. Bulletin of the Geological Society of America. Geology. SUBMERGED PLAIXS OFF EASTERN COAST OF AMERICA merged plains, and is not their limit, as is popularly stated; but this ^ line shows frequent cove-like indentations or culs-de-sac. For 250 miles \ eastward of Cape Cod peninsula the sunken plains maintain their gen- eral monotonous characteristics, being submerged from 200 to 250 feet with a fringing border covered by an additional 200 feet of water; but north of this submarine peninsula is the broad valley of the gulf of Maine, traversed by channels from the direction of the Kennebec, Pen
. Bulletin of the Geological Society of America. Geology. SUBMERGED PLAIXS OFF EASTERN COAST OF AMERICA merged plains, and is not their limit, as is popularly stated; but this ^ line shows frequent cove-like indentations or culs-de-sac. For 250 miles \ eastward of Cape Cod peninsula the sunken plains maintain their gen- eral monotonous characteristics, being submerged from 200 to 250 feet with a fringing border covered by an additional 200 feet of water; but north of this submarine peninsula is the broad valley of the gulf of Maine, traversed by channels from the direction of the Kennebec, Penobscot, and Saint Croix rivers, besides that from the bay of Fundy, showing sound- ings from 720 to 1,080 feet, without reference to the coves or gulfs into which they enter. This region is one of drift deposits, which may give irregularity to the submarine topography, and probably accounts for the obstruction of 200 feet to the valley. South of Nova Scotia this conti- nental border is broken into hills and valleys, showing the remains of typical coastal plains dissected by deep valleys. Between cape Breton and Newfoundland is the Laurentian valley, which will be noticed later. Beyond are the great banks of New^foundland, extending 300 miles south- east of that island. Here is a remarkable repetition of the features of the coastal plains of the continent, largely represented by extensive flats submerged only 200 to 250 feet and forming a plateau elevated 150 to 250 feet above a lower plain. It is entirely separated from Newfoundland by a broad channel in depth corresponding to the lower plain. In both cases the soundings indicate channels from 60 to 200, and, in some cases, to 300 feet in depth, incising their surfaces. These banks appear to have had the same relationship to Newfoundland that the plains of New Jersey now have to the mountainous zones behind them. Evidence of channels similar to those of the Newfoundland banks may be found everywhere on the submerged plains, whi
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
