410 Mr. Weaver on Floetz Formations. [Dec. 



is rich in beds of oolite, giving as instances the oolite near 

 Rumigny, at the south-western foot of the Ardennes, and the 

 oolite of the Jura.* The first notice of the latter, however, is, 

 I believe, due to M. de Saussure.f 



The general character and distribution of the shell limestone 

 formation in England, as consisting of the lias and oolite series, 

 with their accompanying beds of clay, marl, and wood coal, may 

 be learned from Mr. Greenough's Geological Map, comprehend- 

 ing the groups No. 15 up to No. 9 inclusive. And several illus- 

 trative facts may be collected from Mr. Webster's observations 

 in Sir H. Englefield's splendid work on the Isle of Wight, &c. 

 and from Mr. W. Phillips's Compendium of the Geology of 

 England and Wales. 



2. Quader and Planer Sandstein and Kalkstein. 



Third Floetz Sandstone Formation of Werner. 



Ferruginous and Green Sandstone and Limestone Formation. 



In my notices of this formation, I shall confine myself chiefly 

 to the observations of MM. Hausmann, von Schlotheim, and 

 von Raumer. 



1. According to M. Haussmann, the quacfersandstone consti- 

 tutes in Lower Saxony a chain of low hills and eminences, 

 "which commencing at the north-eastern foot oftheHartz, between 

 Quedlinburg and Blankenbmg, proceeds in a north-western 

 direction as far as into Westphalia. It consists of a uniformly 

 fine-grained sandstone, usually of a white colour, composed 

 simply of grains of quartz, with a very slightproportion of cement, 

 often scarcely pereeptible. The cement is commonly argilla- 

 ceous, and frequently more or less iron-shot, so that the white 

 ground is stained with stripes or spots, of a yellow, red, or brown 

 colour ; or the whole substance is thus discoloured. The iron- 

 shot cement passes sometimes into argillaceous ironstone ; and 

 the argillaceous cement is casually penetrated with bituminous 

 matter, then assuming a grey or black colour. The connecting 

 medium sometimes consists also of clay marl, or calcareous 

 marl ; ami more rarely of quartz, or calcedony. Strings of 

 quartz traverse the sandstone occasionally, forming cells when 

 the substance of the rock is decomposed. It is always stratified, 

 in strata from half a foot to several el's in thickness ; but never 

 slaty, like the new red or variegated sandstone. It is further 

 distinguished from the latter by the following characters : it is 

 firmer and more compact, with a smaller proportion of cement, 

 and is less discoloured ; it contains mica much more sparingly, 



* See the appendix to the work of M. von Raumer, quoted above, in which the 

 author offers some remarks on the analogy of the newer floetz formations in England, 

 France, Germany, and the Alps. 



t Voyages dana let Alpes, tea. 368. 



