SMART COMP 2

Pertaining to minerals or rock fragments that formed in one location but were transported to another location and

deposited. Clastic sediments in a rock such as sandstone are allogenic, or formed elsewhere

Pertaining to the subaerial (as opposed to submarine) environment, action and products of a stream or river on its

floodplain, usually consisting of detrital clastic sediments, and distinct from subaqueous deposition such as in lakes

or oceans and lower energy fluvial deposition. Sediments deposited in an alluvial environment can be subject to

high depositional energy, such as fast-moving flood waters, and may be poorly sorted or chaotic

Material deposited in an alluvial environment, typically detrital sediments that are poorly sorted.

. adj. [Geology]

The condition of an environment in which free oxygen is lacking or absent.

Synonyms: anoxic

2. adj. [Geology]

A description of organisms that can survive in the absence of oxygen, particularly bacteria.

3. adj. [Drilling Fluids]

Pertaining to systems, reactions or life processes of species, such as bacteria, in which atmospheric oxygen is not

present or not required for survival.

A surface that separates younger strata from eroded, dipping, older strata and represents a gap in the geologic

record.

Having directionally dependent properties. For a crystal of a mineral, variation in physical properties

observed in different directions is anisotropy. In rocks, variation in seismic velocity measured parallel or

perpendicular to bedding surfaces is a form of anisotropy. Often found where platy minerals such as

micas and clays align parallel to depositional bedding as sediments are compacted, anisotropy is common

in shales.

Predictable variation of a property of a material with the direction in which it is measured, which can

occur at all scales. For a crystal of a mineral, variation in physical properties observed in different

directions is anisotropy. In rocks, variation in seismic velocity measured parallel or perpendicular to

bedding surfaces is a form of anisotropy. Often found where platy minerals such as micas and clays align

parallel to depositional bedding as sediments are compacted, anisotropy is common in shales.

Different from what is typical or expected, or different from what is predicted by a theoretical model. The

difference or anomaly may refer to the measurement of the difference between an observed or measured value

and the expected values of a physical property. Anomalies can be of great interest in hydrocarbon and

mineral exploration because they often indicate hydrocarbon and mineral prospects and accumulations, such as

geologic structures like folds and faults. Geochemical anomalies at the surface of the Earth can also indicate

an accumulation of hydrocarbons at depth. Geophysical anomalies, such as amplitude anomalies

in seismic data and magnetic anomalies in the Earth's crust, can also be associated with hydrocarbon

accumulations.

An entity or property that differs from what is typical or expected, or which differs from that predicted by a

theoretical model. May be the measurement of the difference between an observed or measured value and the

expected values of a physical property. Anomalies can be of great interest in hydrocarbon and mineral exploration

because they often indicate hydrocarbon and mineral prospects and accumulations, such as geologic structures

like folds and faults. Geochemical anomalies at the surface of the Earth can also indicate an accumulation of

hydrocarbons at depth. Geophysical anomalies, such as amplitude anomalies in seismic data and magnetic

anomalies in the Earth's crust, can also be associated with hydrocarbon accumulations.

Alternate Form: anomalous

The condition of an environment in which free oxygen is lacking or absent.