80 



THE GEOLOGIST. 



Tournay to St. Omer. The researches of M. Gosselet, which have been 

 recorded by him in a most able memoir on the Palaeozoics of Belginm, 

 published in 1860, and a few communications made by him to the Geolo- 

 gical Society of France, leave little to be desired, either on the score of 

 descriptive or comparative geology. Led by a desire to ascertain how far 

 the appearance of the rocks representing the uppermost strata of the De- 

 vonian there shown agreed with our own Devonshire types, I made recently 

 a brief excursion to Avesnes and Oltrungt. The former place may be 

 reached by a pleasant walk of about four miles from Aulnoye, a station on 

 the line to Maubeuge, or by country diligence from Landricies. On getting 

 out of the Neocomian plains covered with loamy soil into the more diversi- 

 fied country near Avesnes, the cuttings begin to show a shivered rock of a 

 snuff-brown colour, having a Devonian facies. The road-metal is evidently 

 carboniferous limestone. This continues into the town, and thence south- 

 wards by the great road for about two miles, when a black massive lime- 

 stone crosses the road, and is worked in the field adjoining in vertical 

 beds. Fossils are scarce, but the series of beds are like those of Newton 

 Bushel. Proceeding on to Oltrungt, and visiting the quarries so well 

 described by M. Gosselet, we have undoubtedly the South Devon lime- 

 stones and shales in full force, with abundant fossils. There are a few 

 fossils of the Upper Devonian (Clymenia), and some of the Petherwyn 

 forms, but on the whole the group is that of Plymouth and South Devon. 

 The copious lists of M. Gosselet will furnish comparison with our own lo- 

 calities. The junction in the carboniferous limestone with the Devonian 

 is nowhere shown, though quarries in each formation are wrought near to 

 each other. But it is impossible for any one acquainted with the aspect of 

 the latter in our own country to confuse the two here, as was done for 

 many years here. The former is of the Tournay type, and characterized 

 by Produetus semi-reticulatus and other Tournay forms. The Devonian, 

 as a whole, is characterized by Phacops latjfrons, Spirifer Verneullii, 

 Orthis crenistria, etc. 



I had only a day to devote to Oltrungt, but it would repay a longer 

 stay, and the extensions of the beds on the line of strike well deserve study. 

 I could not detect any true apparent Devonian, or any Carboniferous 

 beds below the Tournay limestone. — S. H. Pattison. 



Boulder Deift at Marlborough. — In a personal note, Mr. Whit- 

 taker, of the Geological Survey, says, "In your review of Flora of Marl- 

 borough, I think you give a quotation, in which the Boulder Drift is said 

 to occur in that neighbourhood. There is nothing of the sort there, and I 

 expect that the faults noted are purely imaginary." 



Errata. — In the description of the section, Plate I., Fig. 1. instead of 

 " Section from Furze Hill to Farringdon," read " Section from Little Cox- 

 well eastward, passing through the pits of Sponge and Red Gravel." — 

 C. J. H. Meyer. 



