Table 3. SHRIMP U-Pb isotopic ages of basement rocks in the field trip area. | ||||
Lithologic Unit |
Sample Number |
Igneous Crystallization Age (Ma) [± 2 sigma] |
Metamorphic Ages (Ma) [± 2 sigma] |
Inheritance Ages (Ma) [± 2 sigma] |
---|---|---|---|---|
low-silica charnockite (Yfqj) | SNP-99-93 | 1050 ± 8 | 1018 ± 14 | |
Old Rag magmatic suite (coarse-grained leucogranite) (Ygr) | OR-97-35 | 1060 ± 5 | 1019 ± 15 | |
979 ± 11 | ||||
1059 ± 8* | 1027 ± 9 | |||
garnetiferous syenogranite (Ygg) | SNP-02-197 | 1064 ± 7 | 1028 ± 14 | 1135 ± 6 1099 ± 9 |
leucogranite gneiss (Ylgg) | SNP-99-90 | 1078 ± 9 | 1028 ± 10 | |
997 ± 19 | ||||
foliated pyroxene granite (Yfpg) | SNP-02-177 | 1117 ± 14 | 1043 ± 12 | 1175 ± 14 |
high-silica charnockite (Ycf) | SNP-96-10 | 1159 ± 14 | 1052 ± 14 | |
foliated megacrystic leucocratic granite (Ylg) | SNP-02-189 | 1183 ± 11 | 1110 ± 38 1043 ± 16 |
* monazite ages indicated by italics; all other ages obtained from zircon.