a. Equal in duration or uniform in time; e.g., an isochronous interval
between two synchronous surfaces, or an isochronous unit of rock
representing the complete rock record of an isochronous interval.
AGI
b. A term frequently applied in the sense of synchronous, such as an
isochronous surface having everywhere the same age or time value within a
body of strata. Syn:isochronal
Adj. of isocline. AGI
A fold whose limbs are parallel. Syn:isocline
See:isoclinal fold
A line (in a stressed body) at all points on which the corresponding
principal stresses have the same direction. Roark
a. A line drawn through all points on the Earth's surface having the same
magnetic inclination. The particular isoclinic line drawn through points
of zero inclination is given the special name of aclinic line.
Hunt
b. An isomagnetic line connecting points of equal magnetic inclination.
AGI
Characteristic of a crystal structure with bond strengths roughly equal in
all directions.
Refers to the hexagonal, trigonal, and tetragonal crystal systems; i.e.,
having the lateral crystal axes a1 and a2 of equal length.
CF:isometric; anisometric.
In mineralogy, both isomorphous and dimorphous; said of certain groups of
minerals. Fay
Any line joining points of equal magnetic intensity. Applicable to the
total intensity or the vertical, horizontal, north-south, or east-west
components. So used in terrestrial magnetism literature, esp. in British
and Canadian writings. AGI
Zero potential or point of electrical neutrality; the hydrogen-ion
exponent at which particles in aqueous suspension are neutral and best
able to flocculate. Also called zero point of change. Pryor, 4
a. Pertaining to rocks belonging to the same metamorphic facies and having
reached equilibrium under the same set of physical conditions.
Syn:isograde
b. Pertaining to rocks belonging to the same sedimentary facies; e.g., an
isofacial line on a map, along which the thickness of stratum of the same
lithologic composition is constant. AGI
In gravity prospecting, a contour line of equal gravity values.
AGI
In magnetic prospecting, a contour line of equal magnetic values.
AGI
A chart showing contour lines of equal magnetic field intensity and
employed in the magnetic methods of geophysical prospecting. Also called
isogal map in gravity surveys. Nelson
A line or surface within the Earth connecting points of equal temperature.
Syn:isogeothermal line; geotherm; geoisotherm. AGI
See:isogeotherm
See:isogonic line
An isomagnetic line connecting points of equal magnetic declination.
See also:agonic line
A line on a map joining points at which metamorphism proceeded at similar
values of pressure and temperature as indicated by rocks belonging to the
same metamorphic facies. Such a line represents the intersection of an
inclined surface with the Earth's surface corresponding to the boundary
between two contiguous facies or zones of metamorphic grade, as defined by
the appearance of specific index minerals; e.g., garnet isograd,
staurolite isograd. AGI
See:isofacial