Drilling samples

For the profile (length from 0.5 to 3 km, point interval of 50 m) sampling, both small hand-dug test pits (depth about 50 cm) and percussion drilling (sampling depth 1 to 1.5 m) have been used. Measurements were made using the ScanMobile system which is a moving... 

Drilled samples, 200-1000 fig and sealed in pure quartz vials, are activated and analyzed in a similar way for silver, copper, and gold content. Drill bits of tungsten carbide and stainless steel, materials much harder than silver, were used in taking samples. Since no significant differences in concentrations of the major elements of the drill bit materials could be found in samples taken with either of them, possible contamination by the drill bits can be neglected. 

Table I. Percent Group Standard Deviation from the Mean in Multiple Analyses of Drilling Samples...

A more serious concern is that of corrosive depletion of the more reactive metals near the surface. Ideally, an internal drilling sample should be taken for analysis. While this is preferable to a streak sample, practical limitations are imposed by the types of objects with which we are working. We doubt if any owner or museum curator would allow us to drill into a coin. However, some museums will occasionally permit drillings to be taken from metallic art objects, and during the past year a group from Brookhaven National Laboratory (including P. Meyers and E. V. Sayre) has obtained drilling samples from silver art objects which we... 

On the other hand, the Brookhaven group found about 10% less gold in the drilling samples vs. our streak samples. As noted below, it is the gold silver ratios that are especially important, and the Brookhaven... 

After the decision to mine a clay site has been made, a mining plan is set up. This is based on the analyses of the drilling samples. Because clay is geologically seen deposited in more or less horizontal layers, it is mined in thin, vertical layers. In this way an average clay composition is obtained. The top layer can contain a lot of plant remains and is therefore often dug up and stored separately. After the clay has been mined this soil can be used to cover the site and recultivate the area. 

Uncertainties in phenocryst abundance estimates are a significant source of error, particularly for major and highly compatible elements in the main phenocryst phases. In most cases related to ocean drilling samples, phenocryst abundances in a particular sample are rarely known to better than about 5 vol.%. The most abundant phenocrysts are olivine and plagioclase, which contain the elements magnesium, silicon, calcium, aluminum, and nickel. 

Core-drilled samples were taken from the in-pot melting glass canisters after the canisters had been stored almost three years and had received 1 X 10 rad or more of radiation. Leach data from the core-drilled samples are shown to bracket the nonradioactive control data in Figure 6. Differences in leach rate of the magnitudes shown are within experimental deviation these differences which are believed to be associated mainly with difficulty in determing surface areas accurately. The shape of the radioactive and nonradioactive leach rate curves for the... 

Field samples come from various soiuces. These include a large suite of hand specimens (collections of E.G.N., M.J.B. and A.M.) core from the 200 m Nercmar hole (E.G.N., M.J.B.) through the Manjeri Fm (Fig. 2) core from the 50 m Saskmar 2 hole in the Cheshire Fm shales (P.A., E.G.N.) and hand-drill samples from the... 

The extent and quality of the deposit is determined from a pattern of core drillings (samples of the subterranean rock brought to the surface), which are... 

The requirements call for a system that can house and contain a CWM up to a ton container in size. Moreover, the system will be portable and allow for drilling, sampling, agent removal, and neutralization while preventing releases of agent during processing. 

Typical deep-sea drilling sampling resolution is on the order of one sample every 3 to 10 meters. 

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