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• APPENDIX F <br />OUTLINE OF KEY POINTS WITH <br />RESPECT TO GEOTECHNICAL CORE LOGGING <br />Sedimentary Rock/ Soil Types <br />General Descriptio <br />1. Break out units within the lithologies only where major changes occur. "Minor" variations i.e. changes over V <br />need to be noted only where clayey intervals are present. Some judgement on the logger must be used when <br />breaking out units. <br />2. Alternating sequences can be described by applying 2 descriptions to repeating beds along with interval length <br />and bed thickness. i.e. 140 -152' Alternating sequence of stiff green clay (average bed thickness —0.2') and tan <br />sandy clay (average bed thickness —0.3'). <br />3. Apply grain size tests (sieve, test tube, texture feel) periodically to calibrate visual estimates and use personal <br />iud eg ment in making grain size descriptions. <br />4. Perform a field estimate of plasticity by assessing the ease at which a bead 3mm in diameter can be rolled. If the <br />soil can be easily rolled into long and thin beads (as thin as 3mm in diameter), then the estimate of plasticity is <br />"high <br />5. Apply USCS codes based on grain size and plasticity. <br />Describe bedding, including: <br />1. Angle to core axis. <br />2. Number of parted bedding planes /ft. <br />3. Describe the nature of bedding planes i.e. deformed by soft sediment deformation, etc. <br />. 4 Represent bedding graphically in the graphic structure log. <br />Igneous Rock Types <br />1. Describe textures briefly. <br />a. Volcanic textural features include: vesicles, amygdules, plagioclase laths, lapilli. Briefly quantity, sizes and <br />percentages. <br />b. Major textural features in plutonic rocks include: mineralogy, crystal morphology (subhedral, euhedral, <br />anhedral), and alteration. Briefly quantity, sizes and percentages. <br />2. Describe structural features <br />Exl slickensided joints with up to 0.2" clay infill @ —45 degree ACA, 3 /ft. <br />Ex2 from 220.3- 250.4, 13.2'/28.3' broken zones w/ angular fragments up to!", —5 % clay. <br />3. Describe broken and brecciated zones including <br />a) Angularity of fragments <br />b) Texture of fragment surfaces if noteworthy i.e. slickensided, jointed, etc. <br />c) Size range or average size (where size is defined as the maximum dimension). <br />d) Percent of clay <br />e) Use the aforementioned observations in support of fault zone designations. <br />Contact Logging <br />1. Use suggested adjectives when describing major lithologic contacts. <br />2. For gradational contacts, break out the contact zone, and describe the relationship between the two lithologies <br />i.e. lakebed clays persistent in fractures in basalt, give % estimates of the rock types present. <br />3. The depth at the last major occurrence of the overlying unit generally defines contact depths. <br />4. For zones where 2 lithologies are interfingering, no distinct contact can be made, simply break out the <br />• interfingering zone. <br />N: \PROJECTS\ACTIVE PROJECTS\I158520037 RioTinto CollomPennit \Draft Permit Text Tables MapPDFs \Exhibits \Exhibit 6 Item 7 - Geology Pre - Feasibility <br />Report\Appendices\Appendix F - Protocols \gtechlog.doc Page 1 of 1 <br />1/16/2009 <br />