COLLECTING GEOLOGICAL SAMPLES

Collection Procedures for Oil Field Samples

Atoka recommends that at each oil field sample point to collect six representative samples at six separate points from within five feet of each other. Clear away the vegetation at each point and scoop a 1/4 to a 1/2 a shovel full and place it in the bag. Vegetation just bulks up the sample and has to be removed anyway by sieving in the lab. In some environments, such as Northern Michigan, this may be difficult, so the sampler needs to do as best as he or she can. After all six geological samples have been placed in the bag, seal the bag. The bag should be 1/2 to 3/4 full. If the soil is silt or clay rich then the bag can be 1/2 full or less. If the soil is predominantly sand and gravel then filling the bag is recommended. The laboratory analyzes the fine fraction. Place in a cool spot inside the vehicle or backpack and out of the sun. It is believed that the sun is a possible catalyst for ioodorganic compounds being formed or broken up. By removing the samples from the sunlight, this minimizes the chance for this to occur. But also more importantly, it is less likely that the label made by the magic marker will fade.

After the sample is taken, mark each oil field sample number clearly on the map. Many GPS systems will provide a sequential numbering "mark" function that can be used to record the bag number.

Collection Procedures for Acid Extraction Soil Gas

Augers are available for sale from a variety of forestry or engineering suppliers, therefore it is relatively easy to obtain an auger and collect your own samples for acid extraction. This method does not work with head space.

To begin collecting the sample, pick an ideal spot, preferably flat ground where soil is present and not bed rock. Clear away vegetation. Auger down three to four feet. The last soil taken is the sample to be placed in the sample bag. The bag should be 1/2 to 3/4 full. If the soil is silt or clay rich then the bag can be 1/2 full or less. If the soil is predominantly sand and gravel then filling the bag is recommended. The laboratory analyzes the fine fraction. Place in a cool spot inside the vehicle or backpack and out of the sun. By keeping the sample bags away from sunlight, the label made by the magic marker is likely not to fade.

After the geological sample is taken, mark each sample number clearly on the map. Many GPS systems will provide a sequential numbering "mark" function that can be used to record the bag number