BY W X. BENSON, W. S. DUN, AND W. R. BROWNE. 



293 



Plains 



n 



Werris Creek Warraoundi fom^ilen Kurfung Scncs, Tamwrth 



Plains (Bosalt-) 



/Indesiffs Sills Plains 



Livert^ool 

 Plains 



B 



Lower Carbs 

 Burindi 5er<es 



L'|3^er Oevonian 

 Barraba 5ene«^ 



D 



Text-fis-2. Geological Structure of the Currabubula and Werris Creek Districts. 



of New England (2) and near Dungog (4). To the west they appear to pass 

 down into the tfpper Devonian (Barraba) rocks at Goonoo Goonoo, which con- 

 tain Lepidodendron australe, but the exact position of the zone of passage has 

 not been determined In the north-western portion of the area mapped, in a 

 small gully in portion 197* there occur four narrow seams of very impure coal, 

 the thickness being only twelve inches. They are all much veined by calcite. 

 They recall the carbonaceous shales of Clarencetown (21) to some extent, but are 

 not among freshwater strata. Among these marine rocks has been thrust a sill 

 of glassy (sometimes lithoidal) andesite which forms the easternmost of the more 

 or less continuous zones of sills in this region, leaches a thickness of about four 

 hundred feet but pinches out south of the railway line; where thickest it forms 

 the high cuesta called Minnarooba. Here, in its northern part in portion 199, the 

 intrusive character of the igneous rocks is clearly indicated at its upper surface 

 where the andesite has enclosed and indurated the fragments of mudstone. The 

 mudstone is also somewhat indurated adjacent to the andesite in the small ridge 

 crossed by the railway cutting in portion 35. A few fossils have been noted in 

 portion 199, but the majority were found near the railway cutting in portions 83 

 85, and 35 in Mr. Donaldson's property (11) . The writer's attention was called 

 to these fossils by Mr. Donald Porter, and in collecting them he was aided by Mr. 

 C. E. Tilley, B.Sc, and Mr. D. A. Pritchard, B.Sc. The gem of the collec- 

 tion, however, the Cactocrinus, was presented by Mr. Donaldson and found prob- 

 ably a short distance south of the railway line. The collection is remarkably 

 depauperate. A i^ebbly or conglomeratic layer is intercalated in the mudstone 

 here and a small lenticular mass of limestone, a few yards in leng-th and width, 

 occurs which is made up almost entirely of crinoidal fragments and Zaphrentis. 



The following are the forms recognised, ob\'iously representing the Burindi 

 fauna: — Cactocrinw hrownei, sp. nov., Zaphrentis culleni, Zaphrentis sp. indet ■ 

 Fenestslla sp. indet.. Chonetes hardrensis, Orthotetes crenistria, Productus longi- 

 spiniis, Ortli'is {Tthipidomella) australis, OrtJiis (Schisophoria) resupinala, Spiri- 



* Portion numbers refer to the Parish of Currabubula except where otherwise stated. 



