1. Thermobarometry of metapelites in the Coast shear zone at Mussel Inlet
Dave Pearson

2. Previous P-T-t work Mostly GASP barometry, garnet-biotite thermometry
2-7.5 kbar, 325°C
8.2 kbar, °C
8.2+1 kbar, °C
kbar, °C
6.4 kbar, °C
6+1 kbar, °C
Mostly GASP barometry, garnet-biotite thermometry
Ages generally inferred from U-Pb pluton ages
6.3+1 kbar, °C
Previous P-T-t work
Generally 3 metamorphic episodes recognized : >101 Ma, Ma, and Ma
6+1 kbar
4-4.5 kbar
6.3 kbar
10.2 kbar
kbar, °C
kbar, ~600°C
6.4 kbar, 525 ºC
~90-60 Ma
kbar, °C
kbar, ºC
~70-60 Ma
kbar, ºC
~90 Ma
kbar, ºC
>101 Ma

3. Previous P-T-t work (cont.)
2-7.5 kbar, 325°C
8.2 kbar, °C
8.2+1 kbar, °C
kbar, °C
6.4 kbar, °C
6+1 kbar, °C
Rusmore et al. (2005) show continuous metamorphism from Ma in Central Gneiss near Douglas Channel
6.3+1 kbar, °C
Previous P-T-t work (cont.)
West of CSZ, pressures generally increase toward the east
6+1 kbar
4-4.5 kbar
6.3 kbar
10.2 kbar
kbar, °C
kbar, ~600°C
6.4 kbar, 525 ºC
~90-60 Ma
kbar, °C
kbar, ºC
~70-60 Ma
kbar, ºC
~90 Ma
kbar, ºC
>101 Ma

4. My preliminary results from Mussell Inlet
So far, 2 samples from Mussell Inlet: GJP-48 and GJP-49
These samples consist of: Qtz+bt+plag+sill+kspar+ms
More P-Ts to come
I will also do Sm-Nd garnet-whole rock dating of these and more samples

7. My preliminary results
kbar, °C
6.4 kbar, 525 ºC
kbar, ~600°C
In Mussell Inlet, probably within CSZ
Sillimanite-bearing metapelites (Yukon-Tanana protolith), with relict kyanite in some samples
For barometry (GASP), used Holland and Powell (1995) data set calibrations
For thermometry (grt-bt), took average of 7 different calibrations
kbar, ºC
kbar, °C
kbar, ºC
kbar, ºC
GJP-49: kbar, oC
GJP-48: kbar, oC

8. ~90-60 Ma ~70-60 Ma ~90 Ma >101 Ma 2-7.5 kbar, 325°C
GJP-49: kbar, oC
>101 Ma
GJP-48: kbar, oC

9. P-T-t references
Crawford et al., 1979, Crawford et al., 1987, Stowell, 1989, Himmelberg et al., 1991, 1994, Himmelberg et al., 1995, Taylor et al., 1996, 1997; Stowell and Goldberg, 1997, Klepeis et al., 1998, Lindline, 1999, Stowell and Crawford, 2000, Stowell et al., 2001, Rusmore et al., 2005