Fluid infiltration of the Tudor Gabbro during regional metamorphism
Conference
·
· Geol. Soc. Am., Abstr. Programs; (United States)
OSTI ID:6875127
The Tudor Gabbro (TG), an ovate body (4 x 9 km) 40 km SE of Bancroft. Ontario, was metamorphosed to upper greenschist facies along with surrounding sediments and volcanics. Allen (1976) delineated concentric isograds around the gabbro, including +sphene, +tremolite (to 1.5 km), +tremolite + clinozoisite, +diopside (approx. 120 m), and +garnet (approx. 80 m). Metamorphic conditions are inferred to be 490+/-50/sup 0/C, 5 kb with no thermal gradient. Allen suggested that H/sub 2/O infiltration of the marble and calc-schist accounts for the isograds. The gabbro mineralogy of titanaugite, andesine to labradorite, and minor hornblende is extensively recrystallized to albite and/or oligoclase + actinolite + epidote + ilmenite + calcite (up to 4 wt%) +/- biotite +/- chlorite +/- sphene +/- scapolite. Isotopic analyses of calcite from 39 TG samples show delta/sup 18/O = 9.4 to 16.6 and delta/sup 13/C = -1.9 to 3.4. Bulk silicate delta/sup 18/O of TG range from 7.1 to 10.2. Calcites in metasediment have delta/sup 18/O = 18.1 to 25.3 and delta/sup 13/C = 1.3 to 5.6. Two whole rock silicate analyses of a skarn developed locally at the contact show intermediate delta/sup 18/O of 16.2 and 17.3. The stability of Czo component in epidote requires H/sub 2/O-rich fluids. The delta/sup 13/C of TG calcites average +0.7 nearly identical to the average of 178 carbonates from Grenville marbles (+1.0), showing that metasediment-derived CO/sub 2/ pervasively infiltrated the TG. The infiltration of H/sub 2/O into both the TG and the metasediment suggests that H/sub 2/O-rich fluids migrated upward along the contact.
- Research Organization:
- Univ. of Wisconsin, Madison (USA)
- OSTI ID:
- 6875127
- Report Number(s):
- CONF-8510489-
- Conference Information:
- Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
- Country of Publication:
- United States
- Language:
- English
Similar Records
Petrologic and stable isotopic evidence for reaction-enhanced fluid flow during metamorphism of Precambrian-Cambrian sedimentary rocks, Lone Mountain, Nevada
Oxygen-isotope exchange and mineral alteration in gabbros of the Lower Layered Series, Kap Edvard Holm Complex, East Greenland
Models for coupled fluid flow, mineral reaction, and isotopic alteration during contact metamorphism: The Notch Peak aureole, Utah
Conference
·
Tue Dec 31 23:00:00 EST 1991
· Geological Society of America, Abstracts with Programs; (United States)
·
OSTI ID:5690287
Oxygen-isotope exchange and mineral alteration in gabbros of the Lower Layered Series, Kap Edvard Holm Complex, East Greenland
Journal Article
·
Thu Aug 01 00:00:00 EDT 1991
· Geology; (United States)
·
OSTI ID:5963874
Models for coupled fluid flow, mineral reaction, and isotopic alteration during contact metamorphism: The Notch Peak aureole, Utah
Journal Article
·
· American Mineralogist; (United States)
·
OSTI ID:7201858
Related Subjects
58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
580400 -- Geochemistry-- (-1989)
CANADA
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
FLUIDS
GABBROS
GEOCHEMISTRY
GEOTHERMAL FLUIDS
HYDROTHERMAL ALTERATION
IGNEOUS ROCKS
ISOTOPE RATIO
METAMORPHISM
MINERALOGY
NORTH AMERICA
ONTARIO
PLUTONIC ROCKS
QUANTITATIVE CHEMICAL ANALYSIS
ROCKS
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
580400 -- Geochemistry-- (-1989)
CANADA
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
FLUIDS
GABBROS
GEOCHEMISTRY
GEOTHERMAL FLUIDS
HYDROTHERMAL ALTERATION
IGNEOUS ROCKS
ISOTOPE RATIO
METAMORPHISM
MINERALOGY
NORTH AMERICA
ONTARIO
PLUTONIC ROCKS
QUANTITATIVE CHEMICAL ANALYSIS
ROCKS