BY A. B. WALKOM. 151 



tinuous with the Carboniferous series at Hudson's Peak. They 

 surround, almost completely, the isolated basin of Permo-Carboni- 

 ferous roeks at Cranky Corner. They consist of a varied series of 

 eruptives — rhyolite, trachyte, dacite, andesite, pitchstone, etc., and 

 also rhyolitic and trachytic tuffs, tuffaceous sandstones and con- 

 glomerates. Professor David has found an abundance of Rhacop- 

 teris in some of the tuffs on the road just south of Cranky Corner, 

 so that there is no doubt that they belong to the same series (Upper 

 Carboniferous) as those Carboniferous rocks occurring further 

 south, at Winder's Hill and Pokolbin.* 



No boundaries of these Carbonifero u s rocks have been surveyed, 

 except where they are in contact with rocks of different age, but 

 field-names have been placed on the map at points where they have 

 been observed. 



(B) Permo-Carboniferous. — There are two separate occur- 

 rences of Permo-Carboniferous rocks in the district, namely, (a) 

 the Cranky Corner Basin, (b) the series west of the Elderslee 

 fault. 



(a) The Cranky Corner Basin. — In this area, there is a develop- 

 ment of some 1,850 feet of Permo-Carboniferous strata, made up 

 approximately of 900 feet of Lower Marine Series, 150 feet of 

 Greta Coal-Measures, and 800 feet of Upper Marine Series. An 

 examination of the dips at once shows that these strata form a 

 somewhat triangular-shaped basin. They are surrounded, for the 

 greater part, by the Tangorin Series, except on a portion of their 

 northern side, where they have been brought into contact with the 

 Webber's Creek Series by the Webber's Creek fault. They are 

 unconformable above the Carboniferous System, there being dif- 

 ferences generally of 30° to 40° in the directions of strike, where 

 Carboniferous and Permo-Carboniferous sedimentary rocks occur 

 close together. Near portions 14 and 11, Parish of Stanhope, the 

 Carboniferous conglomerates strike about N.-S., and dip easterly; 

 while the Permo-Carboniferous rocks strike 327°, and dip at 14° 

 in direction 57°. Near Tamby Creek, about portion 98, Parish of 

 Tangorin, the Carboniferous conglomerate strikes 140°, dipping 



* Journ. Proc. Royal Soc. N. S. Wales, xlv., 1911, pp. 379-408. 



