GE$3050$

Lab $-$ Week $4$

True Dip$/$Apparent Dip

The true attitude of a diabase dike is $N40E,30NW.$ What is the apparent dip of this dike as exposed in a vertical cliff face that trends $N70E?$

The strike of bedding on the horizonal floor of a limestone quarry is $N43E.$ The apparent dip of the bedding on a north$-$south trending quarry wall is $32$ towards the south. What is the true dip of the bedding?

A prospector has dug two small trenches, which are not parallel to each other, at the base of Tabor Ridge in order to expose a thick vein of gold$-$bearing bull quartz. The walls of the pits are vertical. In the first pit the apparent dip of the vein is $24,N17E,$ and in the second pit the apparent dip of the vein is $56,N39W.$ What is the orientation of a shaft that lies in the plane of the vein and parallel to the true dip of the vein?

A chevron fold is one in which the hinge is very angular so that the profile of the fold has the shape of a $"V".$ A chevron fold crops out in Hell's Canyon on the Oregon$/$Idaho border. The attitude of one limb of this fold is $N20W,30NE$ and the other limb is $N50E,60NW.$ What is the plunge and bearing of the fold hinge?

A high concentration of gold occurs at the intersection of a $040,60NW$ fault and a $350,40NE$ sandstone bed. The intersection of the bed and the fault crops out in a wash south of the Morenci Mine in western New Mexico. The owners of the mine have decided to explore the gold play by drilling it$.$ If they start the hole at the outcrop, what should be the plunge and bearing of the drill hole such that the hole follows the intersection lineation $($and stays in the play$)?$

Cross beds can be used to determine paleocurrent directions. Cross beds are often not fully exposed and the true attitude must be calculated from data on apparent dip. Consider a cross bed in sandstone that is exposed on two vertical non$-$parallel joint faces. On one face the apparent dip of the cross bed is $10,016,$ whereas on the other it is $28,082.$ Calculate the true attitude of the cross bed.