Cover Picture. View of the entrance to Calvin Coolidge State Forest Park. Photographwas taken looking north along State Highway 100A.
THE GEOLOGY OF
CALVIN COOLIDGE STATE FOREST
By
HARRY W. DODGE, JR.
DEPARTMENT OF FORESTS AND PARKS
Perry H. Merrill, Director
VERMONT DEVELOPMENT COMMISSION
VERMONT GEOLOGICAL SURVEY
Charles G. Doll, State Geologist
1959
THE GEOLOGY OF
CALVIN COOLIDGE STATE FOREST PARK
By
HARRY W. DODGE, JR.
INTRODUCTION
Each summer hundreds of eager campers, picnickers, hikers andsportsmen visit the Pinney Hollow-Bradley Hill recreational area of theCalvin Coolidge State Forest Park. This area is located a few milesnorth of Plymouth, Vermont, and is easily reached via State Route 100Afrom either Plymouth or Bridgewater Corners (See index map of Vermont,geological map). The excellent camping and recreational facilitiescoupled with the natural scenic beauty of this region provide manyvisitors with an irresistible urge to return, summer after summer, tothis same spot. This pamphlet is designed for all those who visit CoolidgeForest Park and especially for those who possess questioning minds and ageneral desire to learn more about the world around them.
GEOLOGY
Have you ever wondered why the present mountains and valleys arewhere they are and how and when they got there? Has the thought passedthrough your mind that the very rocks on which you stand or see nearbyhave a definite story to tell? The geologist not only wonders about suchthings, but through his training attempts to answer questions of thisnature. His everyday job includes the reconstruction of ancient landand sea areas through a careful study of the rock record. He looks at therock layers as you might the pages of a history book. The professionalgeologist, however, commands many basic geological principles and“tools of the trade” which permit him to read more accurately therecords preserved in stone.
First, the basic geological principles will be explained and you willbe given the proper “tools” for your adventure. Then, you are invitedto travel back through 550 million years of time to see just why CoolidgeState Forest Park is as it is today and what it was like in the distant past.
BASIC PRINCIPLES AND “TOOLS”
To many of you rocks are just “rocks” and very little thought hasbeen given to any history which might be gained from their study.Probably even fewer of you realize that literally billions of years ofEarth history can be derived directly from the rock record. Most geologistsconsider the Earth to be nearly four billion years old with man enteringthe picture a mere million or so years ago. No human was present torecord the events of billions of years of changing land and seas, violentearth movements or the gradual evolution of life through the last 500million years. The study of rocks and their contained eviden