Lias sentence example
The Permian may be represented, but the Trias is absent, and in general the older Palaeozoic rocks are overlaid directly by the Rhaetic and Lias.
It is, however, not impossible that the metamorphic series includes also some of the Lias.
Another well-known bed, formerly known as the "Bristol" or "Lias" Bone Bed, exists in the form of several thin layers of micaceous sandstone, with the remains of fish and saurians, which occur in the Rhaetic Black Paper Shales that lie above the Keuper marls in the south-west of England.
To the Lias also can be traced back the Neuroptera, the Trichoptera, the orthorrhaphous Diptera and, according to the determination of certain obscure fossils, also the Hymenoptera (ants).
From the evidence of fossils it seems that the higher sub-order - Apocrita - can be traced back to the Lias, so that we believe the Hymenoptera to be more ancient than the Diptera, and far more ancient than the Lepidoptera.Advertisement
The Lias and Oolite formations are well represented, but the Sequanian and Kimmeridgian subdivisions are absent.
Fragments of wings from the Lias and Oolitic beds have been referred to ants and bees, but the true nature of these remains is doubtful.
Above these, marine Rhaetic beds appear at intervals, notably near Lame, where they are succeeded by Lower Lias shales and limestones.
At Portrush, the Lower Lias is seen on the shore, crowded with ammonites, but silicified and metamorphosed by invading dolerite.
Gulf of Gabes I o g Lemg.W.of Greenwicir 0 Longitude East of Greenwich B 4 D very complete sequence of formations from the Lias to those of recent date.Advertisement
Rhaetic beds (Infra Lias), consisting of dolomites and siliceous limestones, have been recognized at Saida.
Fossil Neuroptera occur in the Lias and even in the Trias if the relationships of certain larvae have been correctly surmised.
Deposits of brown iron ore of great economic value occur in many sedimentary rocks, such as the Lias, Oolites and Lower Greensand of various parts of England.
In the Mesozoic rocks (Trias and Lias) there have been discovered remains of insects intermediate between those ancient forms and our modern cockroaches, the differentiation between forewings and hindwings having begun.
The most important British ore deposit is the Lower Cleveland bed of oolitic siderite in the Middle Lias, near Middlesborough.Advertisement
Blende, is also found sporadically in sedimentary rocks; for example, in nodules of clay-ironstone in the Coal Measures, in the cement-doggers of the Lias, and in the casts of fossil shells.
There occur also below the Lias on some parts of the west coast unfossiliferous red sandstones, conglomerates and breccias, presenting lithological resemblance to the Rhaetic group of England.
The Jurassic system - comprising, in descending order, the subdivisions of Upper Oolites (Portlandian Kimmeridge Clay), Middle Oolites (coal limestones; Oxford clay), Lower Oolites (Great Oolite series; Inferior Oolite series), Lias (Upper, Middle, Lower) - is well represented on both sides of the Highlands.
Among these the Lower and Middle Lias can be identified by their fossils.
They comprise a consecutive series of deposits from the bottom of the Lias up to the Oxford Clay.Advertisement
The Lower, Middle and Upper Lias consist chiefly of shales and shelly limestones, with some sandstones, well seen along the shores of Broadford Bay in Skye and in some of the adjacent islands.
The fossils from the Rhaetic beds belong to the Avicula contorta zone, those from the Lias to the Ammonites angulatus zone, while the blocks of limestone with chert contain Inoceramus, Cretaceous foraminifera and other organisms. The materials yielding these fossils are embedded in a course volcanic agglomerate which gives rise to crags and is pierced by acid and basic igneous ricks.
The jet is a species of petrified wood found towards the bottom of the Upper Lias, and its use for the purpose of ornament dates from very early times.
The Trias is known only at La Ternera near Copiapo, where coal-seams with Rhaetic plants have been found; but the rest of the Mesozoic series, from the Lias to the Upper Cretaceous, appears to be represented without a break .of more than local importance.
From the Permian to the Lias the sequence in the central Himalaya shows no sign of a break, nor has any unconformity been proved between the Liassic beds and the overlying Spiti shales, which contain fossils of Middle and Upper Jurassic age.Advertisement
The oldest satisfactorily known member of the group is Dimorphodon from the Lower Lias of Dorsetshire.
Equally fine skeletons of Campylognathus have been found in the Upper Lias of Wurttemberg.
South and east of these streams the very similar country is on the Lias clay.
The low escarpments of the harder beds of the Lias are the real, though often scarcely perceptible, boundary between the Triassic plain and the Jurassic belt.
Steep towards the west, where it overlooks the low Lias plain as the Oolitic escarpment, the land falls very gently in slopes of Oxford Clay towards the Cretaceous escarpments on the south and east.Advertisement
The Lias plain is rich grazing country, the Oxford Clay forms valuable agricultural land, yielding heavy crops of wheat.
The towns of the belt are comparatively small, not one attains a population of 75,000, and the favourite site is on the Lias plain below the great escarpment.
Upon the Palaeozoic beds rest a series of Mesozoic deposits, beginning with the Lias and ending with the Upper Cretaceous.
At Cambridge he obtained fossil shells from the Pleistocene deposit at Barnwell; in the Vale of Wardour he discovered in Purbeck Beds the isopod named by Milne-Edwards Archaeoniscus Brodiei; in Buckinghamshire he described the outliers of Purbeck and Portland Beds; and in the Vale of Gloucester the Lias and Oolites claimed his attention.
The Lower Lias appears at intervals under the scarp of the basaltic plateaus, and contributes, as in Dorsetshire and Devonshire, to the formation of landslips along the coast.Advertisement
The alteration of the fossiliferous Lias by dolerite at Portrush into a flinty rock that looked like basalt served at one time as a prop for the " Neptunist " theory of the origin of igneous rocks.
Westward of and above these strata, the Middle and Upper Jurassic formations are found (Lias, Lower Oolite, Oxfordian, &c.), with well-marked and numerous fossils (Ammonites, Nerinaea, Natica, Astarte, Rhynchonella, Echinodermata, &c.); then the Cretaceous rocks, both these and the Jurassic series being largely developed, the Cretaceous fossils including Nautilus, Belemnites, Ostrea, Gryphaea, &c., and some very large Ammonites (Pachydiscus).
At the junction between the Trias and Lias are series of beds termed Rhaetics, which seem to mark a transition from one to the other.
The Lower Lias comes next in order, with a valuable bed of ironstone now largely worked.
The Middle Lias, which enters the county near Woolsthorpe, is about 20 or 30 ft.Advertisement
The Upper Lias enters the county at Stainby, passing by Grantham and Lincoln where it is worked for bricks.
The Lias thus occupies a vale about 8 or 10 m.
The Inferior Oolite, somewhat narrower than the Lias, extends from the boundary with Rutland due north past Lincoln to the vicinity of the Humber; it forms the Cliff of Lincolnshire with a strong escarpment facing westward.
In England, Kimmeridge Clay, Lias clays, London Clay and pulverized shale and slate are all employed for this purpose.
The lias shales of Whitby contain blocks of semi-mineralized wood, or jet, which is black with a resinous lustre, and a fibrous structure.Advertisement
The lowest layer contains ammonites from the topmost zone of the Middle Lias.
Today friends joined us for lunch at the blue Lias pub (blue lias refers to the local stone ).
Lias clay was seen in the north western part of the site.
Lias rubble was found,  .
Lias floor was laid in 1984 to replace an earth floor that was constantly dug by treasure seekers.Advertisement
These marine mudstones are fossiliferous representatives of the Lower Jurassic or Lias.
The Polden Hills are capped by the Blue Lias Limestone, which in places forms a steep scarp.
The sub-horizontal fissures in the breccia are infilled with laminated shale of identical lithology to the overlying basal bed of the Blue Lias Formation.
In the dark, marine shales of the Lower Lias are found well preserved examples.
The lower and middle divisions of the Jurassic, composed of massive limestones more or less siliceous and overlain by the marls amd highly fossiliferous limestones of the Upper Lias, play an important part in the constitution of the chief mountains of the Tell.
The Lias floors the valley of the River Avon and the undulating plain running northwards up to Inkberrow and the Vale of Evesham.
The discovery of their true nature was made by Dr William Buckland, who observed that certain convoluted bodies occurring in the Lias of Gloucestershire had the form which would have been produced by their passage in the soft state through the intestines of reptiles or fishes.