Parkinson, Dave (1991) Age and isotopic character of Early Proterozoic basement gneisses in the southern Monashee Complex, southeastern British Columbia. Canadian Journal of Earth Sciences, 28 (8) 1159-1168 doi:10.1139/e91-106
| Reference Type | Journal (article/letter/editorial) | ||
|---|---|---|---|
| Title | Age and isotopic character of Early Proterozoic basement gneisses in the southern Monashee Complex, southeastern British Columbia | ||
| Journal | Canadian Journal of Earth Sciences | ||
| Authors | Parkinson, Dave | Author | |
| Year | 1991 (August 1) | Volume | 28 |
| Issue | 8 | ||
| Publisher | Canadian Science Publishing | ||
| DOI | doi:10.1139/e91-106Search in ResearchGate | ||
| Generate Citation Formats | |||
| Mindat Ref. ID | 481386 | Long-form Identifier | mindat:1:5:481386:0 |
| GUID | 0 | ||
| Full Reference | Parkinson, Dave (1991) Age and isotopic character of Early Proterozoic basement gneisses in the southern Monashee Complex, southeastern British Columbia. Canadian Journal of Earth Sciences, 28 (8) 1159-1168 doi:10.1139/e91-106 | ||
| Plain Text | Parkinson, Dave (1991) Age and isotopic character of Early Proterozoic basement gneisses in the southern Monashee Complex, southeastern British Columbia. Canadian Journal of Earth Sciences, 28 (8) 1159-1168 doi:10.1139/e91-106 | ||
| In | (1991, August) Canadian Journal of Earth Sciences Vol. 28 (8) Canadian Science Publishing | ||
| Abstract/Notes | The southern Monashee Complex is a fault-bounded exposure of upper-amphibolite-grade basement gneisses (core gneisses) and unconformably overlying mantling metasedimentary gneisses. The eastern margin is marked by the Early Eocene ductile to brittle Columbia River fault zone; the western and southern margins are marked by the Monashee Decollement and structurally higher Selkirk allochthon.The basement gneisses are exposed in the cores of large, northeast-verging nappes that subsequently have been overprinted towards the east by the Columbia River fault zone. The basement gneisses are a supracrustal sequence intruded by at least two distinct orthogneisses: (i) a biotite granite gneiss ("gray gneiss") dated by U/Pb zircon at 1874 ± 21 Ma; and (ii) a ±hornblende–biotite K-feldspar augen gneiss dated by U/Pb zircon at 1934 ± 6 Ma.The supracrustal gneisses are predominantly heterogeneous biotite–quartz–feldspar gneiss interlayered with less common pelitic schist and calc-silicate gneiss. U/Pb zircon data on detrital zircon populations from this heterogeneous supracrustal sequence give 207Pb*/206Pb* ages of less than 2.2 Ga. Whole-rock Pb isotopic data indicate an age of approximately 2.0 Ga. Whole-rock Sm/Nd model ages on the two intrusive suites indicate separate sources, the 1874 Ma gneiss having been produced from similar-age juvenile Early Proterozoic material (TDM ≈ 2.2 Ga). In contrast, Nd data from the 1934 Ma augen gneiss clearly indicate interaction with a component of older (late Archean) material (TDM ≈ 2.8 Ga). Whole-rock Sm/Nd data from the supracrustal gneisses follow this same pattern, with one group (seven samples) similar to the 1874 Ma gneiss (with TDM ≈ 2.3–2.6 Ga) and a second group (five samples) showing provenance or derivation from an Archean source (TDM = 2.8–3.3 Ga). The age of the intrusive suites, combined with the Nd data, strongly argues for a correlation with the Early Proterozoic Wopmay orogenic belt in northern Canada. | ||
See Also
These are possibly similar items as determined by title/reference text matching only.
