|Sample Collection and Field Equipment
A sampler will need: A field map, baggies (Zip-lock), a marking pen (Sharpie, permanent
marker) a pencil (for recording field sample points) and a stout hand shovel. Other useful
items would be a GPS a compass and a backpack.
Geochemistry is a statistical process. A single sample point is used to represent the
geochemical value of an area. The size of this area is determined by the sample
density. The point at which you sample is only one value of the distribution of
potential sample values available in the sampled area. The significance of this is
that geochemical sample points do not have to be precisely located. Therefore the
sampler should adjust the sampling location if the conditions of that sample are poor.
Disturbed or excavated areas should be avoided as should areas contaminated with
hydrocarbons, chemicals or animal wastes. Swamps and areas that are continually or
seasonally under water should not be sampled. The sampler should attempt to locate
on the field map the sample point as closely as possible to the actual sample site
but absolute precision is not critical to the geochemical survey results. A field vehicle
odometer combined with topographic orientation will provide acceptable sample
locating precision unless sample density is less than 1/10 kilometer. GPS systems are
both inexpensive and accurate and are great for geochemical surveys.
Sample identification numbers should be as simple as possible. This saves time in the
field and reduces errors. The simplest system is consecutive numbers beginning with
one. Letters preceding the number (i.e. PRJ1) can uniquely identify the samples for
each of your project areas. Prior to the commencement of collection an adequate
number of bags should be numbered and organized in groups of ten. Using the bags
sequentially and recording the bag number on the field map or "marking" with a GPS
at the time of collection eliminates almost all collection errors. Each sample should be
a composite of four to five equal scoops of soil separated by a few feet. Samples
should come from the top few inches of the soil. Rocks, coarse material, Plant debris,
Insects and small animals should be excluded. The total sample should be 200 to 300
grams (7 to 10 ounces). After collection expel the air and carefully seal the baggie.
Soil should be collected from the top two inches.
The sample should be 7 to 10 ounces unless the
soil is unusually coarse then a larger sample may
be needed to provide sufficient fine fraction.
Three to five equal scoops should
be collected from the immediate
area and placed in the numbered
Samples can be shipped directly to GrayStone Labs. A good way to ship your samples
is in five gallon buckets. Buckets can not be damaged during shipping, they hold forty
to fifty pounds of samples and they have a handle. Small and medium sized cardboard
boxes also work well as long as you place the samples in plastic trash bags to prevent
moisture from reaching the cardboard and tape the box heavily. Keep boxes less than
18 kg (40 lbs). The box should be sealed with heavy shipping tape and addressed
exactly as listed below. If you are sending samples from out of the United States
please call 303-278-3252, and I'll give you the special shipping information you will need
for the importation of soil samples.
GrayStone Exploration Labs, Inc.
15400 W 44th Ave. Suite 21
Golden, CO 80403
Contents: Soil Samples
Ready for the Field
|GrayStone Exploration Labs, Inc.
GrayStone Exploration Labs, Inc.