570 – Structural Geology; Lab 1
Orientations of planes and lines
: strike and dip, dip and dip direction, trend and plunge (rake), parts of a Brunton
compass, magnetic declination, measuring planes and lines, why is this all important?
How to succeed in lab (and in 570)
Do readings from M&M! I don’t (and neither do you) want me to have to re-teach
every section at the beginning of lab
Stay up to par in class
Use each other, me, Liz ,etc. as resources. Ask questions! I won’t always have the
Lab assignments will be due by the beginning of the lab after they are assigned.
Preknowledge/familiarity assumptions: foliation, lineation, topographic maps, geologic
maps, plane vs. a line (using hands vs. fingers to represent them!)
How many have seen a Brunton? Held a Brunton? Used a Brunton? Taken
Strike and dip
What is strike? (a horizontal line on a plane, 90
from the dip direction/from where
water would flow down a plane,
a line connecting points of equal elevation, a mini-
contour line, others?). For PLANES only!
Examples: the shoreline of a lake would define a strike (pg. 5 of M&M), a
contour line on a topo map is like a lot of strike lines connected
What is dip? (the way a marble would roll/water would flow down a plane, a line 90
from strike, others?)
How do we represent strike and dip?
Azimuth (always three numbers)
Quadrant (N, NE, NW, S, SE, SW; never ES/WN/etc.). Everyone comfortable
with how to report quadrant?
What is 099 in quadrant?
North quadrant convention
Right hand rule convention (good to get in the habit of this if you are planning
on becoming a structural geologist)
What is dip and dip direction?
How do we represent this on a map? (bedding, cleavage, S1/S2/etc., will go