
rocks will be at the bottom of
the sequence while the youngest
will be on top.
Identify this symbol
Slipstrike fault
reverse fault
When compressional forces are applied to the fault blocks (such as in a convergent plate boundary tectonic setting), the hanging wall block will move up relative to the foot wall block
Oldest to youngest map symbols
1)p-C (Precambrian)
2)-C (Cambrian)
3)O (Ordovician)
4)S (Silurian)
5)D (Devonian)
6)M (Mississippian)
7)IP (Pennsylvanian)
8)P (Permian)
9)Tr (Triassic)
10)J (Jurassic)
11)K(Cretaceous)
12)T(Tertiary)
13)Q(Quaternary)
Identify this structure
Dome
Identify this structure
Basin
Identify this structure
Plunging anticline
monocline
a simple fold structure that consists of a bend in otherwise horizontal rock layers.
Identify this symbol
Verticle strata
