1857.] HULL TRIAS AND PERMIAN. 221 



Roth-todt-liegendes, and in the latter, according to the hypothesis of 

 Sir R. Murchison, the Freiburg gneiss is a Silurian slate, altered by 

 eruptive granite of probably the same date with that of Heidelberg*. 



In the Odenwald this granite forms the basis upon which the 

 superstructure of the Permian and Triassic formations has been raised. 



The geology of this Range has been illustrated by a map, accom- 

 panied by a memoir, by Dr. von Leonhard, of Heidelberg f, who kindly 

 accompanied me to some of the best sections in the neighbourhood, 

 and to whose work I beg to refer those who wish to become well 

 acquainted with the geology of the Odenwald and Schwarzwald, as 

 the description here given must necessarily be brief. 



Permian. 



The Roth-todt-liegendes of the Odenwald is finely exhibited in 

 a road-cutting leading up the flank of the hill from the village of 

 Handschucheim. A section of nearly 200 feet may be measured, 

 and the upper surface is deeply covered by Loess, which rises on the 

 flanks of these hills about 300 feet above the Rhine. The descrip- 

 tion which Murchison and Morris have given of this rock in the 

 Hartz, will apply equally here, and we might go farther and aflirm 

 that the same description would apply to the Permian trappoid brec- 

 cias of Worcestershire. In the Odenwald this formation consists of 

 unconsolidated breccia in a bright-red marly matrix, presenting only 

 rude traces of bedding. The fragments are of porphyry and granite, 

 the former in excess ; and the parent-masses are in immediate con- 

 tact with strata to which they have supplied materials. At Raitbach 

 and Sackingen, it has the appearance of a drift swept from off the 

 Schwartzwald. At Baden, it is sometimes a coarse, sometimes a 

 fine, breccia of granite, porphyry, clayslate, and gneiss, cemented by 

 red marl. As in Worcestershire, the breccias of the Roth-todt- 

 liegendes may be regarded as a drift % derived from the destruction 

 of more ancient sub -aerial rocks, consisting of eruptive porphyries 

 in the Odenwald and Germany generally, with which they appear 

 intimately associated. 



The resemblance of these beds to the trappoid breccias of Wor- 

 cestershire cannot fail to have struck an observer acquainted with 

 the formations of both countries. The resemblance is perfect, if we 

 except the difference in the composition of the fragments, consequent 

 upon the variations in the rock-masses from which they have been 

 derived. 



The trappoid breccias of the Enville and Lickey Hills do not, 

 however, form the basement-beds of the English Permian system, as 

 similar breccias do in the Odenwald. In the former districts they 

 are underlaid by several hundred feet of red sandstones and marls, 

 with calcareous bands. For these beds we shall probably find repre- 

 sentatives in strata described by Murchison and Morris, as occurring 

 immediately over the coal-strata of the Thiiringerwald, and beloiv 



* ' Siluria,' p. 361. t Geognostische Skizze von Baden, 1846. 



% Of glacial formation according to Professor Ramsay ; Quart. Journ. Geol. Soc. 

 vol. xi. p. 185. 



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