Cargill Township carbonatite complex, District of ... - Geology Ontario
Cargill Township carbonatite complex, District of ... - Geology Ontario
Cargill Township carbonatite complex, District of ... - Geology Ontario
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CARBONATITE - ALKALIC ROCK COMPLEXES: CARGILL TOWNSHIP<br />
brown rims. Magnetite forms anhedral disseminated grains, some <strong>of</strong> which are skeletal. Car<br />
bonate forms anhedral grains interlocking with each other and amphibole. Amphibole forms<br />
elongated grains pleochroic from pale green to dark green. There are some crude amphibole<br />
cross sections. Extinction angle is high and amphibole is likely a sodic variety. Some amphi-<br />
boles are crudely euhedral, others somewhat ragged and nearly anhedral.<br />
Reference No. 819<br />
Sample No. CCM35 100.5-101.0<br />
Magnetite-rich pyroxenite.<br />
Finegrained, massive, equigranular, allotriomorphic, with curved grain boundaries. Minor am<br />
phibole forms brown anhedral interstitial grains. Magnetite forms anhedral, irregular interstitial<br />
grains. Clinopyroxene forms anhedral colourless grains, commonly twinned. Pyroxene forms an<br />
interlocking mosaic with magnetite. Clinopyroxene extinction angles are typical <strong>of</strong> augite.<br />
Reference No. 820<br />
Sample No. CCM41 248.35-248.7<br />
Phlogopite, magnetite, apatite sovite.<br />
Fine to medium grained, massive, inequigranular-seriate, allotriomorphic, with curved to lobate<br />
grain boundaries. Magnetite forms anhedral disseminated grains. Trace <strong>of</strong> magnetite is skeletal<br />
in form. Phlogopite forms anhedral irregular booklets; grains have light brown cores and dark<br />
reddish brown rims. Apatite forms rounded anhedral to subhedral grains. Larger grains tend to<br />
be elongate in form. Carbonate forms an interlocking mosaic <strong>of</strong> anhedral grains with curved to<br />
lobate grain boundaries.<br />
Reference No. 821<br />
Sample No. CCM41 140.0-140.6<br />
Amphibole, apatite, magnetite, phlogopite sovite.<br />
Fine to medium grained, inequigranular-seriate, hypidiomorphic. Amphibole forms acicular,<br />
euhedral, pale green to green grains. Amphibole is somewhat clotty. Magnetite forms dissemi<br />
nated grains. Phlogopite forms anhedral grains, locally with bent (001) cleavage and wavey<br />
extinction. Grains have pale brown cores and reddish brown rims and are thus zoned. Apatite<br />
forms anhedral rounded grains, larger grains are elongate in outline. Carbonate forms an inter<br />
locking mosaic <strong>of</strong> anhedral grains with curved to lobate grain boundaries. Possibly recrystal-<br />
lized.<br />
Reference No. 822<br />
Sample No. CCM46 225.75-226.3<br />
Olivine, amphibole clinopyroxenite.<br />
Fine to medium grained, massive, inequigranular-seriate, hypidiomorphic. Olivine forms an<br />
hedral grains occurring as percrystalline aggregates interstitial to pyroxene and altered to ser<br />
pentine and bowlingite. Magnetite forms anhedral grains interstitial to pyroxene. Amphibole<br />
forms patchy replacements <strong>of</strong> pyroxene and is present along pyroxene grain boundaries. Green<br />
to greenish brown amphibole commonly rims magnetite. Clinopyroxene forms anhedral to sub<br />
hedral, colourless grains, commonly with schiller texture.<br />
Reference No. 823<br />
Sample No. CCM46 223.3-223.7<br />
Olivine, amphibole clinopyroxenite.<br />
Fine to medium grained, massive, inequigranular-seriate, hypidiomorphic. Magnetite forms an<br />
hedral disseminated grains, interstitial to pyroxene. Olivine forms anhedral grains, which con<br />
sist <strong>of</strong> aggregates interstitial to pyroxene. Olivine is extensively altered to serpentine and bowlin<br />
gite. Amphibole is brown to greenish brown in colour and occurs as a patchy alteration <strong>of</strong><br />
pyroxene, along grain boundaries <strong>of</strong> pyroxene, and as narrow rims on magnetite grains.<br />
Clinopyroxene forms anhedral to subhedral, colourless grains; some grains display well devel<br />
oped schiller texture.<br />
Reference No. 824<br />
Sample No. CCM46 191.35-191.9<br />
Olivine, amphibole clinopyroxenite.<br />
Fine to medium grained, inequigranular-seriate, hypidiomorphic. Magnetite forms anhedral ir<br />
regular grains, partially interstitial to pyroxene. Olivine forms anhedral grains and occurs as<br />
percrystalline aggregates interstitial to the pyroxene and may enclose isolated pyroxene grains;<br />
there is minor alteration to serpentine and bowlingite. Amphibole forms patchy alterations <strong>of</strong><br />
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