In
geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
, a sequence is a
stratigraphic unit
A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features ( facies) that characteriz ...
which is bounded by an
unconformity
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...
at the top and at the bottom.
Definition
In a more rigorous and general way, a sequence is defined as a
"relatively conformable
.. genetically related succession of strata bounded by unconformities or their correlative surfaces"
Special cases and related concepts
Special cases of sequences include
type 1 sequences and
type 2 sequences.
A related concept are
parasequences. Contrary to their name they are not smaller sequences.
See also
*
Catena (soil)
A catena in soil science (pedology) is a series of distinct but co-evolving Soil, soils arrayed down a slope. Each soil type or "facet" differs somewhat from its neighbours, but all occur in the same climate and on the same underlying parent materi ...
*
Sequence stratigraphy
In mathematics, a sequence is an enumerated collection of mathematical object, objects in which repetitions are allowed and order theory, order matters. Like a Set (mathematics), set, it contains Element (mathematics), members (also called ''ele ...
References
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Sequence stratigraphy
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