Sunday, July 26, 2009

It's Everywhere! It's Everywhere!

My favorite super hero existed only on the radio. No comics, no TV shows, no bloated-budget movies for him. He was mild mannered shoe salesman Benton Harbor who fought crime as that legendary super hero Chickenman. Each show began with:

Now, another exciting episode in the life of the most fantastic crime fighter the world has ever known.

Bauck, bauck, bauck, bauck. [well, it was some sort of raucous chicken sound]

Chickeeeeenmaaaaan! He’s everywhere! He’s everywhere!

I thought of Chickenman the other day as I explored a beach on the Long Island (New York) side of Long Island Sound. What particularly bubbled up from the recesses of my memory was the catch phrase, “He’s everywhere! He’s everywhere!”

In my previous post I reviewed David William’s new book Stories in Stone: Travels Through Urban Geology. In that post, I discussed the unavoidable connection between paleontology and geology. This Chickenman remembrance is more of the same. As I wandered over that beach, with the Chickenman refrain in my mind, it morphed into “Geology! It’s everywhere! It’s everywhere!”

Long Island is not a productive place for a fossil seeker, particularly not one used to the abundance of the Chesapeake Bay region. Why? Blame the geological history of the island. The current topography of the Long Island is the direct product of glaciation during the Wisconsin Stage of the Pleistocene Epoch which scoured away or covered fossil bearing sedimentary rock. There is some debate over the actual history of glacial movement over the island during the Pleistocene (beginning about 2.6 million years ago and ending approximately 11,700 years ago). It appears that one of the advances of the Wisconsin glacier ended about 55,000 years ago, leaving behind at its southernmost edge what is known as the Ronkonkoma Moraine. (Moraines are ridges of unsorted sediments or till left by glaciers.) A later advance of the Wisconsin glacier ended some 18,000 years ago somewhat north of Ronkonkoma Moraine. The Harbor Hill Moraine is the legacy of this second advance and retreat. These two terminal moraines form twin backbones along the eastern half of Long Island – the Harbor Hill Moraine, on the north side, runs right on the edge of Long Island Sound; the Ronkonkoma Moraine to the south, parallels the Atlantic Ocean. Given this geological history, it’s not surprising that Bradford B. Van Diver, in his book Roadside Geology of New York (1985) describes Long Island as “not much more than an enormous sand and gravel deposit.” (p. 32)

While vacationing on the north fork of Long Island, I succumbed to the Chickenman/geology refrain and began to explore this geological history. This is clearly a work in progress for me, I have so much more to learn. But, the initial steps I’ve taken are gratifying and encouraging.

Much of the shoreline of the Long Island side of Long Island Sound has the Harbor Hill Moraine on glorious display. I went down to the beach that runs below the Horton Point Lighthouse; the lighthouse is about 12 miles from the end of the north fork of the island (Orient Point). The shoreline is lined with so-called erratics, boulders carried by glaciers.

The cliff side (of the Harbor Hill Moraine) that abuts the shore is punctuated with embedded erratics (like raisins or dates in a plum pudding) waiting for erosion and gravity to release them and allow them to join their brethren on the shore.

This is new territory for me, but I’ve been informed that the different erratics consist of banded granite, gneiss, and schist. There is also basalt, among other materials. Quartz certainly appears within the erratics (that much I can tell). The erratics shown below give a feel for the array of beautiful boulders that embellish the Horton Point beach.

The Harbor Hill Moraine largely disappears as one heads further east to the end of the island, though it reappears on Plum Island to the northeast of Orient Point. That is made clear by the view (see picture below) of Plum Island from the Long Island Sound ferry crossing from Orient Point to New London, Connecticut. (Plum Island is home to the Department of Agriculture’s Animal Disease Center.)

On the Horton Point beach, I felt like a 19th century naturalist, seemingly seeing the world for the first time and feeling compelled to collect many, many examples of that newness (those early naturalists usually collected the living and made them dead with their firearms). I was unarmed and my quarry was inanimate. So, I brought back a heavy bag full of small rocks from the beach; identifying them is my homework. Geology is truly everywhere, it’s now in the house.

Information on the geology of Long Island can be found in, among other sources, Van Diver’s Roadside Geology of New York; the U.S. Geological Survey’s Geology of the New York City Region: A Preliminary Regional Field-Trip Guidebook; and the Garvies Point Museum’s Geology of Long Island.

Two Chickenman episodes can be heard at this site.

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