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allostratigraphic unit original
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geologic unit original
definition Geologic unit defined by bounding surfaces. Not necessarily stratified. Donovon (2004, IUGS abstract Florence) makes good case for use of a noncommittal term for the bounding surface. While there may be no agreement that a given stratal boundary is a discontinuity, there is consensus that all the identified boundaries are stratal surfaces. Includes: 1. Unconformity bounded units (Salvador 1994), defined by bounding stratigraphic discontinuities ('significant unconformities', unconformity is defined as surface of erosion in Salvador 1994). 2. Sequence stratigraphic unit, an allostratigraphic unit that is used to interpret the depositional origin of sedimentary strata and assumes, though this is not always stated, an implicit connection to base level change. It does this by establishing how the sequence of strata accumulated in order in the sedimentary section over a subdividing framework of surfaces.
alteration unit original
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geologic unit original
definition Geologic unit defined by alteration process.
artificial ground original
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lithogenetic unit original
definition Geologic unit defined by genesis involving direct human action to deposit or modify material.
biostratigraphic unit original
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geologic unit original
definition Geologic unit defined based on fossil content. Five kinds of biozones are recognized by the revised NACSN (Lenz et al., 2000, Note 64, a recommended complete replacement of Articles 48 through 54 of the North American Stratigraphic Code (NACSN, 1983) accepted for publication 2000.): range biozone, interval biozone, lineage biozone, assemblage biozone, and abundance biozone. These represent different approaches to defining and recognizing biozones.
chronostratigraphic unit original
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geologic unit original
definition Geologic unit that includes all rocks formed during a specific interval of geologic time
deformation unit original
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lithotectonic unit original
definition Lithotectonic unit defined by deformation style or characteristic geologic structure observable in outcrop.
excavation unit original
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lithogenetic unit original
definition Geologic unit defined by human-made genesis involving excavation. Not necessarily defined by landform (a hole...), as they could have been subsequently filled/landscaped etc. If the excavation is filled becomes an excavation with artificial ground wholly or partly superimposed on it. This sort of thing can become quite important in urban geology where an excavation can be filled and landscaped.
geologic unit original
definition Type of geologic unit is unknown, unspecified, irrelevant, or some type not included in the vocabulary. Type makes no implication for required properties or cardinalities. This is the root concept for the type hierarchy.
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allostratigraphic unit original
alteration unit original
biostratigraphic unit original
chronostratigraphic unit original
geomorphologic unit original
geophysical unit original
lithogenetic unit original
lithologic unit original
lithostratigraphic unit original
lithotectonic unit original
pedoderm original
pedostratigraphic unit original
polarity chronostratigraphic unit original
geomorphologic unit original
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geologic unit original
definition Geologic unit defined by surface landform, e.g. hummocky moraine
geophysical unit original
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geologic unit original
definition Geologic unit defined by its geophysical characteristics. Denotes that the properties used to define the unit are measured by intrumental techniques, not directly observable by humans, e.g. density, magnetic susceptibility, magnetization, electrical conductivity.
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magnetostratigraphic unit original