io6 



THE BUILDING OF AN ISLAND. 



west. Hence we see that the line separating the 

 northeast dips from the southern dips passes from 

 east of Springs Point, just south of Longford and 

 north of Cornhill Bridge. We are able to continue 

 it still farther to the northwest by noting that an 

 old quarry (gravel pit) on the main road going 

 south past Catherine's Rest (Longford's new 

 chimney lies southeast-by-east) shows rock layers 

 with a distinct dip to south-southwest at about 45 

 degrees, while another gravel pit to the north of 

 that, namely, at the turning in the road, shows 

 traces of a dip to north-northeast at about 30 de- 

 grees We can therefore continue the line north- 

 west, passing between the.se two quarries. 



Thus we have traced out a line which separates 

 northeastern dips from southern dips, and we find 

 the result confirmed by the dips at Waiter's Point 

 and a point to the east of it. At the latter point it 

 is true that two dips are found, some of the rocks 

 dipping to northeast-by-east, some southwest-by- 

 west, the alternations taking place within an in- 

 terval of only a few yards. These changes to 

 northeast appear, however, to be mere reversions 

 of the dip, which all the facts show should be count- 

 ed with the .south quadrant class. Hence we have 

 laid down a line separating the areas of different 

 dips, and this line is of course an anticlinal axis, 

 just as the line to the north of it is a synclinalaxi?,. 



When we now go back a little in our story, and 

 compare the dips on either side of the above traced 

 anticlinal axis, the first which we have discovered 

 in the eastern triangle, with those ou either side 

 of the anticlinal axis of the Western Oblong, we 

 notice that while an examination of the southeast 

 part of the line, say from Longford to the shore, 

 shows us that the dips bear a similar relation to 

 the present axis as do those of the Northwest anti- 

 clinal to their axis, that is to say, they have on 

 both sides an inclination to the east, an examina- 

 tion of the other part, that is the northwest part, 

 of the line, shows dips tending rather in the other 

 direction, namely, north-northeast or even north- 

 by-east on the north side of the anticlinal and 

 south-southwest or even southwest on the south 

 side. Compare, for example, the pair of dips at 

 Longford and Springs or Fareham and Springs, 

 towards the southeast end, with the pair at Bugby 

 Hole and Corn Hill bridge or Catherine's Rest and 

 Waiter's Point towards the northwest end of the 

 line. 



If now the tendency to the east on either side 

 of the southeastern part of the anticlinal is caused, 

 as suggested in regard to a like arrangement in 

 the Western Oblong, by a cross elevation tilting 

 the rocks towards the east, may not the opposite 

 be the case in the northwest part of the anticlinal ? 

 In other words, may there not be a cross axis of 

 elevation which separates these two diverging ten- 

 dencies, tilting the rocks on its east side towards 

 the east and on its west side towards the west? 

 And if so, where is this axis? It may not be pos- 

 sible to lay it down with any exactness ; but when 



we see that the rocks in Christiansted and on the 

 western boundary of the town dip mostly to west 

 of south, while those immediately to the east of the 

 town dip to south and farther out dip to south-by- 

 east, we may consider that we have found further 

 evidence strengthening the conclusion derived 

 from the arrangement of the rocks on the .south 

 side of the hills. It .seems then to be probable that 

 a cross axis of elevation in the ancient rocks fol- 

 lowed about the .same line as is now taken by the 

 remarkable cleft through the Christiansted Hills, 

 a cleft which perhaps indicates a like cross eleva- 

 tion on a smaller scale in more recent geological 

 times. 



If we now pass northwards over the Christian- 

 sted rocks, with their southerly dips, we find the 

 same dips prevailing till we arrive at the Point at 

 the entrance to the harbour, on which stands the 

 lighthouse and the ruins of Port Augusta. Here 

 the strata are well marked, and although some- 

 what contorted, they dip to about southeast. Not 

 far east of the point the dip changes again, this 

 time to northeast, and it is evident that we have 

 arrived at a second anticlinal axis, the crest of a 

 second fold in the strata. Following up this north- 

 easterly dip we find that it extends along the north 

 shore to a point opposite the islet called Green 

 Cay. and is found in a few strata towards the south 

 end of that islet, and that it stretches southeast in . 

 a band across St. Croix, similar dips being found 

 at Boetzberg, at Lowry Hill, at Mt. Fancy and 

 " Madame Carty " on the south coast. 



Beyond this strip northeastwards we find an- 

 other, in which the dips are once more to southerly 

 and southwesterly points, which may be traced 

 from the north coast past Green Cay and East 

 Hill School house, and appears to be represented 

 on the south shore by the rocks at the west end of 

 "Turner's Hole." 



This narrow strip is succeeded by another band 

 in which northeasterly dips once more prevail, and 

 are shown in the rocks of the north shore from 

 Coakley Bay to east of Solitude Point. In the last 

 named point the strata are well marked and appear 

 along the beach, the dip being about 60 degrees to 

 northeast by east. In one or two places the beds 

 are vertical and even reversed ; but on the whole 

 the dip is as stated. 



Following this strip with northeasterly dips 

 comes another with dips to southwest, changing 

 over, as we proceed eastwards, to southeast ; the 

 southwest dips being found in all the points from 

 "Solitude" eastwards to the west end of Tague 

 Bay, the southeast dips in some rocks near the 

 east end of Tague Bay. 



The lines laid down in the map indicate the 

 various anticlinal and synclinal axes as thus ascer- 

 tained, and it appears to be certain that the same 

 great force which has produced the anticlinal 

 axis and the synclinal axis of the northwest has 

 also pushed up the strata into numerous great 

 ridges in the eastern part of our island. 



