Review of Recent Geological Literature. 127 
Special interest attaches to the more acid rocks, which are of types 
not widely recognized as yet, and which the author apparently demon- 
strates to be derived from the same magma as the noryte and anor- 
ihosyte. The following analyses illustrate the chemical differences re- 
sulting from the dififerentiation: 
I. II. III. IV. V. VI. VII. 
SiOs 46.85 52.21 53.28 57.11 64.35 70.23 73.47 
Ti02 und. 3.12 1.87 1.59 1.63 1.09 0.12 
AlgOg 19.72 19.24 23.30 18.00 15.46 15.59 15.42 
FegOg 11.54 10.46 7.55 11.58 7.50 3.05 1.02 
MgO 7.75 2.36 3.02 1.78 0.50 1.20 0.20 
CaO 13.10 7.28 5.01 3.99 3.38 305 1.35 
NagO 1.56 3.48 3.90 3.96 3.28 4.50 5.57 
KgO 0.09 1.09 1. 5 1 2.59 4.54 1.29 3.64 
I. Williams; Noryte from Baltimore. 
II. Kolderup; Quartz noryte from Soggendal. 
III. Kolderup; Quartz noryte from Theingsvaag near Farsund. 
IV. Kolderup; Monzonyte from Fuldland near Farsund, 
V. Kolderup; Banatyte from Dypvik near Farsund. 
VI. Kolderup; Adamellyte from Farsund. 
VII. Kolderop; Bronzite granite from Birkrem. 
Unfortunately the analyses are not complete, and the iron is all 
calculated as the ferric oxide. Three of them are given in complete 
form elsewhere in the paper. The change consists in a progressive 
increase in the silica and alkali content, with corresponding decrease in 
lime, iron and magnesia; hence in more and more alkali feldspar and 
quartz at the expense of the ferro-magnesian silicates and lime feld- 
spars. Quartz noryte occurs in dikes, and as the central part of the 
Soggendal laccolith; monzonyte as a central type near Haeskestad and 
as peripheral type of the Farsund banatyte; the Listerland adamellyte 
grades into banatyte and at Birkrem adamellyte and bronzite granite 
are associated. 
The author suggests the following as limits between the plagioclase 
and orthoclase-plagioclase rocks on the one hand, and these latter and 
the orthoclase rocks on the other: 
Plagioclase rocks-Pig— PlgOrj. 
Orthoclase-plagioclase rocks.-PljOr, — PljOr^. 
Orthoclase rocks, -PliOrg— Org. 
The passage from noryte into anorthosyte is excellently shown in 
peripheral parts of the anorthosyte intrusion, and noryte is found 
grading into ihnenityte through so-called ilmenite noryte. 
The Principal Anorthosyte Intrusion.* This consists of anortho- 
*The author rejects the term anorthosyte, making the perfectly proper poins 
against it that it would apply equally well to an albitn or oligoclaso rock. Thatdoet 
not, in the reviewer's judgment, furnish sufficient ground for the rejection of a well 
understood and grounded name. It may in future prove convenient to qualify the 
term by prefixing the name of the predominant feldspar. 
