Geology. 281 



The Miocene Orbitoidal limestones, which rest upon the upper 

 volcanic series, take a very large part in the formation of the basis 

 upon which the higher and later limestones rest, and extensive 

 exposures of them occur in several localities. Along the summit of 

 the northern half of the Elying Fish Cove cliff they form a vertical 

 face, varying from 10 to 30 feet in height. On the terrace 

 above they are exposed in low pinnacles roughly ranged in rows 

 parallel to the clitf edge, and at the fault X-X (Fig. 2) they form 

 a prominent cliff running inland for about the third of a mile and 

 terminating at its southern end against the basalt mass described 

 above (see Fig. 6). This clitf occurs on the downthrow side of 

 the fault, the limestone on the upthrow side having apparently 

 slipped down the seaward slope ; the line marked Y-Y indicates 

 the position of a portion of the slip. ISoutb of Y-Y (Fig. 2, A) 

 these limestones thicken out greatly and form cliffs at least 

 200 feet in height, the mass being split bj' a series of vertical 

 fissures roughly parallel to the coast soiith of Smith Point. These 

 fissures mark small slips, which on the terrace above are indicated 

 by a series of small step-like displacements ; the high cliff on the 

 south of the cove (Fig. 2, A, between the letters "W.S.W. and 

 !N".W.) is, in fact, a section across the ends of these terraces. In 

 the extreme south of the cove these limestones have been affected 

 by two or three small faults, which involve the underlying basalt 

 (G) and cause the repetition of the basalt bed in two places in the 

 base of the cliff; the limestones from either side of one of these 

 faults are described above under the numbers 229 (p. 238), 220 

 (p. 239), 219 (p. 240), 861 (p. 237). The last specimen shows 

 conclusively that these limestones were deposited on a basalt 

 surface exposed beneath the sea and thickly coated with Litho- 

 thamnion and other encrusting organisms. Nos. 229 and 571 

 (p. 236) are probably from the same bed, both being taken close 

 to the underlying basalt, and both being devoid of Orlitoides ; 

 571, however, is from a point about 480 feet above the sea, in 

 the middle of the cove, while 229 is from only about 100 feet at 

 the south end, the difference of height being accounted for partly 

 by the slope on which the beds are deposited causing a general 

 dip seaward and partly by the slipping that has occurred. No. 924 

 (p. 233) closely resembles 220, and is likewise taken from close 

 to the basalt, but in this Orhitoides are present, and the same is 

 the case with 9b8 (p. 252), from a little farther west, at a height 

 of about 60 feet above the sea. Of the rest of the limestones 

 from this locality described above by Messrs. Jones & Chapman, 

 595 (p. 240) and 845 (p. 241) are from immediately above the 

 line of slip Y-Y; 596 (p. 241) and 844 (p. 242), from above the 

 last; and 841 (p. 248) and 963 (p. 250) are from the summit 

 of the high cliff' at this point. The two last are stated to be 

 probablj^ of more recent origin than the Miocene rocks below, and 

 may represent a remnant of some much later deposit which formerly 

 covered them. From the north of the fault X-X the specimens 



