PETROLOGICAL ABSTRACTS AND REVIEWS 467 



daily those dealing with new types, are given, and the geographical and 

 geological relations are shown. The new rock terms proposed are: 



Anorthoclase trachyte. — This type was previously described by 

 Professor Gregory as trachyphonolite. As described by Skeats, in 

 a corrected copy of his paper, it is "a dark-greenish rock. Large 

 phenocrysts of anorthoclase are numerous. The ground mass has 

 sometimes a fluidal arrangement of laths of anorthoclase, in other cases 

 the crystals are stouter and the structure orthophyric. Small crystals 

 of aegirine are scattered through the rock, a little green glass, a few sec- 

 tions of nosean, ilmenite, and occasionally apatite are also present." 

 From the description it does not appear that any other feldspar occurs, 

 although the statement, in another place, that "anorthoclase is the 

 dominant felspar," suggests that another is present. 



Anorthoclase-olivine trachyte. — Spoken of as "more basic than the 

 rock just described." It resembles the former rock but contains, in 

 addition, more or less olivine. 



Olivine-anorthoclase basalt. — "A still less acid type It 



differs mainly from the last type in the greater abundance of olivine 

 and less frequent anorthoclase." In the opinion of the reviewer this 

 description would hardly justify the use of the term basalt. 



Macedonite is a non-porphyritic, basaltic-looking rock and in the 

 annotated copy is said to "consist largely of minute felspars, a colour- 

 less to green interstitial mineral, either glass or chlorite, serpentine or 

 chlorite pseudomorphs after olivine, some light-brown biotite and 

 purplish, fibrous apatite prisms. Octahedra of perofskite occur, some 

 of which are opaque, others of a dark grayish-green colour. The exact 

 relations of this rock are difficult to determine. Chemically it is in 

 some respects intermediate between the tephrites and the orthoclase 

 basalts, but mineralogically it is quite distinct. Its nearest relations 

 are with the mugearites, from which it differs in the ratio of soda to 

 potash and in the small amount of olivine present." The writer does 

 not say what kind of feldspar is present, but if the analysis is computed 

 in the Quantitative System of C.I.P.W., the norm shows orthoclase, 

 20.02 per cent, albite, 29.87 per cent, and anorthite, 18.63 per cent. 

 As computed by the reviewer the rock is a Shoshonose. 



Olivine-anorthoclase andesite. — This is a porphyritic, subsiliceous 

 andesite. It contains lath-shaped plagioclase and granular or ophitic 

 augite, magnetite, and olivine as its normal constituents. Corroded 

 phenocrysts of anorthoclase occur and connect this type with the alkali 

 rocks. 



