How to use Lacustrine in a sentence
Lacustrine and fluviatile deposits occur intermingled with the above.
The Lacustrine period has not yet reached its close in Russia.
In the great lacustrine depression of Nicaragua is collected all the drainage from the eastern versant of the volcanic mountains, from the sheer western escarpment of the main cordillera, and from a large area of northern Costa Rica.
The deposits of the Post-Glacial period are represented throughout Russia, Poland and Finland, as also throughout Siberia and Central Asia, by very thick lacustrine deposits, which show that, after the melting of the ice-sheet, the country was covered with immense lakes, connected by broad channels (the fjarden of the Swedes), which later on gave rise to the actual rivers.
But the great lakes which covered the country during the Lacustrine period have disappeared, leaving behind them immense marshes like those of the Pripet and in the N.E.Advertisement
Taking their origin from a series of lacustrine basins scattered over the plateaus and differing slightly in elevation, the Russian rivers describe immense curves before reaching the sea, and flow with a very gentle gradient, while numerous large tributaries collect their waters from over vast areas.
Those of the later Lacustrine period, on the contrary, are so numerous that there is scarcely one lacustrine basin in the regions of the Oka, the Kama, the Dnieper, not to speak of the lake-region itself, and even the White Sea coasts, where remains of Neolithic man have not been discovered.
C. Fremont and Howard Stansbury (1806-1863) furnished a general knowledge of the hydrographic features and geological lacustrine history of the Great Basin, and this knowledge was rounded out by the field work of the U.S. Geological Survey from 1879 to 1883, under the direction of Grove Karl Gilbert.
There are considerable spaces where the strike, or axis, of the main ranges is transverse to the water-parting, which is then represented by intermediate highlands forming lacustrine regions with an indefinite watershed.
Remains of spiders from the Baltic amber beds of Oligocene age and from nearly coeval fluviatile or lacustrine deposits of North America belong to forms identical with or closely related to existing genera, thus proving the great antiquity of our present spider fauna.Advertisement
Between these systems run the main rivers; and these naturally rise near the medial ridge, in the lacustrine district of el-Buka`a, or Coelesyria, and flow in opposite directions.
There are wide areas on the plains of West Siberia and on the high plateau of East Siberia, which, virtually, are still passing through the Lacustrine period; but the total area now under water bears but a trifling proportion to the vast surface .which the lakes covered even at a very recent period, when Neolithic man inhabited Siberia.
Finally, the laws of distribution of animals over Siberia cannot be made out until the changes undergone by its surface during the Glacial and Lacustrine periods are well established and the Post-Tertiary fauna is better known The remarkable finds of Quaternary mammals about Omsk and their importance for the history of the Equidae are merely a slight indication of what may be expected in this field.
The shores of all the lakes which filled the depressions during the Lacustrine period abound in remains dating from the Neolithic Stone period; and numberless kurgans (tumuli), furnaces and so on bear witness to a much denser population than the present.
E.S.E., and separated by high intermont valleys, which are choked with disintegrated material and divided into a chequered pattern of self-contained, shallow lacustrine basins.Advertisement
The Eocene beds are nummulitic. There is a lacustrine group which has usually been placed in the Lower Eocene, but the discovery of Anthracotherium magnum in the interbedded lignites proves it to be Oligocene, in part at least.
The Oligocene period consists of a marine phase confined to the littoral zone of Kabylia, and of a continental phase occupying vast areas composed of lacustrine, alluvial, gypsiferous marls, sandstones and conglomerates.
To the Pliocene period the marine deposits of the Sahel of Algiers and of the Sahel Jijelli must be attributed; also the lacustrine marls and limestone of the basin of Constantine, and the ancient alluviums of the basins and depressions which bear no relation to the existing valleys.
Since fossils afford an immediate and generally a decisive clue to the mode of deposition of rocks, whether marine, lacustrine, fluviatile, flood plain or aeolian, they lead us naturally into palaeophysiography.
Instances of marine and lacustrine analysis have been cited above.Advertisement
They may be divided into two classes; those of the plateau region which occupy lacustrine depressions and receive the drainage of the surrounding country; and the tide-water lagoons of the coast formed by the building up of new sand beaches across the indentations in the coast-line.
Another group of lakes is to be found in the Laguna district of south-western Coahuila, where the Tlahualila, Mairan, Parras and others occupy a large lacustrine depression and receive the waters of the Nazas and Aguanaval rivers from the south-west (Durango).
The great Mapimi desert of western Coahuila is another lacustrine depression, but only marshy lagoons remain.
They occur, however, along the coasts, where they are marine, and also on the central plateau, where they are of lacustrine origin.
The lacustrine system of the St Lawrence flows eastward from a relatively narrow drainage area.Advertisement
It contains land shells, and hence cannot be attributed to marine or lacustrine submergence.
A wonderful series of these forms occurs in southern Utah, where in passing northward from the Carboniferous platform one ascends in succession the Vermilion Cliffs (Triassic sandstones), the ViThite Cliffs (Jurassic sandstones, of remarkably cross-bedded structure, interpreted the dunes of an ancient desert), and finally the Pink Cliffs (Eocene strata of fluviatile and lacustrine origin) of the high, forested plateaus.
The duration of the Pleistocene lakes was, however, brief as compared with the time since the dislocation of the faulted blocks, as is shown by the small dimensions of the lacustrine beaches compared to the great volume of the ravine-heading fans on which the beaches often lie.
In the west the Quaternary deposits are not, in all cases, sharply separated from the late Tertiary, but the deposits of glacial drift, referable to two or more glacial epochs, are readily differentiated from the Tertiary; so, also, are certain lacustrine deposits, such as those of the extinct lakes Bonneville and Lahontan.
Germany and the Miocene of the Danube valley is also in part marine, but in central Germany it is of fluviatile or lacustrine origin.
Extensive areas in the interior, more especially towards Lake Chad, are covered with black earth of alluvial or lacustrine origin.
Its northern part is actually insular, divided from the mainland by the Limfjord or Liimfjord, which communicates with the North Sea to the west and the Cattegat to the east, but this strait, though broad and possessing lacustrine characteristics to the west, has only very narrow entrances.
The quantitative estimate of the amount of this flora has revealed its enormous aggregate amount and therefore its great importance in the economy of oceanic and lacustrine animal life.
The existence of ancient lacustrine beaches, upheaved between the two basins by volcanic agencies or left dry by some enlargement of the San Juan outfall, and a consequent subsidence of the water-level, seems to indicate that the lakes were formerly united.
The various schemes which have been put forward for the conversion of the San Juan and the lacustrine depression into an interoceanic waterway are fully discussed under Panama Canal.
Nicaragua comes within the zone of the wet northeast trade-winds, which sweep inland from the Atlantic. The rainfall is heavy along the west side of the lacustrine basin, with an annual mean at Rivas of 102 in., but this figure is sometimes greatly exceeded on the east coast, where rain is common even in the dry season.
The most densely peopled region and the focus of civilization is the lacustrine depression and the surrounding uplands.
Among the few remains of lacustrine settlements in England and Wales, some are suggestive of the typical crannog structure.
The former of these, representing the bottommoraine of the ice-sheet, are covered with Glacial and post-Glacial clays (partly of lacustrine and partly of marine origin) only in the peripheral coast-region - or in separate areas in the interior depressions.
Then the stream turns south-east and descends into another lacustrine depression, where it receives the Kama, below Kazan.
The great lacustrine depression of the middle Volga was thus reached; and when the Mongol invasion of 1239-42 came, it encountered in the Oka basin a dense agricultural population with many fortified and wealthy towns - a population which the Mongols found they could conquer, indeed, but were unable to drive before them as they had done so many of the Turkish tribes.
Below the Bio-Bio river there is a line of large picturesque lakes extending from the province of Cautin, south through that of Llanquihue, corresponding in character and position to the dry lacustrine depressions extending northward in the same valley.
It is a great lacustrine basin where once existed an inland sea having an outlet to the east through the La Paz gorge.
This is one of the most elevated lacustrine basins in the world, and though it once drained eastward, now has no surface outlet.
Below the town the river divides into several branches, among islands and sandbanks, receiving before it enters the sea the Bolderaa river, and expanding towards the east into wider lacustrine basins.
Coal, iron, sulphur, gypsum, rock-salt, lacustrine salt and naphtha are all known to exist, but only the last two are extracted.
This remarkable phenomenon is explained by the position of Aussa in the centre of a saline lacustrine depression several hundred feet below sea-level.
Another lacustrine region extends from the Shoa heights south-west to the Samburu (Lake Rudolf) depression.
On the Roseninsel, an island in the lake, remains of lacustrine dwellings have been discovered.
In connexion with the objection based upon the sub-boreal character of the regions which were the cradle of the Aryans, as proved by the so-called palaeontology of the Aryan languages, it may be observed that by the end of the Glacial, and during the earlier Lacustrine (Post-Glacial) period, the vegetation of Turkestan and of Central Asia was quite different from what it is now.
The western part of the province is drained by the Bermejo, which flows southward into the closed lacustrine basin of Mendoza.
The Bad Lands and the Arikaree are famous fossil fields, the latter being the source of the Daemonelix, or " Devil's cork-screw," a large spiral fossil, apparently a lacustrine alga.
Lower Cainozoic lacustrine beds with fossil plants, of the same age as those which underlie the older basalts of Victoria, occur in the valleys of northern Tasmania.
The accurate correlation in time of the various scattered plantbearing deposits is a matter of considerable difficulty, for plantremains are preserved principally in lacustrine strata laid down in separate basins of small extent.
In the central parts of North America the lacustrine plant-bearing deposits are of enormous thickness, the Dakota series being followed by marine Cretaceous strata known as the Colorado and Montana groups, and these being succeeded conformably by a thousand feet or more of lacustrine shales, sandstones and coal-seams, belonging to the Laramie series.
Leaving these Scottish and Irish deposits of doubtful age, we find in the Hampshire Basin a thick series of fluviatile, lacustrine and marine deposits undoubtedly of Lower and Middle Oligocene date.
The Miocene lacustrine deposits are contained in a number of silted-up lakebasins, which were successively formed and obliterated during the uprise of the Alps and the continuous folding and bending of the earth's crust which was so striking a feature of the period.
We thus find preserved in the Upper Miocene lacustrine deposits of Switzerland a larger flora than is known from any other period of similar length; in fact, an analysis of its composition suggests that the Miocene flora of Switzerland must have been both larger and more varied than that now living in the same country.
In Well 14/24-1 in the southern part of the Eastern Depocentre, the lacustrine claystones are largely tuffaceous.
Unmistakable traces show that, while during the Glacial period Russia had an arctic flora and fauna, the climate of the Lacustrine period was more genial than it is now, and a dense human population at that time peopled the shores of the numberless lakes.
This immense lacustrine basin is now broken up into numberless ponds, lakes and marshes (see MiNsx).
It is covered with a thick sheet of black earth, a kind of loess, mixed with 5 to 15% of humus, due to the decomposition of an herbaceous vegetation, which developed luxuriantly during the Lacustrine period on a continent relatively dry even at that epoch.
The rest is carried off, almost due north by the Khor Baraka, which occasionally reaches the Red Sea south of Suakin; by the Hawash, which runs out in the saline lacustrine district near the head of Tajura Bay; by the Webi Shebeli (WabiShebeyli) and Juba, which flow S.E.
But the most peculiar lacustrine feature of the presidency is the Runn or Lake of Cutch, which, according to the season of the year, is a salt marsh, an inland lake, or an arm of the sea with an area of 8000 sq.
The Cretaceous sea gradually receded and the plains of the Rolling Downs formation formed on its floor were covered by the sub-aerial and lacustrine deposits of the Desert Sandstone.
The city stands on a small plain occupying the south-western part of a large lacustrine depression known as the Valley of Mexico (El Valle de Mexico), about 3 m.
At its confluence with the Oka the Volga enters the broad lacustrine depression which must have communicated with the Caspian during the post-Pliocene period by means of at least a broad strait.
The great lacustrine basin between the Beni and the Mamore contains several lakes and lagoons, two of them of large size.