To participate in or talk about geology; to practice geology. AGI
The study of the planet Earth--the materials of which it is made, the
processes that act on these materials, the products formed, and the
history of the planet and its life forms since its origin. Geology
considers the physical forces that act on the Earth, the chemistry of its
constituent materials, and the biology of its past inhabitants as revealed
by fossils. Clues on the origin of the planet are sought in a study of the
Moon and other extraterrestrial bodies. The knowledge thus obtained is
placed in the service of humans--to aid in discovery of minerals and fuels
of value in the Earth's crust, to identify geologically stable sites for
major structures, and to provide foreknowledge of some of the dangers
associated with the mobile forces of a dynamic Earth.
See also:historical geology; physical geology. AGI
a. The formal chronostratigraphic unit of rank next lower than "erathem"
and above "series". Rocks encompassed by a system represent a time span
and an episode of Earth history sufficiently great to serve as a worldwide
reference unit. The temporal equivalent of a system is a "period." The
system is the fundamental unit of chronostratigraphic classification of
Phanerozoic rocks, extended from a type area or region and correlated
mainly by its fossil content. System boundaries either have been ratified
by the International Union of Geological Sciences or are under review by a
working group of the International Commission on Stratigraphy. The
Proterozoic systems are related to geologic events with geochronologic
boundaries established by the Subcommission on Precambrian Stratigraphy.
b. Some systems initially established in Europe were later divided or
grouped elsewhere into units ranked as systems, but these are more
appropriately known as "subsystems" or "supersystems".
One who sets up magnetic observatories and stations in order to chart the
Earth's magnetic field and applies data obtained to problems in the fields
of telephony, telegraphy, radio broadcasting, navigation, mapping, and
geophysical prospecting. Also called terrestrial magnetician. DOT
a. Pertaining to the form of the Earth or of its surface features; e.g., a
geomorphic province. AGI
b. Pertaining to geomorphology; geomorphologic. AGI
See:cycle of erosion
That part of geomorphology that deals with the origin, development, and
changes of the Earth's surface features or landforms. AGI
a. The science that treats the general configuration of the Earth's
surface; specif., the study of the classification, description, nature,
origin, and development of present landforms and their relationships to
underlying structures, and of the history of geologic changes as recorded
by these surface features. In the United States, it has come to replace
the term "physiography" and is usually considered a branch of geology; in
Great Britain, it is usually regarded as a branch of geography.
AGI
b. Strictly, any study that deals with the form of the Earth (including
geodesy, and structural and dynamic geology). This usage is more common in
Europe, where the term has even been applied broadly to the science of the
Earth. AGI
c. The features dealt with in, or a treatise on, geomorphology; e.g., the
geomorphology of Texas. AGI
See:geomyricite
A white, waxy resin of approximate composition C32 H62 O
2 in brown coal. Syn:geomyricin
A seismic detector that produces a voltage proportional to the
displacement, velocity, or acceleration of ground motion, within a limited
frequency range. Syn:jug; seismometer; pickup. CF:seismograph;
transducer. AGI
Exploring for minerals or mineral fuels, or determining the nature of
Earth materials by measuring a physical property of the rocks and
interpreting the results in terms of geologic features or the economic
deposits sought. Physical measurements may be taken on the surface, in
boreholes, or from airborne or satellite platforms.
See also:geophysical prospecting
See:well log
Exploring for minerals or mineral fuels, or determining the nature of
earth materials by measuring a physical property of the rocks, and
interpreting the results in terms of geologic features or the economic
deposits sought. Physical measurements may be taken on the surface, in
boreholes, or from airborne or satellite platforms.
See also:geophysical exploration
geophysical prospecting surveyor
Person who locates and marks sites selected for conducting geophysical
prospecting activities concerned with locating subsurface earth formations
likely to contain petroleum or mineral deposits. DOT
The exploration of an area in which geophysical properties and
relationships unique to the area are mapped by one or more geophysical
methods. AGI
One who studies seismic, gravitational, electrical, thermal, radiometric,
and/or magnetic phenomena to investigate geological phenomena, such as
structure and composition of the Earth, forces causing movement and
warping of surface, origin and activity of glaciers and volcanoes, and the
location and cause of earthquakes; charts ocean currents and tides; takes
measurements concerning shape and movements of Earth, and acoustic,
optical, and electrical phenomena in the atmosphere; and locates petroleum
and mineral deposits. DOT
A branch of physics dealing with the Earth, including its atmosphere and
hydrosphere. It includes the use of seismic, gravitational, electrical,
thermal, radiometric, and magnetic phenomena to elucidate processes of
dynamical geology and physical geography, and makes use of geodesy,
geology, seismology, meteorology, oceanography, magnetism, and other Earth
sciences in collecting and interpreting Earth data. Geophysical methods
have been applied successfully to the identification of underground
structures in the Earth and to the search for structures of a particular
type, as, for example, those associated with oil-bearing sands.
AGI
A monoclinic mineral, Pb16 (AsO4 )4 Cl14 (OH)
6 or Pb16 (AsO4 )4 Cl14 O (sub 2) (OH)
2 ; forms stubby tablets; sp gr, 7.1; associated with laurionite,
matlockite, and fiedlerite on altered slags at Laurium, Greece.
The solid portion of the Earth, including water masses; the lithosphere
plus the hydrosphere. Above the geosphere lies the atmosphere, and at the
interface between these two regions is found almost all of the biosphere,
or zone of life. Hunt