HARKER : PETROLOGICAI NOTES. 
421 
doubtless from the same source, though the remains of rhombic 
pyroxene are les.s plentiful. This example is fresher, and shows very 
beautifully the zonary banding of the felspars and the characters 
and mutual relations of all the constituents. No. 127 is very similar, 
but the slice [1146] shows a little brown hornblende, doubtless 
original, associated with the augite, another character met with in 
the Whin Sill, as described by Mr. Teall. Some other rather com- 
pact doleritic rocks in our collection [1062, 1063] have a considerable 
quantity of brown hornblende : these, from their general appearance 
in thin sections, may be also Whin Sill boulders, but the specimens 
are scarcely characteristic enough to decide the point. 
Many of the dolerites have suffered much from weathering, and 
lost some of their most characteristic features. A specimen taken 
between High Stacks and South Sea Landing [1060] shows good 
zoned felspars, mostly once twinned. These and the (juartz (probably 
secondary) are crowded with needles of apatite. The pyroxene is in 
great measure destroyed. Xo. 545 [1145] has the felspars much 
decomposed and without any zonar}' banding. Its other characters 
are like those of the preceding, except that the augite shows very 
clearly the bas.il striation already noticed as a special feature of 
the Whin Sill. This is very clearly exhibited also in Nos. 503 and 
524 [1143, 1144], two moderately coarse-grained dolerites with a 
second generation of felspars, shapeless and strongly zoned. The 
former has relics of a rhombic pyroxene, beside the twinned and 
striated augite. These rocks agree very fairly with some specimens 
of the Whin Sill of Teesdale. No. 214 is a similar-looking rock, and 
the boulders about Flamborough include many examples of rather 
coarse-grained dolerites, often with specks of iron pyrites, wdiich must 
be for the most part derived from the outcrops of Teesdale. 
Olivine-beariug dolerites and basalts are much less abundant. 
No. 240 is a dark compact fresh-looking rock, enclosing porphyritic 
black augites, up to a third of an inch long, and rounded crystal- 
gi-ains of yellow-gTeen olivine. This can scarcely be a North of 
England rock, but could no doubt be matched in Southern Scotland. 
An olivine-basalt from the Basement Clay of Flamborough was 
described in my former notes [933]. 1 have not been successful 
