Core Sampling Policy
1. All samples must be selected by the customer during their visit to the CRC. If a customer wishes to sample a core being viewed, they will consult with the CRC staff member working at the front desk. The CRC staff member will determine if there is sufficient material to sample
1.1. Sampling of archived core, both plugged and slabbed sections is permitted if more than 1/3 of the cross-section remains.
1.2. If not enough archive slab remains for sampling, CRC staff will determine if the butt section is available for the well requested.
1.3. An individual or group may take a maximum of 100 samples per visit. The total number of samples pending return for an individual, or for an entire company, agency or institution, is limited to 200 samples. The limits for international researchers are 25 and 50, respectively.
2. The CRC contains a wealth of analog and digital data on cores from previous sampling and analysis sessions. Prior to taking new samples, it is highly recommended that the customer check the Well Catalog to see if data and/or thin sections already exist for the sample(s) requested. The CRC makes all data and thin section images available via the CRC Website shortly after they are received. All legacy paper files have been scanned and can be downloaded from the CRC Website. Please check to see if data on the samples requested are already available on the CRC Web site.
3. Core Sampling:
3.1. Individual core samples taken may not exceed one-cubic inch or a one-inch plug. If a larger sample size is needed, a scientific justification must be submitted. CRC staff will determine if approval can be granted for larger sample(s) on a case-by-case basis.
3.2. No more than one sample per foot of core may be taken, i.e. side-by-side plugs/sampling is not allowed.
3.3. Plugs will only be taken perpendicular to the axis of the core. Samples will be taken so that a continuous vertical portion of the core remains. Sampling that would result in the total loss of a core interval is not permitted.
3.4. Due to the large amount of material required to produce results, sampling for scarce mineral grains such as zircon, apatite, etc., is not allowed.
3.5. All samples will be cut by the CRC staff.
3.6. Non-destructive analysis performed during a visit using a testing instrument brought in by the researcher is allowed with CRC approval. The raw data produced from these analyses must be submitted to the CRC within six months.
3.7. The CRC expects to receive results (data, thin section, etc.) for each sample taken. Samples should not be collected in excess of the number that can be analyzed within the allotted six month time period. Funding for analyzing every sample should be secured before samples are collected.
4. Temporary core removal:
4.1. Temporary removal of core from the CRC will be determined on a case-by-case basis, i.e. the need to run non-destructive tests that require specialized equipment not available at the CRC. A time frame for returning the core will be determined on a case-by-case basis. Outside labs must be able to start the analysis immediately upon receipt of core.
4.2. Core may be removed from the CRC for slabbing. Core slabbing must be arranged and paid for by customer, and must have CRC approval. A time frame for returning the core will be determined on a case-by-case basis. Slabbed cores must be marked with depth intervals and directional arrows. Cores must be matched by the drilling marks, and the slab ends must fit together.
4.3. Slabbed core must be returned with the thin slab in CRC archive boxes. The CRC will provide boxes to the slabbing company. All boxes must be labeled with the well name, township-range and section, operator, county, state, and depths. Butts are to be returned in the original boxes.
4.4. Sampling is prohibited while cores are removed from the CRC.
5. Any unused portion(s) of sample material, along with appropriate labeling, must be returned to the CRC within six months of sampling unless prior arrangements have been made with the CRC staff.
6. Prior to removing samples from the CRC, a completed sampling form must be approved by a CRC staff member and signed by the individual taking the samples. The name of the individual’s supervisor, company/organization name, business address, e-mail address, telephone number, and date must be legibly written on the form. Students must provide name and contact information for primary professor. Sampling forms are available at the CRC front desk.
7. Generated data/acknowledgement:
7.1. Copies of any analytical results (i.e. chemical, paleontological, petrophysical, and petrographic reports, etc.) and/or any thin sections made from sampled core must be submitted to the U.S. Geological Survey’s CRC within six months of sampling. The data will be made publically available via the CRC website. Customers will not be allowed to view or sample additional material(s) until overdue results or thin sections are returned. Analytical data must be in specified digital format for analysis described in the Data Return Policy. Thin sections must be clearly labeled with the CRC library number, operator, well name, and depth.
7.2. The data will be made publicly available at the CRC and via the CRC website and will become part of the public domain, even if the processing and/or analyses were paid for with private funds. Any interpretations based on the data need not be submitted.
7.3. We request that the USGS Core Research Center be acknowledged as the source of the sample material and/or provider related analytical data in any publication that contains results from studies of the CRC collections. We encourage including detailed information such as library number, API number, well name, location and sample depths which will enable future researchers to locate materials for additional investigations.