BY W. N. BENSON. 617 



The more basic dykes show interesting features; the following- 

 may be recorded : — 



130'2, A dark vein in granite in Portion 114, Nemingha. This 

 consists of a fabric of short laths, and less regular grains of 

 plagioclase and orthoclase with interstitial quartz. A few cor- 

 roded xenocrysts of the two felspars and quartz are also present; 

 the last is very distinct from the groundmass, and is surrounded 

 by a reaction-ring. In addition, there are abundant fresh grains 

 of augite and platy ilmenite. The rock may be termed a micro- 

 monzonite, or monzonite-aplite, 



1308. A vein in Portion 145, Nemingha. This is also a micro- 

 monzonite, but is of a different character. The felspars are 

 larger, more irregular, and partially interlocking. The augite 

 has been replaced by hornblende, and some sphene is present. 



1174. A vein in the granite in Portion 73, Moonbi. This is 

 very similar to 1308, but differs in presence of a groundmass of 

 small felspar-laths, and small crystals of hornblende, and rarely 

 a flake of biotite. The felspar seems to be chiefly plagioclase. 

 The rock may be termed a micro-diorite or a diorite-aplite. 



1175. A vein in the granite in Portion 139, Moonbi. This is 

 the most unusual rock. It is a minette with spheroidal inclu- 

 sions, rather different from the "Kugelminette" of the Odenwald 

 and elsewhere{30). The rock consists of crystals of brown, almost 

 uniaxial biotite in idiomorphic plates, idiomorphic augite, and 

 magnetite, in a finely granular, felsitic matrix, dotted with 

 minute crystals of magnetite, and a few minute prisms of apatite. 

 The spherules are about 2-3 mm. in diameter. They consist of 

 fibrous radiating felspar, with a little quartz in the central parts. 

 Included in these are large crystals of diopside and biotite, which, 

 in one instance, are in completely parallel intergrowth with each 

 other. A little magnetite is dotted about. There is no bounding 

 zone of coloured minerals marking the outline of the spherules. 

 There are, in addition, druses with an angular, irregular outline 

 surrounded by a "fence" of diopside-prisms, directed radially 

 inwards, followed within by an irregular zone of untwinned 

 felspar, with a central quartz-felspar mosaic. The inner zone is 

 dotted with diopside and magnetite. 



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