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NA TU RE 



[Sept. 25, 1 J 



author regarded peat in the light of post-Tertiary coal ; lignite 

 as peat in a transition state to coal ; and coal as the remains of 

 Carboniferous bogs. The author referred to the practical appli- 

 cation of a knowledge of the microscopic structure of coal, as 

 enabling an expert to judge of the nature of a coal from an 

 examination of it with a pocket lens. 



Points of Dissimilarity ami Resemblance between Acadian ami 

 Scottish Glacial Beds, by Ralph Richardson, F.R.S.E., V.P. 

 G.S.Edinb. — Mr. Richardson said that, in his "Acadian 

 Geology," Principal Dawson gave the following as a typical 

 section of the superficial geology of Acadia — that is, Nova 

 Scotia, New Brunswick, and Prince Edward Island — and as, in 

 some respects, also applicable to Canada and Maine, viz. : At 

 the bottom, peaty deposits ; then unstratified Boulder Clay ; 

 then stratified Leda Clay, indicating deep water; and, lastly, 

 gravel and sand beds, the Saxicava sand indicating shallow 

 water. Mr. Richardson pointed out wherein such a section dif- 

 fered from and resembled the glacial beds of Scotland. He said 

 the latter showed no such orderly arrangement as the Acadian, 

 and could not, as a rule, be divided into deep and shallow water- 

 beds. The marine shells in the Scottish beds are all mixed up 

 together, regardless, as a rule, of the province — whether Arctic 

 or British, or both — to which they properly belong, regardless 

 of the depths which they usually tenant, and regardless of the 

 deposit (whether clay, gravel, or sand) in which they are now 

 found fossil. They are likewise met with at all heights, from 

 the level of the sea to more than 500 feet above it. No system 

 of dispersion of boulder-erratics from definite centres in Scot- 

 land seems as yet ascertained. The peaty deposits, occurring in 

 Principal Dawson's section below the Boulder Clay or till, occur 

 in Scotland above it. With regard to points of resemblance, the 

 fades of the shells in Acadia and Scotland is similar, being of the 

 Arctic and British- Arctic type. Again, both in Acadia and 

 Scotland, all the fossiliferous glacial beds occur above the un- 

 stratified Boulder Clay or till. Mr. Richardson cited various 

 Scottish sections to prove this, and remarked that the belief in 

 earlier and later Boulder Clays is of long standing in Scotland. 

 He concluded by pointing out that, in their cardinal features, the 

 Acadian and Scottish glacial beds seemed to coincide. In both 

 Acadia and Scotland that great mass of unstratified clay known 

 as ////existed; and doubtless the geologists of the New World 

 were, like those of the Old, puzzled to account for its origin 

 with certainty and satisfaction. The question was left unsolved 

 by the meeting of the British Association in Edinburgh in 1850; 

 although then discussed by Hugh Miller and Prof. John Fleming. 

 The author hoped that during the present meeting some advance 

 would be made in solving this great problem, as well as in corre- 

 lating and arranging the glacial beds of Canada, Acadia, and 

 Britain. 



On the Mode of Occurrence of Precious Stones and Aletah in 

 India, by V. Ball, M.A., F.R.S.— For full 3000 years India 

 has been known as the source of precious stones and metals, but 

 scarcely 200 years have elapsed since other countries yielding 

 precious stones have entered into competition with her ; and it 

 is only within the present century that she has ceased to hold a 

 pre-eminent position as a supplier of the markets of the world. 

 In order to arrive at a full and satisfactory elucidation of this 

 subject, two branches of inquiry must be undertaken— one based 

 upon what has been actually ascertained by careful geological 

 exploration of the country, and the other upon such historical 

 records as are available of the former production of the minerals 

 in question, and of the indications of the sites where they were 

 mined. By means of our present knowledge of the geology, it 

 has become possible to give definite form to many vague state- 

 ments by early writers, and to recognise the actual positions of 

 mines which are now, by the people of the localities thi mselves, 

 forgotten and deserted. In the majority of these cases, had the 

 geologist not got the historical hand to guide him, he would be 

 unwilling to predicate the presence of such minerals from mere 



'!' al examination. As a collateral result, many of the 



widespread myths and fables connected with mining have proved 

 to have originated in peculiar local customs. They re, I, there- 

 fore, on more substantial bases of facts than could have been 

 suspected by any one unacquainted with these customs. This 

 method of combining the results of geological research with 

 historical records the author has found on previous occasions to 

 have the advantage of bringing the geologist into touch with the 

 rest ol humanity, arranging as it does the interest of historians, 

 linguists, anil others, who find in the facts so presented to them 

 pabulum applicable to the requirements of their own particular 



pursuits. In this paper it will not be necessary or suitable to 

 enter at length into details — the author having done so else- 

 where. 1 His object is rather to direct attention to the subject 

 generally, and to make known the fact that much has been ac- 

 complished of late years which has not as yet found its way into 

 manuals and encyclopaedias. Most of the information to be 

 found in such works is far behind our present knowledge ; and, 

 where not actually incorrect, has been superseded by fuller and 

 more accurate observations. The subjects taken for special 

 consideration are the following : — Diamond, ruby, sapphire, 

 spinel, beryl, emerald, lapis-lazuli, gold, silver. The steel of 

 India, or wootz, might be included here, since, at least 2000 

 years ago, it was one of the most precious productions of India. 

 On tlie Relative A%cs of the American and the English Cretaceous 

 and Eocene Series, by J. Starkie Gardner, F. L.S., F.G S. : — The 

 paper is a contribution towards the determination of the ages of the 

 American Cretaceo-Eocene rocks, relative to those of Europe. 

 It briefly describes the chief characteristics of the various stages 

 of the series in America. The lowest beds there are distin- 

 guished by the presence of well-developed dicotyledonous 

 leaves, associated with Ammonites and other Cretaceous Mol- 

 lusca, considered to warrant their correlation with the Gault 

 and Chalk of England. Newer beds thought to be intermediate 

 in age between Secondary and Tertiary are distinguished by the 

 incoming of palms and a new flora of Dicotyledons, associated 

 with Mosasaurus. The rest are correlated with the various 

 divisions of the Tertiary series recognised in Europe. The en- 

 tire series seems to have been deposited without any consider- 

 able break in continuity, but reveals a sudden transition from a 

 temperate to a subtropical flora, and from a Cretaceous to a 

 Tertiary Vertebrata. The high development of the flora is, 

 however, quite irreconcilable with the accepted correlation. In 

 further comparing the American series with that of Europe, it is 

 observed that the subdivisions of the Cretaceous series were first 

 determined for a limited area, wdien different ideas of evolution 

 and gradual passage prevailed, and subsequently extended to 

 embrace area^ at a distance which may be, rightly or wrongly, 

 correlated with those of England and Western France. The 

 comparisons now drawn are only between the rocks of the 

 original and typical area and of America, excluding the Cre- 

 taceous rocks of other countries. Thus restricted, the Neo- 

 comian of Europe comprises only shore deposits, characterised 

 by a Cretaceo-Jurassic fauna and a Jurassic flora. The ( rault is 

 a deeper sea-deposit, comparable to the "Blue Mud" of the 

 ( 'hallenger, with a typically Cretaceous fauna and a Jurassic 

 flora. The Upper Greensands are more or less the equivalents 

 of the Gault, deposited under differing physical conditions, cor- 

 responding to the "Greensands" of the Challenger, and have 

 been assumed to represent the shore or shallower water condi- 

 tions preceding the Chalk. The Chalk itself is described with 

 a view to prove that it is a truly oceanic deposit, formed at a 

 distance from shore and at a considerable depth, corresponding 

 in all respects with the existing " Globigeriaa Ooze." The 

 arguments against this view are refuted in detail, and the sug- 

 gestion made that the alleged shallower habitats in the tropics 

 of the few surviving Mollusca may be due to the lower tempera- 

 ture prevailing now in the abyssal depths of the ocean having 

 driven heat-loving types from the depths at which they were 

 able to live in the Chalk period. The whole Cretaceous series 

 in the British area is the result of a gradual conversion of land 

 into sea, owing to subsidence. The process commenced with 

 the Neocomian, became more serious with the Gault, and con- 

 tinued until the close of the Chalk. The focus of the depres- 

 sion, so far as its results are accessible, wis the English Channel, 

 whence it spread in an easterly direction across Central Europe. 

 As the land subsided, the gulf increased in magnitude, and Blue 

 and Green Muds were formed on a wider and wider area, to be 

 ucceeded indue time by chalky Ooze. The nearer the focus 

 of subsidence the older the Greensands and Gault, and the 

 farther we recede from it the newer in age they become. The 

 zones of increasing depth travelled outward and forward, and 

 though now represented by continuous bands of the same litho- 

 logical characters, extending over many countries, it would be 

 rash in the extreme to infer the synchronism of portions of these 

 when separated by degrees of latitude. The time required for 

 these zones to travel from Kent to the Crimea, and to accumu- 

 late a mass, mainly composed of minute organisms, of over a 

 thousand feet in thickness, must have been sufficient to account 



1 " Economic Geology of India," and *" A l ;< ,,1 ;i^i\ I . '. .0 1 ral • it 1 . . ■ 1 < . ih. 

 ; ' 1 India," Pro, Roy Dul S, 



