Uso Brujula

Enhancing Quantitative Skills of
Physical-Geology Students with a Geologic Compass
Glenn Blair Stracher
Department of Science & Mathematics
East Georgia College
Swainsboro, Georgia 30401
stracher@ega.peachnet.edu
ABSTRACT
Although the ability to use a geologic compass
is an important skill for geologists and can be a
useful and stimulating skill for any student, most
introductorygeology courses do not include any
work on the use of the compass. This is unfortunate
since compass work, introduced early, can help
improve the quantitative skills of all students by
giving them hands-on experience at solving practical problems. The equipment needed is readily
available at relatively low cost and a variety of
compass-based exercises can be designed to
strengthen studentskills. Worthwhile exercises
include the following topics: quadrant and azimuth notation, magnetic declination, compasstraverse closure, elevation measurement, distance
between two landmarks, and strike and dip.
Keywords: Apparatus; education – geoscience; education – undergraduate; field trips, field study,
summer courses; geology – teaching and curriculum; miscellaneous and mathematical geology.INTRODUCTION
Physical-geology textbooks and lab manuals generally fail to promote the geologic compass as an effective
teaching tool. In the United States, geology students
traditionally do not receive rigorous training in the
use of the compass until they enroll in a field-geology
course, usually during the junior or senior year.
The geologic compass has been an indispensable
field-geologyresearch tool for decades (Bartlett,
2000; Reed, 2000), and teaching physical-geology students how to use one complements a course in which
both geology majors and non-majors are enrolled. Our
justification for teaching compass skills during two
consecutive three-hour physical labs includes the enthusiastic verbal response we have had from students.
Most of them said they enjoyed theexperience of
learning to use an instrument that many professional
geologists use. Some students said the compass skills
they learned were useful in locating themselves on a
map while hiking. All students felt that learning to
use a compass helped them understand angular measurements better than pictures in a book because it
gave them something more concrete to work with.
Other students in variousdisciplines are contemplating undergraduate field-research projects requiring
compass skills. One such project, already underway
by a biology major, involves collecting water samples
for analysis from wells and streams in Emanuel and
Johnson Counties, Georgia. A compass is being used

James Herbert Shea
Department of Geology
University of Wisconsin – Parkside
Kenosha, Wisconsin 53141james.shea@uwp.edu
in this project to determine the bearing and distance
between collecting localities.
The authors believe that all educated individuals,
regardless of their profession, should possess some
quantitative skills in angular measurement. The geologic compass is an excellent tool for teaching these
skills to all physical-geology students, regardless of
their mathematicalbackground, while providing them
with the added benefits students themselves claim
to receive. The purpose of this paper, then, is to promote the geologic compass as a worthwhile complement to physical-geology courses by emphasizing its
usefulness in building quantitative skills based on
the kinds of activities and calculations that many
geologists do while working in the field.
COMPASS SUPPLIES ANDEXERCISES
A variety of geologic compasses are available on
the market. Those offered by the Brunton, Silva, and
Suunto companies are the most popular, with various
models in different price ranges. One particularly
nice kit that is useful for classroom teaching is the
Brunton compass and map-training kit illustrated in
Figure 1.
Software and textbooks useful for teaching and
learning...