414 Transactions. — Geology. 



coalfields of New Zealand to one geological period. '■■ Early 

 in this year I examined Shag Valley, Horse Range, and Shag 

 Point coalfield, and found that the Oamaru series rested 

 unconformably on the Shag Point coal series of Cretaceous 

 age in the noanner shown first by Sir James Hector in his large 

 geological section of Otago, prepared in November, 1864, and 

 now in possession of the Otago University School of Mines; 

 and afterwards by Captain Hutton, in 1875. f 



The late Sir Julius von Haast also identified the uncon- 

 formity between the Oamaru series and the Secondary coal- 

 measures, but he fell into an error in placing the unconformity 

 below, instead of above, the Moeraki Septaria beds.]: 



The geology of Shag Valley disproves the Cretaceo-tertiary 

 theory of the Geological Survey in the most convincing 

 manner. Here the Tertiary coal-measures of the Oamaru 

 series and Secondary measures of the Waipara series exist 

 side by side, the younger abutting against the older with a 

 degree of unconformity not often seen among the younger 

 stratified formations in New Zealand. 



The Tertiary coal-measures in the Shag Valley consist of 

 the following members, as shown by various prospecting-works 

 and outcrops : — - 



Oamaru series — 



(a.) Oamaru stone. 



(b.) Blue sandy clays (foraminiferous). 

 (c.) Marly greensands, with Teiiiary fauna. 

 (d.) Quartz grits and conglomerates, with coal (South 

 Palmerston coalfield). 



The greatest thickness of this series obtained in the Shag 

 Valley was 780 ft. 



The succession of the Secondary coal-measures at Shag 

 Point is as follows : — 



"Waipara series — 



(a.) Shaly clays and sandstones, with septarian boulders 

 incrusted with cone-in-cone limestone and con- 

 taining saurian remains. 



(b.) Greensands (glauconitic). 



(c.) Ferruginous sandstones, grits, and conglomerates, 

 w'ith younger Secondary fossils. 



(d.) Quartz grits, with coal-seams (Shag Point coal- 

 field). 



(e.) Horse Range conglomerates. 



• Trans. N.Z. Inst., vol. xxi., 1888, p. 325; and Proc. Inst. Min. 

 and Met., London, vol. viii., 1899, p. 146. 



t Hutton; "Geology of Otago," 1875, p. 44. 

 J Reps. Geol. Expl., 1872-73, p. 24. 



