Problem: It has been aid that the most creative structural problem is to determine fault displacement. Determining fault displacement requires discovering the offset between two points that were once together. These points are separated but are located on the same fault surface. Strictly speaking, a "point" on the fault surface is a theoretical concept. However, in practice we can approximate a point by

(1) the intersection of three planar geological features (e.g. two beds and the fault surface) or,

(2) by the intersection of a linear geological features and the fault surface (much less common!).
 
 
 
 

1) (Refer to the following figure)

A fault surface (S50W/60NW) cuts two dykes:

dyke A: (E/40S)

dyke B: (N40W/20NE)

Along a horizontal reference surface the following is known:

bb': 250 m

aa': 460 m

b'a': 450 m

ac: 500 m

A very thin bed (C) (S60E/70SW) crosses the fault at c. Determine and draw the continuation of this bed on the northern side of the fault trace.

Calculate graphically the net slip and all the components (angles and distances) of the displacement vector. What type of fault is this?




3) (Refer to the next attached figure)

A limestone bed (CC' and BB') is cut by a major dyke (DD' and EE'). Both the limestone bed and the dyke are cut by a common joint.

Graphically estimate the following:

a) strike and dip of: the dyke, the limestone bed and the fault

b) net-slip and all the components of the total displacement vector (distances and angles)

c) What type of fault are we dealing with?

CONGRATULATIONS!!