Isotopic Evidence for Early Proterozoic Age of the Idono Complex, West-Central Alaska

1991 ◽  
Vol 99 (2) ◽  
pp. 209-223 ◽  
Author(s):  
Marti L. Miller ◽  
J. Y. Bradshaw ◽  
D. L. Kimbrough ◽  
T. W. Stern ◽  
T. K. Bundtzen
Keyword(s):  
Early Proterozoic ◽  
Isotopic Evidence ◽  
West Central ◽  
Proterozoic Age

Provenance of the Old Red Sandstone: Pb isotope evidence from Arran, western Scotland

1984 ◽  
Vol 75 (2) ◽  
pp. 239-241 ◽  
Author(s):  
A. P. Dickin
Keyword(s):  
Significant Contribution ◽  
Strike Slip ◽  
Pb Isotope ◽  
Early Proterozoic ◽  
Red Sandstone ◽  
Boundary Fault ◽  
Crustal Block ◽  
Isotope Evidence ◽  
Strike Slip Movement ◽  
Proterozoic Age

ABSTRACTOld Red Sandstone sediments from Arran in western Scotland yield an array of Pb isotope compositions whose slope corresponds to an age of 1830 ± 400 Ma. These compositions are not consistent with a significant contribution of material from the Southern Highlands, Midland Valley, or Southern Uplands, but are similar to the Torridonian sandstones of NW Scotland. Bearing in mind the probable Laxfordian provenance of the Torridonian assemblage, this points to a source for the Old Red Sandstone in a crustal block of early Proterozoic age corresponding to the age of the Laxfordian episode. Since such a source is not presently in a position to yield the Old Red Sandstone, strike-slip movement along the Highland Boundary fault is a strong possibility.

Geochemistry and petrogenesis of early Proterozoic amphibolites, west-central Colorado, U.S.A.

1988 ◽  
Vol 67 (3-4) ◽  
pp. 209-225 ◽  
Author(s):  
Michael W. Knoper ◽  
Kent C. Condie
Keyword(s):  
Early Proterozoic ◽  
West Central

Isotopic evidence for the extent of early Proterozoic basement in Scotland and northwest Ireland

1991 ◽  
Vol 128 (4) ◽  
pp. 385-388 ◽  
Author(s):  
A. P. Dickin ◽  
D. R. Bowes
Keyword(s):  
Nd Isotope ◽  
Early Proterozoic ◽  
Isotopic Evidence ◽  
Gneiss Complex ◽  
Proterozoic Basement ◽  
Western Ireland ◽  
Isotope Systematics

AbstractTightly clustered Sm–Nd model ages, with an average of 1.96±0.02Ga, for the gneiss complex of Inishtrahull indicate coeval development with the earlyProterozoic gneiss terrane of Islay. The extent of this terrane, largely beneath the Dalradian Supergroup, is argued to be 100×600 km, from northeast Scotland to western Ireland. This is based on the distribution of dated basement in conjunction with Pb, Sr and Nd isotope systematics and inherited zircons in Caledonian granites of the region.

scholarly journals Isotopic studies in the East Greenland Caledonides (72°–74°N) – Precambrian and Caledonian ages

1981 ◽  
Vol 104 ◽  
pp. 47-72
Author(s):  
D.C Rex ◽  
A.R Gledhill
Keyword(s):  
Crystalline Rocks ◽  
Reference Line ◽  
Published Data ◽  
East Greenland ◽  
Early Proterozoic ◽  
Late Proterozoic ◽  
Isotopic Studies ◽  
Data Points ◽  
Proterozoic Age

Rb-Sr isotopic studies on crystalline rocks from different rock units of the East Greenland Caledonides have given a number of isochron and 'errorchron' ages, as well as sets of inconclusive data. All the results are presented here as an illustration of the problems encountered, though previously published data is given in summary form. Eleven collections from Archaean - early Proterozoic rock units have given seven early Proterozoic Rb-Sr whole rock isochrons, while one set of data points plot about a 2450 m.y. reference line. Seven collections from metasediments of presumed middle to late Proterozoic age produced only one 'errorchron' of c. 1245 m.y., but data points from all the collections plot about a 1250 m.y. reference line. Six collections from a suite of 'older' granites gave four isochron ages of 1080, 1000,765 and 650 m.y. Eight collections from Caledonian granites gave four isochron ages, three 'errorchrons' and one mineral-whole rock isochron; the ages fall in the range 377-550 m.y.

Early Proterozoic age of the Tyrkandin fault zone, the Aldan Shield: U-Pb dating of fragments of single zircon grains

2006 ◽  
Vol 408 (1) ◽  
pp. 538-541 ◽  
Author(s):  
E. B. Sal’nikova ◽  
A. B. Kotov ◽  
V. I. Kazansky ◽  
V. A. Glebovitsky ◽  
N. N. Pertsev ◽  
...  
Keyword(s):  
Fault Zone ◽  
Aldan Shield ◽  
Early Proterozoic ◽  
Single Zircon ◽  
Proterozoic Age
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