646 LH: 1 VOCE 
zone, mainly consisting of garnet, immediately adjoining the 
plagioclase. 
1. As is well known, these zones only occur on the boundary 
between the olivine and the plagioclase, but never between the 
olivine and the pyroxenes or the magnetite. 
2. The zones occur not only in rocks rich in olivine in which the 
olivine has in a great measure crystallized earlier than the plagio- 
clase (see, for instance, Fig. 27), but also in rocks deficient in 
olivine where the plagioclase, showing idiomorphic outlines against 
the olivine, must have crystallized earlier than the latter. I beg to 
refer to Figures 48-49, representing an olivine-hyperite from 
Elverum, Norway, consisting of ca. 65 per cent labradorite, ca. 10 per 
cent olivine, and ca. 25 per cent diallage, the labradorite having 
early crystallized in lath-shaped crystals, often projecting into the 
olivine which did not begin to form till a somewhat later stage. 
We fix on the fact that the coronation zones sometimes branch a 
little into the labradorite, in part following local transverse fissures, 
in part twin lamellae, and in part the boundary between vari- 
ous individuals of plagioclase. I further refer to the olivinifer- 
ous labradorite rock (with Ab,An,) illustrated by Figures 23-24, 
in which however, the coronation zones are so thin that they are not 
recognizable in the photomicrograph. High magnifying powers 
are here required to enable a close examination. 
From the very fact that the coronation zones only occur between 
the olivine and the plagioclase, and are never found between the 
olivine and other minerals (diallage, hypersthene, etc.), it may be 
inferred that in rocks rich in olivine the metamorphosis (Umbild- 
ung) of the olivine did not take place at a conjuncture when only 
the olivine had crystallized while the rest were still in a molten 
state. ‘The metamorphosis accordingly, as has been earlier pointed 
out, particularly by Frank D. Adams, must be a phenomenon 
belonging to the solid phase. This theory, moreover, is verified by 
the occurrence of the metamorphism of the olivine as well as of the 
plagioclase, attached to the boundary plan between the two minerals, 
not only where the olivine is to a great extent crystallized earlier 
than the plagioclase, but also where the plagioclase to a great 
extent crystallized earlier than the olivine. 
