Gmelinite and herschelite from the Ilimaussaq intrusion in South Greenland
SUMMARY. Hypogene alteration of ussingite from the southern part of the Ilimaussaq intrusion in South Greenland has resulted in the formation of three associations: gmelinite--apophyllite, gmelinite-herschelite-earthy-natrolite, and earthy natrolite alone. Ossingite reacted with late magmatic fluids...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.602.4207 http://www.minersoc.org/pages/Archive-MM/Volume_40/40-316-867.pdf |
| Summary: | SUMMARY. Hypogene alteration of ussingite from the southern part of the Ilimaussaq intrusion in South Greenland has resulted in the formation of three associations: gmelinite--apophyllite, gmelinite-herschelite-earthy-natrolite, and earthy natrolite alone. Ossingite reacted with late magmatic fluids, producing the secondary minerals either by in situ replacement of the ussingite or in cavities, which may be up to 3 cm across. IN I972 a 25 cm large angular ussingite block (specimen GGU 15o113) was found in the southern part of the Ilimaussaq intrusion in South Greenland. It was located near the edge of the naujaite plateau just north-east of the head of the Kangerdluarssuk fjord. Small amounts of aegirine, steenstrupine, and sphalerite have crystallized penecontemporaneously with the ussingite. The following minerals, present in small amounts, have developed uring hypogene alteration of the ussingite: gmelinite, herschelite, apophytlite, and 'earthy natrolite'. They occur in or near cavities up to 3 cm across (fig. I). Gmelinite and herschelite have not previously been found in Greenland. Mineral descriptions |
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