42 
THE CAROLINE STONY METEORITE 
some distance below the surface; they are independent of 
the secondary limonite veins and were probably developed 
during the flight of the meteorite through the atmosphere. 
Examination was confined to microscopical study of thin 
sections and polished surfaces, together with some chemical 
tests. No quantitative chemical analysis was undertaken 
since oxidation of much of the nickel-iron and pyrrhotite 
prevents satisfactory separation into magnetic and non- 
magnetic fractions, which is the initial step in chemical 
analysis of stony meteorites. 
Examination in Transmitted Light. 
Thin sections show the Caroline meteorite is a veined 
bronzite olivine chondrite. 
Numerous chondrules, both monosomatic and polysomatic, 
are distributed through a crystalline matrix of olivine and 
pyroxene with small amounts of pyrrhotite and nickel-iron, 
scattered minute grains of chromite and rare interstitial 
areas of merrillite. Some chondrules are sharply defined and 
more or less spherical ; others more irregular in shape appear 
to merge into the groundmass or have their outlines obscured 
by dense iron-staining. One monosomatic chondrule consists 
of a single grain of olivine 1 mm. in diameter. The poly- 
somatic chondrules are usually aggregates of olivine crystals 
or of olivine and pyroxene. One of the clearest examples is 
a spheroid 17 mm. in diameter, formed largely of radiating 
prisms of bronzite which appears granular between crossed 
nicols, owing in part to intergrown monoclinic pyroxene; 
others consist of bronzite without the fan structure. One is 
composed of olivine grains separated by fine granular 
material including olivine, pyroxene and merrillite. Another, 
which is finely granular, contains minute specks of chromite 
and^ is made conspicuous by a rim of coarsely crystalline 
olivine and pyroxene. 
Both orthorhombic and monoclinic pyroxenes are present. 
In sections normal to the optic axis, the orthorhombic pyroxene 
gives an interference figure in which the hyperbola is prac- 
tically a straight line and the optical sign is indeterminate ; the 
optic axial angle is, therefore, approximately 90° and the 
minm’al is bronzite, not enstatite nor hypersthene. The mono- 
clinic pyroxene has extinction angles up to 27°, indicating 
clino-bronzite rather than diopside. 
The matrix is wholly crystalline ; coarse crystals of olivine 
are in considerable excess over crystals of pyroxene; the 
