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1 <br />• 4.0 JOINT MAPPING <br />a.l Fielrl Work <br />On the fast day joint mapping started at the Deer Trail zone and proceeded from <br />east to west as we made our first traverse along the outcrop observing joint patterns, rock <br />failures and assessing hazards. Where possible, a line survey was carried out along a 100 ft <br />tape. Otherwise joint orientations within a defined area were collected. In addition to <br />measurements of joint orientations, a coding system was used to record information on the <br />size and spacing of the joints as well as filling, aperture, and roughness when appropriate. <br />Joints were measured only where accessible i.e. along the base of the cliff, and only joints <br />1 greater than 3 ft in length were mapped. <br />By the beginning of the second day we had determined Hazard Zones (or Zones). <br />The six Hazard Zones refer to portions of the outcrop which are homogenous from the point <br />`• of view of assessing hazards. <br />On the second day, we set out to fill in the gaps from the first day. We traversed <br />from west to east. Falling snow hampered our efforts (particularly during the first half of <br />the day) but we completed a traverse of the whole outcrop in the study area. <br />1 Joint orientations were recorded in terms of dip direction and dip. These can <br />J easily be converted from strike and dip. The advantage of dip direction and dip is that a <br />joint orientation can be completely described by two numbers (otherwise at least three items <br />J of information are needed). For example, the bedding plane joints, with a strike of N75E <br />and a dip of 7W, can be described as 345/7 in the dip directionldip convention (see Table 2 <br />1 for more examples of conversions from one system to the other). The dip direction/dip <br />notation has the advantage that it can be directly input into rock fabric computer programs, <br />J such as those used to produce Figures 5-10, and directly used in stereographic analyses of <br />rock slope stability. <br />• 15 <br />