TERTIARY COALS OF NEW ZEALAND. 169 



found on Scrogg's Hill — a continuation southwards of Saddlehill — where they were 

 included in a Government coal-reserve ; in M'Coll's Creek, on the seaward base of 

 Saddlehill ; and at other points on the flanks or base of this basaltic nucleus. 

 I was led, while on the spot, to the conclusion that the Trappean mass of Saddle- 

 hill, with adjacent minor eruptive Trappean masses, had burst through what had 

 at one time been a continuous coal-bed or basin subsequent to the deposition of 

 the latter ; or, in other words, in newer Tertiary times. That the coal-bed in 

 question is more or less continuous is so far proved by the fact, that since I left 

 Otago no less than three large collieries have been established in the immediate 

 vicinity of my former residence. The first of these — the Fairfield Colliery — was 

 opened on the lands of Fairfield itself, very near the old workings of Abbott's 

 Creek, which I frequently examined. The proprietor, my friend Mr Martin, late 

 Member of the Provincial Council of Otago, tells me* there are here two main 

 seams, the upper six and the lower four feet thick, with a " dirt-bed" between 

 them. The other pits, all within a few hundred yards of each other, are the Shand 

 and the Walton Park Collieries. The strata associated with the brown coal are 

 mostly various shales ; clays, bituminous, and arenaceous, some of them plastic, 

 white, and micaceous ; and sands or sandstones of various degrees of coarseness. 

 The whole are overlaid by the newer Tertiaries so abundant in the district, con- 

 sisting of variously coloured clays, sands, and conglomerates. 



Daily pedestrian excursions during my residence in the Saddlehill district 

 gave me frequent opportunities of studying all the natural and artificial sections 

 of the brown coal strata of this basin, and of collecting hand-specimens of every 

 quality of the coals so exposed. The latter were brought home, and a suite 

 thereof submitted in 1862 to careful chemical analysis by Professor Murray 

 Thomson, a Fellow of this Society, then an analytical chemist in Edinburgh, and 

 now Professor of Experimental Science in the Thomason College, Roorkee, 

 Bengal. The results of his analysis are embodied in Table II., and fully bear out 

 the opinions to which, when in Otago, f I gave public expression, regarding the 

 economical value of the Otago brown coals. 



While in Otago I also visited the Kaitangata coal-field at the mouth of the 

 Clutha, about 60 miles southward of Dunedin. Here there are works which were 

 originated, and are now carried on, under the patronage of the Otago govern- 

 ment. There are not only regular adits at the pit ; but the pit is connected by 

 means of a rail or tramway two miles in length, with a jetty on the Clutha 



* Letters of January 1862 and September 1863. 



f In a lecture on " The Place and Power of Natural History in Colonisation-, with special 

 reference to Otago (New Zealand)," prepared for and printed by the " Young Men's Christian 

 Association of Dunedin," Dunedin, January 1862. Extracts therefrom reprinted in the "Edin- 

 burgh New Philosophical Journal" for April and July 1863. 



Vide chapter on the " Geology of the Otago Lignites." 



