McKay. — On a Deposit of Moa Bones near Motanau. 413 



surface of the flats undulates in low rolling downs, and one or two isolated 

 hills stand above the general level. Close past the southern side of one of 

 these hills runs the little creek in the banks of which the moa bones are 

 found. Just abreast of the little hill the creek breaks the surface of the 

 flat and plunges into the deeper channel, which it cuts through the gravels, 

 and further down its course into the underlying tertiary strata. Along this 

 and other creeks numerous sections show that a heavy deposit of well- 

 rounded gravel of uniform size overlies the tertiary marine beds. The gravels 

 are parted 20 or 30 feet from their base by sandy clays, which at many 

 places contain trunks of trees or pass into beds of impure peaty lignite. 

 This is the horizon of the moa bones. Above this lies an indefinite thickness 

 of gravel and silt, variable on account of having been unequally denuded in 

 different localities. 



Professor Haast's researches at Glenmark appear to have led him to the 

 conclusion that there the moa bones occurred in three different horizons. 

 These in descending order are : — 



1. The turbary deposits near Glenmark homestead, from which the 



great bulk of the collections in the Canterbury Museum were 

 made. 



2. The alluvial deposits of Glenmark Creek and the Omihi Valley. 



3. Pleistocene deposits occurring in Glenmark Creek, one mile above 



the home station. 



In trying to correlate the Motanau bone-bed with either of these it is at 

 once apparent that this can only be 'done with No. 2 or 3. 



The character of the deposits forming No. 2 agrees well, both as regards 

 the material and the sequence, with the Motanau beds ; but the alluvial 

 deposits of the Omihi Valley show not the least sign of having been denuded 

 further than by the excavation of the present creek beds, while the Motanau 

 flats, especially towards the northern end, have been so far denuded that 

 the surface forms low rolling downs with here and there a low isolated 

 hill, of which an example stands close to the locality where the bones are 

 found. 



It is true that at Motanau these gravels are isolated from the fringe of 

 gravels skirting the coast line near the mouth of the Waipara, and also from 

 an extensive development of gravels on both banks of the Hurunui, and near 

 Gore Bay, Cheviot Hills. At Gore Bay these gravels are in their lower beds 

 alternations of silt and angular* gravels, in which large angular blocks are 

 of frequent occurrence. The upper beds are well rounded gravels, clay, and 

 loam, as at Motanau, but here the total thickness is much greater, ranging 

 from 300 to 500 feet. 



