Before discussing the more detailed aspects of the geology of Darling
State Park, certain basic geologic concepts must be explained. But, even
before such a discussion, it might be best to clarify the position of
geology among the many other, and oftentimes interrelated, sciences.
The basic reason for the science of geology might be said to be twofold;
one is economic, the other related to Man’s basic curiosity. In the
first, the geologist through the use of his knowledge of the earth’s
rocks, locates those indispensable minerals and fuels without which our
advanced society and technology could not exist. In the second, the
geologist tries to unlock the many mysteries within the earth’s crust
merely to satisfy a thirst for knowledge and to pass such knowledge on
to his fellow man. These two basic reasons complement each other and
allow continued advancements in geology, both as a pure science and as a
primary economic aid to the nation.
As found in most spheres of present-day scientific endeavor, the
geologist relies heavily on other related sciences for insight into
problems at hand. A basic knowledge, and oftentimes an advanced
knowledge, of physics, chemistry, mathematics and zoology, to name only
some, are needed before the geologist can approach many of his own
problems. It might be obvious to you by now, but a geologist will be
certainly included in the first scientific party to journey to the moon
and planets.
Within the general science of geology are several branches, to name only
a few; paleontology, sedimentology, mineralogy, petrology, stratigraphy,
petroleum geology, and structural geology. Each of these branches or
specialty-areas contributes basic data for the overall interpretation of
the past geologic history of any given geographic area. The historical
geologist takes all these clues and attempts to fit the pieces of
information together into a picture of past events.
The concept of Geologic Time must be understood before the history of
Darling State Park can be unraveled. Usually we think of time in terms
of minutes, hours, days, weeks, months and years. The geologist thinks
and talks in terms of millions or even billions of years. Time units as
short as hundreds of years are impossible to distinguish in the past
history of the Earth. When it is realized that the earth is probably 4
to 6 billion (4,000 to 6,000 million) years old, and the record of these
years is incomplete, it is easy to understand why the geologist speaks
in terms of millions of years instead of years. With modern methods of
radioactive dating the geologist hopes for finer time definitions in the
future.
In short then, the geologist interprets and puts order into millions of
years of history which can only be “read” as recorded in the rocks
beneath our very feet. Of course, just looking at the rocks does not
magically open the book of geologic history. This pamphlet is designed
to sharpen your powers of observation and to help you in your
interpretation of these observations.
[Illustration: Figure 2. Thin-section of granite from Burke
Mountain. The main minerals seen in this photograph are feldspar
(light gray center right, marked with “F”); quartz (whitish, marked
with “Q”); biotite (light gray, speckled appearance, marked with
“B”). Note the interlocking nature of the minerals which make up
this rock. Magnified 15 times, under crossed nicols.]