62 BULLLTIN OF THE NATURAL HISTORY SOCIETY. 



shales and sandstones. The age of these shales, etc., is deter- 

 minable from fossils which they contain in some places not far 

 from the igneous rock. 



The name " Ox-bow," used in connection with one of these 

 rocks, was applied to a sharp bend in the "Nerepis" Road at the 

 locality designated. This road is the main highway between 

 St. John and Fredericton. — Editor]. 



I have taken opportunity to look over the sections of some 

 rocks gathered last summer, and send a few notes on them for 

 the Natural History Society [of New Brunswick]. 

 1. Barlow's Blujf' granite. 



A coarse grained grano-diorite (Tonalite). The thin section 

 shows much quartz, orthoclase and plagioclase in about equal 

 amounts, occasional green hornblendes, slight zonal tendency in 

 a few of the feldspars. The hand specimen shows a few idio- 

 morphic quartz crystals, but no trace of these appears in the 

 section examined. 



This rock is entirely of the type of the post-Laurentian granites 

 at St. John, and belongs probably to the same series of intrusions. 

 ^. Hornblende Basalt. From the heavy dyke in Cambrian slates 

 back of Barlow's Bluff. 



Augite and brown basaltic hornblende crystals, the former 

 younger, with a little quartz and considerable plagioclase, much 

 decomposed. No marked diabase structure. Considerable sec- 

 <mdary green hornblende chlorite and calcite. 

 S. ? Feldspathic Diabase. Fine grained. From the centre of 

 smaller dyke in Cambrian slates, same locality as No. 2. 



Fine-grained, porphyritic with triclinic feldspars. Very 

 feldspathic ; the little dark silicate entirely decomposed. Porphy- 

 ritic feldspars not very sharply outlined ; those in the ground- 

 mass show the diabase structure, and are probably a not very 

 basic labradorite. 



4- <k 5. Augite porphyrite. From near edge of smaller dyke, 

 locality same as the last. 



Fine grained, the porphyritic crystals decomposed but having 

 the outlines of augites, in a groundmass of minute idiomorphic 



