3 research outputs found
SHRIMP U–Pb zircon dating of anatexis in high-grade migmatite complexes of Central Spain: implications in the Hercynian evolution of Central Iberia
U–Pb SHRIMP ages obtained in zircons
from the Sotosalbos and Toledo anatectic complexes
in Central Spain give new constraints to the evolution
of the inner part of the Hercynian Iberian belt. Pre-
Hercynian ages in zircons from the Sotosalbos complex
(~464 Ma) are well preserved and reveal that an
age diversity of the Lower Paleozoic magmatism in
the area exists, as previous data on westernmost orthogneisses
yield significant older ages. Zircon ages in
the pelite-derived granites from the Toledo complex
also show an important Neoproterozoic age component
which points to a metasedimentary protolith
deposited maximally 560 Ma ago. Younger zircon
populations in both complexes at ~330 Ma in the
Sotosalbos region and ~317 Ma in the Toledo complex
indicate an important diachronism between the
anatectic processes in both areas but also that these
processes are mainly unrelated to the generation of
the later Hercynian granite batholith of Central
Spain, which could be of deeper crustal derivation. In
addition, as migmatization occurred late in the
metamorphic cycle, after peak conditions were attained,
the age of anatexis is younger than the age of
the main Hercynian metamorphic event, which still is
not well constrained