Making Observations:
The first step in collecting geologic field data
from an outcrop is to examine the outcrop and make observations.
These preliminary observations provides geologists with the data they
need to study how organisms and environments change over time.
Common observations taken at outcrops includes the type of rocks
present, the thickness of the layers, the identification of
sedimentary
features (bedding, ripple marks, bioturbation), grain size, color,
paleocurrent indicators, and fossil content.
These observations may also include an examination of the outcrops
"attitude," (the orientation of beds), by measuring the
strike and dip of the beds with a compass. All of these
observations provide us with information we can interpret as we try to
determine the depositional environment of a sedimentary rock layer, for
example,
the water depth, species composition, paleogeography, and climate at
the time it formed.