10.6084/m9.figshare.3454541.v1
GRIT STEINHOEFEL
GRIT
STEINHOEFEL
ERNST HEGNER
ERNST
HEGNER
GRAHAME J.H. OLIVER
GRAHAME J.H.
OLIVER
Chemical and Nd isotope constraints on granitoid sources involved in the Caledonian Orogeny in Scotland
Geological Society of London
2016
source
Nd isotope constraints
Nd isotope compositions
Midland Valley island arc
pattern
crust
Ma
ϵ Nd values
Scotland
REE
Grampian Highlands
Andean plate margin
Caledonian Orogeny
granitoid
granite
Midland Valley arc
Geology
2016-06-21 12:11:42
Dataset
https://geolsoc.figshare.com/articles/dataset/Chemical_and_Nd_isotope_constraints_on_granitoid_sources_involved_in_the_Caledonian_Orogeny_in_Scotland/3454541
<p>Major- and trace-element data and Nd isotope compositions for granitoid samples from the Grampian Highlands in Scotland show
a systematic evolution in the composition of their sources in the course of the Caledonian Orogeny. Granitoids of 511–451
Ma, related to the collision of the Midland Valley island arc with the Grampian terrane, show S-type affinity and fractionated
REE patterns with minor Eu anomalies and low initial ϵ<sub>Nd</sub> values of −14.1 to −11.2 suggesting melting of predominantly Dalradian metasediments. Subsequently formed granitoids of 425–406
Ma derived from an assumed Andean plate margin comprise a wide spectrum of rock types including I-type granite–granodiorite,
and S-type granitoids, monzonites and alkali granites. The trace-element patterns of these rocks and the range of initial
ϵ<sub>Nd</sub> values of −2.1 to −6.9 are consistent with melting of variably rejuvenated crust as found in continental margin settings.
We conclude that the Grampian Highlands were affected by two major crust-modifying events during the Caledonian Orogeny: predominantly
recycling of older crust during docking of the Midland Valley arc and addition of juvenile, mantle-derived material to the
crust during the convergence of Avalonia with Laurentia.
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