Table 2

Tiburon Peninsula Franciscan40Ar/39Ar phengite ages, with ±1σ uncertainties. The 37 Tiburon analyses together average 153 ± 3 My with a MSWD of 5. See Fig. 2 for average ages and MSWD for each sample. For each sample, numbers in parentheses indicate the grain and spot number, respectively.

SampleAge (My)
Eclogite and garnet amphibolite
T-90-3AG (1-3)151.6 ± 4.1
T-90-3AG (1-5)155.8 ± 8.1
T-90-3AG (1-4)157.2 ± 9.1
T-90-3AG (1-1)157.5 ± 1.8
T-90-3AG (1-2)157.5 ± 1.8
T-90-3AB (1-2)152.2 ± 2.8
T-90-3AB (1-1)153.6 ± 3.1
T-90-3AB (2-3)153.8 ± 1.8
T-90-3AB (2-1)154.6 ± 1.7
T-90-3AB (2-2)157.1 ± 1.1
T-90-2AH (2-2)151.8 ± 1.3
T-90-2AH (2-1)152.1 ± 1.4
T-90-2AH (1-3)152.5 ± 1.8
T-90-2AH (1-4)152.9 ± 3.0
T-90-2AH (1-2)153.4 ± 3.6
T-90-2AH (1-1)156.3 ± 1.5
Rind
T90-2B (3-2)141.0 ± 1.7
T90-2B (2-1)144.1 ± 4.3
T90-2B (3-1)145.9 ± 3.3
T90-2B (2-3)148.9 ± 4.1
T90-2B (2-4)149.6 ± 4.1
T90-2B (1-3)150.1 ± 1.6
T90-2B (1-2)150.1 ± 1.8
T90-2B (2-2)151.5 ± 4.3
T90-2B (1-1)160.6 ± 3.3
Phengite-chlorite vein
T90-2V (2-1)150.2 ± 1.1
T90-2V (1-4)152.0 ± 1.5
T90-2V (1-1)153.5 ± 0.9
T90-2V (1-6)153.6 ± 3.1
T90-2V (2-4)154.0 ± 1.1
T90-2V (1-2)155.4 ± 1.8
T90-2V (2-2)155.8 ± 0.7
T90-2V (1-3)156.6 ± 1.9
T90-2V (2-3)157.0 ± 0.9
T90-2V (1-5)157.0 ± 1.5
T90-2V (1-8)157.2 ± 1.3
T90-2V (1-7)160.3 ± 5.2