REPORT OF THE CHIEF ASTRONOMER 351 



SESSIONAL PAPER No. 25a 



a few pebbles of the neighbouring trap-rock as well as some of blackish chert 

 and others of fine-grained, granite, while the pebbles are more generally rounded 

 than at Lake mountain. The cement is arenaceous. The sandy lenses range 

 from six inches to two feet in thickness and are never continuous for any 

 great distance on the outcrop. One hundred yards northeast of the Boundary 

 monument a bed of sandy shale, containing poorly preserved dicotyledonous 

 leaves, was found. These obscure fossils were examined by Professor Penhallow 

 who reported as follows: — 



' The impression of a leaf is certainly a very poor one to found an 

 opinion upon, and the difficulty is complicated by the crossing impressions 

 of superimposed leaves. All I can do is to make a very wide guess. After 

 very careful examination and consideration, I am inclined to think the 

 leaves are those of Ulmus speciosa, Newb. If this determination is at all 

 correct, then the age is Tertiary and possibly Miocene; I do not think 

 it can be Cretaceous. Assuming this guess to be correct, I find the speci- 

 men to be quite in harmony with specimens in Mr. Lambe's collection 

 from Coal gully, since in both cases the species is the same and the matrix 

 has been similarly metamorphosed.' 



At the Boundary monument the conglomerate dips northwest at an average 

 angle of 31°. Seven hundred yards to the northwest of the monument the dip 

 was again determined on sandy intercalations as 80° to the southeast. Along 

 the Velvet mine wagon-road the average dip is about 75° S.E. The attitude 

 of the bedding is, on account of the massiveness of the conglomerate, very 

 difficult to determine, but these readings suffice to show that the conglomerate 

 has been greatly disturbed. The exposures are not sufficiently continuous to 

 warrant a statement as to the thickness of the conglomerate; it is certainly 

 a heavy deposit, possibly a thousand or more feet thick. Just south of the 

 monument it is seen, at one point, to be apparently resting on the older Bossland 

 volcanics and in spite of the general lack of satisfactory contacts, this relation 

 can scarcely be doubted. At one horizon a 20-foot amygdaloidal sill (?) or 

 flow of augite-biotite latite is interbedded with the conglomerate. 



At monument 174 the conglomerate is cut by several dikes of augite- 

 biotite monzonite porphyry in composition similar to the flow just mentioned 

 and to latite occurring on Record mountain ridge to the northward. 



Conglomerate Area at Monument 112. — The third occurrence of conglo- 

 merate was found on the Boundary line at monument 172, a distance of five 

 miles west of the Sophie mountain monument. The stratified deposit forms 

 part of the roof of an irregular intrusion of syenite porphyry which will be 

 described on a later page. Erosion has greatly broken that roof so that the 

 conglomerate crops out now in the form of a number of detached blocks which 

 are apparently immersed in the porphyry. The largest block measures 250 feet 

 by 750 feet in ground-plan. About 200 feet of thickness is represented in this 

 heaviest mass of the conglomerate. The strike of the bedding is N. 30° W.; the 

 dip, 28° N.E. The conglomerate is much brecciated in an east-west zone 100 



