A B C c b a c A B H= a(sinB) B = drill plunge a =(cSinA/SinC) A =Tan -1 {tan( dip bedding plane)*sin(strike difference) h= (cSinA/SinC)*Sin(drill plunge) b a C

A B C

A B C A= Tan -1 {tan( dip bedding plane)*sin(strike difference)} or derive on stereonet B = Drill plunge C = 180-(A+B)

A B C c b a c A B b a c = distance along drill trend to plane exposure C

Law of Sines c A B h b a c = distance along drill trend to plane exposure a = (cSinA/SinC b = (cSinb/SinC h= a(sin B) C

A B C c b a c A B H= a(sinB) B = drill plunge a =(cSinA/SinC) A =Tan -1 {tan( dip bedding plane)*sin(strike difference) h= (cSinA/SinC)*Sin(drill plunge) b a C

H =(cSinA/SinC)*Sin(drill plunge) B = drill plunge a == (cSinA/SinC) A =Tan -1 {tan( dip bedding plane)*sin(strike difference) c= horizontal distance h = [{horizontal*sin(apparent dip)} / Sin {180-(drill plunge +apparent dip)}] * Sin (drill Plunge

A B C c b a c A B Now we know (h) = vertical depth b a C

Get the plunge of intersection line

h’ A x B a’ h w C x = distance between drills w = vertical change h’= w + h a’ = new drill depth w = h’ = [{horizontal*sin(apparent dip)} / Sin {180-(drill plunge +apparent dip)}] * Sin (drill Plunge)] + {x/cos(strike diff)}* tan (plunge intersection)} a’ = h’/Sin (drill plunge)

A B C c b a c A B b a C = a + drill distance * tan (angle between horizontal line on the drill plane and intersection line)

Consider Three drill holes Orientation Bedding to Core axis a 200/40 40 b 090/50 55 c 298/58 5

Calculating Core axis pole to bedding angle 60 Core Axis 30 Bedding Pole to Bedding Drill hole Orientation Bedding to Core axis Core axis to Pole a 200/40 40 50 b 090/50 55 35 c 298/58 5 85

Rotations 30

3 1

Rotate to the Horizontal 1 3

Possible bedding pole orientations – comparing hole 1 & 3

Now compare Hole 1 with Hole 2

Compare possibilities = pole to bedding of ~ 135 / 40

True Orientation of Bedding

N 20o Hinge Trace 40o 60o A 70o B 20 Meters