758 E. HILL AND T. G. BONNEY ON THE 



the colours are not much contrasted, but the bands are perfectly di- 

 stinct. The dip is much the same as that of the beds in the north 

 quarry ; but the strike would bring them above those. Ascending 

 the same knoll, and unquestionably continuous with these slates, we 

 find intercalated among them a series of remarkable beds. These are 

 conglomerates of pebbles (subangular to well-rounded) in a greenish 

 ashy matrix. The pebbles are generally not larger than a horse- 

 bean, but occasionally two inches in the longer diameter ; some are 

 quartz and quartzite ; but most of them arc felstone or an indurated 

 felspathic mud and a fine slate. The beds are from one to two feet 

 in thickness ; and there may be four or five of them, each a yard or 

 two apart, occupying a thickness of at least 20 feet ; turf hides the 

 base of the series. These beds cannot be traced very far, perhaps- 

 only some fifty yards along their strike, the direction of which 

 slightly changes in this short distance, so that, though in full view of 

 and at no great distance from the beds exposed in the north quarry r 

 it is impossible to say whether the latter overlie or underlie them. 

 We incline to the latter view. 



The uppermost bed of these conglomerates seems to pass into a 

 grit-bed, of which more hereafter ; and this into blue slate of slightly 

 ashy character. 



Unquestionably well below these beds, in the centre of the space, 

 is a fine outcrop of massive rocks, forming a cliff twenty or thirty 

 feet high. This consists of a mass of pinkish fragments and crystals 

 of felspar in a dark slaty matrix. There are small grains of slate 

 in it, but little if any quartz, and no quartz granules. Here and 

 there is an appearance of large included fragments, but very few* 

 It is, we have no doubt, a bed of volcanic ash. Dip is shown by 

 banded slates just below it, and by an intercalated bed of whitish 

 felspathic matter, very hard, and closely imitating an intrusive dyke, 

 but undoubtedly sedimentary. At one point this has an appearance 

 of rather considerable contortion, though only on a small scale, 

 probably a result of false -bedding. Below this thick mass are ex- 

 posures of banded slates, and beneath these again another thick ash 

 bed, very like the one just described, but apparently not so thick. 

 This may agree with the similar bed some 200 yards north, pre- 

 viously described, though it does not look quite the same. Beyond 

 this nothing more is visible in the grounds of the Hanging Rocks. 

 Crossing the road and entering the moorland of Beacon Hill, we 

 ascend its long slopes, only occasionally meeting with exposures. 

 Careful search on the left side shows more than appear at first sight, 

 but very far short of a good series. They are all banded slates ; and 

 the summit of Beacon Hill itself is entirely composed of the same 

 rocks. The cliff at the north end affords an excellent section ; but 

 there is no trace of any thick ash bed or breccia, or any thing which 

 one could hope to identif)^. 



There are no further exposures till the Anticlinal is reached. 



4. The next district, that of Woodhouse Eaves and Broombriggs, 

 contains a number of isolated exposures, whose relative position it 

 is not oasy to determine. Woodhouse windmill stands on a high 



