Abstract
Ion microprobe U-Pb zircon ages have been obtained from four sampl es of Cretaceous granitoid and two samples of volcanogenic sediment from the northwest Nelson-Westland region of the South Island of New Zealand. Crow Granite, which intrudes lower Paleozoic metasedimentary rocks in the Buller Terrane on the eastern side of the Karamea Batholith, has given a crystallisation age of 137 {+-} 3 Ma (2 {delta}). This age is typical of the Jurassic-Early Cretaceous plutonic rocks that dominate the median Tectonic Zone, and raises the possibility that the Western province and the media Tectonic Zone were linked some 20 m.y. earlier than previously proposed. The `Gouland granodiorite`, which forms a large pluton at the northeastern margin of the Karamea Batholith, has a crystallisation age of 119 {+-} 2 Ma (2 {delta}). This age is similar to the Separation point Batholith (118 Ma) , and the distinctive chemistry of the batholith (high Na, Al, Sr and low Y) is also displayed by the Gouland granodiorite. The `Big Deep granite`, which intrudes Devonian granites of the Karamea Batholith in the upper Buller Gorge, has a crystallisation age of 110 {+-} 3 Ma (2 {delta}), similar to the age of Buckland Granite (Rahu Suite)
More>>
Muir, R J;
[1]
Ireland, T R;
[2]
Weaver, S D;
[1]
Bradshaw, J D;
[1]
Waight, T E;
[1]
Jongens, R;
[1]
Eby, G N
[3]
- Department of Geology, University of Canterbury, Christchurch (New Zealand)
- Research School of Earth Sciences, Australian National University, Canberra (Australia)
- Department of Earth Sciences, University of Massachusetts, Lowell (Mass.)
Citation Formats
Muir, R J, Ireland, T R, Weaver, S D, Bradshaw, J D, Waight, T E, Jongens, R, and Eby, G N.
SHRIMP U-Pb geochronology of Cretaceous magmatism in northwest Nelson-Westland, South Island, New Zealand.
New Zealand: N. p.,
1997.
Web.
Muir, R J, Ireland, T R, Weaver, S D, Bradshaw, J D, Waight, T E, Jongens, R, & Eby, G N.
SHRIMP U-Pb geochronology of Cretaceous magmatism in northwest Nelson-Westland, South Island, New Zealand.
New Zealand.
Muir, R J, Ireland, T R, Weaver, S D, Bradshaw, J D, Waight, T E, Jongens, R, and Eby, G N.
1997.
"SHRIMP U-Pb geochronology of Cretaceous magmatism in northwest Nelson-Westland, South Island, New Zealand."
New Zealand.
@misc{etde_604029,
title = {SHRIMP U-Pb geochronology of Cretaceous magmatism in northwest Nelson-Westland, South Island, New Zealand}
author = {Muir, R J, Ireland, T R, Weaver, S D, Bradshaw, J D, Waight, T E, Jongens, R, and Eby, G N}
abstractNote = {Ion microprobe U-Pb zircon ages have been obtained from four sampl es of Cretaceous granitoid and two samples of volcanogenic sediment from the northwest Nelson-Westland region of the South Island of New Zealand. Crow Granite, which intrudes lower Paleozoic metasedimentary rocks in the Buller Terrane on the eastern side of the Karamea Batholith, has given a crystallisation age of 137 {+-} 3 Ma (2 {delta}). This age is typical of the Jurassic-Early Cretaceous plutonic rocks that dominate the median Tectonic Zone, and raises the possibility that the Western province and the media Tectonic Zone were linked some 20 m.y. earlier than previously proposed. The `Gouland granodiorite`, which forms a large pluton at the northeastern margin of the Karamea Batholith, has a crystallisation age of 119 {+-} 2 Ma (2 {delta}). This age is similar to the Separation point Batholith (118 Ma) , and the distinctive chemistry of the batholith (high Na, Al, Sr and low Y) is also displayed by the Gouland granodiorite. The `Big Deep granite`, which intrudes Devonian granites of the Karamea Batholith in the upper Buller Gorge, has a crystallisation age of 110 {+-} 3 Ma (2 {delta}), similar to the age of Buckland Granite (Rahu Suite) in the Paparoa Batholith. Berlins Porphyry in the Lower Buller Gorge also has a mid-Cretaceous age of 111 {+-} 2 Ma (2 {delta}). Two samples of Stitts Tuff from the Lower Buller Gorge have given crystallisation ages of 101 {+-} 2 Ma (2 {delta}) and 102 {+-} 3 Ma (2 {delta}). These ages constrain the timing of initiation, of fault-bounded sedimentary basins on the West Coast, related to a major period of crustal extension before the opening of the Tasman Sea Basin. (author). 30 refs., 2 tabs., 3 figs.}
journal = []
issue = {4}
volume = {40}
journal type = {AC}
place = {New Zealand}
year = {1997}
month = {Dec}
}
title = {SHRIMP U-Pb geochronology of Cretaceous magmatism in northwest Nelson-Westland, South Island, New Zealand}
author = {Muir, R J, Ireland, T R, Weaver, S D, Bradshaw, J D, Waight, T E, Jongens, R, and Eby, G N}
abstractNote = {Ion microprobe U-Pb zircon ages have been obtained from four sampl es of Cretaceous granitoid and two samples of volcanogenic sediment from the northwest Nelson-Westland region of the South Island of New Zealand. Crow Granite, which intrudes lower Paleozoic metasedimentary rocks in the Buller Terrane on the eastern side of the Karamea Batholith, has given a crystallisation age of 137 {+-} 3 Ma (2 {delta}). This age is typical of the Jurassic-Early Cretaceous plutonic rocks that dominate the median Tectonic Zone, and raises the possibility that the Western province and the media Tectonic Zone were linked some 20 m.y. earlier than previously proposed. The `Gouland granodiorite`, which forms a large pluton at the northeastern margin of the Karamea Batholith, has a crystallisation age of 119 {+-} 2 Ma (2 {delta}). This age is similar to the Separation point Batholith (118 Ma) , and the distinctive chemistry of the batholith (high Na, Al, Sr and low Y) is also displayed by the Gouland granodiorite. The `Big Deep granite`, which intrudes Devonian granites of the Karamea Batholith in the upper Buller Gorge, has a crystallisation age of 110 {+-} 3 Ma (2 {delta}), similar to the age of Buckland Granite (Rahu Suite) in the Paparoa Batholith. Berlins Porphyry in the Lower Buller Gorge also has a mid-Cretaceous age of 111 {+-} 2 Ma (2 {delta}). Two samples of Stitts Tuff from the Lower Buller Gorge have given crystallisation ages of 101 {+-} 2 Ma (2 {delta}) and 102 {+-} 3 Ma (2 {delta}). These ages constrain the timing of initiation, of fault-bounded sedimentary basins on the West Coast, related to a major period of crustal extension before the opening of the Tasman Sea Basin. (author). 30 refs., 2 tabs., 3 figs.}
journal = []
issue = {4}
volume = {40}
journal type = {AC}
place = {New Zealand}
year = {1997}
month = {Dec}
}