ACCESSIBILITY: 1. Being able to
legally move onto a location and mine. 2. Being able to reach a location
one intends to mine with little or no trouble.
ACCRETION BAR: A
low-level deposit of sand and gravel formed in a stream by the gradual
addition of new material. Accretion bars are typically formed along the
short or inside radius of curves.
ACCUMULATION: In placer mining,
this concerns the collection of gold into substantial amounts worth
mining.
ACCUMULATIVE PLACER: When there is a continuous build-up of
gold over time in one spot, such as a "catch," it is called an
"accumulative placer."
AFFLUENT: See "tributary."
ALLUVIAL:
Relating to or composed of alluvium.
ALLUVIAL DEPOSIT: See
"alluvial placer."
ALLUVIAL FAN: A cone-shaped deposit of alluvium
made where a stream runs out onto a level plain or meets a slower stream.
The fans generally form where streams issue from mountains upon the
lowland.
ALLUVIAL GOLD: Gold found in association with water-worn
material.
ALLUVIAL GRAVEL'S: Water worn gravel's of any size; sand,
cobbles rocks, and boulders, etc. In this book, it is referred to as
"materials."
ALLUVIAL MATERIALS: This refers to any alluvial
gravel's; rocks, cobbles, sand, clay, silt, etc., ancient or otherwise, no
matter what form it is in. The same can be said of a streambed;
"materials" which rest on bedrock channels. This would include anything
held in suspension over bedrock; the bed load, suspended load, and
dissolved load. Also called "streambed materials."
ALLUVIAL PLAIN:
1. Flood pains produced by the filling of a valley bottom are alluvial
plains, consisting of fine mud, sand, or gravel. 2. A plain resulting from
the deposition of alluvium by water.
ALLUVIAL PLACER: Gravel's that
have been transported and deposited by flowing waters, streams, creeks,
etc., depositing placer gold and other valuable minerals. Also called an
"alluvial deposit."
ALLUVIUM: A general term for all detrital
deposits resulting from the flow of present waterways, thus including the
sediments laid down in streambeds, flood plain, lakes, fan at the foot of
mountain slopes, and estuaries.
AMALGAM: A mixture of different
elements or substances; such as an alloy of mercury with another
metal.
AMALGAMATED GOLD: Mercury and gold combined. When found as
alluvial gold during a placer mining operation with traces of mercury on
it. The mercury may be dry to the touch as if it were just silver paint,
or wet as if the mercury had no gold in it at all. Also called "mercury
gold."
ANCIENT MATERIALS: The alluvial gravel's and materials,
which ancient streambeds are comprised of. These would include those that
have been swept away from virgin ground during a major flood to be
redeposited; basically intact; elsewhere. Those more recent "ancient
streambeds" still inside an active waterway or still within reach of
modern dredging equipment are usually called "old beds."
ANCIENT
BED: See "ancient streambed."
ANCIENT STREAMBED: These are
streambeds, which were formed long ago and are generally classified, as
those that have been in place since before the "gold rush" era and are
comprised from alluvial gravel's from the present waterway. Also called
"ancient bed" for short.
ANNUAL FLOODING: See "seasonal;
flooding."
ASSAY: This is to determine the amount of values
contained within an ore sample, streambed sample, or valuable metal
sample; such as native placer gold; compared to the amount of waste
material therein.
CAP ROCK: Volcanic flow materials or agglomerates
that cover, and in some cases, conceal underlying auriferous gravel's.
Commonly found associated with Tertiary channels.
CATCH: A fixed
site, where gold has been trapped or caught; such as in cracks, crevices,
lull behind boulders or other obstructions, or changes in bedrock that
form obstructions; faults, outcroppings, upcroppings, etc.; or holes which
would allow gold to drop out of the force of flow; such as bedrock holes,
potholes, etc. Also short for "gold catch."
CHALCOPYRITE: A mineral
often mistaken for "fools gold," though not a very common one." This
mineral is very similar to marcasite in its characteristics; it tarnishes
easily, going from bronze or brassy yellow to yellowish or grayish brown,
has a dark streak, and are lighter in weight and harder than gold. Neither
of these minerals commonly occur in crystalline form and most often are
found as irregularly shaped masses.
CHANNEL: See "bedrock
channel."
CHANNEL FOUNDATION: The lowest point along a bedrock
channel, where the greatest amount of water action cuts deeper into the
bedrock foundation during floods.
CLASSIFIED MATERIALS: Materials
which have been processed through a screen, grill, or grizzly into a
specific size. Example; #60 to #80 mesh size would be material that passed
through the #60 mesh screen, but did not pass through the #80 mesh screen
size.
CLASSIFIER: The screening device or instrument used to
classify and separate materials into various sizes. This device; usually a
grill or classifier screen; can be found in the bottom of the header box
or at the head of the sluice on a modern dredge.
CLASSIFY: The
process of screening out the larger sized materials or the screening of
materials or heavy concentrates into size groups by means of one or more
size of wire mesh screens; sieves.
CLEAN CONCENTRATE: Gold; or
other values; that are relatively clean and free of other materials after
being processed through a clean-up concentrator.
CLEAN -UP: This is
the final process of removing gold; or other values; from heavy
concentrates and the cleaning of the gold itself; such as the removal of
outside impurities; for display or sale.
CLEAN-UP CONCENTRATOR: A
device used to process heavy concentrates into clean concentrate. Some of
these concentrators can work concentrates down to the gold itself or
relatively close.
COARSE GOLD: Usually any particle that is
relatively thick in diameter and can be easily picked up with your
fingers.
COBBLES: They are small to large size rocks that can be
moved by hand. In dredging these would be of a size that could not enter
the intake nozzle and would need to be removed from the hole by hand; or
wench and rock net.
COLLOIDAL GOLD: Gold in an extreme state of
subdivision. In a true colloid, the individual particles are of almost
molecular dimensions.
COLLUVIAL: Consisting in part of alluvium and
also containing angular fragments of the original rocks.
COLOR: A
minute particle of metallic gold found in the prospector's pan after a
sample of earth or concentrate has been washed. Prospectors say, "The dirt
gave me so many colors to the pan." Also called a
"shiner."
CONFLUENCE: A junction or flowing together of streams;
the place where streams meet.
CONGLOMERATE: Rounded, water-worn
fragments of rock or pebbles, cemented together by another mineral
substance.
CREEK PLACER: Gravel deposits in the beds and
intermediate flood plains of small streams.
CREVICE: A large crack
or fissure in bedrock or large boulder.
D
DECOMPOSITION: This is the chemical break-down of
materials into their basic elements.
DELTA: This is usually a
triangle shaped alluvial deposit found at the mouth of a large waterway.
This happens more often where the waterway levels out and widens into
standing water.
DEPOSIT: To place something; that which was
placed.
DEPOSITION: In placer mining, this is when gold drops out
of suspension and is deposited.
DETRITUS: 1. A general name for
incoherent sediments, produced by the wear and tear of rocks through
various geological agencies. 2. Disintegrated matter; debris. The name is
Latin for "worn" rock waste or a deposit of such
material.
DISCOVERY: In placer mining, this is the original finding
of a substantial gold; or other valuable mineral;
deposit.
DISTURBED MATERIALS: Tailings or other worked
materials.
DISSOLVED LOAD: A "dissolved load" would include
materials which dissolve and are carried in solution, much like that of
mineral water or hard water. When conditions are right for it, materials
carried in solution by the water flow, will deposit by means of
"precipitation."
DRIFT: 1. Placer. 2. A horizontal mine passage;
tunnel; from the outside entrance to the workings of the lode; or placer
as in buried Tertiary channels; also called "adit."
DRY PLACER: Any
placer found above an active waterway's highest watermark.
DRYWASH:
1. The mechanical processing of materials through a drywasher; drywash
concentrator; to recover gold or other heavy minerals. 2. A dry ravine, in
which placers are formed along bedrock, during heavy rains.
E
EDDY: A current of water, moving contrary to the
direction of the main current or flow in a waterway. In placer mining,
this contrary movement would allow gold or other heavy minerals to slow
down and settle where this occurs. There are three types of eddies; back
eddy, pressure eddy, and suction eddy.
ELUVIUM: Loose material
resulting from the decomposition of rock by the elements.
ELUVIAL
DEPOSIT: See "eluvial placer."
ELUVIAL PLACER: An eluvial placer is
"materials" derived from decomposing out-croppings of bedrock or strata,
that may have been washed, fallen, or blown by the wind, downhill for a
short distance; generally anything more than a few feet; from their
source; such as in a "residual placer"; but not transported by a stream,
creek, etc., depositing placer gold or other valuable minerals. Also
called "eluvial deposit."
ESTUARY: The wide lower course of a
river, where its currents meet the open sea tides.
F
FALSE BEDROCK: There are two definitions of false
bedrock among miners; 1. Anything resembling or that can be mistaken for
true bedrock. 2. A hard or relatively tight formation within a placer
deposit, at some distance above true bedrock.
FILLER: The small
gravel's or other materials, which fill the space between the larger
streambed gravel's. These filler materials over time can contribute
somewhat to the hardening or cementing of the surrounding larger
rocks.
FINE GOLD: 1. A loose description of small particles of
gold; usually runs #20 to #40 mesh and constitutes a rough 12,000 flakes
or colors per ounce. 2. Gold of a small size that can be picked up with
tweezers. This size of gold, is commonly found in flood gold deposits
along gravel bars and the outside of bends in a waterway.
FINES: 1.
The sand or other small-sized components of a placer deposit. 2. The
material passing through a screen during washing or other processing steps
of a placer mining operation.
FINENESS: The proportion of pure gold
or other precious metal in bullion or in a natural alloy, expressed in
parts per thousand. Natural gold is not found in pure form; it contains
varying proportions of silver, copper, or other substances. For example, a
piece of natural gold containing 150 parts of silver and 50 parts of
copper per thousand, with the remainder being pure gold, would be 800
fine. The average fineness of placer gold obtained in California is 800
fine or better. There are areas in the gold country where placer gold is
as high as 950 fine (such as California's "Mother Lode"
area).
FISSURE: See "crevice."
FLAKY GOLD: Very thin
scale-like pieces of gold.
FLAT: See "flat bar."
FLAT BAR:
An essentially level bar placer or deposit, along the banks of a river or
large stream; also called "flat" for short.
FLOAT: A term often
used among miners and geologists, for pieces of ore or rock that have
fallen from veins; or strata; or have been separated from the parent vein
by weathering agencies. Not usually applied to stream gravel's, but can be
washed into a waterway over time.
FLOAT GOLD: Particles of gold so
small and thin that they float. This type of gold is liable to be carried
downstream by the water flow; see "flood gold."
FLOOD GOLD: 1. Fine
sized particles of gold carried or redistributed by flood waters and
deposited on gravel bars as the flood waters recede. 2. Gold of any size
washed in and deposited along side or in a waterway as a storm layer,
after a flood.
FLOOD LAYER: See "storm layer."
FLOOD PLAIN:
That portion of a river valley adjacent to the river channel that is built
of sediments during the present regimen of the stream., which is covered
with water when the river overflows its banks during flood
conditions.
FLOUR GOLD: A loose description of fine size particles
of gold; usually runs minus #40 mesh and constitutes a rough 40,000 or
more flakes or colors per ounce. This size of gold is commonly found in
flood gold deposits along gravel bars and the outside of bends in a
waterway.
FLUVIAL: See "fluviatile."
FLUVIATILE: Caused, or
produced by the action of a waterway; fluvial.
FOOLS GOLD: Anything
that can be mistaken for gold. Most all of what is termed "fool's gold,"
is a mineral; usually pyrite FeS2 a sulfide of iron, others are biotite,
chalcopyrite, marcasite, and pyrrhotite.
FREE GOLD: Gold uncombined
with other substances; gold not found in chemical combination with other
minerals; found largely in placer gold form.
FREE MILLING ORE: Rock
formations containing free-gold; gold that is not in chemical combination
with other minerals. These must be milled to remove the gold contained
within.
FREE WASH GRAVEL: 1. Gravel that readily disintegrates and
washes in a sluice. 2. Loose, clay-free gravel, such as those found in
accretion bars are generally free-wash gravels.
BR> G
GLORY HOLE: A bedrock hole or
pothole, containing or suspected of containing large amounts of
gold.
GOLD BULLION: Unrefined gold that has been melted and cast
into a bar. In placer mining, the gold sponge obtained by retorting is
commonly melted with borax or other fluxes, then poured into a bullion
bar.
GOLD DUST: A loose description of small pieces and particles
of gold. Commonly a mix of unseparated sizes, generally considered
anything under #16 mesh. This size of gold, is commonly found in flood
gold deposits along gravel bars and the outside of bends in a
waterway.
GOLD ROUTE: The general path(s) which gold takes, during
its movement by water action though a given section of waterway; the
general line of gold's travel.
GOLD VEIN: A gold bearing fissure or
streak in bedrock or Tertiary deposits that contains lode gold. Sizes
range from small microscopic particles, to hundred pound nuggets, and may
suddenly change to a "pocket" concentration at any time.
GRADE: 1.
The amount of fall or inclination from the horizontal in ditches, flumes,
or sluices; usually measured in inches fallen per foot of length or inches
fallen per section of sluice. 2. The slope of land or bedrock surface;
usually measured in percentages. A 1% grade is equivalent to a rise or
fall of 1 foot per 100 feet. 3. The slope of a stream or any surface over
which water flows; usually measured in feet per mile. Streams having
grades of about 30 feet per mile, favor the accumulation of placers,
particularly where a fair balance between transportation and deposition is
maintained for a long time. 4. The relative value or tenor of an ore or of
a mineral product.
GRADED STREAM: A stream in equilibrium, that is,
a stream or a section of a stream, that is essentially neither cutting or
filling its channel.
GRANITE: A coarse-grained, hard igneous rock
commonly found everywhere in mountainous regions. The rock consists mainly
of quartz, orthoclase or microline, feldspar, and mica. Granite is the
most common bedrock in the Sierra Nevada mountain range.
GRAVEL: A
comprehensive term applied to the water-worn mass of detrital material
making up a placer deposit. Placer gravel are sometimes arbitrarily
described as fine, heavy, large, small, boulder gravel, etc.
GRAVEL
BAR: See "bar placer."
GRAVEL PLAIN PLACERS: Placers found in
gravel plains that formed where a river canyon flattened and widened or,
more often, where it entered a wide, low gradient valley.
GULCH
PLACER: A somewhat direct accumulation of materials, washed down from the
immediate surrounding hillsides into a waterway, where the streambed
allows for it.
GUTTER: The lowest portion of an alluvial deposit;
commonly a relatively narrow depression or trough in the bedrock or the
bedrock itself. In some placers the "pay streak" is largely confined to a
narrow streak or "gutter."
H
HANG-UP: Generally rough bedrock or false bedrock
that has caught and collected some gold or other heavy
minerals.
HARDPACKED MATERIALS: These are materials which have been
cemented together naturally. Though this is not a true indication of a
virgin bed, it does indicate it has been laid down for some time. If found
as a layer it would be called a "hardpan."
HARDPAN: A layer of
hardened or cemented gravel found underlying a storm layer in a waterway.
This gravel is cemented mainly with clay, but can be any calcareous,
siliceous, or ferruginous material. These can be found spotty or cover
large sections of the streambed and may be found with one or more of them
overlying bedrock.
HARDROCK MINING: Same as "lode
mining."
HEAVY GOLD: High purity gold in compact pieces, that weigh
heavy in proportion to their size. Most often nugget gold.
HEAVY
MINERALS: The accessory detrital minerals of a sedimentary rock with a
high specific gravity. The "black sand" concentrate common to placers,
would more properly be called a "heavy mineral."
HEMATITE: The
chief ore of iron (Fe2O3, 70% iron), having a blackish-red to brick red
color. In water or when wet they look black in color; see "black
sands."
HIGH-GRADE: 1. Rich ore. A term applied to ores rich in the
values they are mined for. 2. To steal or pilfer ore or precious metals,
as from a mine by a miner.
HIGH PRESSURE AREA: A "high pressure
area" is a general term referring to a place where water is moving fast,
in comparison to the main flow of water. Low-pressure areas can be of any
size and are classified into three categories to clarify a particular
size; large, medium and small.
HILLSIDE PLACERS: A group of
intermediate gravel deposits between creek and bench placers. Their
bedrock is slightly above the creek bed, and the surface topography shows
no indication of benching.
I
ILMENITE: Titanium ore (FeTiO3), having a lustrous
black to brown color; see "black sands."
IMPURITY: Something that
is not pure. Gold is the best example of this, because both lode and
placer gold will be found to contain impurities; such as silver &
copper. Raw-gold needs to be processed, to extract these impurities, to
become pure gold; bullion.
INLET: The point where a channel is cut
off by a ravine or canyon on the upstream end. Usually applied to buried
Tertiary channels.
IRON SAND: 1. Magnetite or ilmenite rich sand.
2. Black sand concentrate containing an abundance of magnetite.
J
JEWELRY GOLD: Good-sized pieces of gold that are of
proper quality to be used in the jewelry making trade; 1. Nuggets with
quartz still attached, or quartz with gold showing that could be used for
jewelry, called either "gold quartz" or "jewelry quartz." 2. Oddly shaped
or unusual nuggets of placer gold. 3. Small size gold.
K
L
LARGE HIGH PRESSURE AREA: A "high pressure area" the
size of an entire section of waterway; generally a few miles long or more.
Also called "major high pressure areas." See "high pressure
area."
LARGE LOW PRESSURE AREA: A "low pressure area" the size of
an entire section of waterway; generally a few miles long or more. See
"low pressure area."
LAVA: The term "lava" as used by a placer
miner may designate any solidified volcanic rock, including volcanic
agglomerates.
LEAD: See "pay dirt."
LIGHT GOLD: Gold that is
in very thin flake form that looks large compared to its weight and could
easily be moved during flood conditions.
LODE: These are gold
bearing veins or pocket gold found in or upon exposed bedrock or as an
ore; rock formations containing particles of gold, that may or may not be
in chemical combination with other minerals.
LODE MINING: The
mining of lode deposits. Also called "hardrock
mining."
LOOSE-PACKED MATERIALS: This would be materials which are
not cemented together or hardpacked which is resting loosely in the
streambed. These are generally a problem to dredge, since the side walls
of the hole will continually slide in.
LOW-GRADE: A term applied to
ores relatively poor in the metal they are mined for, lean
ore.
LOW/BACK PRESSURE AREA: A "back pressure area" may be found at
times located in a small size low-pressure area. "Low and back pressure
areas" are often found together and formed in the same manner; because of
some major change off to one side of the waterway, change in the bedrock
floor, or where the waterway changes direction.
LOW PRESSURE AREA:
A "low pressure area" is a general term, referring to a place where water
slows down or even stops, in comparison to the main flow of water.
Low-pressure areas can be of any size and are classified into three
categories to clarify a particular size; large, medium, and small.
M
MAGNETITE: Magnetic iron ore (Fe3O4, 75% iron),
having a blackish-red to very dark red color. Magnetite is slightly darker
in color than hematite. In water or when wet they look black in color; see
"black sands."
MAJOR FLOOD: A flood of an exceptional magnitude,
that is not usually seen for many long years; approximately every 30 to 50
years or longer.
MAJOR LOW/BACK PRESSURE AREAS: A low and/or back
pressure area of any size, with a very strong force of
action.
MAJOR STORM: A rainfall of an exceptional magnitude. See
"major flood."
MARCASITE: A mineral often mistaken for "fools
gold," though not very often. This mineral is very similar to chalcopyrite
in its characteristics; it tarnishes easily, going from bronze or brassy
yellow to yellowish or grayish brown. It has a dark streak, and are
lighter in weight and harder than gold. Neither of these minerals commonly
occur in crystalline form and most often are found as irregularly shaped
masses.
MATRIX: The surrounding substance within which something
else originates, develops or is contained.
MAXIMUM DEPTH ALLOWANCE:
The amount of depth one should agree upon or determine, that would
effectively dredge a sample hole; taking into consideration the
capabilities of the dredge to be used, personal experience and
preference.
MEANDER: One of a series, of somewhat regular and
loop-like bends in the course of a stream, developed when the stream is
flowing at grade-level through lateral shifting of its course toward the
convex side of the original curves.
MEDIUM HIGH PRESSURE AREA: A
"high pressure area" the general size of an entire section of streambed;
roughly one mile in length. Also called "minor high pressure areas." See
"high pressure area."
MEDIUM LOW PRESSURE AREA: A "low pressure
area" the general size of an entire section of streambed; roughly one mile
in length. See "low pressure area."
MERCURY GOLD: See "amalgamated
gold."
MESH SIZE: The number of openings within a 1 inch square of
screen in which materials are sifted. The most common sizes for screens
used with concentrates in mining are: #20, #30, #40, #60, #80, and #100
mesh size.
MICRO-FINE GOLD: A loose description of very fine size
particles of gold. This gold is so fine, that it takes thousands of pieces
to make a grain; 480 grains = 1 troy ounce; and can run as small as 1,000
flakes or colors a milligram; 31,103 milligrams = 1 troy ounce. Also
called "ultra-fine" gold.
MILLING ORE: Rock formations containing
particles of gold, that is in chemical combination with other minerals.
These must be broken up and chemically processed to free the
gold.
MINE DUMPS: Discarded low-grade ore or waste materials that
are found accumulated into piles, next to or downhill from tunnel or shaft
openings etc.; mine tailings. Also called "waste debris."
MINER
LOW/BACK PRESSURE AREAS: A low and/or back pressure area of any size, with
a very weak force of action.
MINIMUM DAILY ACCEPTABLE ALLOWANCE:
The amount of gold recovery; pay; needed per day that would not only pay
for expenses incurred but be an acceptable profit for those mining it
out.
MINING SEASON: 1. The length of time a particular area of
government owned land is open to mining. 2. A "mining season" can also be
interpreted loosely as; the time generally allowed by an areas particular
seasonal changes or weather conditions that allows one to
mine.
MOTHER LODE: 1. The source or main vein. 2. The name of
California's largest gold producing area, derived from its source or main
vein of which the gold comes from. It is in an area, which begins east of
Sacramento, on the western slope of the Sierra Nevada mountains and covers
some 100 square miles.
N
NATIVE GOLD: Typical metallic gold found naturally
through a mining region or a particular strata.
NATURAL BED: See
"natural streambed formation."
NATURAL STREAMBED FORMATION: A
section of streambed that is fully reformed or reverted to its natural
state; the majority of the larger cobbles and rock are found to be placed,
to the least resistance to the flow. Also called a "naturally formed
streambed" or "natural bed" for short.
NATURALLY FORMED STREAMBED:
See "natural streambed formation."
NEW GOLD: Gold of any size,
found in a recently reformed streambed after a major flood; a flood of a
magnitude to reform the streambed materials into "naturally formed
streambed." Anything less would be flood gold."
NUGGET GOLD: A
water-worn piece of native gold. The term is restricted to pieces of some
size, not mere particles. Anything larger than, one pennyweight for
example, may be considered a nugget. Fragments and lumps of vein gold are
not called "nuggets," because the idea of alluvial origin is
implicit.
O
OLD BEDS: This is a loose term used by dredgers,
referring to those more recent "ancient streambeds," still inside the
waterway or still within reach of modern dredging equipment.
OLD
GOLD: Gold of any size, found in an old streambed; ancient, Tertiary, or
otherwise; or parts thereof that have washed into the waterway, or gold
found contained within hardpan would be considered "old
gold."
OUTCROPPING: Portions of bedrock protruding through the soil
or gravels along the shoreline of a waterway. Those of interest to the
dredger will be found to extent out into the waterway.
OUTLET: The
point where a channel is cut off and exposed by a ravine or canyon on the
downstream end. Usually applied to buried Tertiary
channels.
OVERBURDEN: Worthless or low-grade surface material
covering a body of useful mineral. Gravel, rock, clay, sand, etc. that
covers the bottom of a river or stream down to the bedrock. The term
"overburden" is also used as a measurement of depth; example, if the water
depth is 6 feet to the bottom, and the overburden is 10 more feet to the
bedrock, you would have 16 feet to bedrock, with a 10 foot overburden to
work.
P
PAY DIRT: Any type of ground, earth, gravels, sand,
etc. that is profitable to mine. This depends on the miner's own viewpoint
as to what is profitable. It may also be called "pay-lead," or
"lead."
PAY LEAD: See "pay dirt."
PAYSTREAK: A limited
horizon within a streambed placer, containing a concentration of valuables
or made up of material rich enough to mine. Pay streaks in gold placers,
are commonly found in well-defined areas on, or near bedrock; also called
"stringer" or "stringer deposit." They are commonly narrow, sinuous, and
discontinuous.
PAY VALUE: The worth or value placed on materials to
be mined; amount of expected gold recovery from a given amount of
materials.
PERMANENT DEPOSIT: In placer mining, this refers to gold
deposited on the bedrock floor; especially those caught within the bedrock
itself. It would take a major flood of equal or greater magnitude to
release this kind of deposit. See "retention."
PIPE CLAY: A term
used for clays, or clay like materials found in finely laminated beds,
within Tertiary channels. Some may consist of volcanic material that has
fallen into the water in the form of ash and taken on a stratified form
resembling clay in appearance.
PITCH: Used in connection with
bedrock in the channel or rim to express descent.
PLACER GEOLOGY:
The study of all types of placers; alluvial & eluvial; how they were
formed and how they interact or work together.
PLACER: A place
where gold is obtained by the washing of materials: rocks, boulders, sand,
clay, etc. containing gold or other valuable minerals by the elements.
These are deposits of valuable minerals, in our case, native gold, are
found in the form of dust, flakes, grains, and nuggets. In the United
States mining law, mineral deposits, not veins in place, are treated as
placers as far as locating, holding, and patenting are concerned. The term
"placer" applies to ancient (Tertiary) gravel as well as to recent
deposits, and to underground (drift mines) as well as surface
deposits.
PLACER MINING: The obtaining of values; minerals; from
placers by washing or dredging.
PLACER DEPOSIT: A mass of gravel,
sand, or similar material resulting from the crumbling and erosion of
solid rocks, which contains valuable minerals; gold, silver, platinum,
tin, ect.; that have been derived from the rocks or
vein.
PLANATION: Lateral mechanical erosion, as of a valley, by a
running stream.
PLAYED-OUT: This is when a deposit of gold being
mined becomes less than the minimum acceptable allowance in recovery or is
fully recovered and mined out. Also called "play out."
POCKET GOLD:
Native gold found in concentration in the remnants of ore veins, or
sometimes seen as bulging sections of "spill" from these veins or quartz
veins containing veins and/or pockets of free-gold. These are
characterized by sharp, jagged rough surfaces in many unusual and
distinctive nforms and shapes. It is usually distinguished by its
roughness, since it hasn't traveled any distance from its original
location.
POINT BARS: See "skim bar."
POPCORN GOLD: A loose
description of small pieces of gold, resembling popcorn in shape and
size.
PRESSURE EDDY: An eddy with a circular motion, formed when
the streams current pushes against a natural or artificial
obstruction.
PROSPECTING: 1. In most cases, prospecting simply is
the searching for new deposits. 2. Work merely intended to discover a pay
lead in a drift mine, or to locate a channel. 3. Drilling a known placer;
including that of an active waterway; deposit to determine its value or
delineate a mineable area; placer drilling.
PROSPECTOR: One who
prospects likely areas for signs of gold, prior to starting a production
mining operation; also called a "sniper." Samples are taken at likely
sites; usually by digging or dredging sample holes; or at random to locate
payable ground. Sampling is continued until a deposit is either suspected
or found acceptable to those that will be working the deposit
out.
PUMPKIN SEED GOLD: A loose description of small pieces of gold
resembling a pumpkin seeds basic shape and size; smooth, thick, and
flat.
PUNCHING A HOLE: To dredge a sample hole through streambed
materials down to bedrock or to your maximum depth allowance to determine
how rich the site is.
PYRITE: The most common mineral mistaken for
gold; "fools gold." It occurs as veins or as scattered grains in many
types of rocks. Seen in exposed surfaces in a rock, or as grains in a
stream, it is often brown in color on the outside. This is the result of
the exposed parts having been oxidized to limonite, a more stable iron
mineral. The crystal faces are often striated parallel to the edges of the
face. Pyrite can be distinguished from gold by its greater hardness, its
lower specific gravity; weight; its dark streak, and by the striations on
crystal faces, when it is present.
PYRRHOTITE: A mineral often
mistaken for "fools gold," though not very often. Very similar to that of
Chalcopy-rite and Marcasite except that pyrrhotite, when pure, is magnetic
and can be picked out of mixed gravel with a strong magnet; the same as
magnetic black sand. Pyrrhotite has the same dark streak and and tarnishes
easily, going from bronze or brassy yellow to yellowish or grayish brown.
It is harder and more light weight than gold. Pyrrhotite does not occur in
crystalline form and is most often found as irregularly shaped
masses.
Q
QUARTZ: A component of granite
and sandstone, SiO2. In its pure or common state, it is a six sided
crystal clear in color like glass. Usually found as all-white or marbled
white with brown or red. It is often found as veins or pockets layered in
bedrock. Geologists believe gold was originally crystallized from
hydrothermal solutions in the seams, crevices, veins, and cleavage planes
within quartz formations.
QUARTZ GOLD: Gold within a quartz rock,
or running through an exposed vein, wire gold exposed in a pocket of
quartz rock, or gold with a piece or pieces of quartz still attached.
Natural placer gold in California, is formed in quartz.
QUATERNARY
GRAVEL: Gravel deposited from the end of the Tertiary geologic time period
to and including the present.
R
RAW GOLD: High-grade ore in free form; gold that
is not in chemical combination with other minerals withing the ore; in
which gold is visible from the outside of the ore. The best example of
this is pocket-gold.
RECOVERY SYSTEM: This is the equipment used to
process materials for its gold; or other values. In dredging, the bulk of
the materials would be processed through a hydraulic separator in the
hedder box, then recovered in the sluice box concentrator. During this
process it may also be classified into size groups. The complete process
would be considered a recovery system. Final clean-up may also employ
another recovery system designed to process these heavy concentrates into
clean concentrates.
RED GOLD: Placer gold found under or in
"hardpan," or cemented gravels, in rivers and streams with red rust-like
spots. Usually considered very old or has been cemented in place for a
long time. This "old" gold has been called "blood gold," because the color
at times is either dull or bright red when freshly dug or dredged
up.
RESIDUAL PLACER: Essentially an enrichment of gold or other
heavy minerals/metals, caused by weathering and subsequent removal of the
lode or other parent material, leaving the heavier, valuable
minerals/metals in a somewhat concentrated state. This type of placer
occurs at the surface of the ground, where a vein of gold crops out and is
exposed to the elements; generally anything found within a few feet of the
parent lode outcropping.
RETENTION: In placer mining, this refers
to the tendency of gold, to stay in place after it is deposited. The
ability for gold to stay in place, greatly depends on where it is
deposited in the streambed and is classified into three groups; permanent,
transitory, and temporary.
RICE GOLD: A description of small grains
of placer gold resembling rice in shape and size. Found mainly in the
Alaskan and Yukon gold country.
RIM ROCK: The bedrock rising to
form the boundary of a placer or gravel deposit. Called "rim" for
short.
RIVER BAR: This is a "bar placer" found alongside or in a
river; also called "river bar placer." The term "river" refers to the size
of the waterway, thus, "stream bar" or "stream bar placer," would be found
on a larger size waterway; creek bar, etc.
RIVER PLACER: This type
of placer occurs very near, at, or under the surface of a river; also
called "riverbed placer." The term "river" or "riverbed" refers to the
size of waterway, thus, a "stream placer" or "streambed placer," would be
of a smaller size waterway; creek placer, etc.
ROSE GOLD: Native
gold that is found with a high concentration of copper; usually 15 to 25%;
to give a gold pink appearance. This can also, be found man-made in the
jewelry trade for its attractive "rose" color.
ROUGH GOLD: Gold
that has not been appreciably worn or smoothed by movement and abrasion.
It may be more angular than rounded, and may have included or attached
quartz particles. As a rule, rough gold is found near its place of
origin.
RUSTY GOLD: Free gold that does not readily amalgamate, as
the particles are covered with a siliceous film, a thin coating of oxide
of iron; usually hematite or magnetite which cause iron stains. When used
as a loose term, it may include other outside impurities such as sulfides,
oxides, and limonite rust.
TAIL END: The down stream end of a paystreak
deposit, where it begins toloosening or
removal from the ground or streambed.
T
TAIL END: The down stream end of a paystreak
deposit, where it begins to drop below one's minimum acceptable
allowance.
TAILINGS: The material that washes out from the end of
the sluice or other recovery device, in a placer operation. The tailings
from hydraulic mines are generally referred to as "debris" and are
designated as such in legislative documents.
TAIL RACE: The channel
which nforms from the washing of tailings exiting a recovery system in a
surface mining operation.
TEMPORARY: In placer mining, this refers
to gold deposits, found mainly on the outside of curves or on accretion
bars. Though, these can be found at times to contain substantial deposits
of fine gold, they are easily washed away during the slightest water
action. See "retention."
TERTIARY: The earliest of the two geologic
periods comprising the Cenozoic era, in the classification generally used;
up to a little over a million years ago. Also, the system of strata
deposited during that period; see "geologic time scale" end of this
section.
TERTIARY CHANNELS: Buried ancient waterway systems, often
auriferous, composed of Tertiary stream alluvium. Tertiary gravel is
abundant in the Sierra Nevada gold belt of California, where many of the
ancient waterway systems, have been covered by extensive volcanic
eruptions and subsequently elevated by mountain uplifts, and are now found
as deeply buried channels high above the present stream
beds.
TERTIARY BED: See "Tertiary streambed."
TERTIARY
STREAMBED: The materials which formed over the bedrock channels and
benches of ancient waterway systems. Also called "Tertiary bed" for short.
See "Tertiary" for geologic time period.
TRACE GOLD: A very small
quantity of gold; usually a speck too small to weigh by common scales. In
reporting samples it is abbreviated "Tr."
TRANSITORY: In placer
mining, this refers to gold deposited within the materials; overburden;
between the bedrock floor and the surface of the "stream load." All storm
layers as a whole, are considered temporary; being extremely susceptible
to release by future flooding. See "retention."
TRANSPORTATION: In
placer mining, this is a term referring to the movement of gold by water
action.
TRIBUTARY: This is a small waterway adjoining a larger
waterway. Also called "affluent."
TRIBUTARY DEPOSIT: A "tributary
deposit" is concentrations of gold formed at and shortly downstream from
where a tributary enters into a larger waterway. It may form a secondary
gold route for a short ways downstream until conditions allow it to join
the main line of gold's travel.
TOP WASH: A deposit of gravel, not
in a channel on bedrock, but resting on cement; hardpan; overlaying the
bottom deposit.
U
ULTRA-FINE GOLD: See "flood
gold."
UPCROPPING: Bedrock protruding through overburdon in a
waterway.
V
VALUES: The valuable ingredients obtainable, by
treatment, from any mass or compound; specifically, the precious metals
contained in rock, gravel, etc.
VIRGIN: The term "Virgin" is
defined as that which has never been mined before by anyone," such as
"virgin bed or bedrock," "virgin placer," "virgin ground," "virgin
materials," etc.
VIRGIN BED: See "virgin streambed."
VIRGIN
STREAMBED: This is a "natural streambed formation," whether it is an
ancient, Tertiary, or present streambed which has never been mined, or a
section of streambed which was formed more recently, into a naturally
formed streambed during a major flood, even if it has been redeposited
into a location, which has been previously mined and worked out. Also
called "virgin bed" for short.
W
WASH: 1. A western miner's term for any loose
surface deposits of sand, gravel, boulders, etc. 2. The dry bed of an
intermittent stream, which sometimes is at the bottom of a canyon. Also
called a "dry wash." 3. To subject gravel, etc. to the action of water to
separate valuable material from worthless or less valuable material
simply, to wash gold. 4. In drift mining, the term "wash" is used
indifferently in describing channel gravel, volcanic mud flows, or masses
of lava boulders.
WASTE: Low-grade material not profitable to mine,
such as barren gravel or overburden.
WASTE DEBRIS: Discarded
low-grade ore or waist materials, that are found scattered around near
mine tunnel or shaft openings etc.; mine tailings. Also called "mine
dumps."
WATER FORCE: See "water pressure."
WATER PRESSURE:
The force, momentum, velocity of flow, or current in a waterway or the
absence (lack of) of such.
WATER TABLE: The upper limit of the
portion of ground wholly saturated with water. This may be very near the
surface or many feet below it.
WATERWAY SYSTEM: This would
encompass all waterways, regardless of size; tributaries, feeder creeks,
streams, etc.; that directly flow into and contribute to a larger
waterway, thus all are related as one system.
WET PLACER: Any
placer, which is within an active waterways highest water
mark.
WHITE GOLD: 1. Strictly man made for use in jewelry, etc. An
alloy of gold, nickel and silver or other metals used with gold to harden
it. White gold has a platinum-like color tint. 2. A nickname for platinum
used by miners.
WIRE GOLD: It looks like its description: fine,
short pieces of wire, or a tangled wire-like mass. Usually in bunches of
tangled wire-like form, mostly found in pockets of veins; see "pocket
gold."
Y
YELLOW GOLD: Any placer gold is usually yellow in
color. Even with impurities it still remains yellow. There are variations
in lightness & darkness, depending on the impurities; silver, nickel,
copper, etc. The grade of gold has much to do with its color, and its
quality depends mostly on the darkness and brightness of its
color.