Laurentian sentence example
The Sea of Japan has a wide shelf only in the north, the central part forms a broad basin with depths of 1650 fathoms. The Laurentian Sea (Gulf of St Lawrence) has a narrow branching gully running between wide shelves, in which a depth of 312 fathoms is found south of Anticosti.
This is a very ancient mountain mass of crystalline rocks resembling more the Laurentian mountains of Canada than the Appalachians.
Laurentian gneiss forms the greatest mass of the exposed rocks of the country bare of ice.
Giuliano became de facto head of the government, but he did not pursue the usual vindictive policy of his house, although he resorted to the Laurentian method of amusing the citizens with splendid festivities.
Such veins often attain a thickness of several feet, and sometimes possess a columnar structure perpendicular to the enclosing walls; they are met with in the crystalline limestones and other Laurentian rocks of New York and Canada, in the gneisses of the Austrian Alps and the granulites of Ceylon.Advertisement
In a north-eastern section, practically all of New England is occupied by the older crystalline belt; the corresponding northern part of the stratified belt in the St Lawrence and Champlain-Hudson valleys on the inland side of New England is comparatively free from the ridge-making rocks which abound farther south; and here the plateau member is wanting, being replaced, as it were, by the Adirondacks, an outlier of the Laurentian highlands of Canada which immediately succeeds the deformed stratified belt west of Lake Champlain.
The Superior Oldland.An outlying upland of the Laurentian highlands of Canada projects into the United States west and south of Lake Superior.
The Adirondack Mountains .T his rugged district of northern New York may be treated as an outlier in the United States of the Laurentian highlands of Canada, from which it is separated by the St Lawrence Valley.
The strata are the deposits of an ancient sea, which in the earlier stage of geological investigation was thought to be part of the primeval ocean, while the Laurentian highlands were taken to be the first land that rose from the primeval waters.
Inasmuch, however, as the floor on which the overlapping strata rest is, like the rest of the Laurentian and Superior Oldland, a worn-down mountain region, and as the lowest member of the sedimentary series usually contains pebbles of the oldiand rocks, the better interpretation of the relation between the two is that the visible oldiand area of to-day is but a small part of the primeval continent, the remainder of which is still buried under the Palaeozoic cover; and that the visible oldiand, far from being the first part of the continent to rise from the primeval ocean, was the last part of the primeval continent to sink under the advancing Palaeozoic seas.Advertisement
This vast area, shaped like a broad-limbed V or U, with Hudson Bay in the centre, is made up chiefly of monotonous and barren Laurentian gneiss and granite; but scattered through it are important stretches of Keewatin and Huronian rocks intricately folded as synclines in the gneiss, as suggested earlier, the bases of ancient mountain ranges.
In most parts the Laurentian hills are bare roches moutonnees scoured by the glaciers of the Ice Age, but a broad band of clay land extends across northern Quebec and Ontario just north of the divide.
Georgian Bay and the northern part of Lake Huron with the whole northern margin of Lake Superior bathe the foot of the Laurentian plateau, which rises directly from these lakes; so that the older fertile lands of the country with their numerous cities and largely-developed manufactures are cut off by an elevated, rocky and mostly forest-covered tract of the Archean from the newer and far more extensive farm lands of the west.
This interior plain of the continent represents the area of the ancient sea by which it was occupied in Mesozoic times, with a more ancient margin towards the north-west against the Archean, where undisturbed limestones and other rocks of the Silurian and Devonian rest upon the downward slope of the Laurentian Shield.
Between the Palaeozoic area near Ottawa, and Georgian Bay to the north of the region just referred to, there is a southward projection of the Archaean protaxis consisting of granite and gneiss of the Laurentian, enclosing bands of crystalline limestone and schists, which are of interest as furnishing the only mines of "Old Ontario."Advertisement
While all the larger cities and most of the manufacturing and farming districts of the province belong to old Ontario, there is now in process of development a "New Ontario," stretching for hundreds of miles to the north and north-west of the region just described and covering a far larger area, chiefly made up of Laurentian and Huronian rocks of the Archaean protaxis.
It was found in the Laurentian rocks, regarded as the oldest known geological system.
Malocello's name and nationality are certainly preserved by those early Portolani or scientific charts (such as the "Dulcert" of 1339 and the "Laurentian Portolano" of 1351), in which the African islands appear, for the first time in history, in clear and recognizable form.
Thus Dulcert reads Insula de Lanzarotus and Marocelus, the Laurentian map I.
The region was once covered, with the exception of the higher summits, by the Laurentian glacier, whose erosion, while perhaps having little effect on the larger features of the country, has greatly modified it in detail, producing lakes and ponds, whose number is said to exceed 1300, and causing many falls and rapids in the streams. Among the larger lakes are the Upper and Lower Saranac, Big and Little Tupper, Schroon, Placid, Long, Raquette and Blue Mountain.Advertisement
A place called Mogador is marked in the 1351 Portulan of the Laurentian library, and the map in Hondius's Atlas minor shows the island of Mogador, I.
The hills of the north-western shore afford a variety of granites and crystalline slates of the Laurentian system, whilst Valamo island is made up of a rock which Russian geologists describe as orthoclastic hypersthenite.
Lake Superior lies in a deep rift in rocks principally of Archean and Cambrian age, of the Laurentian, Huronian and Keweenaw formations, rich in minerals that have been extensively worked.
The pope, travelling by way of Florence and discussing there the great new scheme of the Laurentian library, entertained the idea of giving the commission to Leonardo; but Michelangelo came in hot haste from Rome and succeeded in securing it for himself.
In 1427, again, with the co-operation of his father King John, he seems to have sent out the royal pilot Diogo de Sevill, followed in 1431 by Goncalo Velho Cabral, to explore the Azores, first mentioned and depicted in a Spanish treatise of 1345 (the Conosrimiento de todos los Reynos) and in an Italian map of 1351 (the Laurentian Portolano, also the first cartographical work to give us the Madeiras with modern names), but probably almost unvisited from that time to the advent of Sevill.Advertisement