Haedcastle. — 0)1 the Drift in South Canterbury. 313 



clay-beds. Beyond the Cave, on the opposite side of The 

 Brothers Mountain, is a seam of good hgnite, about 2ft. thick, 

 associated with a dirt-bed of greater thickness, and white 

 sands and clays. These rest upon a denvided surface of bhie 

 fossihferous (Pareora) sand-rock, and the two formations liave 

 been steeply tilted together. The fresh-water and carboni- 

 ferous beds must belong to the same period as those lower 

 down the river, and I feel sure some of the lignites of the 

 Upper Kakahu are of the same age. Silts, clays, and sands 

 resembling those of the Tengawai (but with less whitish ma- 

 terial), with a dirt-bed, and a seam or pocket of lignite near 

 the base, are exposed in the south bank of the Hare Eiver, 

 near Geraldine. This section contains two or three thin beds 

 of quartz-gravel, with some admixture of sandstone pebbles. 

 The quartz is evidently vein-quartz ; much or most of it is 

 angular, and, as the section is only two or three miles from 

 hills of slaty rocks that yield readily to frost, these beds, 

 equally with those of the Tengawai, shovs^ that during the 

 time of their deposition a practically if not perfectly frostless 

 climate prevailed in this region. The base of the Hare beds 

 is not exposed, but in sinking through the denuded crown of 

 the arch into which they have been thrown, some years ago, 

 in search of lignite, I soon reached loose red sands, resembling 

 those I have since seen beneath the Tengawai fresh-water 

 beds. I have no doubt there are other exposures of these 

 beds, but the two described are the only ones I have 

 examined. 



The Tengawai beds were disturbed and denuded before any 

 later beds of different material w'ere deposited upon them. No 

 such gap of unconformability exists in the Hare section, 

 where the line-grained series is regularly overlain by red 

 grcvels of the succeeding formation. The junction has been 

 brought into \iew by denudation following a disturbance 

 which elevated both together into an independent anticlinal 

 fold. 



This brings us to the red gravels, which I take to bo the 

 " drift," or " dispersed gravels," of writers in the Transactions 

 and Geological Eeports. As these terms, however, seem to 

 imply a partial or complete ignorance of the mode of origin and 

 deposit of this formation, neither of which does there seem 

 any necessity for admitting so far as the red gravels of South 

 Canterbury are concerned, T prefer to avoid them, and to use 

 the descriptive term " red gravels." They form " red chffs " 

 everywhere. 



In South Canterbury the red gravels, usually wath a cover- 

 ing of loess, form a large part of the country east of the ranges, 

 generally in the shape of downs, Vvdiose easy contours and 

 good loess soil make them first-rate agricultural country. They 



