ARCHIVED REPORTS XR0010482 - Laserfiche WebLink

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• barrel, modified to hold 5, 6" long x 2 1/2" diameter brass tubes. A latching mechanism in the first auger flight held the core barrel while drilling advanced. When the interval had been cored, the barrel was retrieved with a wireline, a blanking plug was installed, and augering continued. When another core was desired, the blanking plug was retrieved, and a clean core barrel was lowered into the flights & locked into the latching assembly. Two (2) core barrels were used to avoid downtime between sampling intervals; while one was in use, the other was cleaned with TSP & warm water, filled with clean tubes & set aside until needed. A Thermo Environmental model 580B OVM meter was used to screen the cores; prior to start of operations, it was calibrated with a bottle of isobutylene at a concentration of 100 ppm. The calibra- tion was witnessed by Mr. Hunter. Operations began at 0945 hours; cuttings showed the top 3 feet to consist of black, sticky clay-loam. It graded to slightly sticky tan to brown clay. At 20' drilled depth, the blanking plug was Pulled, and a clean core barrel was inserted into the auger flights. This type of drilling equipment does not use a drive hammer for advancing the core barrel, (it is done by rotating the • auger flights, ) and therefore blow counts are not recorded. The core barrel was advanced from 2Q, to OV 6", and was retrieved with the wireline. It was laid on the tailgate of the Del-Tech truck and carefully opened & examined by the geologist_ Recovery was 20" of tan to brown sandy clay; it had a mottled appearance due to color variations. A portion of the bottom of the core was Placed in a brass tube which was sealed on the bottom with a Plastic cap. The top was then sealed with another cap which had a small slat to allow insertion of the probe of the PID meter. After allowing the tube to sit for 10-15 minutes, the probe of the PID meter was inserted into the tube and the reading on the dial was recorded. It was 0, (zero. ) While waiting for the above mentioned sample to warm, the cored material was examined and described by the geologist. The middle sleeve was promptly sealed by placing teflon tape on the ends of the tube, covering it with plastic caps, and sealing both ends with duct tape. The tube was then labeled & placed on ice pend- ing transport to the laboratory for analysis. While the core was being analyzed and preserved, the other core barrel was cleaned and prepared for use. The augers were advanced to 251 , the blanking plug removed, the clean core barrel inserted, and a core was taken from 25' to When the barrel was retrieved and opened, it contained 4