Roemer, the chalk assumes a new lithological type, a large portion of it consisting of hard siliceous limestone, but the organic remains leaving no doubt in regard to its age.
The subordinate members of the New York series, founded on lithological and geographical considerations, are most useful in the United States, but even there are only of local importance.
In lithological character, the Silurian strata vary greatly when we trace them through Europe and North America.
The coal-seams often wedge out or disappear; and sections, at places nearly contiguous, present marked lithological distinctions.
But although, in fact, some formations may be continuous over districts as large as half of Europe, or even more, yet most of them either terminate wholly within narrower limits, or soon change their lithological character.
Now every feature of a rock, lithological or petrological, finds its highest interest in the light which it throws upon the history of the rock, i.
Bucklandi; being everywhere characterised by the presence of the same groups of organic remains, and the same general lithological character of the beds.
Defn: From a lithological point of view; as, to consider a stratum lithologically.
Their lithological characters vary according to the type of the massive rocks of the district.
Much of the vast area involved is not yet well explored; but over it all, so far as it has been fully examined, the same lithological and stratigraphical structures reappear with the persistence of a repeating decimal.
The modern form of the theory substitutes onion-coats of fossiliferous rocks for onion-coats of mineral and lithological characters; and a brief consideration of this theory is now in order.
If the strata remained continuous and unbroken, we should merely have to ascertain the dimensions and lithological character of the strata in order to determine their water value.
The lithological character and thickness of the water-bearing deposit, and the extent of its underground range.
If the strata b were always bare, we should have to consider their outcrop as an absorbent surface, of power varying according to the lithological character and dip of the strata only.
Certainly the known Devonian exceeds in extent the known Silurian in the Central Andes but its lithological character is generally quite unlike the character of the slates here referred to the Silurian.
Since lithological and physical heterogeneity are characteristics of glacial drift, they together afford a criterion which is often of service in distinguishing glacial drift from other surface formations.
Lithological heterogeneity is one of the notable characteristics of glacial formations.
The heterogeneity of the drift arising from the diverse nature of the rocks which contributed to it is lithological heterogeneity--a term which implies the commingling of materials derived from different rock formations.
The Reuss has also stamped the lithological character of its own mountainous region upon the lower part of its hydrographical basin by covering it with its peculiar Alpine drift.
In many instances, the Permian rocks are seen to repose unconformably upon the underlying Carboniferous, from which they can in addition be readily separated by their lithological characters.
The subdivisions of d'Orbigny were based upon the fossil contents and not upon the lithological characters of the rocks.
A group of strata having the same general lithological characters throughout may be marked by a great discrepance between the fossils above and below a certain line.
Only to a limited degree is there any coincidence between lithological variations in the strata and the sequence of the zones.
Little or no reliance can be placed upon lithological resemblances or differences in comparing the sedimentary formations of different countries.
In lithological characters the two may closely resemble each other, and there may be nothing to show that the gap represented by their unconformability is of an important character.
But in all speculations of this kind we must bear in mind that the length of time represented by a given depth of strata is not to be estimated merely from their thickness or lithological character.
But the relative chronological importance of the bars or lines in the geological record can seldom be satisfactorily discussed merely on lithological grounds.
But besides this family feature they display many minor varieties of aspect according to their lithological composition.
But no such lithological reason, betokening geographical changes that would affect living creatures, can be adduced as a universally applicable explanation of the occurrence and limitation of palaeontological zones.
The lithological characters of the Cambrian rocks possess a remarkable uniformity in all quarters of the globe.
The lithological characters are impersistent, and the sandy phase encroaches sometimes more, sometimes less, upon the true Oxford Clay.
Once more, certain red conglomerates and grits on the north-west coast of Scotland, long supposed from their lithological aspect to belong to the Old Red Sandstone, are now identified with the Lower Silurians.
Thus, there are at this moment being produced in different places multitudinous strata differing from one another in lithological characters.
Murchison contends theoretically for this relation between lithological character and date.
The earlier subdivisions of the Cretaceous rocks were founded upon the uncertain ground of similarity in lithological characters, assisted by observed stratigraphical sequence.
The name furnishes an excellent illustration of the inconvenience of employing a local lithological feature in the descriptive title of a wide-ranging rock-system.
The great difference between the lithological characters of the northern and southern deposits is accompanied by an equally striking difference between their respective organic contents.
These beds were formerly classed, on purely lithological grounds, as the base of the Lingula Flags, but Messrs.
Footnote 66: In giving this description the red (Glyn) slates of North Wales are treated as belonging to the Caerfai series, though this correlation depends on lithological characters only at present.
The general change in the lithological characters of the beds of the Lower Carboniferous division when traced from south to north is shewn in the following diagram (Fig.
The crystalline schists consist of rocks of very varied lithological characters, some with gneissose, and others with schistose structure, and they vary in degree of acidity from ultrabasic rocks to those of acid composition.
They have a wider distribution over Britain than have the Permian rocks, and the lithological characters of the different subdivisions do not as a rule vary to a remarkable degree when traced laterally.
The detailed researches of the geological surveyors prove that the rocks of this system have a much greater thickness and are of more varied lithological characters than was previously supposed.
We speak of the lithological character of a stratum as distinguished from its zoological character.
A French provincial name for some tertiary strata abounding in shells in Touraine, which resemble in lithologicalcharacters the "Crag" of Norfolk and Suffolk.
Rocks having the same lithological characters exist in situ north of where the boulders and other drift are now found, though at a distance often of one or two hundred miles.
It does not differ in lithologicalcharacters from the same rock in the higher strata.
This system consists of three parts, distinguished by lithological and fossil characters.
The chalk and greensand are largely developed in England; and the same formation, with different lithological characters, is found in great force flanking the principal mountain ranges of southern Europe, and extending into Asia.
The fossiliferous rocks are divided into seven systems, which are readily distinguished by the order of superposition, lithological characters and organic remains.
If we could trace the strata through all the intermediate space, we might be certain of their being the same formation, notwithstanding the change in lithological characters.
Illustration] And yet it is important to determine what formations are of the same age, notwithstanding their displacements, difference in lithological characters, and separation by great distances and by mountains or oceans.
Thus, throughout the Earth, there are at this moment being produced an immense number of strata differing from each other inlithological characters.
To the south-west, as between Caermarthen and Pembroke, these Old Red Sandstone strata exhibit considerable lithological changes; and there is an absence of fossil fishes.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "lithological" in a variety of sentences. We hope that you will now be able to make sentences using this word.
