The following article which was written by M. L. Fernald '97, Fisher Professor of Natural History, is reprinted from the current issue of the Harvard Alumn Bulletin.
Years ago, when asked by an English solicitor at St. John's to tell him what there is in botany to interest a man, I explained certain of the inter-relations of botany and geology, only to receive the astounding reply: "Why, Sir, do you not realize that you are prying into the secrets of the Creator?" Again, when visiting my home-village in Maine, I was seriously upbraided by a former schoolmate for my apparent disloyalty to the United States, which seemed evident to him because I was working on scientific problems connected with foreign countries.
Newfoundland is Important
But, singularly enough, Newfoundland, lying at the extreme eastern angle of North America, presents some remarkable features in the natural distribution of its native plants which throw a vivid light upon the recent geological history, not only of that region, but also of areas on the continent and by extension, of Northern Europe as well.
Common Conception is Wrong
To the conventionally educated New Englander the conception of a recent continental ice-sheet is familiar. This is supposed to have originated in the southwestern section of the Labrador Peninsula and to have swept south to Nova Scotia. Cape Cod, Long Island, northern Pennsylvania, and the Ohio valley; and recent studies, especially by Antevs, indicate that the front of this sheet began to rot approximately 25,000 years ago. As a natural outgrowth of this everyday conception, we are inclined to infer that all the region south of the entire Labrador Peninsula was similarly crossed and denuded by the last or Wisconsin ice-sheet.
Ice Avoided Salt Water
In brief, we now have very conclusive evidence that the last continental ice-sheet (the Wisconsin) which originated on the Labrador Peninsula and pushed southward, did not cross the outer Gulf of St. Lawrence, the glacial ice having there, as elsewhere, a natural dislike for deep salt water. Nevertheless, in many parts of Newfoundland, Wisconsin-time saw small local sheets of ice on some mountain-slopes and on some of the open plains; and these local Wisconsin sheets did as effective work in Newfoundland as in New England.
Southern District was Denuded
For example, witness the photograph of a thoroughly scoured and denuded area of southern Newfoundland which was unquestionably crossed by very recent ice. Here (at Burgeo) the granitic hills are absolutely stripped of all soil and rotten rock-mantle, and the conspicuously striated ledges contain gourges which look as if they might have been hacked only yesterday by a sharp mattock or heavy chisel. In this region, too, great boulders as large as small houses are scattered irregularly over the hills, the boulders having fresh and undecayed surfaces.
Much Land Undisturbed
In most of Newfoundland, however, the hills and high tablelands are deeply carpeted with a mantle of angular frost-broken and lichen-crusted material; transported boulders are not seen, or are small and conspicuously weathered; and the cliffs have very high talus-slopes, such as that of Hannah's Head on the lower Humber. The largest area in which the surface mantle is undisturbed and the rock-walls covered with a rotted crust that has never been scraped off is on the western side of the island, embracing the Long Range of mountains and the adjacent foreland.
Area Invaded Long Ago
In parts of this area, especially along the valleys and on the lower slopes of the hills, there are obvious signs of recent glaciation, but in others the rare glacial striae and the few transported boulders present are so far obliterated or rotted away that Professor Coleman concludes these regions were invaded only at the very beginning of Pleistocene time (many hundreds of thousands of years ago). On some of the tablelands, to quote Coleman's words, "No signs of glaciation were seen above the edge of the escarpment at 970 feet (aneroid), and a walk of four or five miles inland over the rolling surface of the tableland reaching 1.908 feet (aneroid), showed only angular blocks of Archaean rock of local origin. No foreign boulders were found, and the conclusion was reached that the southern part of the Long Range had never been glaciated."
Plants have not Migrated