The physiognomy of the upper Yukon Valley supports this contention, and even to-day the river has not yet fully escaped from a lacustrine condition which is merely fragmental of a previous state.
Some hand-specimens would be taken for pure palagonite; but the fragmental nature appears at once in the slide.
Through the palagonitic alteration the fragmental character is somewhat obscured, zeolites being extensively developed in the interstices.
The isolated conical peak that so unexpectedly intrudes itself into the view is the dacitic core of some submarine volcano long since stripped of most of its fragmental coverings.
The volcanic material, he adds, seems to have been almost exclusively of fragmental character.
Hers was a fragmental family, true; but its sentiment was unanimous; she had the combined support of a pleased mother and of an enthusiastic maiden aunt.
He enjoyed immensely the fragmental half-hours given him through those two days.
The result is the production of huge amounts of fragmental volcanic debris.
Many plugs and necks are largely or wholly composed of fragmental volcanic material and of fragments of wallrock, which can be of any type.
Other Volcanic Structures Plugs (necks) Congealed magma, along with fragmental volcanic and wallrock materials, can be preserved in the feeding conduits of a volcano upon cessation of activity.
Placers are detrital or fragmental sediments containing the ore in mechanical fragments, which are derived from the erosion and transportation of solid-rock veins or lodes, sometimes called the "mother lode.
These are similar in composition to the leaner iron ores of Brazil, called itabirite, but differ in that the silica is in the form of chemically deposited chert, rather than fragmental quartz grains.
But we know that, at least in our harmonious-equipotential systems, quite another process occurs after parts have been taken away: the development that occurs is not fragmental but whole, only on a smaller scale.
These are overlaid by a series of alternating beds of crystalline (c) and fragmental (t) igneous rocks.
Fragmental rocks are often quite indurated--the matrix being as hard as the included stones.
At the present time the fissure is traced by a line of several hundred insignificant mounds of fragmental materials which mark where the lava issued.
To study the nature of these explosions we may visit Stromboli, a low volcano built chiefly of fragmental materials, which rises from the sea off the north coast of Sicily and is in constant though moderate action.
The cone-building stage may be said to continue until eruptions of lava and fragmental materials cease altogether.
But the most important fragmental materials are those derived from the lava itself.
Sedimentary rocks are divided into the fragmental rocks--which are made of fragments, either coarse or fine--and the far less common rocks which are constituted of chemical precipitates.
No evidence appears that the molten rock ever reached the surface, and if volcanic eruptions ever took place either in lava flows or fragmental materials, all traces of them have been effaced.
Ancient tuffs are known by the fragmental character of their volcanic material, even though they have been altered to firm rock.
The beds of fragmental material are of the nature of flow breccias and of coarse agglomerates on the higher slopes, while tuffs occur at a greater distance from the center of eruption.
In several cases the lava masses, as seen in cross section, are lens-shaped, and where associated with fragmental beds have unconformable relations.
The rocks, so far as I saw them, are massive lavas, and not fragmentalscoriae or other products of explosive eruptions.
The distribution of the volcanic rocks, as determined in the study of reconnaissance collections, indicates that the cone has been built up by eruptions of lava and of fragmental material.
Beneath the reef are thick beds of limestone, composed largely of the remains of foraminifers, which cover the lavas and fragmental materials of the old submarine volcano.
At the present time the fissure is traced by a line of several hundred insignificant mounds of fragmental materials which mark where the lava issued (Fig.
The sedimentary rocks are composed principally of fragmental material derived from the disintegration of older rocks transported and deposited mechanically, and resulting in the formation of sandstone, shale, etc.
It is not known to occur independently of the forms of Eozoon except in fragmental deposits.
Indications exist of other organic bodies in the limestones containing Eozoon, and also of the Eozoon being preserved not only in reefs but in drifted fragmental beds as in the case of modern corals.
I now figure similar bodies found mixed withfragmental Eozoon and in separate thin layers at St. Pierre (fig.
Other specimens of fragmental Eozoon from the Petite Nation localities have their canals filled with dolomite, which probably penetrated them after they were broken up and imbedded in the rock.
C] In some of the layers are found other and more minute fossils than Eozoon, and these, together with its fragmental remains, as ingredients in the limestone, will be discussed in the sequel.
I have also found some masses clearly not fragmental which consist altogether of acervuline cells.
Unlike the fragmental rocks, the rocks of this division not only admit, but require, a chemical classification.
Before they become consolidated the finer fragmental lava, of whatever composition, is called volcanic dust, and the coarser lapilli or volcanic sand; while the consolidated materials are known as tuff and agglomerate respectively.
Falling on the slopes of the volcano or over the surrounding country, as in the case of the buried city of Pompeii, the fragmental lavas remain largely unstratified.
These fragmental rocks cannot be classified chemically, since the same handful of gravel, for instance, may contain pebbles of many different kinds of rocks, and thus be of almost any and very variable composition.
It is plain then that in each of the principal groups of fragmental rocks we must recognize an unconsolidated division and a consolidated division.
Hence, we find that the fragmental rocks are composed principally of two minerals, quartz and kaolin,—the former predominating in the conglomerate and arenaceous groups, and the latter in the argillaceous group.
The fragmental materials thus accumulated are of all sizes, from the finest dust up to blocks many tons in weight, the latter being naturally piled around nearest to the orifice.
The whole mass of the mountain consists of volcanic rock, varieties of andesite; there is no trace of a crater, nor of any fragmental materials, such as are usually ejected from a volcanic vent of eruption.
Hence the form or outline of many of these fragmental craters is crescent-shaped.
The interior wall of Monte di Somma, the original crater of Vesuvius, presents a good illustration of such fragmental beds.
They are built up of a great variety of ancient lavas and fragmentaltuffs or "ashes," which are inclined in many different directions.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "fragmental" in a variety of sentences. We hope that you will now be able to make sentences using this word.
