Abstract
At Napoleon Bay, Baffin Island, fibrous aggregates define the contacts of Mesoproterozoic lamproite dykes with feldspathic wall-rock. The aggregates are composed of nepheline, pectolite and andesine, with fibre extensions along c, b and an indeterminate axis, respectively. Optically continuous, polymineralic fibre bundles are 0.1 to 0.2 mm long at the contact (all three minerals), 0.01 to 0.05 mm long in the wall-rock, but were not found beyond 8 mm from the dykes. Strongly alkaline, hydrothermal solutions, emanating from the dykes, reacted with labradorite in the wall-rock producing the fibrous agregates. Nepheline and pectolite were possibly derived from an unidentified, high-temperature phase that decomposed during cooling. Andesine may have been generated independently. Growth was directed across a set of tension fractures and proceeded with the aid of a thermal gradient as heat was removed continuously through the wall-rock.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 51-56 |
| Number of pages | 6 |
| Journal | European Journal of Mineralogy |
| Volume | 13 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2001 |
| Externally published | Yes |
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Keywords
- Andesine
- Baffin Island
- Fibrous aggregates
- Labradorite
- Lamproite
- Mesoproterozoic
- Nepheline
- Pectolite
ASJC Scopus subject areas
- Geochemistry and Petrology
Cite this
Fibrous nepheline, pectolite and plagioclase from Baffin Island. / Hogarth, D. D.; Pósfai, H.; Buseck, P R; Smith, J.
In: European Journal of Mineralogy, Vol. 13, No. 1, 2001, p. 51-56.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fibrous nepheline, pectolite and plagioclase from Baffin Island
AU - Hogarth, D. D.
AU - Pósfai, H.
AU - Buseck, P R
AU - Smith, J.
PY - 2001
Y1 - 2001
N2 - At Napoleon Bay, Baffin Island, fibrous aggregates define the contacts of Mesoproterozoic lamproite dykes with feldspathic wall-rock. The aggregates are composed of nepheline, pectolite and andesine, with fibre extensions along c, b and an indeterminate axis, respectively. Optically continuous, polymineralic fibre bundles are 0.1 to 0.2 mm long at the contact (all three minerals), 0.01 to 0.05 mm long in the wall-rock, but were not found beyond 8 mm from the dykes. Strongly alkaline, hydrothermal solutions, emanating from the dykes, reacted with labradorite in the wall-rock producing the fibrous agregates. Nepheline and pectolite were possibly derived from an unidentified, high-temperature phase that decomposed during cooling. Andesine may have been generated independently. Growth was directed across a set of tension fractures and proceeded with the aid of a thermal gradient as heat was removed continuously through the wall-rock.
AB - At Napoleon Bay, Baffin Island, fibrous aggregates define the contacts of Mesoproterozoic lamproite dykes with feldspathic wall-rock. The aggregates are composed of nepheline, pectolite and andesine, with fibre extensions along c, b and an indeterminate axis, respectively. Optically continuous, polymineralic fibre bundles are 0.1 to 0.2 mm long at the contact (all three minerals), 0.01 to 0.05 mm long in the wall-rock, but were not found beyond 8 mm from the dykes. Strongly alkaline, hydrothermal solutions, emanating from the dykes, reacted with labradorite in the wall-rock producing the fibrous agregates. Nepheline and pectolite were possibly derived from an unidentified, high-temperature phase that decomposed during cooling. Andesine may have been generated independently. Growth was directed across a set of tension fractures and proceeded with the aid of a thermal gradient as heat was removed continuously through the wall-rock.
KW - Andesine
KW - Baffin Island
KW - Fibrous aggregates
KW - Labradorite
KW - Lamproite
KW - Mesoproterozoic
KW - Nepheline
KW - Pectolite
UR - http://www.scopus.com/inward/record.url?scp=0034809066&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034809066&partnerID=8YFLogxK
U2 - 10.1127/0935-1221/01/0013-0051
DO - 10.1127/0935-1221/01/0013-0051
M3 - Article
AN - SCOPUS:0034809066
VL - 13
SP - 51
EP - 56
JO - European Journal of Mineralogy
JF - European Journal of Mineralogy
SN - 0935-1221
IS - 1
ER -