2 E. 0. Thide: 



This series has been described as Devonian, but the northern 

 portion is now generally accepted as Carboniferous, chiefly on 

 account of the revision of the fossil fish from the INIanstield 

 district by A. Smith Woodward, LL.D., F.R.S.-' As, however, 

 our knowledge of the relation of the southern part of this region 

 to the Mansfield series is scanty, it is thought preferable at 

 present to refer to the rocks of the Mt. Wellington series as 

 simply Upper Palaeozoic. 



At the junction of the Wellington River with the Dolodrook 

 River, the writer obtained a series of well preserved graptolites 

 from highly inclined black slates. These fossils have been 

 handed over to Mr. T. S. Hall, M.A., who intends to work them 

 shortly. Mr. Hall says that these graptolites represent an 

 undoubted Upper Ordovician age, and, as the associated rocks 

 were traced for some miles along the Wellington River and also 

 observed in numerous sections along the Dolodrook River, an 

 extensive inlier of Ordovician rocks is thus shown to exist in the 

 Upper Palaeozoic area. The older rocks are much folded and in 

 places show faulting accompanied by considerable crushing and 

 crumpling. The Upper Palaeozoic rocks show little disturbance 

 and I'est unconformably on the Ordovician series with a general 

 prevailing dip westerly, in this locality, at a low angle. 



The observations in the serpentine area were confined princi- 

 pally to an interesting conglomerate noted at the north-west end 

 of the serpentine belt. 



The occurrence was reached by following up the Dolodrook 

 River from its junction with the Wellington for less than half-a- 

 mile, and then branching off to the left up a small steep tributary 

 cully, locally known as Black Soil Gully, This small creek 

 owes its name to the fact that there is a considerable accu. 

 mulation of black soil filling up the upper portion. The soil 

 has evidently been derived mainly from the decomposition 

 of the serpentine rocks, but also contains numerous small 

 flakes of indurated black slate. Along the serpentine occurrence 

 the black to reddish colour of the soil forms a marked contrast to 

 the barren nature of the Ordovician rocks on either side. 



Just above the head of Black Soil Gully there is a lower 

 portion of a spur forming what is generally known as the Monu- 



1 Brit. Assoc. Belfast, Sept., 1902. 



