NATURE NOTES FROM ACADIA

GLACIER-POLISHED ROCK

While following the shoreline around Bennet Cove, near the southern-most extremity of Mount Desert Island, I came upon a smooth face of rock, several square yards in area which sloped gently toward the sea and which presented a fine example of glacial polish and scratching. At its upper limit this polished rock disappeared beneath a thick layer of soil on which blueberries, lichens, and spruces grow, while at its lower limit, just above high tide mark, it was littered with course gravel. As illustrated in the drawing below, it was evident that up to very recent times a protecting layer of soil - a continuation of the present soil cover - extended completely over the polished and striated rock thereby preserving its glaciated face just as the massive ice sheets had left it. Recent removal of the protecting glacial till which covered it, both by storm waves as well as by the abrading action of ice in winter, has exposed this interesting well-polished rock face. A compass, placed upon the surface, showed clearly the NW-SE trend of the scratches.

- Temporary Park Naturalist