Tertiary Sentence Examples

The Tertiary deposits cover the whole of the central depression, where they are associated with extensive flows of lava and beds of volcanic ash.

The tertiary glycols are known as pinacones and are formed on the reduction of ketones with sodium amalgam.

Gruidae, cranes, cosmopolitan, allied Phororhacos, Tertiary of Argentina.

The Vicksburg formation lies next in order south-west, in a narrow strip of fairly regular width which alone of the Tertiary formations runs as far west as the Mississippi River; it is probably nowhere more than 110 ft.

Although in late Tertiary times widely spread over southern Europe and India, giraffes are now confined to Africa south of the Sahara.

The later beds of the island belong to the Jurassic, Cretaceous and Tertiary systems. At the western foot of the Ida massif calcareous beds with corals, brachiopods (Rhvnchonella inconstans, &c.) have been found, the fossils indicating the horizon of the Kimmeridge clay.

The celebrated iron ore of Elba is of Tertiary age and occurs indifferently in all the older rocks.

Here may be interpolated a short account of the very peculiar avifauna found in the Tertiary strata of Santa Cruz in Patagonia.

Seven formations (or groups) of the Tertiary strata have been distinguished in Mississippi.

In the eastern region this was the last folding which has affected the country, and the Mesozoic and Tertiary beds are almost undisturbed.

Tertiary beds cover a considerable area, especially in the Amazonian depression.

There is considerable difference of opinion as to the chronology of the succeeding beds, and the boundary between the Cretaceous and Tertiary systems is drawn at various horizons by different observers.

It belongs either to the Upper Cretaceous or to the Lower Tertiary, or possibly in part to the one and in part to the other.'

The older formation of the Quaternary period is the Lafayette (also called "Orange-sand" or "stratified drift"), which immediately overlies all the Cretaceous groups except the prairies of the Selma chalk, and all the Tertiary except the Porters Creek and Vicksburg formations and parts of the Jackson.

Well-worn pebbles of amorphous quartz (agate, chalcedony, jasper, &c.) are found in the stratified drift along the western side of the Tertiary region of the state, and from Columbus northward.

E Arabian Sea Ba Of G A L e Geological information incomplete Desert Deposits Quaternary Tertiary Mesozoic Palaeozoic Archaean and Metamorphic Younger Volcanic Rocks English Miles b iuHi iiiiuiiiiii after llargl,aua Geology The geology of Asia is so complex and over wide areas so little known that it is difficult to give a connected account of either the structure or the development of the continent, and only the broader features can be dealt with here.

In the south, in Syria, Arabia and the peninsula of India, none but the oldest rocks are folded, and the Upper Palaeozoic, the Mesozoic and the Tertiary beds lie almost horizontally upon them.

North of this lies a broad belt in which the Mesozoic deposits and even the lower divisions of the Tertiary system are thrown into folds which extend in a series of arcs from west to east and now form the principal mountain ranges of central Asia.

North of the folded belt, and including Emery the greater part of Siberia, Mongolia and northern China, lies another area which is, in general, free from any important folding of Mesozoic or Tertiary age.

Here again there are no marine beds of Mesozoic or Tertiary age, while plant-bearing deposits belonging to the Angara series are known.

Southern China is very different in structure, consisting largely of folded mountain chains, but the geological succession is very similar, and excepting near the Tibetan and Burmese borders, there are no marine deposits of Mesozoic or Tertiary age.

Between India and China there is a broad belt in which marine deposits of Mesozoic and Tertiary age are well developed.

Marine Tertiary beds occur in Burma; in the Himalayas and in south Tibet there is a nearly complete series of marine deposits from the Carboniferous to the Eocene; in Afghanistan the Mesozoic beds are in part marine and in part fluviatile.

Gondwanaland, however, did not long survive, and the portion which lay between India and South Africa sank beneath the waves in Tertiary times.

In the northern unfolded region great flows of basic lava lie directly upon the Cambrian and Ordovician beds of Siberia, but are certainly in part of Tertiary age.

These highlands exhibit very considerable evidences of volcanic activity both in remote geological periods and also since the Tertiary epoch.

Genus includes several hundred extinct species ranging from the Silurian to the Tertiary.

In Tertiary times the higher Diptera, besides Lepidoptera and Hymenoptera, referable to existing families, become fairly abundant.

This latter order, which is not certainly known to have existed before Tertiary times, has become the most highly specialized of all insects in the structure of the pupa.

Volcanic activity took place around its shores at the end of the Tertiary or during the Quaternary Age, and great streams of lava cover the Sayan and Khamar-daban mountains, as well as the valley of Irkut.

The fauna, explored by Dybowski and Godlewski, and in 1900-2 by Korotnev, is much richer than it was supposed to be, and has quite an original character; but hypotheses as to a direct communication having existed between Lake Baikal and the Arctic Ocean during the Post-Tertiary or Tertiary ages are not proved.

It should be pointed out that the deposits which have been hitherto of chief commercial importance occur in the old rocks (Carboniferous to Silurian) on the one hand, and in the comparatively new Tertiary formations on the other, the intermediate periods yielding but little or at any rate far less abundantly.

The faulting which formed the depressions is certainly later than the deposition of the Cretaceous beds and probably belongs to the later portion of the Tertiary era.

Teeth and jaws probably referable to the Condylarthra have been obtained in European early Tertiary formations.

Polymethylenes can give only secondary and tertiary alcohols, benzene only tertiary; these latter compounds are known as phenols.

The phenols more closely resemble the tertiary alcohols, since the hydroxyl group is linked to.

Mixed aromatic-aliphatic amines, both secondary and tertiary, are also more strongly basic than the pure aromatic amines, and less basic than the true aliphatic compounds; e.g.

The combination of nitrogen with carbon may result in the formation of nitriles, cyanides, or primary, secondary or tertiary amines.

It is of Tertiary formation (Miocene), and has a chain of volcanic elevations along the axis, reaching a height of 2600 ft.

Mogilev is built up of Devonian deposits in the north, of Cretaceous in the east, and of Tertiary elsewhere, but generally is covered with a thick layer of Glacial and later alluvial deposits.

The group is represented by the families Palaeosyopidae and Titanotheriidae in the Tertiary deposits of North America.

In the Tertiary region are found small quantities of iron ore and an indifferent brown coal.

At Esperanza and other places in the Santa Clara province, bituminous plant-bearing beds occur beneath the Tertiary limestones, and at Baracoa a Radiolarian earth occupies a similar position.

It is the Tertiary limestones which form the predominant feature in the geology of Cuba.

It thus appears that since early Tertiary times there has been a great change in the climate of Greenland.

Nathorst has suggested that the whole of Greenland is a "horst," in the subordinate folds of which, as well as in the deeper " graben," the younger rocks are preserved, often with a covering of Tertiary or later lava flows.'

The sides of the triangle slope down abruptly towards the west, more gradually towards the east; at the base stands the cone of Ayala Hill, the last outpost of the Rudnik Mountains, which extend far away to the south; and, at the apex, a cliff of Tertiary chalk, 200 ft.

Concealed in part by later deposits, this ancient mountain chain extends from Castelnaudary to the neighbourhood of Valence, where it sinks suddenly beneath the Tertiary and recent deposits of the valley of the Rhone.

The Secondary and Tertiary beds of the Languedoc were crushed against the central plateau and were frequently overfolded.

The occurrence of such a series of Tertiary deposits appears to be unknown elsewhere.

In the province of Sergipe, on the east coast, the beds are approximately on the horizon of the Cenomanian; in the valley of the Amazon they belong to the highest parts of the Cretaceous system, and the fauna shows Tertiary affinities.

West of this line the rocks are chiefly Tertiary and Quaternary; east of it they are mostly Palaeozoic or gneissic. In the western mountain ranges the beds are thrown into a series of folds which form a gentle curve running from south to north with its convexity facing westward.

Coal is found in the Tertiary deposits in the valley of the Irrawaddy and in Tenasserim.

The famous ruby mines of Upper Burma are in metamorphic rock, while the jadeite of the Bhamo neighbourhood is associated with the Tertiary intrusions of serpentine-like rock already noticed.'

Even the Scotland series probably belongs to the Tertiary system, but owing to the want of characteristic fossils, it is impossible to determine with any degree of certainty the precise homotaxis of the several formations.

Generally, however, the Cretaceous beds do not appear, and the greater part of southern Arabia seems to be formed of Alveolina and nummulite limestones of Tertiary age.

The replacement of one hydrogen atom by one alkyl or aryl group gives rise to primary amines; of two hydrogen atoms by two groups, to secondary amines; of three hydrogen atoms by three groups, to tertiary amines.

The tertiary amines possess the power of combining with one molecular proportion of an alkyl iodide to form quaternary ammonium salts.

They are ionized in aqueous solution to a much greater extent than ammonia, the quaternary ammonium bases being the most ionized, and the secondary bases being more strongly ionized than the primary or tertiary bases.

By the action of ammonia on the alkyl iodides a complex mixture of primary, secondary and tertiary amines, along with a quaternary ammonium salt, is obtained, the separation of which is difficult.

The tertiary amine is then distilled off, the residual products separated by filtration and finally hydrolysed by a caustic alkali.

The primary, secondary and tertiary amines may be readily distinguished by their behaviour with various reagents.

The secondary and tertiary amines do not give this reaction.

When heated with alkyl or aryl iodides, they are converted into secondary and tertiary amines.

The tertiary amines may also be of two types, the purely aromatic and the mixed type.

The mixed tertiary amines are produced by the action of alkyl halides on the primary amines.

The simplest aromatic tertiary amine, triphenylamine, is prepared by the action of brombenzene on sodium diphenylamine (C. Heydrich, Ber., 1885, 18, p. 2156).

Geology.'--The Eastern Cordillera., which, however, is but little known, appears to consist, as in Bolivia, chiefly of Palaeozoic rocks; the western ranges of the Andes are formed of Mesozoic beds, together with recent volcanic lavas and ashes; and the lower hills near the coast are composed of granite, syenite and other crystalline rocks, sometimes accompanied by limestones and sandstones, which are probably of Lower Cretaceous age, and often covered by marine Tertiary deposits.

The Cainozoic or Tertiary system forms a fringe round the coasts of many portions of the empire.

The igneous rocks occur at several geological horizons, but the great volcanic eruptions did not begin until the Tertiary period.

Ketones, secondary alcohols and tertiary alcohols yield a mixture of acids on oxidation.

Between the two zones lies a row of Klippen, while towards the Hungarian plain the inner zone is bordered by a fringe of volcanic eruptions of Tertiary age.

It is formed almost entirely of a succession of sandstones and shales of Cretaceous and Tertiary age - the so-called Carpathian Sandstone - and these are thrown into a series of isoclinal folds dipping constantly to the south.

The Maltese Islands consist largely of Tertiary Limestone, with somewhat variable beds of Crystalline Sandstone, Greensand and Marl or Blue Clay.

The formation of the existing rift-valley seems in any case to date from Tertiary times only.

Not a few cases are known in which a parasitic larva is itself pierced by the ovipositor of a " hyperparasite," and even the offspring of the latter may itself fall a victim to the attack of a " tertiary parasite."

The manganese nodules afford the most ample proof of the prodigious period of time which has elapsed since the formation of the red clay began; the sharks' teeth and whales' ear-bones which serve as nuclei belong in some cases to extinct species or even to forms derived from those familiar in the fossils from the seas of the Tertiary period.

Sir John Murray believes that no more than a few feet of red clay have accumulated in the deepest depressions since the close of the Tertiary period.

Mesozoic coals are more abundant in the southern hemisphere, while Tertiary coals seem to be tolerably uniformly distributed irrespective of latitude.

Poetsch in 1883, and originally applied to shafts passing through quicksands above brown coal seams, has been applied with advantage in opening new pits through the secondary and tertiary strata above the coal measures in the north of France and Belgium, some of the most successful examples being those at Lens, Anzin and Vicq, in the north of France basin.

This is covered to a considerable extent by rocks of recent and late Tertiary ages.

Older Tertiary rocks form the bluffs of Lindi.

The deposits near Caylus and in Quercy occupy fissures and pockets in Jurassic limestone, and have yielded a remarkable assemblage of the relics of Tertiary mammals and other fossils.

In the Great Plains region the geological structure is very simple, consisting of nearly horizontal strata of Cretaceous rock in the middle and western portions, and of Tertiary rock on the eastern border, but in the mountain region the rocks have been folded and faulted until the structure is intricate and obscure.

The higher elevations are mostly either Archean or Paleozoic formations projecting above Tertiary deposits.

Fossil remains of mammals, fish and reptiles found in the Tertiary deposits of south-western Montana are preserved in the Carnegie Museum at Pittsburg, Pennsylvania, and in the museum of the university of Montana.

A range of hills, compose3 of Tertiary deposits, and named Hedenstriim's Mountains, runs along its south-western coast, and the same rocks form a promontory protruding northwards.

Basalts and Tertiary brown coal deposits enter into the composition of the southern extremity of Bennett Island, and the mountains of Sannikov Land, seen by Toll, have the aspect of basaltic "table mountains."

Compound trusses consist of simple trusses used as primary, secondary and tertiary trusses, the secondary supported on the primary, and the tertiary on the secondary.

Early in life he published observations on the Tertiary and Post-Tertiary deposits in the Thames valley, and on fossil plants and various invertebrata, in the Magazine of Natural History, the Annals of Nat.

The principal orchard districts are the valleys of the Darent and Medway, and the tertiary soils overlying the chalk, between Rochester and Canterbury.

It appears to be composed chiefly of Palaeozoic rocks, concealed, in the plains, by Quaternary, and possibly Tertiary, deposits.

The coastal plain comprises a sandy, unproductive belt immediately on the coast, back of which is a more fertile tertiary plain, well suited, near the higher country, to the production of sugar and cotton.

There is an older series, ranging from the Devonian to the Cretaceous, which is folded and faulted and forms all the higher hills, and there is a newer series of Tertiary age, which lies nearly horizontal and rests unconformably upon the older beds.

Slates belong mostly to the older geological systems, being commonest in Pre-Cambrian, Cambrian and Silurian districts, though they may be found of Carboniferous or even of Tertiary age, where mountain-building processes have folded and compressed these more recent formations.

An interesting and orderly petrological sequence of Tertiary igneous rocks has been determined.

The rocks of Secondary and Tertiary ages have been profoundly affected by the Alpine movements, and are thrown into a series of complex folds, so that in numerous instances their stratigraphy is imperfectly understood.

Among the Tertiary volcanic rocks those of acid types (granites, granulites) were the first to appear and are developed latitudinally; rocks of intermediate type (dacites, andesites) characterize the Miocene and early Pliocene periods; while the basic rocks (ophites, elaeolite syenites and basalts) attained their maximum in later Pliocene and Quaternary times.

In Italy, where shells of the subApennine formations were discovered in the extensive quarrying for the fortifications of cities, the close similarity between these Tertiary and the modern species soon led to the established recognition of their organic origin.

His joint memoirs with Brongniart, Essai sur la geographie des environs de Paris avec une carte geognostique et des coupes de terrain (1808) and Description geologique des environs de Paris (1835) were based on the wonderful succession of Tertiary faunas in the rocks of the Paris basin.

Following Cuvier's Recherches sur les ossemens fossiles, the rich succession of Tertiary mammalian life was gradually revealed to France through the explorations and descriptions of such authors as Croizet, Jobert, de Christol, Eymar, Pomel and Lartet, during a period of rather dry, systematic work, which included, however, the broader generalizations of Henri Marie Ducrotay de Blainville (1778-1850), and culminated in the comprehensive treatises on Tertiary palaeontology of Paul Gervais (1816-1879).

These and other early monographs on the Tertiary shells of the Paris basin, of the environs of Bordeaux, and of the sub-Apennine formations of Italy, brought out the striking distinctness of these faunas from each other and from other molluscan faunas.

Recognition of this threefold character led Deshayes to establish a threefold division of the Tertiary based on the percentage of molluscs belonging to types now living found in each.

These latter discoveries supply us with the ancestry of the elephants and many other forms. They round out our knowledge of Tertiary history, but leave the problems of the Cretaceous mammals and of their relations to Tertiary mammals still unsolved.

The analysis of continental faunas into those inhabiting rivers, lowlands, forests, plains or uplands, affords a key to physiographic conditions all through the Tertiary.

Among extinct Tertiary mammals we can actually trace the giving off of these radii in all directions, for taking advantage of every possibility to secure food, to escape enemies and to reproduce kind; further, among such well-known quadrupeds as the horses, rhinoceroses and titanotheres, the modifications involved in these radiations can be clearly traced.

Successive discoveries have revealed certain grand centres, such as (1) the marsupial radiation of Australia, (2) the littleknown Cretaceous radiation of placental mammals in the northern hemisphere, which was probably connected in part with the peopling of South America, (3) the Tertiary placental radiation in the northern hemisphere, partly connected with Africa, (4) the main Tertiary radiation in South America.

This principle has been demonstrated recently among Tertiary rhinoceroses and titanotheres, in which remains of four or five genetic series in the same geologic deposits have been discovered.

The brachiopods, generally classed collectively as Spirifer mucronatus, follow at least five distinct lines of evolution in the Middle Devonian of North America, while more than twenty divergent lines have been observed by Grabau among the species of the gastropod genus Fusus in Tertiary and recent times.

The geological formation is principally of volcanic rocks, with schists and tertiary limestone; and an early physical connexion of the islands with New Zealand is indicated by their geology and biology.

The sedimentary deposits of the Tertiary era do not occupy a very wide area.

But by far the most important of the Tertiary rocks are the volcanic lavas, agglomerates and ashes, which cover so much of the country.

These deposits are held by Passarge to indicate Tertiary desert conditions, to which the basin of the Zambezi is slowly reverting.

They occur in the Lower Chalk formations, and in Tertiary times were widely diffused; the genus is represented in the Eocene flora of Great Britain, and in the succeeding Miocene period was widely distributed in Europe and western Asia.

In the form of certain salts iodine is very widely used, for internal administration in medicine and in the treatment of many conditions usually classed as surgical, such as the bone manifestations of tertiary syphilis.

In its tertiary stages - and also earlier - this disease yields in the most rapid and unmistakable fashion to iodides; so much so that the administration of these salts is at present the best means of determining whether, for instance, a cranial tumour be syphilitic or not.

It is a tertiary base, and has also the properties of an acid and an alcohol.

These were followed by a period of minor tilting and faulting in early Mesozoic, by a moderate upwarping in Tertiary, and by a moderate uplift in post-Tertiary time.

Evi-Jently, therefore, the Appalachians as we now see them are not the still surviving remnants of the mountains of late Palaeozoic deformation; they owe their present height chiefly to the Tertiary upwaroing and uoliftinr.

The crystalline belt of the middle Appalachians, 60 or 80 m- wide, is to-day of moderate height because the Tertiary upwarping was there of moderate amotint.

The height is greatest along the inner or north-western border of the belt, and here a sub-mountainous topography has been produced by normal dissection, chiefly in the Tertiary cycle; the valleys being narrow because the rocks are resistant.

The south-east course of the middle-section rivers is the result of many changes from the initial drainage; the Mesozoic and Tertiary upwarprngs were probably very influential in determining the present general courses.

The coastal plain, however, is the result, not of a single recent uplift, but of movements dating back to Tertiary time and continued with many oscillations to the present; nor is its surface smooth and unbroken, for erosion began upon the inner part of the plain long before the outer border was revealed.

The strata here are Cretaceous or early Tertiary, lying nearly horizontal.

The Plateau province, next west of the southern Rocky Mountains, is characterized for the most part by large-textured forms, developed on a great thickness of nearly horizontal Palaeozoic, The Plateau Mesozoic and Tertiary formations, and by a dry climate.

The Sierra Nevada may be described, in a very general way, as a great mountain block, largely composed of granite and deformed metamorphosed rocks, reduced to moderate relief in an earlier (Cretaceous and Tertiary?) cycle of erosion, sub-recently elevated with a slant to the west, and in this position sub-maturely dissected.

Tertiary Systems.The formations of the sevefl Tertiary peripds have many points of similarity, but in some respects they are sharply differentiated one from another.

Terrestrial sedimentation was, indeed, a great feature of the Tertiary.

The marine Tertiary formations are confined to the borders of the continent, appearing along the Atlantic, Gulf and Pacific coasts.

The present height of the deposits, in some places as much as 10,000 ftgives some suggestion of the changes in topography which have taken place since the early Tertiary.

Deformative movements of the minor sort seem to have been in progress somewhat generally during the Tertiary periods, especially in the western part of the country, but those at the close of the Pliocene seem to have exceeded greatly those of the earlier stages.

This epoch of great deformation and warping marks the transition from the Tertiary to the Quaternary.

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.

Igneous rocks, whether lava flows or pyroclastic ejections, are less important in the Quaternary than in the Tertiary, though volcanic activity is known to have continued into the Quaternary.

Geologically the anthracite and bituminous coals mainly belong to the same formation, the Carboniferous, and this is especially true of the better qualities; though it is stated by the United States Geological Survey that the geQlogic age of the coal beds ranges from Carboniferous in the Appalachian and Mississippi Valley provinces to Miocene (Tertiary) on the Pacific coast, and that the quality of the coal varies only to a very uncertain degree with the geologic age.

The lode was an ore channel of great dimensions included within volcanic rocks of Tertiary age, themselves broken through pre-existing strata of Triassic age, and exhibited some of the features of a fissure vein, combined in part with those of a contact deposit and in part with those of a segregated vein.

Most of the plains are underlain by Cretaceous and early Tertiary shales and sandstones lying nearly unaltered and undisturbed where they were deposited, although now raised far above sea-level, particularly along the border of the Rocky Mountains where they were thrust up into foot-hills when the range itself was raised.

The most important of the former is the gumm y of tertiary syphilis; this may steadily and completely disappear under the influence of iodide of potassium.

In 1849 he became curator of the Natural History Museum at Wiesbaden, and began to study the Tertiary strata of the Mayence Basin, and also the Devonian fossils of the Rhenish provinces, on which he published elaborate memoirs.

Extinct species of capybara occur in the tertiary deposits of Argentina, some of which were considerably larger than the living form.

The grounds for referring the African jumpinghares (Pedetidae) to the Anomaluroidea rest largely on the evidence of certain Tertiary rodents from Europe, such as Issiodoromys.

It may be mentioned, however, that the distribution of these later Tertiary types accords very closely with that of their existing relatives; the families of South American hystricoids being represented by a number of extinct genera in the formations of Argentina and Brazil.

A number of secondary standards separated by about 50 A, and tertiary standards at intervals of from 5 to 10 A have also been determined.

Tschelinzeff (Ber., 1904, 37, p. 4534) showed that the ether may be replaced by benzene containing a small quantity of ether or anisole, or a few drops of a tertiary amine.

The islands of these outer arcs consist chiefly of crystalline schists and limestones, overlaid by Jurassic, Cretaceous and Tertiary deposits.

Eruptive rocks of supposed Cretaceous age are met with in these outer islands, but Tertiary and recent volcanic lavas are confined to the innermost arc. Halmahera lies outside these arcs.

It has an alkaline reaction, and is a tertiary monacid base.

The Tertiary deposits form a fringe around the older rocks, and in some places this fringe extends far up into the interior of the island.

In a tertiary sense the word appears to have been occasionally employed as equivalent to the Latin miles - usually translated by thegn - which in the earlier middle ages was used as the designation of the domestic as well as of the martial officers or retainers of sovereigns and princes or great personages.

Subsequently, in the Tertiary period, there were two enormous outpourings of volcanic material - first andesitic lava, and later, after a long interval of quiet, rhyolitic - which nearly half filled the basin, converted it into a plateau and broke up the mountain rim.

The Eastern Alps consist of a central mass of crystalline and schistose rocks flanked on each side by a zone of Mesozoic beds and on the north by an outer band of Tertiary deposits.

The Tertiary zone of the northern border is of especial significance and is remarkable for its extent and uniformity.

Upon the outer side of the arc the central zone of crystalline rocks is flanked by Mesozoic and Tertiary belts; towards the west, indeed, the individuality of these belts is lost, to a large extent, but the rocks remain.

Upon the inner side the Tertiary band is found only in the eastern part of the chain, while towards the west, first the Tertiary and then the Mesozoic band disappears against the modern deposits of the low land.

The most conspicuous folding, that of the Mesozoic and Tertiary belts, must have occurred in Tertiary times, and it was not completed till the Miocene period.

Tertiary deposits are very widely spread over the plains and low-lying country.

The present volcanoes lie along a line (with offshoots) which runs parallel to the west coast, but some distance to the east of the fissures from which the early Tertiary lavas were poured.

With the Grignard reagent, they form addition compounds which on the addition of water yield tertiary alcohols, except in the case of ethyl formate, where a secondary alcohol is obtained.

It was found that the normal primary alcohols were all esterified at about the same rate, the secondary alcohols more slowly than the primary, and the tertiary alcohols still more slowly.

Westward the chain lies buried beneath the Mesozoic and Tertiary beds of Belgium and the north of France, but it reappears in the west of England and Ireland.

Upon its northern margin lie the nearly undisturbed Cretaceous and Tertiary beds which cover the greater part of Belgium.

The Ordovician and Silurian are absent here, and the Devonian rests unconformably upon the Cambrian; but along the northern margin of the Palaeozoic area, Ordovician and Silurian rocks appear, and beds of similar age are also exposed farther north where the rivers have cut through the overlying Tertiary deposits.

Except along the southern border of the Ardennes, and at one or two points in the middle of the Palaeozoic massif, Triassic and Jurassic beds are unknown in Belgium, and the Palaeozoic rocks are directly and unconformably overlaid by Cretaceous and Tertiary deposits.

Exclusive of the Ardennes the greater part of Belgium is covered by Tertiary deposits.

The Tertiary deposits are similar in general character to those of the north of France and the south of England.

St Kilda is probably the core of a Tertiary volcano, but, besides volcanic rocks, contains hills of sandstone in which the stratification is distinct.

The primary veins give off secondary veins, and these in their turn give off tertiary veins, and so on until a complete network of vessels is produced, and those veins usually project on the under surface of the leaf.

During the early Tertiary age it belonged to the Sarmatian Ocean, which reached from the middle Danube eastwards through Rumania, South Russia, and along both flanks of the Caucasus to the Aralo-Caspian region, and westwards had open communication with the great ocean, as indeed the ancient geographers Eratosthenes, Strabo and Pliny believed it still had in their day.

Geology.Germany consists of a floor of folded Palaeozoic rocks upon which rest unconformably the comparatively little disturbed beds of the Mesozoic system, while in the North German plain a covering of modern deposits conceals the whole of the older strata from view, excepting some scattered and isolated outcrops of Cretaceous and Tertiary beds.

The precise age of the volcanoes of the Eifel, many of which are in a very perfect state of preservation, is not clear, but they are certainly Tertiary or Post-tertiary.

The mountain range that runs out towards the north-east of Sicily is composed of crystalline rocks precisely similar to those forming the parallel range of Aspromonte in Calabria, but both of these are girt about by sedimentary strata belonging in part to an early Tertiary epoch.

The Monti Peloritani at the north-eastern extremity of the island consists of gneiss and crystalline schists; but with this exception the whole of Sicily is formed of Mesozoic and later deposits, the Tertiary beds covering by far the greater part.

Basalt and tuff, probably of Tertiary age, form the great mass of the Cameroon mountain, also the island of Fernando Po.

Limestones, with fossils indicating a Tertiary age, have been found near Sokoto.

In the Tertiary epoch alligators, crocodiles and long-snouted gavials existed in Europe.

In many instances the Tertiary formation, which occurs betweeii Esna and Cairo, unconformably overlies the Cretaceous, the Lower Eocene being absent.

The fluvio-marine deposits of the Upper Eocene and Oligocene formations contain an interesting mammalian fauna, proving that the African continent formed a centre of radiation for the mammalia in early Tertiary times.

Miocene strata are absent in the southern Tertiary areas, but are present at Moghara and in the north.

The islands are volcanic, the main geological formation being Tertiary or Jurassic basalt, which occasionally protrudes through the ice-cap in high isolated blocks near the shore.

Important deposits of salt are developed in many parts of the Tertiary strata.

At Cardona, near Barcelona, Tertiary salt forms hill-masses, while the Carpathian sandstone in Galicia and Transylvania is rich in salt.

Deposits of salt, regarded as either Cretaceous or Tertiary, occur in the island of Petite Anse, west of Vermilion Bay, in Louisiana.

The fish of Lake Aral belong to fresh-water species, and in some of its rapid tributaries the interesting Scaphirhynchus, which represents a survival from the Tertiary epoch, is found.

The geologic record is, as perhaps is to be expected, exceedingly poor, except as regards the calcareous Siphonales, which are well represented at various horizons, from the Silurian to the Tertiary; even the Diatomaceae, which are found in great quantities in the Tertiary deposits, do not occur at all earlier than the chalk.

It is believed, however, that the Devonian fossil, Nematophycus, is a Laminarian alga, but it is not until the late Secondary and the Tertiary formations that fossil remains of algae become frequent.

There is a central region, roughly triangular in shape, with its base resting upon the Quaternary K Triassic Tertiary Carboniferous q & Metamorphic 7 Jurassic Aegean Sea and its apex in Servia.

Finally, beyond the Balkans lies the great Rumanian depression, occupied chiefly by undisturbed Cretaceous and Tertiary strata.

The core is formed by the mountain masses of Rhodope, Belasitza, Perin and Rila; and here Palaeozoic and Mesozoic beds are absent, and the earliest sedimentary deposits belong to the Tertiary period and lie flat upon the crystalline rocks.

Extensive volcanic outbursts occurred in this region during the Tertiary period.

In the Giraffidae, which include not only giraffes (Giraffa) but also the okapi (Ocapia) and a number of extinct species from the Lower Pliocene Tertiary deposits of southern Europe, Asia and North Africa, the appendages on the skull are of type No.

Crystalline rocks crop out at several capes; Cretaceous limestones, containing an abundant and specific fauna of gigantic ammonites, occur at Dui on the west coast, and Tertiary conglomerates, sandstones, marls and clays, folded by subsequent upheavals, in many parts of the island.

Though dating back only to older Tertiary time, this plain has been so deeply trenched by the forces of denudation that it has been reduced to mere scattered fragments.

Archean gneiss, Cambrian sandstone, Silurian quartzite, limestone and schist, Jurassic sandstone and limestone, Cretaceous sandstone, and Tertiary basalts, gabbros, and granitic rocks all enter into the composition of the islands.

Over much of this region they owe their preservation largely to the mass of lavas poured over them in Tertiary time.

The presence of these fossils indicates that the eruptions were subaerial, and a comparison of them with those elsewhere found among Older Tertiary strata shows that they probably belong to the Oligocene stage of the Tertiary series of formations, and therefore that the basalt eruptions took place in early Tertiary time.

Fossil as well as living animals engaged his attention, and in his studies of the strata around Paris he was instrumental in establishing the Tertiary formations.

Most of the country between the Andes and the sea is covered by Tertiary and Quaternary beds; but the range of hills which runs north-west from Guayaquil is formed of Cretaceous and porphyritic rocks similar to those of the Andes.

Farther north nearly the whole of the depression is filled with lavas, tuffs and agglomerates, derived from the Tertiary and recent volcanoes which form the most striking feature of the Andes of Ecuador.

Unfortunately, the precise age of the formation from which it was obtained is unknown, but it is considered probable that it dates from the later Tertiary.

Be this as it may, the identification of a North American type of camel from the Tertiary strata of eastern Europe forms another connecting link between the extinct faunas of the northern half of the Old World and North America, and thus tends to show that the claim of America to be the exclusive birthplace of many Old World types may have to be reconsidered.

It is noteworthy that a molar from the Tertiary of India has been referred to Agriochoerus, a determination which if correct probably indicates the occurrence of Oreodonts in the unknown Tertiary deposits of Central Asia.

Geologically the group is composed mainly of Triassic, Cretaceous and Tertiary strata, penetrated by intrusive rocks.

The Ionian islands consist almost entirely of Cretaceous and Tertiary beds, but in Corfu Jurassic deposits belonging to various horizons have also been found.

As riebeckite-granophyre has been found in Skye it may be of Tertiary age.

Through these, again, pierce other granites in dikes or lava flows, and overlying the whole are limestones of Cretaceous and Tertiary age, themselves cut through by later volcanic eruptions.

In early and middle Tertiary times, when the Indian peninsula was an island, and the sea which stretched into Europe washed the base of the Himalayan hills, Sokotra was in great part submerged and the great mass of limestone was deposited; but its higher peaks were still above water, and formed an island, peopled mainly by African species - the plants being the fragmentary remains of the old African flora - but with an admixture of eastern and other Asian forms. Thereafter it gradually rose, undergoing violent volcanic disturbance."

It was not till the Tertiary age, and even late in that age, that much of the land area of Afghanistan was raised above the sea-level.

Tertiary and recent deposits are widely spread, filling most of the valleys and covering the plains of the Helmund.

The former, from the Tertiary period even to the present day, has been -a region of compression; the latter, since the Carboniferous period at least, has been a region of equilibrium or of tension.

These are of Tertiary and Cretaceous ages, the latter rocks resting on a reddish sandstone of older date.

Rocks of Tertiary age are met with at Dombe Grande, Mossamedes and near Loanda.

Coral limestones, probably of Middle Tertiary age, are also found, sometimes 4000 ft.

They contain a few seams of coal, but the most important coal-bearing deposits of the country belong to the Tertiary period.

Their southern edge is covered with cretaceous deposits, and their eastern edge is covered as well with the tertiary deposits of the Gulf plains.

Enormous quantities of borax, already exploited, and of nitrate of soda, are known to be present in the surrounding country, the former as almost pure borate of lime in Tertiary lake sediments.

One of the striking features in the geology of Arran is the remarkable series of intrusive igneous rocks of Tertiary age which occupy nearly one-half of the area and form the wildest and grandest scenery in the island.

Another granite area appears on the south side of the road between Brodick and Shiskine, where it is associated with granophyre and quartz-diorite and traverses the volcanic vent of post-Cretaceous or Tertiary age already described.

But the Muller range, the Madi plateau, and the Schwaner Mountains of west Borneo, consist chiefly of almost undisturbed sedimentary and volcanic rocks of Tertiary age.

The low-lying country between the mountain ranges is covered for the most part by Tertiary and Quaternary deposits, but Cretaceous beds occur at several localities.

The Tertiary system includes conglomerates, sandstones, limestones and marls, which appear to be of Eocene, Oligocene and Miocene age.

The Tertiary beds generally lie nearly horizontal and form the lower hills, but in the Madi plateau and the Schwaner range they rise to a height of several thousand feet.

Volcanic rocks of Tertiary and late Cretaceous age are extensively developed, especially in the Muller Mountains.

Around the coast flat-lying deposits of Tertiary age are found, and these often extend high up into the mountain region.

They are now extinct, but were probably active till the close of the Tertiary period.

Marine Eocene beds occur near the Dardanelles, but the Tertiary deposits of this part of Asia Minor are mostly freshwater and belong to the upper part of the system.

Not till the Tertiary do we find remains of Aptera in any quantity, species both of living and extinct genera being represented in the amber.

The Red Sea is formed by a line of fracture, probably dating from Pliocene times, crossing the centre of a dome of Archean rocks, on both flanks of which, in Egypt and Arabia., rest Secondary and Tertiary deposits.

The Luray cavern does not date beyond the Tertiary period, though carved from the Silurian limestone.

The overlying Tertiary series includes nummulitic beds and valuable seams of coal.

The border ranges of the east and south of Assam belong to the Burmese system of mountain chains (see Burma), and consist largely of Tertiary beds, including the great coal seams of Upper Assam.

Compared with the Gondwana coal of the peninsula of India the Tertiary coal seams of Assam are remarkable for their purity and their extraordinary thickness.

Along the coast lies a belt of granite and schist overlaid unconformably by Cretaceous and Tertiary deposits; inland the mountains are formed chiefly of folded Mesozoic beds, together with volcanic rocks of later date.

They are strongly folded and are overlaid unconformably by Cretaceous and Tertiary deposits.

In the north both the Cretaceous and Tertiary beds of this zone are limited in extent, but towards the south Mesozoic beds, which are at least in part Cretaceous, form a band of considerable width.

The Tertiary beds include both marine and terrestrial deposits, and appear to be chiefly of Miocene and Pliocene age.

The whole of the north part of Tierra del Fuego is occupied by plateaus of horizontal Tertiary strata.

The Chilean Andes correspond with the Western Cordillera of Bolivia and Peru, and consist almost entirely of Jurassic and Cretaceous beds, together with the products of the Tertiary eruptions.

Through the Mesozoic beds are intruded granitic and other igneous rocks of Tertiary age, and upon the folded Mesozoic foundation rise the volcanic cones of Tertiary and later date.

In uniting three colours an " achromatism of a higher order " is derived; there is yet a residual " tertiary spectrum," but it can always be neglected.

The genus was represented in the Tertiary flora of Europe, when it extended into the polar regions; nineteen species have been recorded from the Miocene strata of Oeningen in Switzerland.

The mountain ranges of Baluchistan consist chiefly of Cretaceous and Tertiary beds, which are thrown into a series of folds running approximately parallel to the mountain ridges.

Besides the Cretaceous and Tertiary beds, Jurassic rocks are known to take a considerable part in the formation of the hills of British Baluchistan.

With the exception of the later Tertiary beds the deposits are mostly marine.

But in the upper Cretaceous and lower Tertiary, especially in north-western Baluchistan, there is an extensive development of volcanic tuffs and conglomerates, which are probably contemporaneous with the Deccan Traps of India.

Great masses of syenite and diorite were intruded during the Tertiary period, and within the curve of the folded belt a line of recent volcanic cones stretches from western Baluchistan into eastern Persia.

Coal has been worked in the Tertiary beds along the Harnai route to Quetta, but the seams are thin and the quality poor.

The true subterranean fauna may be regarded as chiefly of Pleistocene origin; yet certain forms are possibly remnants of Tertiary life.

The southern zone comprises the Sub-Himalaya and consists entirely of Tertiary beds, and especially of the upper Tertiaries.

The sub-Himalaya are formed of Tertiary beds, chiefly Siwalik or upper Tertiary, while the lower Himalaya proper consist mainly of pre-Tertiary rocks without fossils.

He was distinguished for his researches on the Tertiary floras of various parts of Europe, and on the fossil floras of Australia and New Zealand.

The Tertiary deposits cover the plain of the Tagus and are found in other low-lying areas near the coast.

Here both Cretaceous and Tertiary forms are found, and the Mondego beds seem to represent the passage between the.

The Cintra granite sends veins into the base of the Upper Jurassic, and is very probably of Tertiary age.

No later marine deposits have been found either in the eastern Andes or in the plains of Bolivia, but freshwater beds of Tertiary and later date occupy a wide area.

Thick Tertiary deposits, probably Miocene, overlie the middle portions of the west coast.

The southern parts of the central range are composed of granites, syenites, porphyries and crystalline slates, while in the north of Ichinskaya volcano, which is the highest summit of the peninsula (16,920 ft.), the mountains consist chiefly of Tertiary sandstones and old volcanic rocks.

Coalbearing clays containing fresh-water molluscs and dicotyledonous plants, as also conglomerates, alternate with the sandstones in these Tertiary deposits.

It has an alkaline reaction and behaves as a tertiary, monacid base; its salts are soluble in water and alcohol.

In 1838 he made important investigations in regard to the conditions and range of induction from electrical currents - showing that induced currents, although merely momentary, produce still other or tertiary currents, and thus on through successive orders of induction, with alternating signs, and with reversed initial and terminal signs.

The' four topographic belts of the state correspond very closely to the outcrops of its geological formations; the rocks of the Appalachian belt being of Palaeozoic age; the formation of the Highlands, Archaean; that of the Triassic Lowland, Triassic; that of the irregular hills of the Coastal Plain, Cretaceous and Tertiary.

A few Isopoda are known from Secondary rocks, but their systematic position is doubtful and they throw no light on the evolution of the group. The Amphipoda are not definitely known to occur till Tertiary times.

It is a tertiary base, and combines readily with the alkyl halides to form pyridinium salts.

In exactly the same way the whole of the south-east of the island appears to have been covered uniformly with gently dipping beds of Tertiary sands and clays, beneath which the Cretaceous strata dipped.

In these hollows the Tertiary rocks were protected from erosion, and remain to form the London and the Hampshire Basins respectively, while on the anticlinal axis the whole of the Tertiary and the upper Cretaceous strata have been dissected away, and a complex and beautiful configuration has been impressed on the district of the Weald.

This is closely followed on the south-east by the Chalk country, occupying the whole of the rest of England except where the Tertiary Basins of London and Hampshire cover it, where the depression of the Fenland carries it out of sight, and where the lower rocks of the Weald break through it.

The Thames is the one great river of the division, rising on the Jurassic Belt, crossing the Chalk country, and finishing its course in the Tertiary London Basin, towards which, in its prevailing west-to-east direction, it draws its tributaries from north and south.

The rivers from the gentle southern slopes of the Oolitic heights pass by deep valleys through the Chalk escarpments, and flow on to the Tertiary plains within.

From the upland of Salisbury Plain, which corresponds to the axis of the anticline marking the centre of the double fold into which the strata of the south of England have been thrown, the great Chalk escarpment runs north-eastward; fingers of Chalk run eastward one each side of the Weald, forming the North and South Downs, while the southern edge of the Chalk sheet appears from beneath the Tertiary strata at several places on the south coast, and especially in the Isle of Wight.

Reading flourishes from its position on the edge of the London Tertiary Basin, Croydon is a suburb of London, and Hull, though on the Chalk, derives its importance from the Humber estuary, which cuts through the Chalk and the Jurassic belts, to drain the Triassic plain and the Pennine region.

The Eastern plain thus includes a portion of the Triassic plain in the north, a portion of the Jurassic and Chalk belts in the middle, and a portion of the Tertiary plain of the London Basin in the south.

The London Basin occupies a triangular depression in the Chalk which is filled up with clays and gravels of Tertiary and later age.

There are very few dwellings situated at a higher level than moo ft., and on the lower ground the Chalk and the Oolitic limestones, where they crop out on the surface, are extremely thinly peopled, and so as a rule are areas of alluvial deposits and the Tertiary sands.

But in the eastern and southern counties the Chalk is covered by younger deposits of Tertiary age; the Pliocene Crags of Norfolk and Suffolk, the Lower London Tertiaries (London Clay, Woolwich and Reading Beds, &c.) of the London Basin comprising parts of Essex, Hertfordshire, Middlesex, Bucks and Berks, and northern Kent.

It was not until quite late in Tertiary time that these islands began to assume anything like their present form.

When again the volcanic forces became active, it was in the early Tertiary era; the evidences for this lie outside the English border.

And whereas the main range is built up of hard eruptive or crystalline rocks, the subsidiary chains are composed of softer (Cretaceous and Tertiary) laminated formations, which easily become disintegrated and dislocated.

They are laccolites of trachytic rock, and raised the Tertiary beds above them in the form of blisters.

The Mesozoic beds are followed by the Tertiary deposits, which on the Math.

Rocks of Cretaceous and Tertiary ages are confined to the maritime zone.

The fishes of the Palaeozoic age are in no respect the ancestors of the reptiles of the Secondary age, nor does man descend from the mammals which preceded him in the Tertiary age.

While numerous remains of grass-like leaves are a proof that grasses were widespread and abundantly developed in past geological ages, especially in the Tertiary period, the fossil remains are in most cases too fragmentary and badly preserved for the determination of genera, and conclusions based thereon in explanation of existing geographical distribution are most unsatisfactory.

Of more recent date (probably Tertiary) are some igneous rocks, rich in alkalis, occurring in certain localities in southern Abyssinia.

In later years he gave special attention to the Tertiary strata, including the Brown Coal of North Germany.

In 1854 he proposed the term Oligocene for certain Tertiary strata intermediate between the Eocene and Miocene; and the term is now generally adopted.

During the Triassic and Jurassic periods the genus Baiera - no doubt a representative of the Ginkgoales--was widely spread throughout Europe and in other regions; Ginkgo itself occurs abundantly in Mesozoic and Tertiary rocks, and was a common plant in the Arctic regions as elsewhere during the Jurassic and Lower Cretaceous periods.

Through the succeeding ages the Ginkgoales were represented by numerous forms, which gradually became more restricted in their distribution and fewer in number during the Cretaceous and Tertiary periods, terminating at the present day in one solitary survivor.

The greater part of the main island of Tierra del Fuego is formed by the continuation of the Tertiary beds of the Patagonian tableland cut by the transversal depression of Magellan Strait and by the low land extending from Useless Bay on the west to San Sebastian Bay on the east, of so recent origin that there exist still some salt lakes, this depression being represented in the old charts as an inter-oceanic passage for small boats.

Some peaks of Tertiary granite break the uniformity, such as Mt Sarmiento (7200 ft.), Mt Darwin, of which two peaks have been measured (6201 and 7054 ft.), and Mt Olivaia (4324 ft.).

Buhrstone, a cellular variety of chalcedonic quartz from the Tertiary strata of the Paris basin, is largely used for millstones.

Just as the amines are derived from ammonia, so from phosphine are derived the primary, secondary and tertiary organic phosphines by the exchange of hydrogen for alkyl groups, and corresponding to the phosphonium salts there exists a series of organic phosphonium bases.

The tertiary phosphines are characterized by their readiness to pass into derivatives containing pentavalent phosphorus, and consequently they form addition compounds with sulphur, carbon bisulphide, chlorine, bromine, the halogen acids and the alkyl halides with great readiness.

The axis of the Transylvanian Alps consists of sericite schists and other similar rocks; and these are followed on the south by Jurassic, Cretaceous and Early Tertiary beds.

In the Dobrudja crystalline rocks, presumably of ancient date, rise through the Tertiary and recent deposits and form the hills which lie between the Danube and the Black Sea.'

The geological history of the state covers the period from Algonkian to late Carboniferous time, after which there is a gap in the record until Tertiary time, except that there was apparently a temporary depression of the north-western and southwestern corners in the Cretaceous age.

Canine is a secondary base, forming a nitroso derivative with nitrous acid, a urethane with chlorcarbonic ester and a tertiary base (methyl conine) with methyl iodide; reactions which point to the presence of the = NH group in the molecule.

Coal-bearing beds, possibly of Tertiary age, occur in Antioquia and elsewhere.

On the western side of this depression there are red sandstones with coal-seams, possibly Tertiary; the floor and the eastern side consist chiefly of ancient crystalline and schistose rocks.

Thirty-two septa are present, six in the entocoeles of the primary cycle of mesenteries, I; six in the entocoeles of the secondary cycle of mesenteries, II; four in the entocoeles of the tertiary cycle of mesenteries, III, only four pairs of the latter being developed; and sixteen in the entocoeles between the mesenterial pairs.

These latter are in turn embraced by the couples of the tertiary cycle of mesenteries, and new septa are formed in the exocoeles on either side of them, and so forth.

The genus occurs in a fossil state, four species having been described from rocks of Tertiary age.

The remaining marsupials (namely the families Didelphyidae and Epanorthidae) are American, and mainly South and Central American at the present day; although during the early part of the Tertiary period representatives of the first-named family ranged all over the northern hemisphere.

The folding of the old rocks took place towards the close of the Palaeozoic era; but the faulting to which they owe their present position was probably Tertiary.

The Apennines, indeed, consist almost entirely of Mesozoic and Tertiary beds, like the outer zones of the Alps.

But that in Tertiary times there was a high interior zone of crystalline rocks is indicated by the character of the Eocene beds in the southern Apennines.

Suess to conclude that even in Tertiary times a large land mass consisting of ancient rocks occupied the space which is now covered by the southern portion of the Tyrrhenian Sea.

On the Italian border of this land there was raised a mountain chain with an inner crystalline zone and an outer zone of Mesozoic and Tertiary beds.

In Calabria the chain consists chiefly of crystalline and schistose rocks; it is the Mesozoic and Tertiary zone which has here been sunk beneath the sea.

This low range, which most probably separated the lowlands of the AralCaspian region (submerged during the Post-Pliocene period) from the higher plains which had emerged by the end of the Tertiary period, now divides the Transcaspian steppes from the somewhat different higher plains.

Within that period the principal valleys were excavated, and their lower parts have been filled up subsequently with J urassic, Cretaceous and Tertiary deposits.

One of the most striking instances of this is the very thick Cretaceous and Tertiary deposits which cover the bottom of the valley of the Vakhsh (right tributary of the Amu) and are continued for about 300 m.

While upheavals having a north-eastern strike continued to take place after the Carboniferous epoch,' another series of upheavals, having a north-western strike, and occasioned by the expansion of diabases, dolerites, melaphyres and andesites, occurred later, subsequently at least to the close of the Tertiary period, if not also before it, dislocating former chains and raising rocks to the highest levels by the addition of new upheavals to the older ones.

Cretaceous and Tertiary deposits occur extensively along the edge of the highlands.

Representatives of all the Tertiary formations are met with in Turkestan; but while in the highlands the strata are coast-deposits, they assume an open sea character in the lowlands, and their rich fossil fauna furnishes evidence of the gradual shallowing of that sea, until at last, after the Sarmathian period, it became a closed Mediterranean.

In the lowlands the Aral-Caspian deposits, which it is difficult to separate sharply from the later Tertiary, cover the whole of the area.

There have been no active volcanoes since the Pliocene Tertiary time, but the country is still subject to dangerous earthquakes.

It is improbable that there has been any connexion by water between the two oceans here since Tertiary time.

Iceland is one of the most volcanic regions of the earth; volcanic activity has gone on continuously from the formation of the island in the Tertiary period down to the present time.

Iceland is built up almost entirely of volcanic rocks, none of them older, however, than the middle of the Tertiary period.

Deposits of clay, with remains of plants of the Tertiary period, lignite and tree-trunks pressed flat, which the Icelanders call surtarbrandur, occur in places in the heart of the basalt formation.