E. MINERALOGY AND GEOLOGY. 243 



portion of the region where the metal occurs, amounts to 

 about 800 tons during the past year. The principal mines 

 are on Coke's Creek, Middle Creek, and Maclntyre River. 

 The rocks are granite, greenstone trap, carboniferous beds, 

 miocene, pliocene, quaternary, the latter including drift de- 

 posits. The stream tin is found in the drift as well as in the 

 miocene, and valuable veins of tin ore occur in granite which 

 is believed to be of upper carboniferous age. 4 2>, Novem- 

 ber, 1874, 403. 



GOLD IN EASTERN SIBERIA. 



Gold was obtained during the year 1874, in large quanti- 

 ties, from the region of the Upper Amoor of Eastern Siberia. 

 13 A, November 14, 1874, 532. 



ORIGIN OF THE RED CHALK AND THE RED CLAY. 



Professor Church, in a recent number of the Chemical 

 JVeics, communicates an article upon the red chalk and the 

 red clay, in which he points out a striking relationship be- 

 tween these substances as existing in England, and the gath- 

 erings in the recent deep-sea explorations from the bottom 

 of the sea. We have already referred to Professor Thomson's 

 explanation of the origin of the latter; and Professor Church 

 gives us good reason to suspect a close parallelism in point 

 of origin between the two, the chemical composition as well 

 as physical character of the chalk agreeing very closely with 

 those of the red residue obtained by Mr. Buchanan from the 

 globigerina ooze, and those of the red smooth clay brought 

 up from the deeper part of the sea bottom. 



There are differences between the two, to which Professor 

 Church adverts, but these, in his opinion, may be caused by 

 subsequent conditions which we are at present unable to ap- 

 preciate. Both substances appear to be entitled to the desig- 

 nation of a silicate of red oxide of iron and alumina, and to 

 have been derived in all probability by the removal, in dif- 

 ferent degrees, of the calcareous matter from the original ma- 

 terial. The question of the occurrence and origin of glau- 

 conite, a variable silicate of grayish green color, is also dis- 

 cussed ; and the similarity caused by its presence between 

 the cretaceous and greensand strata in Europe and America, 

 to the recent greensands of the Australian seas and of the 



