346 PKOCEEDINGS or THE GEOLOGHCAL SOCIETY. 



down the stream towards the bridge, they are seen to be covered 

 by several hundred feet of thin-bedded sandstones with pebbles and 

 bands of red and grey micaceous shales, interstratified with harder 

 beds of sandstone-conglomerate, in which a quarry is worked under 

 a stratum nearly 30 feet thick of a very coarse conglomerate, con- 

 taining large boulders of primary rocks and some angular fragments 

 of sandstone. This passes gradually into a series of ferruginous and 

 schistose sandstones and fine conglomerates, effervescing violently in 

 acid and falling down into a red clay and grains of white quartz. 

 The cement of the conglomerates is sometimes a nearly pure calc-spar. 

 They resemble in lithological and agricultural characters the beds 

 covering the ichthyolites of Lethen and Cromarty, but they are too 

 deeply buried under drift to influence the fertility of the soil, ex- 

 cept where applied as a manure. From the dip and direction of 

 these strata, they were correctly inferred by Mr. Gordon to lie under 

 the band of cornstone which extends from Elgin to the '' Boar's 

 Head" on the coast; but their true position with reference to the 

 Scat-craig and Findhom beds could not be ascertained previously to 

 the discovery of the Lethen fossils, and of the extent to which de- 

 nudation had taken place during the period of the deposit of the Old 

 Red Sandstone. 



Sections through the Inferior Fish-heds at Tynat and Buckie in 

 Banffshire (PI. XI. fig. 7). — Following the strike of the Dipple 

 beds into Banflfehire, we discovered at the Burn of Tynat, four miles 

 E. of Fochabers, another series of beds containing ichthyolites 

 (fig. 7). They consist of thin bands of shale, interstratified with red 

 sandstones and conglomerates, which have been much disturbed, but 

 dip to the north in the usual manner. The fossils generally occur in 

 small, flat, compact nodules of the same outline as the fish; but 

 fragments of the tuberculated bones have also been found in the 

 finer conglomerates ; and Mr. Martin discovered a very fine specimen 

 of Dipterus in a red slaty sandstone (Tile-stone*), at h in the Sec- 

 tion, PL XI. fig. 7. The total thickness of the strata between the 

 upper and lower fish-beds does not exceed 50 feet. The arched bone 

 of the Coccosteus (fig. 3, d. 4) was found in the lowest band of shale ; 

 and many finely-preserved specimens common to Lethen, Cromarty, 

 &c., have been procured from the highest stratum, which is unfor- 

 tunately very difficult to reach. 



The inferior strata exposed in the bed of the stream higher up 

 consist of a coarse conglomerate ; and gneiss is seen a short way 

 above. A little lower down, on the opposite side, the fish-beds have 

 been brought, by a fault, into direct contact with a stratum of very 

 coarse conglomerate, resembling that covering the Dipple and Gamrie 

 beds, as represented in PI. XL fig. 8, the relations of which are 

 obscured by a slip or fault that has brought down the superior red 



* This name, applied by Mr. Murchison to the inferior division of the Old 

 Red Sandstone of England, is very inapplicable to these rocks as they appear in 

 Scotland ; yet in this and other instances a certain degree of similarity of cha- 

 racter can be traced. 



