10.6084/m9.figshare.3452954.v1
Sarah H. Vorhies
Sarah H.
Vorhies
Jay J. Ague
Jay J.
Ague
Pressure–temperature evolution and thermal regimes in the Barrovian zones, Scotland
Geological Society of London
2016
metamorphism
mineral composition data
evolution
GPa
crustal heat flow
2 D garnet maps
pulse
advective heat input
T conditions
Scotland
garnet zoning profiles
tectonically overthickened crust
Barrovian type area
Glen Clova
Geology
2016-06-21 11:00:44
Dataset
https://geolsoc.figshare.com/articles/dataset/Pressure_temperature_evolution_and_thermal_regimes_in_the_Barrovian_zones_Scotland/3452954
<p>We constrain the <em>P</em>–<em>T</em> evolution of the Barrovian metamorphic zones from the southwestern to the northeastern coasts of Scotland using thermobarometry
and pseudosection analysis based on mineral composition data, garnet zoning profiles and 2D garnet maps. Twenty-five samples
were investigated from the garnet to the sillimanite zones. In the western half of the field area there was relatively high-<em>P</em> metamorphism (0.9–1.1 GPa) followed by near-isothermal decompression. In and around the Barrovian type area of Glen Clova
maximum pressures were also high (<em>c</em>. 0.8–0.9 GPa); however, peak-<em>T</em> conditions were driven by a brief (of the order of 1 Ma or less) thermal pulse or pulses during exhumation at <em>c</em>. 0.6 GPa. Pressures at peak-<em>T</em> conditions along the eastern coast were the lowest observed, <em>c</em>. 0.4–0.5 GPa. These rocks were probably affected by the same thermal pulse activity evident around Glen Clova. All three
regions initially developed during regional metamorphism associated with thermal relaxation of tectonically overthickened
crust. The eastern part of the sequence, including Glen Clova, is fundamentally different from the western part because it
required additional advective heat input to achieve peak thermal conditions. This heat was probably supplied by synorogenic
magmas (e.g. Newer Gabbros) and the associated elevated crustal heat flow.
</p>