Unit symbol: | TKgd |
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Age range | Tertiary, Paleocene, or Late Cretaceous, Maastrichtian (72.1 to 56 Ma) |
Lithology: | Igneous - Plutonic |
Group name: | Granitic rocks of southern and interior Alaska |
Source map | Patton, W.W., Jr., Wilson, F.H., Labay, K.A., and Shew, Nora, 2009, Geologic map of the Yukon-Koyukuk basin, Alaska: U.S. Geological Survey Scientific Investigations Map SIM-2909, 26 p., 2 sheets, scale 1:500,000. |
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Symbol | TKm |
Unit name | Monzonite |
Description | Medium- to coarse-grained, equigranular, biotite and hornblende monzonite, quartz monzonite, monzodiorite, and quartz diorite. Subordinate monzogabbro and gabbro. Forms small plutonic bodies in Medfra and Ophir quadrangles |
Lithology | Igneous |
Label | TKgd |
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Description | More mafic granitic rocks, tonalite, monzonite |
Geologic age | Maastrichtian to Paleocene |
Geologic setting | Intrusive |
Lithology | Form | Importance |
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Granodiorite < Granitic < Plutonic < Igneous | Pluton | Major |
Monzonite < Syenitic < Plutonic < Igneous | Pluton | Major |
Diorite < Dioritic < Plutonic < Igneous | Pluton | Indeterminate, major |
Monzodiorite < Dioritic < Plutonic < Igneous | Pluton | Indeterminate, major |
Quartz-monzodiorite < Dioritic < Plutonic < Igneous | Pluton | Indeterminate, major |
Quartz-monzonite < Syenitic < Plutonic < Igneous | Pluton | Indeterminate, major |
Tonalite < Granitic < Plutonic < Igneous | Pluton | Minor |