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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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