Topic
Rhinns complex
About: Rhinns complex is a research topic. Over the lifetime, 9 publications have been published within this topic receiving 223 citations.
Papers
TL;DR: Fitches et al. as discussed by the authors showed that the deformed alkaline igneous complex on Inishtrahd, County Donegal, Ireland yield near-concordant U-Pb ages of 1779 * 3 Ma interpreted as dating the igneous crystallization of the gneiss9s precursor.
Abstract: Smd zircon fractions from the deformed alkaline igneous complex on Inishtrahd, County Donegal, Ireland yield near-concordant U-Pb ages of 1779 * 3 Ma interpreted as dating the igneous crystallization of the gneiss9s precursor. Sm-Nd depleted mantle model ages range from 1912 Ma to 1978 Ms. The similarity of the model ages and the crystallization age indicates that the protoliths were derived from a depleted mantle source essentially uncontaminated by older crust. The isotopic data confirm previous tentative correlations of the Inishtrahull rocks with those of Islay in southwestern Scotland. Archaean crust is apparently absent from this region, consistent with recent models placing a southern limit on the Archaean along the line of the Great Glen fault zone. Pre-Caledonian orthogneisses in Scotland and Ireland, south of the Great Glen fault zone, have generally been correlated with the late Archaean Lewisian Complex of northwestern Scotland (e.g. Wilkinson 1907; McCallien 1930; Bowes & Hopgood 1975; Dixon et al. 1990) although Aftalion & Max (1987) concluded that the Lewisian was absent from the Annagh Division gneisses of north Mayo, Ireland. There are now several lines of evidence to suggest that Archaean crust may be absent southeast of the Great Glen fault zone (e.g. Fitches et al. 1990; Daly 1990; Halliday et al. 1985). A large area of pre-Caledonian basement, here termed the Rhinns Complex, is thought to be present within the fault-bounded Colonsay-West Islay block (Fig. 1; Bentley et al. 1988; Fitches et al. 1990; Marcantonio et al. 1988)), which extends from Colonsay in
52 citations
TL;DR: In this paper, a multidisciplinary provenance study, including in situ U-Pb dating of detrital titanite, was undertaken on the enigmatic low-grade metasediments of the Colonsay Group, SW Scotland to determine their source and assess previous correlations with major Neoproterozoic sedimentary sequences within the Scottish Caledonides.
48 citations
TL;DR: Paleoproterozoic basement occurs on the islands of Islay and Colonsay in western Scotland and on Inishtrahull off the north coast of Ireland The basement is composed of a deformed alkalic igneous association, collectively referred to as the Rhinns complex as mentioned in this paper.
Abstract: Paleoproterozoic basement occurs on the islands of Islay and Colonsay in western Scotland and on Inishtrahull off the north coast of Ireland The basement is composed of a deformed alkalic igneous association, collectively referred to as the Rhinns complex Isotopic data indicate that the complex represents new addition of mantle-derived material to the crust at ca 18 Ga The Rhinns complex may link with rocks of similar age in North America, Greenland, and Scandinavia, which formed part of the southern margin of the Laurentia-Baltica supercontinent
39 citations
TL;DR: The presence of major crystalline basement provinces at depth in NW Ireland is inferred from in situ Hf isotope analysis of zircons from granitoid rocks that cut structurally overlying metasedimentary rocks.
Abstract: The presence of major crystalline basement provinces at depth in NW Ireland is inferred from in situ Hf isotope analysis of zircons from granitoid rocks that cut structurally overlying metasedimentary rocks. Granitoids in two of these units, the Slishwood Division and the Tyrone Central Inlier, contain complex zircons with core and rim structures. In both cases, cores have average ϵHf values that differ from the average ϵHf values of the rims at 470 Ma (the time of granitoid intrusion). The Hf data and similarity in U–Pb age between the inherited cores and detrital zircons from the host metasedimentary rocks suggests local contamination during intrusion rather than transport of the grains from the source region at depth. Rims from the Slishwood Division intrusions have average ϵHf470 values of −7.7, consistent with a derivation from juvenile Palaeoproterozoic crust, such as the Annagh Gneiss Complex or Rhinns Complex of NW Ireland, implying that the deep crust underlying the Slishwood Division is made of similar material. Rims from the Tyrone Central Inlier have extremely negative ϵHf470 values of approximately −39. This isotopic signature requires an Archaean source, suggesting rocks similar to the Lewisian Complex of Scotland, or sediment derived wholly from it, occurs at depth in NW Ireland.
31 citations
TL;DR: In this paper, a deformed igneous association of mainly syenite and gabbro, with minor mafic and felsic intrusions, is collectively referred to as the Rhinns Complex.
Abstract: The Precambrian basement on the islands of Islay, Colonsay and Inishtrahull comprises a deformed igneous association of mainly syenite and gabbro, with minor mafic and felsic intrusions. This association is collectively referred to as the Rhinns Complex. Isotopic data indicate that the complex represents new addition of material to the crust at c. 1·8 Ga. The igneous protolith was juvenile mantle-derived material, not reworked Archaean crust. Overall, the complex has an alkalic composition, with major and trace element patterns similar to igneous rocks generated in a subduction-related setting: high LILE/HFSE and LREE/HREE ratios, together with negative Nb, P and Ti anomalies. The formation of the Rhinns Complex was contemporaneous with the Laxfordian tectonothermal cycle in the Lewisian Complex. These Proterozoic events are most likely associated with an extensive 1·9–1·7 Ga mobile belt around the southern margin of Laurentia-Baltica. As part of this belt, the Rhinns Complex forms a link between the Ketilidian province of South Greenland and the Svecofennian of Scandinavia. Inherited isotopic signatures in the Caledonian granites on the north side of the Highland Boundary Fault may reflect the presence of a large area of Proterozoic basement (?Rhinns Complex) beneath Scotland and NW Ireland. Alternatively, the Proterozoic signature could be derived from the incorporation of Moine or Dalradian sediment into the granitic magmas.
29 citations
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| Year | Papers |
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| 2014 | 1 |
| 2013 | 1 |
| 2010 | 1 |
| 2009 | 2 |
| 1995 | 1 |
| 1994 | 1 |