Rocks of the Hoivqua River. 57 



.and Climacograptus. If this is correct, they probably are of 

 Upper Ordovician age. These sporadic occurrences of imperfectly 

 preserved fossils are tantalizing, but they indicate that great 



-caution is' necessary in interpreting the stratigraphy of the region. 



(6) Structure of the Lower Palaeozoic Area. 



In general, the prevailing dip on the eastern side of the main 

 •diabase, as far as observed, appears to be consistently easterly, 

 while on the western side it is to the west. Ihe structure, however, 

 is clearly not that of a simple anticline, for the evidence of the 

 fossils on either side, together with the lithological discordance ex- 

 cludes the possibility of such a view. 



A faulted anticline, with the fault approximating to the western 

 ^margin of the main diabase, is suggested, but this requires an 

 enormous down throw on the western side to bury the great thick- 

 ness of Lower Palaeozoic sediments represented on the eastern side. 

 The Upper Ordovician, and possibly Silurian fossils on the 

 western side close to the diabase, would appear to demand this 

 view, in the absence of any recognised unconformity to afford any 

 other explanation. The presence of the second diabase occurrence 

 to the west offers certain difficulties, however, in the way of this 

 interpretion. 



Another alternative would be to assume that the Upper Ordo- 

 vician, with possibly Silurian, is but a small fragment that has 

 been nipped in by the intense folding to which the area has been 

 subjected. The fossiliferous area is very restricted, further search 

 anay extend it, but the writer has spent much time without success 

 looking for fossils in the surrounding strata. It may, therefore, 

 be that the bulk of the rocks which, so far, have proved unfossil- 

 ferous, are very much older, and may be Lower Ordovician. or 

 »even Cambrian. With tlie present evidence at hand the matter 

 must be left an open question. (See Fig. 3.) 



(c) PJiosphate Depof^its. 



While searching diligently to obtain graptolites to confirm, if 

 possible, the presence of Silurian, as indicated by a reported Mono- 

 graptus found by Mr. Ilowitt, Professor Skeats and the writer 



'discovered a phosphatic breccia. This was of considerable interest, 

 because it was the report of phosphatic rock from this district that 



'Jed to Mr. A. M. Hewitt's flying visit. The piece shown to Mr. 



