Regular Meeting of the Gratz Historical Society, October 24, 2013 at 7pm
Basement Social Hall, Simeon Lutheran Church, Gratz, Pa.
Steve E. Troutman will present the evening program entitled, “The Geology of the Mahanoy, Mahantongo and Lykens Valleys -Something about the Earth We Walk on.”
A power point photo presentation will be shown describing the formation of the Ridge and Valley Province of Central Pennsylvania. The geologic time scale pertaining to our area will be discussed, beginning 400 million years ago and ending with the present time. Sediments were first deposited in an ancient ocean basin which were later formed into sedimentary rock layers. These rock strata were uplifted to form a mountain range. Erosion of these mountains occurred during the geologic history of our earth, resulting in the formation of the ridges and valleys we see today. The ice ages will also be discussed. They are a recent geologic event ending only 10,000 years ago. The effects of this severe climate change in the Susquehanna Valley will be addressed. Photos of ice age evidence will be presented including gravel terraces, rock glaciers, rock falls, and sand dunes formed by the movement of ice, water, and winds of this very interesting era. Native Americans appeared in our valley at the end of the Ice Age. European settlers arrived here only 250 years ago.
It is difficult to imagine the 400 million years of geologic time that has passed. The age of our Appalachian Mountains could be represented by a measuring stick 4 feet in length. Each foot represents 100 million years. The last half inch of the last foot is when native American arrived. The last one sixteenth of an inch represents when Europeans arrived. Of the 48 inches on the measuring stick, 47 and 15/16th inches are pre-historic. Only the last 1/16th inch represents recorded history.
Robert Fromme of Millersburg will have a display of fossils, and free relief maps of Central Pennsylvania will be available.
Light refreshments to follow the hour long program.