Thomson. — The Hawera Series. 415 



on the Kai Iwi blue clays, Okehu beds, Waitotara limestone, Whenuakura 

 and Patea clays. On the Taranaki coast also it lies on the younger 

 Tertiaries between the Waiau and the White Cliffs, and on the Cretaceo- 

 Tertiary strata at the Mokau. 



" The submerged forest already alluded to as underlying the drift is 

 associated with a bed of lignite of variable thickness, which is well exposed 

 at Languard Bluff, and in many places north of Wanganui. 



" It is remarkable that, although the drifts extend inland a great 

 many miles, the evidences of a submerged forest and lignite are never 

 met with more than a mile or two from the present shore-line, and then 

 only in low-lying areas. It would thus appear that this ancient forest 

 flourished in a narrow belt of low, swampy land adjacent to the sea. The 

 occurrence of irregular beds of marine shells at the base of the drift points 

 to the existence of shallow brackish lagoons within the influence of the 

 tide. The shells are all marine and Recent, and include the following 

 forms : Venus stutchburyi, Venus mesodesma, and Turritella rosea." 



My own observations of this formation concern only parts of the coast 

 between Wanganui and Hawera, along the whole of which it is well exposed 

 in the sea-cliffs. My visits to this coast were primarily for the purpose of 

 collecting fossils from the Wanganuian beds, and it was only at the sea-cliff 

 at the " Zigzag," near Hawera, that I made any detailed notes of the Noto- 

 pleistocene beds. This cliff is about 200 ft. in height, the lower 50 ft. being 

 composed of mudstone (papa), the exact horizon of which cannot be quite 

 definitely stated at present. It lies in nearly horizontal beds which continue 

 without any appreciable dip along the coast as far as the head west of the 

 Patea River. The Hawera papa is thus probably of about the same age 

 as the Patea blue clays, which are placed by Park below the Ostrea ingens 

 bed of Waitotara. It is certainly older than Castle cliffian, and is probably 

 Waitotaran. 



The upper 150 ft. of the cliff at Hawera, with the exception of a super- 

 ficial layer of a few feet, consist of the so-called drift formation, which is here 

 better displayed than at any other point, and which, therefore, I propose 

 to term the Hawera series, using that term in a purely local strati- 

 graphical and not a general systematic sense. It is in the main composed of 

 loose sands which are thinly and irregularly bedded, and in places exhibit 

 good current bedding. In the lower half there are several layers of blue clay, 

 each about 1 ft. thick, interbedded with the sands, and formed presumably 

 by a rewash of the papas. There is at least one seam of lignite in the lower 

 half, while at the base there is a gravelly shell-bed resting on a surface of 

 hard papa bored by the molluscs Barnea and Venerupis reflexa. Owing to 

 the predominance of loose sands the cliff is much obscured by slipped material, 

 and it would be a matter of difficulty to give a detailed account of the order 

 of succession of the various beds ; nor is this especially desirable, since the 

 beds vary rapidly in a lateral direction. The sands in the lower half are 

 loose, and are often dark owing to an abundance of green and black 

 ferruginous minerals. Some layers in the lower third contain quite large 

 flakes of both black and white mica. The layers in the upper half are 

 harder, owing to the presence of a ferruginous cement resembling a bog 

 iron-ore. The bedding, except where current bedding occurs, is approxi- 

 mately horizontal. 



The wind-blown sand which forms dunes resting above the Hawera 

 series lies imconformably upon it, and is doubtless derived from it. This 

 is important from an economic point of view, as showing the source of the 



