2003-06-09_REPORT - M1977211 - Laserfiche WebLink

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IVED JUN 0 9 2003 Divisi n sf Mi~era~ a~d G~od°~~ ushed eastward over the face of the B. Little if any material from t~re ay ac sou p quarry and down on to limestone yet to be mined. Alternatively, if work continues on [he layback in the current location, then whatever is pushed off should be disposed of quickly as backfill in the cove on the south end of the quarry. Unfortunately, it will not be long before the land where the layback rock is landing will need to be lowered. When that time comes, the area should be free of granite. 5. It is recommended that layback excavation, if it must continue, cease on the current location and move to the next point to the north. Material excavated from there should be pushed northward to create the access ramping up to that area. Two concerns are evident here. First, continued work on the current layback area is producing a lazge volume of material that can go nowhere except over the face of the quarry where it interferes with current mining. Second, there is only one rather long and tortuous route to reach the layback workings. It is believed that having two access routes is important for this very isolated area. In the event of serious injury, landslides, or forest fires it seems prudent to have two access routes. Diving off the face of the quarry is not really a feasible escape route. It seems wise to have one access from the south (the existing access) and a second from the north. To create that north access will take a considerable amount of material. But that material needs to come out anyway and pushing it over the face of the quarry is counterproductive. It interferes with the limestone mining. By the time the north access route is created, much of the limestone above the Area H elevation should be removed. 6. Recommendations on mining Area H: As the limestone above Area H is removed, the fill that has been placed in the deep excavation on the north end can be removed and used to help create the north access to the layback. This will uncover that area. Mining of Area H should then proceed from north to south starting at the existing deep hole. It is important to point out that the bottom of that deep hole on the north is at an elevation of about 7215' (underneath the existing fill). This elevation is almost exactly where Area H begins in vertical elevation. It may actually be a slight distance into Area H, but not significantly so. By the time this is started, a significant part of the mountainside above the north end of Area H will have been removed to create the north access. This effectively alleviates at least some of the load on this mountainside making it safer to work under. It may still not be safe, but it will be safer.