528 Ol- THE PHYSICAL STRUCTURE 



author, through the Dromagh coal-field.* Similar phenomena 

 would seem to be referred to, also, by Mr. Austin, when, in speak- 

 ing of the neighborhood of Waterford, he ascribes the numerous 

 contortions of schistose rocks, considered by him as being of the 

 age of the Silurian, to excessive lateral p)'essure.T 



From the delineations and descriptions of the structure of the 

 Alps, and more particularly of the Jura, which we have met with, 

 we are led to believe that precisely similar structural features 

 prevail in those disturbed chains. The various sections, illustrative 

 of M. Thurman's worlv, ' Essai sur les Soulevemens Jm-assiques,' 

 may be appealed to as furnishing conclusive proof, that the axis- 

 planes of the numerous parallel anticlinal and synclinal axes of 

 the Jura, are in every case oblique, and that they dip, in a great 

 majority of instances, soUth-southeast, or towards the Alps. 



Belgium, and the Rhenish provinces, seem to exhibit features 

 of structm'e strildngly analagous to those of our Appalachian 

 chain ; and we think we do not go too far, when we afRi'm, that 

 in those " extraordinary derangements and disturbances," and 

 those " almost incredible phenomena of dislocation, contortion, 

 and inversion," referred to by Dr. Buckland, as having been so 

 ably elucidated by M. Dumont, we clearly recognize some of the 

 general laws described in this paper, and made familiar by our 

 researches in the Appalachian belt. On this head we would 

 refer to the observations of Messrs. Murchison and Sedgewick, 

 contained in their memoir " On the Classification and Distribution 

 of the Older Rocks of Germany," of which an abstract is published 

 in the Proceedings of the Geological Society of London. These 

 distinguished geologists, when speaking of the groups of strata 

 beneath the lower Westphalian limestone, thus describe the struc- 

 ture of the region northwest of the chain of the Taunus. " For 

 many miles south of the undistm-bed range of the lower West- 

 phalia limestone, the prevailing dip is about north-northwest ; the 

 country round Seigen is regarded as a kind of dome of elevation, 



* See Memoir on the Geological Relations of the South of Ireland, by Thomas Weaver, 

 Esq. Trans. Geol. Soc. Lond., 2d series, vol. V. 



+ See Proceedings of the Geol Soc, Lond.. No. 74. 



