174 



THE GEOLOGIST. 



6. Soft bright red and pale green shales, alternating in the 

 lower part with red sandstones — 650 feet. 



7. Limestone — twenty feet. 



The limits of the coal deposits of Nova Scotia have not 

 been defined, and great care would be necessary in attempt- 

 ing to ascertain them, on account of the overlying strata. 

 Mr. Logan is of opinion that the Pictou deposit probably 

 extends westward across Colchester county, to the north side 

 of the Basin of Mines, including the seams of Kemptown 

 and Onslow; and he believes that a parallel trough exists to 

 the southward, ranging from Hawkesbury on the western side 

 of Cape Breton Island to Windsor on the south side of the 

 Basin of Mines (lat. 44^ 49', long. 64^ 19' W.), three miles 

 south of which Mr. Logan discovered coal measures. He 

 states that they are also found at Middle Stewick, on the line 

 of strike between Hawkesbury and Windsor ; and they are 

 reported to occur at Beaver Lake, which is situated on the 

 same bearing. 



With respect to the gypsiferous marls and limestones of 

 Nova Scotia, Mr. Logan is of opinion that they are newer 

 than the coal measures, because in a section near Windsor 

 the former rise out unconformably at an angle of 45^ from 

 beneath the latter, and because the fossils collected by him 

 have been ascertained not to belong to any of the deposits 

 more ancient than the coal measures, but to agree generally 

 with those characteristic of the magnesian limestone and 

 triassic series. 



2. — On the Tchornoi Zem, or Black earth, of the Central 

 Regions of Russia. By Mr. Murchison. 



This earth constitutes a superficial deposit, the northern- 

 most limits of which may be defined by a curved line dra\\Ti 

 from a Uttle south of Lichwin (54" N. lat., 33° 44' E. long.) 

 and the left bank of the Volga, in lat. 57° ; it occurs also near 

 Casan, and at Crasnoi Glasnova, on the Asiatic side of the 



