PETROLOGICAL ABSTRACTS AND REVIEWS 491 



porphyrite as well as those in many lamprophyres are thought to have sunk 

 from the overlying acid magma layers, in which they were beginning to form, 

 into the basic lower layers from which the basic rocks were derived. 



Kato, Takeo. "A Contribution to the Knowledge of the Cas- 

 siterite Veins of Pneumato-Hydatogenetic or Hydrothermal 

 Origin, Jour. Col. Sci. Imp. Univ. Tokyo, XLIII (1920), Art. 5. 

 Pp. 60, map I, pis. 6, figs. 11. 



Largely economic, although a considerable number of pages are devoted to 

 igneous rocks. Among these are diorite, gabbroid-diorite, diorite-mylonite, 

 and a rock to which the new name "akenobeite" is given. Dike-rocks are 

 hornblende-hypersthene-andesite, garnetiferous-felsite-porphyry, felsite, por- 

 phyrites, and diabase, and there is extrusive rhyolite. The rocks are 

 described in some detail but neither chemical nor modal analyses are given. 

 The akenobeite is a quartz-monzonite-pegmatite or -aplite, according to Kato. 

 It consists of tabular crystals of feldspar in haphazard orientation with the 

 interstices filled with an aggregate of quartz. The feldspar is orthoclase and 

 oligoclase, the latter always in excess. How much in excess is not stated, so it 

 is a question whether the rock might not be called a granodiorite-aplite. Biotite 

 is very subordinate and occurs in minute flakes in the feldspars or attached to 

 its borders. In the system of the reviewer it belongs to Class i, Order 2, 

 Family 7 (new form), and probably in 7". The amount of quartz is not stated, 

 but from the two photographs given it appears to amount to 15 or 20 per cent. 



Klemm, G. "Die Granitporphyre und Alsbachite des Oden- 

 waldes," Notizhl. d. Vereins f. Erdk., etc., z. Darmstadt, IV 

 Folge, Hf. 35, 1914. Pp. 10-50, pis. 2, fig. I. 



In the crystalline schists of the Odenwald there are various dikes of anortho- 

 clase-granite-porphyxy and of alsbachite. Of the former rock there are twelve 

 chemical analyses, eight of them apparently new, and of the latter, three, of 

 which two are new. Five new analyses of dike granites are also given. All the 

 analyses are re-computed into Osann's system. 



Klemm, G. "Bemerkungen iiber die im Gabbro des Franken- 

 steins gangartig aufsetzenden Gesteine und iiber seine Ein- 

 schliisse von Korundfels," Notizhl. d. Vereins J. Erdk., etc., z. 

 Darmstadt, IV Folge, Hf. 35, 19 14, 5-9. 



Describes certain corundum-bearing rocks occurring in the Frankenstein 

 gabbro. The author disagrees with Kalkowsky, who regards them as diff- 



