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diff --git a/old/3772-h/files/ch8.html b/old/3772-h/files/ch8.html new file mode 100644 index 0000000..e81838a --- /dev/null +++ b/old/3772-h/files/ch8.html @@ -0,0 +1,1289 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<!-- saved from url=(0036)http://../Lyell/The Student's Elements of Geology --> +<html> +<head> +<meta name="generator" content="HTML Tidy, see www.w3.org"> +<title>The Student's Elements of Geology: Title</title> +<meta content="text/html; charset=iso-8859-1" http-equiv= +"Content-Type"> +<meta content="MSHTML 5.00.2919.6307" name="GENERATOR"> +<link rel="stylesheet" href="geology.css" type="text/css"> +</head> +<body> +<p><b>The Student’s Elements of Geology</b></p> + +<hr> +<p class="page"><a name="page 121">[ 121 ]</a></p> + +<p> </p> + +<center><b>Chapter VIII</b><br> +<br> +CHRONOLOGICAL CLASSIFICATION OF ROCKS.</center> + +<p class="intro">Aqueous, Plutonic, volcanic, and metamorphic +Rocks considered chronologically. — Terms Primary, +Secondary, and Tertiary; Palæozoic, Mesozoic, and Cainozoic +explained. — On the different Ages of the aqueous Rocks. +— Three principal Tests of relative Age: Superposition, +Mineral Character, and Fossils. — Change of Mineral +Character and Fossils in the same continuous Formation. — +Proofs that distinct Species of Animals and Plants have lived at +successive Periods. — Distinct Provinces of indigenous +Species. — Great Extent of single Provinces. — +Similar Laws prevailed at successive Geological Periods. — +Relative Importance of mineral and palæontological +Characters. — Test of Age by included Fragments. — +Frequent Absence of Strata of intervening Periods. — +Tabular Views of fossiliferous Strata.</p> + +<p><b>Chronology of Rocks.</b>— In the first chapter it was +stated that the four great classes of rocks, the aqueous, the +volcanic, the Plutonic, and the metamorphic, would each be +considered not only in reference to their mineral characters, and +mode of origin, but also to their relative age. In regard to the +aqueous rocks, we have already seen that they are stratified, +that some are calcareous, others argillaceous or siliceous, some +made up of sand, others of pebbles; that some contain +fresh-water, others marine fossils, and so forth; but the student +has still to learn which rocks, exhibiting some or all of these +characters, have originated at one period of the earth’s +history, and which at another.</p> + +<p>To determine this point in reference to the fossiliferous +formations is more easy than in any other class, and it is +therefore the most convenient and natural method to begin by +establishing a chronology for these strata, and then to refer as +far as possible to the same divisions, the several groups of +Plutonic, volcanic, and metamorphic rocks. Such a system of +classification is not only recommended by its greater clearness +and facility of application, but is also best fitted to strike +the imagination by bringing into one view the contemporaneous +revolutions of the inorganic and organic creations of former +times. For the sedimentary formations are most readily +distinguished by the different species of fossil animals and +plants which they inclose, and of which one assemblage after +another has flourished and then disappeared from the earth in +succession.</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 122">[ 122 ]</a></p> + +<p>In the present work, therefore, the four great classes of +rocks, the aqueous, Plutonic, volcanic, and metamorphic, will +form four parallel, or nearly parallel, columns in one +chronological table. They will be considered as four sets of +monuments relating to four contemporaneous, or nearly +contemporaneous, series of events. I shall endeavour, in a +subsequent chapter on the Plutonic rocks, to explain the manner +in which certain masses belonging to each of the four classes of +rocks may have originated simultaneously at every geological +period, and how the earth’s crust may have been continually +remodelled, above and below, by aqueous and igneous causes, from +times indefinitely remote. In the same manner as aqueous and +fossiliferous strata are now formed in certain seas or lakes, +while in other places volcanic rocks break out at the surface, +and are connected with reservoirs of melted matter at vast depths +in the bowels of the earth, so, at every era of the past, +fossiliferous deposits and superficial igneous rocks were in +progress contemporaneously with others of subterranean and +Plutonic origin, and some sedimentary strata were exposed to +heat, and made to assume a crystalline or metamorphic +structure.</p> + +<p>It can by no means be taken for granted, that during all these +changes the solid crust of the earth has been increasing in +thickness. It has been shown, that so far as aqueous action is +concerned, the gain by fresh deposits, and the loss by +denudation, must at each period have been equal (see above, Chap. +VI, p. 96); and in like manner, in the inferior portion of the +earth’s crust, the acquisition of new crystalline rocks, at +each successive era, may merely have counterbalanced the loss +sustained by the melting of materials previously consolidated. As +to the relative antiquity of the crystalline foundations of the +earth’s crust, when compared to the fossiliferous and +volcanic rocks which they support, I have already stated, in the +first chapter, that to pronounce an opinion on this matter is as +difficult as at once to decide which of the two, whether the +foundations or superstructure of an ancient city built on wooden +piles may be the oldest. We have seen that, to answer this +question, we must first be prepared to say whether the work of +decay and restoration had gone on most rapidly above or below; +whether the average duration of the piles has exceeded that of +the buildings, or the contrary. So also in regard to the relative +age of the superior and inferior portions of the earth’s +crust; we can not hazard even a conjecture on this point, until +we know whether, upon an average, the power of water above, or +that of heat below, is most efficacious in giving new forms to +solid matter.</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 123">[ 123 ]</a></p> + +<p>The early geologists gave to all the crystalline and +non-fossiliferous rocks the name of Primitive or Primary, under +the idea that they were formed anterior to the appearance of life +upon the earth, while the aqueous or fossiliferous strata were +termed Secondary, and alluviums or other superficial deposits, +Tertiary. The meaning of these terms, has, however, been +gradually modified with advancing knowledge, and they are now +used to designate three great chronological divisions under which +all geological formations can be classed, each of them being +characterised by the presence of distinctive groups of organic +remains rather than by any mechanical peculiarities of the strata +themselves. If, therefore, we retain the term +“primary,” it must not be held to designate a set of +crystalline rocks some of which have been proved to be even of +Tertiary age, but must be applied to all rocks older than the +secondary formations. Some geologists, to avoid misapprehension, +have introduced the term Palæozoic for primary, from +<i>palaion,</i> “ancient,” and <i>zoon,</i> “an +organic being,” still retaining the terms secondary and +tertiary; Mr. Phillips, for the sake of uniformity, has proposed +Mesozoic, for secondary, from <i>mesos,</i> “middle,” +etc.; and Cainozoic, for tertiary, from <i>kainos,</i> +“recent,” etc.; but the terms primary, secondary, and +tertiary have the claim of priority in their favour, and are of +corresponding value.</p> + +<p>It may perhaps be suggested that some metamorphic strata, and +some granites, may be anterior in date to the oldest of the +primary fossiliferous rocks. This opinion is doubtless true, and +will be discussed in future chapters; but I may here observe, +that when we arrange the four classes of rocks in four parallel +columns in one table of chronology, it is by no means assumed +that these columns are all of equal length; one may begin at an +earlier period than the rest, and another may come down to a +later point of time, and we may not be yet acquainted with the +most ancient of the primary fossiliferous beds, or with the +newest of the hypogene.</p> + +<p>For reasons already stated, I proceed first to treat of the +aqueous or fossiliferous formations considered in chronological +order or in relation to the different periods at which they have +been deposited.</p> + +<p>There are three principal tests by which we determine the age +of a given set of strata; first, superposition; secondly, mineral +character; and, thirdly, organic remains. Some aid can +occasionally be derived from a fourth kind of proof, namely, the +fact of one deposit including in it fragments of a pre-existing +rock, by which the relative ages of the two may, even in the +absence of all other evidence, be determined.</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 124">[ 124 ]</a></p> + +<p><b>Superposition.</b>—The first and principal test of +the age of one aqueous deposit, as compared to another, is +relative position. It has been already stated, that, where strata +are horizontal, the bed which lies uppermost is the newest of the +whole, and that which lies at the bottom the most ancient. So, of +a series of sedimentary formations, they are like volumes of +history, in which each writer has recorded the annals of his own +times, and then laid down the book, with the last written page +uppermost, upon the volume in which the events of the era +immediately preceding were commemorated. In this manner a lofty +pile of chronicles is at length accumulated; and they are so +arranged as to indicate, by their position alone, the order in +which the events recorded in them have occurred.</p> + +<p>In regard to the crust of the earth, however, there are some +regions where, as the student has already been informed, the beds +have been disturbed, and sometimes extensively thrown over and +turned upside down. (See <a href="ch5.html#page 73">p. 73,</a> <a +href="ch5.html#page 87">p. 87.</a>) But an experienced geologist +can rarely be deceived by these exceptional cases. When he finds +that the strata are fractured, curved, inclined, or vertical, he +knows that the original order of superposition must be doubtful, +and he then endeavours to find sections in some neighbouring +district where the strata are horizontal, or only slightly +inclined. Here, the true order of sequence of the entire series +of deposits being ascertained, a key is furnished for settling +the chronology of those strata where the displacement is +extreme.</p> + +<p><b>Mineral Character.</b>—The same rocks may often be +observed to retain for miles, or even hundreds of miles, the same +mineral peculiarities, if we follow the planes of stratification, +or trace the beds, if they be undisturbed, in a horizontal +direction. But if we pursue them vertically, or in any direction +transverse to the planes of stratification, this uniformity +ceases almost immediately. In that case we can scarcely ever +penetrate a stratified mass for a few hundred yards without +beholding a succession of extremely dissimilar rocks, some of +fine, others of coarse grain, some of mechanical, others of +chemical origin; some calcareous, others argillaceous, and others +siliceous. These phenomena lead to the conclusion that rivers and +currents have dispersed the same sediment over wide areas at one +period, but at successive periods have been charged, in the same +region, with very different kinds of matter. The first observers +were so astonished at the vast spaces over which they were able +to follow the same homogeneous rocks in a horizontal direction, +that they came hastily to the opinion, that the whole</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 125">[ 125 ]</a></p> + +<p>globe had been environed by a succession of distinct aqueous +formations, disposed round the nucleus of the planet, like the +concentric coats of an onion. 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. Sometimes they thin out gradually, as if the supply of +sediment had failed in that direction, or they come abruptly to +an end, as if we had arrived at the borders of the ancient sea or +lake which served as their receptacle. It no less frequently +happens that they vary in mineral aspect and composition, as we +pursue them horizontally. For example, we trace a limestone for a +hundred miles, until it becomes more arenaceous, and finally +passes into sand, or sandstone. We may then follow this +sandstone, already proved by its continuity to be of the same +age, throughout another district a hundred miles or more in +length.</p> + +<p><b>Organic Remains.</b>—This character must be used as a +criterion of the age of a formation, or of the contemporaneous +origin of two deposits in distant places, under very much the +same restrictions as the test of mineral composition.</p> + +<p>First, the same fossils may be traced over wide regions, if we +examine strata in the direction of their planes, although by no +means for indefinite distances. Secondly, while the same fossils +prevail in a particular set of strata for hundreds of miles in a +horizontal direction, we seldom meet with the same remains for +many fathoms, and very rarely for several hundred yards, in a +vertical line, or a line transverse to the strata. This fact has +now been verified in almost all parts of the globe, and has led +to a conviction that at successive periods of the past, the same +area of land and water has been inhabited by species of animals +and plants even more distinct than those which now people the +antipodes, or which now co-exist in the arctic, temperate, and +tropical zones. It appears that from the remotest periods there +has been ever a coming in of new organic forms, and an extinction +of those which pre-existed on the earth; some species having +endured for a longer, others for a shorter, time; while none have +ever reappeared after once dying out. The law which has governed +the succession of species, whether we adopt or reject the theory +of transmutation, seems to be expressed in the verse of the +poet:—</p> + +<p> <small>Natura il fece, e poi ruppe la stampa. + <i>Ariosto.</i></small><br> + <small>Nature made him, and then broke the +die.</small></p> + +<p> </p> + +<hr> +<p class="page"><a name="page 126">[ 126 ]</a></p> + +<p>And this circumstance it is, which confers on fossils their +highest value as chronological tests, giving to each of them, in +the eyes of the geologist, that authority which belongs to +contemporary medals in history.</p> + +<p>The same can not be said of each peculiar variety of rock; for +some of these, as red marl and red sandstone, for example, may +occur at once at the top, bottom, and middle of the entire +sedimentary series; exhibiting in each position so perfect an +identity of mineral aspect as to be undistinguishable. Such exact +repetitions, however, of the same mixtures of sediment have not +often been produced, at distant periods, in precisely the same +parts of the globe; and even where this has happened, we are +seldom in any danger of confounding together the monuments of +remote eras, when we have studied their imbedded fossils and +their relative position.</p> + +<p><b>Zoological Provinces.</b>—It was remarked that the +same species of organic remains can not be traced horizontally, +or in the direction of the planes of stratifications for +indefinite distances. This might have been expected from analogy; +for when we inquire into the present distribution of living +beings, we find that the habitable surface of the sea and land +may be divided into a considerable number of distinct provinces, +each peopled by a peculiar assemblage of animals and plants. In +the “Principles of Geology,” I have endeavoured to +point out the extent and probable origin of these separate +divisions; and it was shown that climate is only one of many +causes on which they depend, and that difference of longitude as +well as latitude is generally accompanied by a dissimilarity of +indigenous species.</p> + +<p>As different seas, therefore, and lakes are inhabited, at the +same period, by different aquatic animals and plants, and as the +lands adjoining these may be peopled by distinct terrestrial +species, it follows that distinct fossils will be imbedded in +contemporaneous deposits. If it were otherwise—if the same +species abounded in every climate, or in every part of the globe +where, so far as we can discover, a corresponding temperature and +other conditions favourable to their existence are +found—the identification of mineral masses of the same age, +by means of their included organic contents, would be a matter of +still greater certainty.</p> + +<p>Nevertheless, the extent of some single zoological provinces, +especially those of marine animals, is very great; and our +geological researches have proved that the same laws prevailed at +remote periods; for the fossils are often identical throughout +wide spaces, and in detached deposits, consisting of rocks +varying entirely in their mineral nature.</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 127">[ 127 ]</a></p> + +<p>The doctrine here laid down will be more readily understood, +if we reflect on what is now going on in the Mediterranean. That +entire sea may be considered as one zoological province; for +although certain species of testacea and zoophytes may be very +local, and each region has probably some species peculiar to it, +still a considerable number are common to the whole +Mediterranean. If, therefore, at some future period, the bed of +this inland sea should be converted into land, the geologist +might be enabled, by reference to organic remains, to prove the +contemporaneous origin of various mineral masses scattered over a +space equal in area to half of Europe.</p> + +<p>Deposits, for example, are well known to be now in progress in +this sea in the deltas of the Po, Rhone, Nile, and other rivers, +which differ as greatly from each other in the nature of their +sediment as does the composition of the mountains which their +drain. There are also other quarters of the Mediterranean, as off +the coast of Campania, or near the base of Etna, in Sicily, or in +the Grecian Archipelago, where another class of rocks is now +forming; where showers of volcanic ashes occasionally fall into +the sea, and streams of lava overflow its bottom; and where, in +the intervals between volcanic eruptions, beds of sand and clay +are frequently derived from the waste of cliffs, or the turbid +waters of rivers. Limestones, moreover, such as the Italian +travertins, are here and there precipitated from the waters of +mineral springs, some of which rise up from the bottom of the +sea. In all these detached formations, so diversified in their +lithological characters, the remains of the same shells, corals, +crustacea, and fish are becoming inclosed; or, at least, a +sufficient number must be common to the different localities to +enable the zoologist to refer them all to one contemporaneous +assemblage of species.</p> + +<p>There are, however, certain combinations of geographical +circumstances which cause distinct provinces of animals and +plants to be separated from each other by very narrow limits; and +hence it must happen that strata will be sometimes formed in +contiguous regions, differing widely both in mineral contents and +organic remains. Thus, for example, the testacea, zoophytes, and +fish of the Red Sea are, as a group, extremely distinct from +those inhabiting the adjoining parts of the Mediterranean, +although the two seas are separated only by the narrow isthmus of +Suez. Calcareous formations have accumulated on a great scale in +the Red Sea in modern times, and fossil shells of existing +species are well preserved therein; and we know that at the mouth +of the Nile large</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 128">[ 128 ]</a></p> + +<p>deposits of mud are amassed, including the remains of +Mediterranean species. It follows, therefore, that if at some +future period the bed of the Red Sea should be laid dry, the +geologist might experience great difficulties in endeavouring to +ascertain the relative age of these formations, which, although +dissimilar both in organic and mineral characters, were of +synchronous origin.</p> + +<p>But, on the other hand, we must not forget that the +north-western shores of the Arabian Gulf, the plains of Egypt, +and the Isthmus of Suez, are all parts of one province of +<i>terrestrial</i> species. Small streams, therefore, occasional +land- floods, and those winds which drift clouds of sand along +the deserts, might carry down into the Red Sea the same shells of +fluviatile and land testacea which the Nile is sweeping into its +delta, together with some remains of terrestrial plants and the +bones of quadrupeds, whereby the groups of strata before alluded +to might, notwithstanding the discrepancy of their mineral +composition and <i>marine</i> organic fossils, be shown to have +belonged to the same epoch.</p> + +<p>Yet, while rivers may thus carry down the same fluviatile and +terrestrial spoils into two or more seas inhabited by different +marine species, it will much more frequently happen that the +coexistence of terrestrial species of distinct zoological and +botanical provinces will be proved by the identity of the marine +beings which inhabited the intervening space. Thus, for example, +the land quadrupeds and shells of the valley of the Mississippi, +of central America, and of the West India islands differ very +considerably, yet their remains are all washed down by rivers +flowing from these three zoological provinces into the Gulf of +Mexico.</p> + +<p>In some parts of the globe, at the present period, the line of +demarkation between distinct provinces of animals and plants is +not very strongly marked, especially where the change is +determined by temperature, as it is in seas extending from the +temperate to the tropical zone, or from the temperate to the +arctic regions. Here a gradual passage takes place from one set +of species to another. In like manner the geologist, in studying +particular formations of remote periods, has sometimes been able +to trace the gradation from one ancient province to another, by +observing carefully the fossils of all the intermediate places. +His success in thus acquiring a knowledge of the zoological or +botanical geography of very distant eras has been mainly owing to +this circumstance, that the mineral character has no tendency to +be affected by climate. A large river may convey yellow or red +mud into some part of the ocean, where</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 129">[ 129 ]</a></p> + +<p>it may be dispersed by a current over an area several hundred +leagues in length, so as to pass from the tropics into the +temperate zone. If the bottom of the sea be afterwards upraised, +the organic remains imbedded in such yellow or red strata may +indicate the different animals or plants which once inhabited at +the same time the temperate and equatorial regions.</p> + +<p>It may be true, as a general rule, that groups of the same +species of animals and plants may extend over wider areas than +deposits of homogeneous composition; and if so, +palæontological characters will be of more importance in +geological classification than the test of mineral composition; +but it is idle to discuss the relative value of these tests, as +the aid of both is indispensable, and it fortunately happens, +that where the one criterion fails, we can often avail ourselves +of the other.</p> + +<p><b>Test by included Fragments of older Rocks.</b>—It was +stated, that proof may sometimes be obtained of the relative date +of two formations by fragments of an older rock being included in +a newer one. This evidence may sometimes be of great use, where a +geologist is at a loss to determine the relative age of two +formations from want of clear sections exhibiting their true +order of position, or because the strata of each group are +vertical. In such cases we sometimes discover that the more +modern rock has been in part derived from the degradation of the +older. Thus, for example, we may find chalk in one part of a +country, and in another strata of clay, sand, and pebbles. If +some of these pebbles consist of that peculiar flint, of which +layers more or less continuous are characteristic of the chalk, +and which include fossil shells, sponges, and foraminifera of +cretaceous species, we may confidently infer that the chalk was +the oldest of the two formations.</p> + +<p><b>Chronological Groups.</b>—The number of groups into +which the fossiliferous strata may be separated are more or less +numerous, according to the views of classification which +different geologists entertain; but when we have adopted a +certain system of arrangement, we immediately find that a few +only of the entire series of groups occur one upon the other in +any single section or district.</p> + +<p>The thinning out of individual strata was before described <a +href="ch2.html#page 42">(p. 42).</a> But let the diagram (Fig. +84) represent seven fossiliferous groups, instead of as many +strata. It will then be seen that in the middle all the +superimposed formations are present; but in consequence of some +of them thinning out, No. 2 and No. 5 are absent at one extremity +of the section, and No. 4 at the other.</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 130">[ 130 ]</a></p> + +<center><img src="../images/fig84.jpg" width="356" height="89" alt= +"Fig. 84: Seven fossiliferous groups."></center> + +<p>In another diagram (Fig. 85), a real section of the geological +formations in the neighbourhood of Bristol and the Mendip Hills +is presented to the reader, as laid down on a true scale by +Professor Ramsay, where the newer groups 1, 2, 3, 4 rest +unconformably on the formations 5, 6, 7 and 8. At the southern +end of the line of section we meet with the beds No. 3 (the New +Red Sandstone) resting immediately on Nos. 7 and 8, while farther +north as at Dundry Hill in Somersetshire, we behold eight groups +superimposed one upon the other, comprising all the strata from +the inferior Oolite, No. 1, to the coal and carboniferous +limestone. The limited horizontal extension of the groups 1 and 2 +is owing to denudation, as these formations end abruptly, and +have left outlying patches to attest the fact of their having +originally covered a much wider area.</p> + +<center><img src="../images/fig85.jpg" width="411" height="242" alt= +"Section South of Bristol."></center> + +<p>In order, therefore, to establish a chronological succession +of fossiliferous groups, a geologist must begin with a single +section in which several sets of strata lie one upon the other. +He must then trace these formations, by attention to their +mineral character and fossils, continuously, as far as possible, +from the starting-point. As often as he meets with new groups, he +must ascertain by superposition their age relatively to those +first examined, and thus learn how to intercalate them in a +tabular arrangement of the whole.</p> + +<p>By this means the German, French, and English geologists</p> + +<p> </p> + +<hr> +<p class="page"><a name="page 131">[ 131 ]</a></p> + +<p>have determined the succession of strata throughout a great +part of Europe, and have adopted pretty generally the following +groups, almost all of which have their representatives in the +British Islands.</p> + +<hr width="30%"> +<br> +<center><img src="../images/table.jpg" width="411" height="603" alt= +"Abridged General Table of Fossiliferous Strata."></center> + +<p> </p> + +<hr> +<p class="page"><a name="page 132">[ 132 ]</a></p> + +<center>TABULAR VIEW OF THE FOSSILIFEROUS STRATA,<br> + <small>SHOWING THE ORDER OF SUPERPOSITION OR CHRONOLOGICAL +SUCCESSION OF THE PRINCIPAL GROUPS DESCRIBED IN THIS +WORK.</small></center> + +<br> +<hr width="20%"> +<br> +<center>POST-TERTIARY<br> +<small>EXAMPLES</small></center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata"> +<tr> +<td align="center" valign="middle" rowspan="2">POST-<br> +TERTIARY</td> +<td valign="middle" align="center">1.<br> +RECENT<br> +Shells and mammals, all of living species.</td> +<td align="left"><b>British</b><br> +Clyde marine strata, with canoes (<a href="ch10.html#page 146">p. +146</a>).<br> +<b>Foreign</b><br> +Danish kitchen middens (<a href="ch10.html#page146">p. +146</a>).<br> +Lacustrine mud, with remains of Swiss lake-dwellings (<a href= +"ch10.html#page148">p. 148</a>).<br> +Marine strata inclosing Temple of Serapis, at Puzzuoli (<a href= +"ch10.html#page146">p. 146</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">2.<br> +POST-<br> +PLIOCENE.<br> +Shells, recent mammalia in part extinct.</td> +<td align="left"><b>British</b><br> +Loam of Brixham cave, with flint implements and bones of extinct +and living quadrupeds (<a href="ch10.html#page 157">p. +157</a>)<br> +Drift near Salisbury, with bones of mammoth, Spermophilus, and +stone implements (<a href="ch10.html#page 161">p. 161</a>).<br> +Glacial drift of Scotland, with marine shells and remains of +mammoth (<a href="ch11.html#page 176">p. 176</a>.<br> +Erratics of Pagham and Selsey Bill (<a href= +"ch11.html#page 182">p. 182</a>).<br> +Glacial drift of Wales, with marine fossil shells, about 1400 +feet high, on Moel Tryfaen (<a href="ch11.html#page 181">p. +181</a>).<br> + <b>Foreign</b><br> +Dordogne caves of the reindeer period (<a href= +"ch10.html#page 150">p. 150</a>).<br> +Older valley-gravels of Amiens, with flint implements and bones +of extinct mammalia (<a href="ch10.html#page 152">p. +152</a>).<br> +Loess of Rhine (<a href="ch10.html#page 154">p. 154</a>).<br> +Ancient Nile-mud forming river-terraces (<a href= +"ch10.html#page 154">p. 154</a>).<br> +Loam and breccia of Liege caverns, with human remains (<a href= +"ch10.html#page 156">pp. 156, 157</a>).<br> +Australian cave breccias, with bones of extinct marsupials (<a +href="ch10.html#page158">p. 158</a>).<br> +Glacial drift of Northern Europe (<a href="ch11.html#page 166">p. +166</a>, <a href="ch12.html#page 174">p. 174</a>).</td> +</tr> +</table> +</center> + +<br> +<center>TERTIARY OR CAINOZOIC</center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata."> +<tr> +<td align="center" valign="middle" rowspan="2">PLIOCENE</td> +<td valign="middle" align="center">3.<br> +NEWER<br> +PLIOCENE.<br> +The shells almost all of living species.</td> +<td align="left"><b>British</b><br> +Bridlington beds, marine Arctic fauna (<a href= +"ch13.html#page 189">p. 189</a>).<br> +Glacial boulder formation of Norfolk cliffs (<a href= +"ch13.html#page 190">p. 190</a>).<br> +Forest-bed of Norfolk cliffs, with bones of <i>Elephas +meridionalis,</i> etc. (<a href="ch13.html#page 191">p. +191</a>).<br> +Chillesford and Aldeby beds, with marine shells, chiefly Arctic +(<a href="ch13.html#page 192">p. 192</a>).<br> +Norwich crag (<a href="ch13.html#page 193">p. 193</a>).<br> +<b>Foreign</b><br> +Eastern base of Mount Etna, with marine shells (<a href= +"ch13.html#page 204">p. 204</a>).<br> +Sicilian calcareous and tufaceous strata (<a href= +"ch13.html#page 205">p. 205</a>, 206).<br> +Lacustrine strata of Upper Val d’Arno (<a href= +"ch13.html#page 207">p. 207</a>).<br> +Madeira leaf-bed and land-shells (<a href="ch29.html#page 532">p. +532</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">4.<br> +OLDER<br> +PLIOCENE.<br> +Extinct species of<br> +shells forming a<br> +large minority.</td> +<td align="left"><b>British</b><br> +Red crag of Suffolk, marine shells, some of northern forms (<a +href="ch13.html#page 194">p. 194, 195</a>).<br> +White or coralline crag of Suffolk (<a href= +"ch13.html#page 197">p. 197</a>).<br> +<b>Foreign</b><br> +Antwerp crag (<a href="ch13.html#page 204">p. 204</a>).<br> +Subapennine marls and sands (<a href="ch13.html#page 208">p. +208</a>).</td> +</tr> +</table> +</center> + +<p> </p> + +<hr> +<p class="page"><a name="page 133">[ 133 ]</a></p> + +<center><small>EXAMPLES</small></center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata"> +<tr> +<td align="center" valign="middle" rowspan="2">MIOCENE</td> +<td valign="middle" align="center">5.<br> +UPPER<br> +MIOCENE.<br> +Majority of the<br> +shells extinct.</td> +<td align="left"><b>British</b><br> +Wanting.<br> +<b>Foreign</b><br> +Faluns of Touraine (<a href="ch14.html#page 211">p. 211</a>).<br> +Faluns, proper, of Bordeaux (<a href="ch14.html#page 214">p. +214</a>).<br> +Fresh-water strata of Gers (<a href="ch14.html#page 215">p. +215</a>).<br> +Swiss Oeningen beds, rich in plants and insects (<a href= +"ch14.html#page ">pp. 215-23</a>).<br> +Marine Molasse, Switzerland (<a href="ch14.html#page 223">p. +223</a>).<br> +Bolderberg beds of Belgium (<a href="ch14.html#page 224">p. +224</a>).<br> +Vienna basin (<a href="ch14.html#page 224">p. 224</a>).<br> +Beds of the Superga, near Turin (<a href="ch14.html#page 226">p. +226</a>).<br> +Deposit at Pikermé, near Athens (<a href= +"ch14.html#page 226">p. 226</a>).<br> +Strata of the Siwâlik hills, India (<a href= +"ch14.html#page 226">p. 226</a>).<br> +Marine strata of the Atlantic border in the United States (<a +href="ch14.html#page 227">p. 227</a>).<br> +Volcanic tuff and limestone of Madeira, the Canaries, and the +Azores (<a href="ch30.html#page 536">).</a></td> +</tr> + +<tr> +<td align="center" valign="middle">6.<br> +LOWER<br> +MIOCENE.<br> +Nearly all the<br> +shells extinct.</td> +<td align="left"><b>British</b><br> +Hempstead beds, marine and fresh-water strata (<a href= +"ch15.html#page 244">p. 244</a>).<br> +Lignites and clays of Bovey Tracey (<a href= +"ch15.html#page 245">p. 245</a>).<br> +Isle of Mull leaf-bed, volcanic tuff (<a href= +"ch15.html#page 247">p. 247</a>).<br> +<b>Foreign</b><br> +Calcaire de la Beauce, etc. (<a href="ch15.html#page 230">p. +230</a>).<br> +Grès de Fontainebleau (<a href="ch15.html#page 230">p. +230</a>).<br> +Lacustrine strata of the Limagne d’Auvergne, and the Cantal +(<a href="ch15.html#page 233">p. 233</a>).<br> +Mayence basin (<a href="ch15.html#page 242">p. 242</a>).<br> +Radaboj beds of Croatia (<a href="ch15.html#page 242">p. +242</a>).<br> +Brown coal of Germany (<a href="ch15.html#page 244">p. +244</a>).<br> +Lower Molasse of Switzerland, fresh-water and brackish (<a href= +"ch15.html#page 235">p. 235-9</a>).<br> +Rupelmonde, Kleynspawen, and Tongrian beds of Belgium (<a href= +"ch15.html#page ">p. 241</a>, 242).<br> +Nebraska beds, United States (<a href="ch15.html#page 248">p. +248</a>).<br> +Lower Miocene beds of Italy (<a href="ch15.html#page 244">p. +244</a>).<br> +Miocene flora of North Greenland (<a href="ch15.html#page 239">p. +239</a>).</td> +</tr> + +<tr> +<td valign="middle" rowspan="3" align="center">EOCENE</td> +<td align="center">7.<br> +UPPER<br> +EOCENE.</td> +<td align="left"><b>British</b><br> +Bembridge fluvio-marine strata (<a href="ch16.html#page 252">p. +252</a>).<br> +Osborne or St. Helen’s series (<a href= +"ch16.html#page 255">p. 255</a>).<br> +Headon series, with marine and fresh-water shells (<a href= +"ch16.html#page 255">p. 255</a>).<br> +Barton sands and clays (<a href="ch16.html#page 258">p. +258</a>).<br> +<b>Foreign</b><br> +Gypsum of Montmartre, fresh-water with <i>Palæotherium</i> +(<a href="ch16.html#page 270">p. 270</a>).<br> +Calcaire silicieux, or Travertin inférieur (<a href= +"ch16.html#page 273">p. 273</a>),<br> +Grès de Beauchamp, or Sables moyens (<a href= +"ch16.html#page 273">p. 273</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">8.<br> +MIDDLE<br> +EOCENE.</td> +<td align="left"><b>British</b><br> +Bracklesham beds and Bagshot sands (<a href= +"ch16.html#page 259">p. 259</a>).<br> +White clays of Alum Bay and Bournemouth (<a href= +"ch16.html#page 262">p. 262</a>).<br> +<b>Foreign</b><br> +Calcaire grossier, miliolitic limestone (<a href= +"ch16.html#page 274">p. 274</a>).<br> +Soissonnais sands, or Lits coquilliers, with <i>Nummulites +planulata</i> (<a href="ch16.html#page 275">p. 275</a>).<br> +Claiborne beds of the United States, with <i>Orbitoides</i> and +<i>Zeuglodon</i> (<a href="ch16.html#page 279">p. 279</a>).<br> +Nummulitic formation of Europe, Asia, etc. (<a href= +"ch16.html#page 277">p. 277</a>).</td> +</tr> + +<tr> +<td valign="middle" align="center">9.<br> +LOWER<br> +EOCENE.</td> +<td align="left"><b>British</b><br> +London clay proper (<a href="ch16.html#page 263">p. 263</a>).<br> +Woolwich and Reading series, fluvio-marine (<a href= +"ch16.html#page 267">p. 267</a>).<br> +Thanet sands (<a href="ch16.html#page 269">p. 269</a>).<br> +<b>Foreign</b><br> +Argile de Londres, near Dunkirk (<a href="ch16.html#page 252">p. +252</a>).<br> +Argile plastique (<a href="ch16.html#page 276">p. 276</a>).<br> +Sables de Bracheux (<a href="ch16.html#page 276">p. +276</a>).</td> +</tr> +</table> +</center> + +<br> +<center>SECONDARY OR MESOZOIC.</center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata"> +<tr> +<td align="center" valign="middle" rowspan="2">CRETACEOUS</td> +<td valign="middle" align="center">10.<br> +UPPER<br> +CRETACEOUS.</td> +<td align="left"><b>British</b><br> +Upper white chalk, with flints (<a href="ch17.html#page 290">p. +290</a>).<br> +Lower white chalk, without flints (<a href= +"ch17.html#page 298">p. 298</a>).<br> +Chalk marl (<a href="ch17.html#page 298">p. 298</a>).<br> +Chloritic series (or Upper Greensand), fire-stone of Surrey (<a +href="ch17.html#page 298">p. 298</a>).<br> +Gault (<a href="ch17.html#page 300">p. 300</a>).<br> +Blackdown beds (<a href="ch17.html#page 301">p. 301</a>).</td> +</tr> +</table> +</center> + +<p> </p> + +<hr> +<p class="page"><a name="page 134">[ 134 ]</a></p> + +<center><small>EXAMPLES</small></center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata"> +<tr> +<td align="center" valign="middle" rowspan="2">CRETACEOUS</td> +<td valign="middle" align="center">10.<br> +UPPER<br> +CRETACEOUS.</td> +<td align="left"><b>Foreign</b><br> +Maetricht beds and Faxoe chalk (<a href="ch17.html#page 233">p. +233</a>).<br> +Pisolitic limestone of France (<a href="ch17.html#page 285">p. +285</a>).<br> +White chalk of France, Sweden, and Russia (<a href= +"ch17.html#page 286">p. 286, 287</a>).<br> +Planer-kalk of Saxony (<a href="ch17.html#page 293">p. +293</a>).<br> +Sands and clays of Aix-la-Chapelle (<a href= +"ch17.html#page 302">p. 302</a>).<br> +Hippurite limestone of South of France (<a href= +"ch17.html#page 305">p. 305</a>).<br> +New Jersey, U.S., sands and marls (<a href= +"ch17.html#page 307">p. 307</a>).</td> +</tr> + +<tr> +<td valign="middle" align="center">11.<br> +LOWER<br> +CRETACEOUS or<br> +NEOCOMIAN.</td> +<td align="left"><b>British</b><br> +Sands of Folkestone, Sandgate, and Hythe (<a href= +"ch18.html#page 308">p. 308</a>).<br> +Atherfield clay, with <i>Perna mulleti</i> (<a href= +"ch18.html#page 309">p. 309</a>).<br> +Punfield marine beds, with <i>Vicarya lujana</i> (<a href= +"ch18.html#page 318">p. 318</a>).<br> +Speeton clay of Flamborough Head and Tealby (<a href= +"ch18.html#page 311">p. 311</a>).<br> +Weald clay of Surrey, Kent, and Sussex, fresh-water, with +<i>Cypris</i> (<a href="ch18.html#page 313">p. 313-5</a>).<br> +Hastings sands (<a href="ch18.html#page 316">p. 316-8</a>).<br> +<b>Foreign</b><br> +Neocomian of Neufchatel, and Hils conglomerate of North Germany +(<a href="ch18.html#page 312">p. 312</a>).<br> +Wealden beds of Hanover (<a href="ch18.html#page 319">p. +319</a>).</td> +</tr> + +<tr> +<td valign="middle" align="center" rowspan="3">OOLITE</td> +<td align="center" valign="middle">12.<br> +UPPER OOLITE.</td> +<td align="left"><b>British</b><br> +Upper Purbeck beds, fresh-water (<a href="ch19.html#page 323">p. +323</a>).<br> +Middle Purbeck, with numerous marsupial quadrupeds, etc. (<a +href="ch19.html#page 324">p. 324</a>).<br> +Lower Purbeck, fresh-water, with intercalated dirt-bed (<a href= +"ch19.html#page 330">p. 330</a>).<br> +Portland stone and sand. (<a href="ch19.html#page 334">p. +334</a>).<br> +Kimmeridge clay (<a href="ch19.html#page 335">p. 335</a>).<br> +<b>Foreign</b><br> +Marnes à gryphées virgules of Argonne (<a href= +"ch19.html#page 336">p. 336</a>).<br> +Lithographic-stone of Solenhofen, with <i>Archæopteryx</i> +(<a href="ch19.html#page 337">p. 337</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">13.<br> +MIDDLE OOLITE.</td> +<td align="left"><b>British</b><br> +Coral rag of Berkshire, Wilts, and Yorkshire (<a href= +"ch19.html#page 339">p. 339</a>).<br> +Oxford clay, with belemnites and Ammonite (<a href= +"ch19.html#page 340">p. 340</a>).<br> +Kelloway rock of Wilts and Yorkshire (<a href= +"ch19.html#page 341">p. 341</a>).<br> +<b>Foreign</b><br> +Nerinæan limestone of the Jura (<a href= +"ch19.html#page 339">p. 339</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">14.<br> +LOWER OOLITE.</td> +<td align="left"><b>British</b><br> +Cornbrash and forest marble (<a href="ch19.html#page 341">p. +341</a>).<br> +Great or Bath oolite of Bradford (<a href="ch19.html#page 342">p. +342</a>).<br> +Stonesfield slate, with marsupials and <i>Araucaria</i> (<a href= +"ch19.html#page 345">p. 345</a>).<br> +Fuller’s earth of Bath (<a href="ch19.html#page 348">p. +348</a>).<br> +Inferior oolite (<a href="ch19.html#page 349">p. 349</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">LIAS</td> +<td align="center" valign="middle">15.<br> +LIAS.</td> +<td align="left">Upper Lias, argillaceous, with <i>Ammonites +striatulus</i> (<a href="ch20.html#page 353">p. 353</a>).<br> +Shale and limestone, with <i>Ammonites bifrons</i> (<a href= +"ch20.html#page 353">p. 353</a>).<br> +Middle Lias or Marlstone series, with zones containing +characteristic Ammonites (<a href="ch20.html#page 353">p. +353</a>).<br> +Lower Lias, also with zones characterised by peculiar Ammonites +(<a href="ch20.html#page 356">p. 356</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle" rowspan="3">TRIAS</td> +<td align="center" valign="middle">16.<br> +UPPER TRIAS.</td> +<td align="left"><b>British</b><br> +Rhætic, Penarth or <i>Avicula contorta</i> beds (beds of +passage) (<a href="ch21.html#page 366">p. 366</a>).<br> +Keuper or Upper New Red sandstone, etc. (<a href= +"ch21.html#page 369">p. 369</a>).<br> +Red shales of Cheshire and Lancashire, with rock-salt (<a href= +"ch21.html#page 371">p. 371</a>).<br> +Dolomite conglomerate of Bristol (<a href="ch21.html#page 373">p. +373</a>).<br> +<b>Foreign</b><br> +Keuper beds of Germany (<a href="ch21.html#page 375">p. +375</a>).<br> +St. Cassian or Hallstadt beds, with rich marine fauna (<a href= +"ch21.html#page 376">p. 376</a>).<br> +Coal-field of Richmond, Virginia (<a href="ch21.html#page 382">p. +382</a>).<br> +Chatham coal-field, North Carolina (<a href= +"ch21.html#page 383">p. 383</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">17.<br> +MIDDLE TRIAS.</td> +<td align="left"><b>British</b><br> +Wanting.<br> +<b>Foreign</b><br> +Muschelkalk of Germany (<a href="ch21.html#page 378">p. +378</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">18.<br> +LOWER TRIAS.</td> +<td align="left"><b>British</b><br> +Bunter or Lower New Red sandstone of Lancashire and Cheshire (<a +href="ch21.html#page 372">p. 372</a>).<br> +<b>Foreign</b><br> +Bunter-sandstein of Germany (<a href="ch21.html#page 380">p. +380</a>).<br> +Red sandstone of Connecticut Valley, with footprints of birds and +reptiles (<a href="ch21.html#page 381">p. 381</a>).</td> +</tr> +</table> +</center> + +<p> </p> + +<hr> +<p class="page"><a name="page 135">[ 135 ]</a></p> + +<center>PRIMARY OR PALÆOZOIC<br> +<small>EXAMPLES</small></center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata"> +<tr> +<td align="center" valign="middle">PERMIAN</td> +<td align="center" valign="middle">19.<br> +PERMIAN.</td> +<td align="left"><b>British</b><br> +Upper Permian of St. Bees’ Head, Cumberland (<a href= +"ch22.html#page 386">p. 386</a>).<br> +Middle Permian, magnesian limestone, and marl-slate of Durham and +Yorkshire, with <i>Protosaurus</i> (<a href= +"ch22.html#page 387">p. 387</a>).<br> +Lower Permian sandstones and breccias of Penrith and +Dumfriesshire, intercalated (<a href="ch22.html#page 390">p. +390</a>).<br> +<b>Foreign</b><br> +Dark-coloured shales of Thuringia (<a href= +"ch22.html#page 392">p. 392</a>).<br> +Zechstein or Dolomitic limestone (<a href="ch22.html#page 392">p. +392</a>).<br> +Mergel-schiefer or Kupfer-schiefer (<a href= +"ch22.html#page 392">p. 392</a>).<br> +Rothliegendes of Thuringia, with <i>Psaronius</i> (<a href= +"ch22.html#page 392">p. 392</a>).<br> +Magnesian limestones, etc., of Russia (<a href= +"ch22.html#page 393">p. 393</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle" rowspan="2">CARBONIFEROUS</td> +<td align="center" valign="middle">20.<br> +UPPER CARBONIFEROUS.</td> +<td align="left"><b>British</b><br> +Coal-measures of South Wales, with underclays inclosing +<i>Stigmaria</i> (<a href="ch23.html#page 397">p. 397</a>).<br> +Coal-measures of north and central England (<a href= +"ch23.html#page 395">p. 395</a>).<br> +Millstone grit (<a href="ch23.html#page 395">p. 395</a>).<br> +Yoredale series of Yorkshire (<a href="ch23.html#page 395">p. +395</a>).<br> +Coal-field of Kilkenny with <i>Labyrinthodont</i> (<a href= +"ch23.html#page 407">p. 407</a>).<br> +<b>Foreign</b><br> +Coal-field of Saarbruck, with <i>Archegosaurus</i> (<a href= +"ch23.html#page 406">p. 406</a>).<br> +Carboniferous strata of South Joggins, Nova Scotia (<a href= +"ch23.html#page 409">p. 409</a>).<br> +Pennsylvania coal-field (<a href="ch23.html#page 403">p. +403</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">21.<br> +LOWER CARBONIFEROUS.</td> +<td align="left"><b>British</b><br> +Mountain limestone of Wales and South of England (<a href= +"ch24.html#page 430">p. 430</a>).<br> +Same in Ireland (<a href="ch24.html#page 437">p. 437</a>437).<br> +Carboniferous limestone of Scotland alternating with coal-bearing +sandstones (<a href="ch23.html#page 396">p. 396</a>).<br> +Erect trees in volcanic ash in the Island of Arran (<a href= +"ch30.html#page 546">p. 546</a>).<br> +<b>Foreign</b><br> +Mountain limestone of Belgium (<a href="ch24.html#page 436">p. +436</a>).</td> +</tr> + +<tr> +<td valign="middle" align="center" rowspan="3">DEVONIAN or<br> +O<small>LD</small> R<small>ED</small> +S<small>ANDSTONE</small></td> +<td align="center" valign="middle">22.<br> +UPPER<br> +DEVONIAN.</td> +<td align="left"><b>British</b><br> +Yellow sandstone of Dura Den, with <i>Holoptychius</i>, etc. (<a +href="ch25.html#page 440">p. 440</a>); and of Ireland with +<i>Anodon Jukesii</i> (<a href="ch25.html#page 441">p. +441</a>).<br> +Sandstones of Forfarshire and Perthshire, with +<i>Holoptychius</i>, etc. (<a href="ch25.html#page 442">p. +442</a>).<br> +Pilton group of North Devon (<a href="ch25.html#page 449">p. +449</a>).<br> +Petherwyn group of Cornwall, with <i>Clymenia</i> and +<i>Cypridina</i> (<a href="ch25.html#page 451">p. 451</a>).<br> +<b>Foreign</b><br> +Clymenien-kalk and Cypridinen-schiefer of Germany (<a href= +"ch25.html#page 450">p. 450</a>)</td> +</tr> + +<tr> +<td align="center" valign="middle">23.<br> +MIDDLE<br> +DEVONIAN.</td> +<td align="left"><b>British</b><br> +Bituminous schists of Gamrie, Caithness, etc., with numerous fish +(<a href="ch25.html#page 443">p. 443</a>).<br> +Ilfracombe beds with peculiar trilobites and corals (<a href= +"ch25.html#page 450">p. 450</a>).<br> +Limestones of Torquay, with broad-winged Spirifers (<a href= +"ch25.html#page 451">p. 451</a>).<br> +<b>Foreign</b><br> +Eifel limestone, with underlying schists containing +<i>Calceola</i> (<a href="ch25.html#page 453">p. 453</a>).<br> +Devonian strata of Russia (<a href="ch25.html#page 454">p. +454</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">24.<br> +LOWER<br> +DEVONIAN.</td> +<td align="left"><b>British</b><br> +Arbroath paving-stones, with <i>Cephalaspis</i> and +<i>Pterygotus</i> (<a href="ch25.html#page 446">p. 446</a>).<br> +Lower sandstones of Forfarshire, with <i>Pterygotus</i> (<a href= +"ch25.html#page 446">p. 446</a>).<br> +Sandstones and slates of the Foreland and Linton (<a href= +"ch25.html#page 454">p. 454</a>).<br> +<b>Foreign</b><br> +Oriskany sandstone of Western Canada and New York (<a href= +"ch25.html#page 456">p. 456</a>).<br> +Sandstones of Gaspe, with <i>Cephalaspis</i> (<a href= +"ch25.html#page 455">p. 455</a> ).</td> +</tr> +</table> +</center> + +<p> </p> + +<hr> +<p class="page"><a name="page 136">[ 136 ]</a></p> + +<center><small>EXAMPLES</small></center> + +<center> +<table border="1" cellpadding="4" cellspacing="0" summary= +"Tabular view of the Fossiliferous Strata"> +<tr> +<td align="center" valign="middle" rowspan="2">SILURIAN</td> +<td align="center" valign="middle">25.<br> +UPPER SILURIAN</td> +<td align="left"><b>British</b><br> +Upper Ludlow formation, Downton sandstone, with bone-bed (<a +href="ch26.html#page 459">p. 459</a>).<br> +Lower Ludlow formation, with oldest known fish remains (<a href= +"ch26.html#page 461">p. 461</a>).<br> +Wenlock limestone and shale (<a href="ch26.html#page 465">p. +465</a>).<br> +Woolhope limestone and grit (<a href="ch26.html#page 467">p. +467</a>).<br> +Tarannon shales (<a href="ch26.html#page 468">p. 468</a>).<br> +<i>Beds of passage between Upper and Lower Silurian:</i><br> +Upper Llandovery, or May-hill sandstone, with <i>Pentamerus +oblongus</i>, etc. (<a href="ch26.html#page 468">p. 468</a>).<br> +Lower Llandovery slates (<a href="ch26.html#page 469">p. +469</a>).<br> +<b>Foreign</b><br> +Niagara limestone, with <i>Calymene, Homalonotus</i>, etc. (<a +href="ch26.html#page 479">p. 479</a>).<br> +Clinton group of America, with <i>Pentamerus oblongus</i>, etc. +(<a href="ch26.html#page 479">p. 479</a>).<br> +Silurian strata of Russia, with <i>Pentamerus</i> (<a href= +"ch26.html#page 477">p. 477</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">26.<br> +LOWER SILURIAN.</td> +<td align="left"><b>British</b><br> +Bala and Caradoc beds (<a href="ch26.html#page 470">p. +470</a>).<br> +Llandeilo flags (<a href="ch26.html#page 473">p. 473</a>).<br> +Arenig or Stiper-stones group (Lower Llandeilo of Murchison) (<a +href="ch26.html#page 475">p. 475</a>).<br> +<b>Foreign</b><br> +Ungulite or Obolus grit of Russia (<a href= +"ch26.html#page 477">p. 477</a>).<br> +Trenton limestone, and other Lower Silurian groups of North +America (<a href="ch26.html#page 479">p. 479</a>).<br> +Lower Silurian of Sweden (<a href="ch26.html#page 477">p. +477</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle" rowspan="2">CAMBRIAN</td> +<td align="center" valign="middle">27.<br> +UPPER CAMBRIAN.</td> +<td align="left"><b>British</b><br> +Tremadoc slates (<a href="ch27.html#page 483">p. 483</a>).<br> +Lingula flags, with <i>Lingula Davisii</i> (<a href= +"ch27.html#page 484">p. 484</a>).<br> +<b>Foreign</b><br> +"Primordial" zone of Bohemia in part, with trilobites of the +genera <i>Paradoxides</i>, etc. (<a href="ch27.html#page 487">p. +487</a>).<br> +Alum schists of Sweden and Norway (<a href= +"ch27.html#page 489">p. 489</a>).<br> +Potsdam sandstone, with <i>Dikelocephalus</i> and <i>Obolella</i> +(<a href="ch27.html#page 489">p. 489</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">28.<br> +LOWER CAMBRIAN.</td> +<td align="left"><b>British</b><br> +Menevian beds of Wales, with <i>Paradoxides Davidis</i>, etc. (<a +href="ch27.html#page 484">p. 484</a>).<br> +Longmynd group, comprising the Harlech grits and Llanberis slates +(<a href="ch27.html#page 485">p. 485</a>).<br> +<b>Foreign</b><br> +Lower portion of Barrande’s "Primordial" zone in Bohemia +(<a href="ch27.html#page 486">p. 486</a>).<br> +Fucoid sandstones of Sweden (<a href="ch27.html#page 489">p. +489</a>).<br> +Huronian series of Canada? (<a href="ch27.html#page 490">p. +490</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle" rowspan="2">LAURENTIAN</td> +<td align="center" valign="middle">29.<br> +UPPER LAURENTIAN.</td> +<td align="left"><b>British</b><br> +Fundamental gneiss of the Hebrides? (<a href= +"ch27.html#page 493">p. 493</a>).<br> +Hypersthene rocks of Skye? (<a href="ch27.html#page 491">p. +491</a>).<br> +<b>Foreign</b><br> +Labradorite series north of the river St. Lawrence in Canada (<a +href="ch27.html#page 491">p. 491</a>).<br> +Adirondack mountains of New York (<a href="ch27.html#page 491">p. +491</a>).</td> +</tr> + +<tr> +<td align="center" valign="middle">30.<br> +LOWER LAURENTIAN.</td> +<td align="left"><b>British</b><br> +Wanting?<br> +<b>Foreign</b><br> +Beds of gneiss and quartzite, with interstratified limestones, in +one of which, 1000 feet thick, occurs a foraminifer, <i>Eozoon +Canadense</i>, the oldest known fossil (<a href= +"ch27.html#page 491">p. 491</a>).</td> +</tr> +</table> +</center> + +<br> +<hr> +<small><a href="contents.html">Contents</a> / <a href= +"ch7.html">Chapter VII</a> / <a href="ch9.html">Chapter +IX</a></small> +</body> +</html> + + |