This cache is a part of my Jenkins/Skug Series (JSS). On two log sheets in the series are the north and west coordinates of the bonus cache. I took everything I enjoyed most about geocaching and made it into a series. If you choose to find all seven geocaches in the two reservations, you will experience a variety of terrains, hide types, scenic views, musical tributes, local history, geology, and a bonus cache to top it off.
This cache was originally intended to be an EarthCache. After the questions were shot down by the reviewer, I have decided to make it another traditional in the series. Below is the EarthCache description about glacial erratics like this one.
Woah! How in the world did such a massive rock get in the middle of the woods? In order to answer this, we must first learn what a glacial erratic is.
Glacial erratics are stones or boulders that differ in size or type of rock as compared to the area in which they rest and have usually been transported from a different location through the force of ice or water. The name "erratic" is based on the errant location of these stones. Although technically they can be as small as pebbles, generally speaking we're talking about larger boulders (when they are enormous, some people call them "massives”). Andover is known to have a few glacial erratics around town.
If you’ve already done the rest of the series, you remember that the Jenkins family owned a soapstone quarry in what is now the Jenkins Quarry reservation. You might be wondering, what is soapstone?
Soapstone is a type of talc-schist metamorphic rock. Also other naming’s are steatite or soaprock. The composed primarily of talc, with varying amount of micas, chlorite, amphiboles, carbonates and other minerals. It is produced by dynamothermal metamorphism and metasomatism. It occurs in the regions where tectonic plates are present, replacing the rocks with heat and pressure, with the flow of liquids, but without melting. It has been an environment for carving for thousands of years. It is composed primarily of talc so it usually very soft. It is typically gray, bluish, green, or brown in color, often variegated. Its name is derived from its “soapy” feel and softness.
The soapstone mined at the Jenkins Quarry was reported to be bluish in hue. The stone, in the contract called Blue Free Stone, was referred to at different times as steatite, free stone, and blue soapstone. A geologist was quoted as saying this material was “quite different from ordinary soapstones and certainly a peculiar one.”An 1841 report by state geologist Edward Hitchcock spelled out the advantages of this particular stone: “This is the softest of all the rocks employed in architecture, this property rendering it easy to be sawed or cut without injuring an edge tool.” The soapstone was thus worked with a star drill, hammers and wedges. The star drill would make holes in a line; wedges were inserted to split the stone. Also noted from people acquainted with the rock was the “striking characteristic” of its "greasy or soapy feel.” After cutting, the stone was then polished into a certain shape depending on its intended use. Examples of these cuts can still be seen at the quarry site. The Blue Soapstone from the Jenkins land could also be seen in Andover. Uses include monuments at West Parish Cemetery and a wall at a home on Salem Street. A memorial to William Jenkins, the founder of the Jenkins Quarry, is made out of his own soapstone and is located in Andover.
Another prominent example of building with soapstone is the Christ the Redeemer statue in Rio de Janeiro, Brazil.
This raises the question, is this monolith any different from the rest of Andover's geology? According to the United States Geological Survey (USGS), Andover is primarily made up of crystalized granite. A USGS study asserts that "field and petrographic studies of the Andover Granite and surrounding rocks have afforded an opportunity for an explanation of its emplacement and crystallization. The investigation has contributed secondarily to an understanding of the geologic history of southeastern New England, particularly as it is revealed in the Lawrence, Wilmington, South Groveland, and Reading quadrangles of Massachusetts. The Andover Granite and Sharpners Pond Tonalite together comprise up to 90 percent of the Acadian(?) subalkaline intrusive series cropping out within the area of study."