is much more powerful than the ice. Where the two unite their action, the sea leaves the more conspicuous records. The waters are active and aggressive, while the glacier is passive. Where the glacier enters the ocean its records are at once modified and to a great extent obliterated. The presence of large bowlders in marine sediments, or in gravels and sands along the coast is about all the evidence of glacial action that can be expected under the conditions referred to. Where the swift streams from the Malaspina glacier enter the ocean the supremacy of the waves, tides, and currents is even more marked. The streams are immediately turned aside by the accumulation of sand bars across their mouths, and nothing of the nature of stream-worn channels beneath the level of the ocean can exist. All of the deposits along the immediate shore between the Yahtse and Yakutat bay have the characteristic topographic features resulting from the action of waves and currents and do not even suggest the proximity of a great glacier.

Recent advance.-On the eastern margin of Malaspina glacier, about four miles north of Point Manby, there is a locality where the ice has recently advanced into the dense forest and cut scores of great spruce trees short off and piled them in confused heaps. After this advance the ice retreated, leaving the surface strewn with irregular heaps of bowlders and stones and inclosing many basins which, at the time of our visit, were full to the brim. The glacier during its advance plowed up a ridge of blue clay in front of it, thus revealing in a very satisfactory manner the character of the strata on which it rests. The clay is thickly charged with sea-shells of living species, proving that the glacier, during its former great advance, probably extended to the ocean, and that a rise of the land has subsequently occurred. This is in harmony with many other observations which show that the coast adjacent to Malaspina glacier is now rising. The blue color of the subglacial strata is in marked contrast with the browns and yellows of the moraines left on its surface by the retreating ice, which, in common with the fringing moraines still resting on the glacier, show considerable weather

ing. Among the shells collected in the subglacial clay Dr. W. H. Dall has identified the following;

Cardium gronlandicum, Gronl.

Cardium islandicum, L.

Kennerlia grandis, Dall.

Leda fossa, Baird.

Macoma sabulosa, Spengler.

Similar shells, all of living species, were previously found at an elevation of five thousand feet on the crest of a fault scarp at Pinnacle pass, showing that recent elevations of land much greater than the one recorded in the marine clay just noticed have taken place. In fact there are several indications that the coast in the vicinity has been rising and that the same process is still continuing. ISRAEL C. RUSSELL.

THE QSAR GRAVELS OF THE COAST OF MAINE.1

In the interior of Maine we find the long osars interrupted near the tops of transverse hills crossed by the glacial rivers, and still more interrupted on steep southern slopes. In such situations it is evident that the velocities of the osar rivers would be greater than the average, with the result that the rivers swept their channels clear of sediments. The conditions were those of transportation by the glacial rivers rather than deposition.

If we follow the osars southward toward the ocean we find at about the average distance of thirty miles from the shore that the osars begin to be interrupted in a different manner from that in the interior. Gaps begin to appear in the ridges in level ground where the land slopes could not cause an accelerated motion of the glacial rivers. Indeed, the gravels more often appear on the tops of low hills than in the lower grounds. Going southward the sizes of the ridges become on the average smaller, their materials rather coarser, the intervals longer, and finally near the northern ends of the bays or fjords of the coast they disappear. If they continue farther southward or into the sea, it is in masses that are so small as to be covered out of sight by the marine beds. The coastal towns are usually covered by clays, and road gravel is often in great demand. The vigilance of town officers has often detected beneath the marine clays small mounds of gravel that form the southern ends of gravel systems. To the south we reach a region where no gravels have been found. When we find an osar system graduating into mounds so small that not even the selectmen of a Maine town can find waterwashed road gravel, we may be sure that our osar has come practically to an end. I have examined the charts of the Coast

I Condensation of chapters of a report on the Glacial Gravels of Maine, written for the U. S. Geological Survey.

Survey showing the sea bottom for a few miles off the coast. If there were any broad gravel hills 100 to 150 feet high, such as are found thirty miles north from the bays, they ought to be shown, and I do not find them. The charts often report gravelly bottom but it is uncertain whether this is till or glacial gravel. I find no evidence that these soundings showing gravel are connected with ridges of any considerable size. While then it is as yet impossible to know the geological significance of the gravel reported on the sea floor, yet in most cases the gravels end so evidently north of the shore that the interpretation is distinctly favored that none of the gravel systems reach far beneath the sea. No osar gravels have I been able to find on the islands situated south of the apparent ends of the gravel systems.

There are other significant peculiarities of the coastal gravels than those to be named in this paper, and many collateral or alternative questions and hypotheses had to be worked out. For the present we confine our attention to the three following characteristics :

1. The decrease in the average size of the glacial gravel masses as we go toward the coast till they often become cones not more than twenty or thirty feet in diameter and four or five feet high. In general, the marine clays are twenty feet or more in depth and would easily cover out of sight masses smaller than those above named.

2. The increasing discontinuity of the osar systems, the gaps between the successive ridges, massive mounds or plains, lenticular hills, domes, cones, and mounds increasing from a few rods up to two or three miles.

3. The practical ending of the osar gravels near the north ends of the fjords (fjord line). It is not meant to assert that there are absolutely no osar mounds beneath the sea or on the land south of the discovered gravels. But if any exist they are hidden by the marine beds, and are so insignificant in size as compared to the osar gravels found a few miles farther north that for all practical purposes we may assume that they end. If the osar mounds go on decreasing as fast southward as they do

within the last few miles of their traceable courses, they certainly must entirely disappear within three to five miles of their apparent endings. We omit here the overwash gravels that were deposited in front of the ice beneath the present ocean.

It is to be noted that these gravels are in lines or systems, and often toward the north pass into continuous osars. They are regarded as having been deposited by a single glacial river, that is, all that are classed as a single system. The intervals between the separated gravel masses are not due to erosion of a once continuous body. But the problem relates to the reasons why a single glacial river deposited sediments at intervals here and there within its channel.

In placing the problem before us, we have to consider the extent of the region in question. The above-named characteristics are associated with each other along two hundred miles of coast. Every few miles throughout this district we come to places where a glacial river has left its sediments. All these gravel systems exhibit the first two of the above named characteristics, and all but four or five, the last. Three osars end at the shore but near the north end of Penobscot bay several miles north of the general fjord line. Two others, perhaps the largest systems in the state, come down to the shore and the soundings seem to support the conclusion that they extend for a short distance under the sea. Horizontally, these changes mostly take place within a belt not far from thirty miles in breadth; vertically in most cases between sea level and the two hundred feet contour. The last named, the ending of the gravels, occurs between contours hardly fifty feet apart.

It is granted that the sea in late glacial time stood along the outer coast line, a little more than two hundred feet above its present level. In the interior its elevation was more than twice this height. All the beaches along the outer coast, whose height I have measured, have nearly the same elevation. In other words, the surface of the sea in late glacial time was substantially parallel to its present surface in the direction of the coast, though at a higher level.