Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/74

4 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 11, whence the amber has been derived from what came under my own notice. The late Emperor Nicholas presented to me a monthpiece of a pipe formed out of a block of amber which Avas dug out in his presence, at a depth of 18 feet, in the province of Grodno. On asking me if I was aware of amber occurring in that region, I opened the Geological Map of Russia prepared by myself and friends, and, pointing to the yellow colour which extended from that province to the Baltic Sea, I directed His Majesty's attention to the word amber inscribed on the coast-line as being found in these Tertiary deposits.

Discussion.

Sir EoDERiCK MuECHisoisr, in explanation of the paper, referred to a geological map of Eussia, and gave a general sketch of the bearing of the paper on the previously known geology of that country. He mentioned the discovery by M. Grewinck of beds of brown coal containing amber, and overlying true chalk. The amber in the Baltic had been supposed to have been washed out of beds beneath the sea ; but Count Kej^serling has suggested that the amber may have been brought down by the rivers from the interior, and depo- sited in the Baltic. Sir Roderick also called attention to the absence of igneous rocks in Russia to the west of the Ural Mountains.

2. On a Section 0/ a Well at Kissingen. By Dr. F. Saos^dbeegeii, For. Corr. G.S. [Communicated by Sir E. I. Murchison, Bart., K.C.B., F.E.S., F.G.S.] (Abstract.)

The beds which have been pierced by the bore of the Schonborn Well (2001 feet 9 in. in depth) at the Upper Salinen, near Kissingen, have already been several times described, but, in the author's opinion, not in a manner which has led to a clear knowledge of them. He therefore examined carefully the specimens which still retained the original labels, and even conveyed them to Wiirzburg for analysis.

He coQsidered it highly desirable, in the first place, to ascertain a datum-line remaining constant over a wide area ; and such he deter- mined to be the blackish-blue limestone which was bored through at the depth of from 1698 to 1740 feet (see Section, p. 6). It con- sists of two varieties — one pyritous and the other free from bisul- phide of iron. The colour is deep blackish grey, the structure close, and the fracture almost conchoidal. A quantitative determination gave 60-20 per cent, of carbonate of lime, and 17-22 per cent, of carbonate of magnesia. The rock is therefore a very bituminous and argillaceous dolomite. It corresponds accurately with the upper- most bituminous Plattendolomit of the Zechstein of the Hartz and Thuringia, and with hand-specimens from Eisenach, Aschaffenberg, and Gera.

The upper boundary of the Zechstein-formation having been thus