256 



THE GEOLOGIST. 



Enslern aiul Eastern Comities of Eng-land, ineludiiio- Laiioashive, Chcsliiro, and Staf- 

 Ibrdsliire. Tlie nearest body of tLe Oolite and Lias series would be in the East 

 llidino- of Yorkshire, and in the northern part of Ijineohishire. The 

 nearest o-ranites, probably, are Sliap Fell, and those near Ravengdass in Westmore- 

 land. Huddersfield is ' nearly equidistant from the Trap-rocks of Buttermere, 

 Ulleswater, &c., from those of Charnwood Forest, and from those of W'ellingtonand 

 the Breidden, on the borders of Wales. The Brown Coal of Gerriiany presents 

 several varieties of lignite, some of it being in the condition of bog-oak, and 

 some almost approaching to glance-coal. There seem to be two main seams of 

 brown-coal over the north of Germany, but for the most ])art the numerous 

 patches of these lignites spread over Europe are more or less isolated accimiu- 

 lations of vegetable matter in the sediments of the estuaries and lakes of the 

 middle Tertiary period, tlie u]iper Eocene of some geologists, the oligocene of Dr. 

 Beyrlck, and some of the brov\ n-coals of Southern Germany belong to the upper 

 Tertiary period. A paper, treating of the brown-coal of Germany, read by Mr. 

 Hamilton, was printed in Vol. X. of the Geological Society's Journal. 



Septaeia of the Loxdox Clay. — "Sie, — Could you oblige by informing me, 

 through the medium of your valuable periodical, how those concre( i(ms, called by 

 geologists ^scptaria.' wliich are met with so almndantly in the London Clay, came 

 intothe position in which we nowlind lliem, viz.,in such horizontal strata, what is the 

 reason for their peculiar internal sl rut'tuvo. ol" \\ liat minerals ;ire they ci'.sentially com- 

 posed, and in ^\hat books am 1 likely to find a tuU account of the Lower Eocene 

 strata, more especially ? Yours, &c., — A:matot{. Nattjii^ (Cavendish S([uare)." — 

 The septaria of the London clay are composed of clay and cavlxmate of lime, 

 with, some silica. Similar concretions have been found to contain asnmch as 50 per 

 cent, of lime, wliilst their clay-matrix contained only about 10 per cent. ])r. 

 Jackson has obsers ed that the crystallizing force of the carl)onate of lime is the 

 cause of the concretionary structure and form of such nodules ; the foi'eign bodies 

 frequently found within them having served as nxiclei around which this semi- 

 crystallisation took ]~)lace : the carbonate of lime has segregated and carried 

 Avith it the inert particles of clay; and their sphaeroidal form is that which would 

 result from this action v.dien the force was not adequate to the production of 

 crystals. Sul)sequently, during the contraction of the nodular mass, crevices were 

 formed, in which carbonate of lime more or less freely crystallized, forming veins 

 or hard divisional plates; hence the name sep far ium. The ajtparent horizontality 

 of these nodules is owing to the original bedding of the sevei-al layers of clay with 

 ditTerent proportions of fossil remains, which may have been, to some extent, a 

 source of the carlwnate of lime. Mr. Prestwicli is the chief English author on 

 the tertiary strata of England, His numerous memoirs have appeared in the 

 " Journal of the Geological Society ; " and the small work he has lately publislied, 

 " The Ground beneath us," contains a concise epitome of his views and deductions ; 

 we recommend it for our querist's perusal. 



Neav Bed Coxceetioxs.— The note of W. R. B., of Stockport, referring to 

 New Bed Sandstone specimens from the Mersey, between Egremont and New 

 l.righton, is difficult to answer, as we have none of the specimens before us. 

 Possildy they are ripple-formed layers Avith argillo-calcareous concretions, the 

 origin of Avhich cannot be determined Avlthout actual inspection. Our correspon- 

 dent's suggestion of their being " mud-balls " may be correct. 



WoEKS ON THE Geology op Noeth Stapfobdsiiiee. — Sie, — I have been 

 much interested by the articles in the Geologist, on the carboniferous beds; and 

 AM'ito to ask if you can recommend any books which give full information as to 

 that iovniation. especially of the coal-beds themselves? As I have opportunities and 

 facilu'ux i;,r personal ins]iection of the Xorth Stafibrdshire coal-field, I shall feel 

 l)ariii'ularly t^Migod it you can direct me to any books written with si)eclal 

 reference to tli;!i i\Ad. in yonv hi.st number, 1 saw a notice of the Mim'nf/ 

 Journol ; is the >,ortli Stnii'ordvhivo roi'l-tield, in its a-eolodcal aspects, noticed in 

 this work, if so, what is its ]n'irc r — C. 1- , L. Lcelc."— V\'o cannot point to anv special 

 Avork on the North St:;!!' 'rd^hiro co.d-llcld. ^roros^or .lukos has described that of 

 South StalVordshire in miuute detail in the " Becords of the School of Mines" 



