In geophysics, a signal used to indicate the time of explosion in a
shothole and successive intervals of time on the recording.
CF:time break
A body of rock established to serve as the material reference for all
rocks formed during the same span of time. Each of its boundaries is
synchronous. Chronostratigraphic units in order of decreasing rank are
eonothem, erathem, system, series, stage. Syn:chronostratic unit;
chronolithologic unit; time-rock unit; chronolith. AGI
A detailed investigation in which the average time taken to do each
operation of a complete cycle is recorded. See also:method study;
motion study. Nelson
In seismograph continuous profiling, a coincident travel path for seismic
energy initiated at opposite ends of the path. The use of such coincident
travel paths on adjacent reflection layouts facilitates correlation from
one layout to the next as the shot point or recording position is changed.
AGI
See:diachronous
The interval of geologic time represented by or involved in producing a
stratigraphic unit, an unconformity, the range of a fossil, or any
geologic feature or event. AGI
The time elapsing between two successive exposures of an aircraft camera
when taking vertical photographs. See also:photogrammetry
Hammond
One of a series of marks or lines placed on seismic records at precisely
determined intervals of time (usually at intervals of 0.01 or 0.005 s) for
the purpose of measuring the arrival time of recorded events. AGI
a. A tetragonal mineral, Sn : rare; soft; malleable: bluish white.
b. The metal extracted from cassiterite; used as a coating to protect iron
and copper, such as a foil, and in solder, bronze, and other alloys.
Commercially, tin is available in three grades: Grade A must assay 99.75%;
grade B must assay 99.7%; and grade C, or common tin, must assay 99% tin.
c. To coat with tin, such as to tin iron; tinplate. Standard, 2
d. Metallic element that has a highly crystalline structure. Symbol, Sn.
Found chiefly in cassiterite, SnO2 . Used in alloys such as soft
solder, type metal, fusible metal, pewter, bronze, and bell metal and as a
crystalline tin-niobium alloy. Handbook of Chemistry and Physics, 3
e. See:zinn
a. Corn. To mark a limit, as on a tract of waste land, within which one
claims or reserves the right to mine unworked tin ore. Standard, 2
b. Land so reserved. Standard, 2
The name given, since early itmes, to crude borax obtained from salt lakes
in Kashmir, India, and Xizang (formerly Tibet), China. Also spelled
tinkal. Syn:borax
A trigonal mineral, Na2 B4 O5 (OH)4 .3H (sub
2) O . Syn:mojavite; octahedral borax.
A Davy lamp placed inside a tin can or cylinder having a glass in front,
airholes near the bottom, and an open top. Fay
An impure variety of jamesonite. Standard, 2
A pan used by prospectors for washing gold-bearing materials and
extracting the gold. See also:pan
The extraction of tin-bearing ore from placers by means of dredges.
Nelson
The actual excavating tooth or point of a grab bucket, scraper loader,
dragline, or excavator bucket. Hammond
a. Corn. A thin flat mass of tinstone between beds of rock. Fay
b. A flat mass of tin ore. Standard, 2
A color designation. A faint trace of a hue that modifies another hue, as
a blue with a tinge of green, i.e., blue tinged with green or, stated
differently, very slightly greenish-blue.
Corn. Tin-bearing alluvium, stream works. Arkell
A head covering made of reinforced sheet aluminum or plastic-impregnated
fabric and shaped somewhat like a sun helmet; worn for protection and/or
to reduce the severity of head injuries from falling objects. Also called
hard hat. Syn:safety hat