1813.] 



0?i Formations^ 



19S 



and all tlie phennmeria they present attest the partiality of their 

 deposition. We cannot, from' these appearances, infer any 

 thing in regard to the general structure of the earth ; and how- 

 ever interesting they may appear to us, it would lead to erroneous 

 views were we to deduce from them general inferences in regard 

 to the structure of the eartli ; for every general inference of this 

 kind from a local appearance mast be false. These series of 

 rocks, to distinguish them iiO... .1.2 ^or^ widely distributed or 

 universal, are denominated partial or local foniiat ions. This 

 interesting division was first pointed out? by Werner. Fie was kd 

 to it by the examination of a series of rocks at Wehrau, in 

 Lusatia. To the common ol)server these rocks might have 

 passed for members of the universal series ; but his judgment 

 and penetration led him to ascertain that tiieir characters were of 

 such a nature as to afford proofs of the existence of a kind of 

 formation of solid rocks fiitherto unsuspected. The idea was 

 not lost with him ; for he inferred that such formations would be 

 found in other similar sitnaiions. and that the bottoins of lakes, 

 tlie sides of rivers, &c. would frequently present appearances of 

 this kind. These local formations are less striking in low and flat 

 countries than in mountainous regions — -wliere they are contained 

 in valleys and their boundaries strongly marked. Hence we 

 must be careful, in describing the rocks of low and flat countries, 

 not to confound partial or local with universtil formation. 



The celebrated Von Buch, in one of the late numbers of the 

 magazine published by the Society of the Friends of Natural 

 History in Berlin, describes an uncommonly interesting local 

 formation which he discovered at Locle, in the district of Jura. 

 It is contained in a high enclosed valley, situated 1665 Fr. feet 

 above the level of the lake of Neufchatel, and 2959 Fr. feet 

 above the level of the sea. The valley, and the strata it contains, 

 are about two miles and a quarter long, and about a mile 

 broad. It is surrounded with high mountains of white com- 

 pact limestone; and its bottom is of the same species of 

 rock. It is completely inclosed ; and the water that falls 

 in it escapes by subterraneous unknown canals. These canals 

 may have opened for the first time not many centuries ago, 

 before which period the whole valley of Locle must have 

 been a lake. Even still thjC canals are so narrow that, the 

 valley is frequently overflowed : this circumstance induced the 

 inhabitants in the year 1802 to cut long levels into the sides of 

 the bounding mountains, in order to permit the water to escape 

 into the lower valieys. This undertaking succeeded completely. 

 The valley contains many small hills, from 200 to 300 feet high. 

 The lowest stratum of these hiHs, which rests immediately on 

 the limestone, is a very coarse conglomerate of masses of the 

 neighbouring limestone. On it rests a pretty thick bed of marly 



Vol. L N° Oi N 



