About 12,000 years ago, pro-glacial Lake Iroquois occupied all of the current Lake Ontario and extended significantly south and east into New York. The glacial ice was retreating but had not yet melted far enough north to expose the St. Lawrence Seaway, forcing the significantly larger Lake Iroquois to drain east through the Mohawk Valley and then south along the Hudson River. All of Rochester, NY was beneath this lake.
I have a confession to make. I have become an arenophile. Fortunately, it is not illegal (unless trespassing while doing it or if you are in Sardinia), and it should not be harmful to my health. I would say it is generally not contagious, but I did catch it this past spring when Jim Rienhardt introduced us to the hobby in the Wayne County Gem and Mineral Club November 2018 newsletter and later at the March meeting. I did not realize I was hooked until this summer. While collecting minerals on club trips to Maine and in Michigan, I looked for sands to collect and proceeded to fill quart freezer bags at a few dozen locations along lakes, rivers, and even from glacial deposits. You see an “arenophile” is a lover of sand. The word is derived from the Latin “arena” (sand) and the Greek ”phil” (love).
Last March, Jim Rienhardt brought his collection of some 270 sands to the WCGMC meeting and told us about arenophiles (sand collectors) (Reinhardt, 2018). Jim repeated his presentation at the Rochester Academy of Science later that month. At that meeting RAS member Paul Dudley brought along some sand he had collected from Hamlin State Beach some 50 years ago. Paul’s sand was red and dominated by garnet, but full of other heavy minerals. He told us that the sand had been collected during a college field trip late in the spring when Lake Ontario first started to recede from winter highs.
I parked that in my memory and on my calendar and on July 8th set out to find some “garnet” sand for myself. I was not disappointed. The first stop I made was at Area #5 at the west end of Hamlin State Beach. The Lake level seemed to have dropped, perhaps a foot from its highest erosional cut. And in the bank left when the lake level was highest was a 2-3 cm thick band of black and red sand. I sampled and took pictures and moved to other areas of the park.