APES- FGeology120,000 years ago ice began to form at a rapid pace in northernCanada(Grette, www.
biomass. umass. edu). This sheet quickly (on a geologicscale) swept down the eastern seaboard and engulfed the northeast down topresent day Long Island, New York in a sheet of solid ice. This ice-sheetlater in history became known as the Laurentide ice-sheet, named after theregion in Canada in which it made its descent(Oldale,http://pubs.
usgs. gov). Little did anything know back then that it wouldhave had such a profound impact on a region as it did on the northeast. Particularly in Massachusetts’ case we owe the ice-sheet for giving it thedistinctive “flexed armed” appearance we see with Cape Cod jutting out intothe Atlantic Ocean.
This formation was created by the active Laurentidesheet approximately 14,000 years ago(Pinet, 1992). The advancing ice-sheetbrought and pushed sediment that has created the Cape Cod peninsula. Thisglaciation of the area brought huge boulders and rocks down from Canada onits descent, and ground up native rocks and gravel to sand and sediment. After reaching its furthest extent about 10,000 years ago, and has longbegan its retreat. It had left behind all the rocks, sediment, and debrislocked in its frozen vaults.
After it had completely left the area, behindit was the recessional moraine, Glacial Cape Cod Lake. As the glacier fullyreceded water levels rose, filling in an area of about 3 miles of shoreonce a part of Massachusetts, and consequently filling in the glacial lake. Resulting from the receding Laurentide Ice-sheet, many new minerals androcks were deposited on the area that have never been seen here before. Thebedrock was formed in the late Precambrian and Paleozoic eras, and is madeup of crystalline igneous and metamorphic rocks.
So, these have been hereall along. Glaciers in the Pleistocene and Holocene eras, deposited manysedimentary(eastern Mass. ), igneous(middle/eastern Mass. ), and metamorphicrocks(eastern/middle Mass. ) throughout the state.
These deposits (most prevalent sedimentary) are found along the coast ofeastern Massachusetts and makes up the entire arm of Cape Cod. This may notseem like such a big deal, however the Till made of Pleistocene andHolocene sediments is a very loose and grainy type. Though this sedimenthelps make the Cape a wonderful beach area, it may lead to its demise aswell. In some areas of the Cape may erode bluffs 10-15 feet in a 2-7 periodof time(www.
whoi. edu). Many of these problems have been magnified my humanoccupation and alteration of the shoreline. Today, the innovative species we are, have taken this material brought tous on a proverbial flying carpet and made a business out of it. Many of therocks mined throughout Massachusetts are used as building materials,gravel, and sand. Though this may seem petty, it is a very lucrativebusiness and the state makes a lot of many though exporting naturalminerals and rocks.
In the state of Massachusetts mineral, stone, and steel exports make thestate over a one hundred-million dollars annually and employ thousands ofworkers in mines, processing plants, and excavation. On the states list ofthe top 97 exports six of them involve the geology of the state directlywhile others also are connected, yet indirectly. On that list ranks basemetals(23), aluminum(26), stone for art purposes(38), copper(39), salt andsulfur(61), and mineral fuel(67). Ancient Massachusetts was a very different place than it is today. Oncecovered by a huge glacier only 13,000 years ago, now has one of the mostrecognizable coastlines on the eastern seaboard. Massachusetts has trulybeen molded by the glaciation of the past.
What remains of that giant sheetnow helps our economy run(somewhat) smoothly, our citizens to enjoy thebeaches, and a distinctive land formation, that is Cape Cod.