Barrow Zones
Photomicrographs from my project on the Grampian Highlands
No.1
LL1.2
Loch Lomond, near Aldochlay
Chl zone
ppl 1 mm
Chl and Ms in centre
xpl 1 mm
ppl 8 mm
xpl 8 mm
xpl 1 mm
Pl in centre
ppl 1 mm
xpl 1 mm
Pl in centre
ppl 1 mm
Blue mineral (at the top)
xpl 1 mm
ppl 1 mm
Texture
xpl 1 mm
ppl 1 mm
Blue mineral centred
xpl 1 mm
Blue mineral in extinction
xpl 1 mm
No.2
LL1.6
Loch Lomond, near Stuckgowan
Chl zone
ppl 8 mm
xpl 8 mm
(!!!)
ppl 8 mm
Tight folding
xpl 8 mm
xpl 2 mm
xpl 2 mm
Ms inclusions in Qz
ppl 1 mm
xpl 1 mm
ppl 2 mm
xpl 2 mm
ppl 1 mm
Potentially chloritised Bt
xpl 1 mm
ppl 2 mm
Cal (right of centre)
xpl 2 mm
xpl 2 mm
Wavy oxide
No.3
LL2.2
Loch Lomond, near Crianlarich
Grt zone
ppl 2 mm
xpl 2 mm
ppl 8 mm
A row of garnets
xpl 8 mm
xpl 8 mm
ppl 2 mm
(A two-urmaline)
xpl 2 mm
ppl 2 mm
ppl 2 mm
Bt in centre
xpl 2 mm
ppl 2 mm
Grt surrounded by Chl
xpl 2 mm
Characteristic anomalous purple / blue birefringence (Chl)
ppl 1 mm
Tur
xpl 1 mm
xpl 1 mm
ppl 1 mm
xpl 1 mm
Ab twin
ppl 2 mm
ppl 2 mm
Tur (with grey cores)
xpl 2 mm
ppl 8 mm
xpl 8 mm
(!!!)
ppl 2 mm
An unhappy Grt
xpl 2 mm
Chl alteration
No.4
LL2.2-2
(Same locality as No.3)
ppl 8 mm
xpl 8 mm
ppl 1 mm
Ep within retrogressive Chl (emanating from Grt)
xpl 1 mm
ppl 1 mm
Ab in centre
xpl 1 mm
No.5
LL2.4
Loch Lomond, near Auchreoch
Grt zone
ppl 2 mm
xpl 2 mm
Grt pressure shadow. Lots of Chl
ppl 2 mm
xpl 2 mm
Yellow streakiness... seemingly associated with the holes in the section
ppl 2 mm
xpl 2 mm
ppl 1 mm
Inclusions in Grt
xpl 1 mm
ppl 8 mm
xpl 8 mm
ppl 8 mm
xpl 8 mm
No.6
LL2.4-2
(Same locality as No.5)
ppl 1 mm
xpl 1 mm
ppl 8 mm
xpl 8 mm
ppl 8 mm
xpl 8 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
No.7
LL2.5
Loch Lomond, near Auchreoch
Grt zone
ppl 8 mm
xpl 8 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
ppl 2 mm
Amp
ppl 2 mm
Pleochroism
xpl 2 mm
xpl 2 mm
Max birefringence
No.8
LL2.5-2
(Same locality as No.7)
ppl 2 mm
xpl 2 mm
ppl 1 mm
xpl 1 mm
Possible lamellar twinning in the centre grain
xpl 1 mm
ppl 2 mm
xpl 2 mm
Lamellar twinning
ppl 2 mm
Simple twin visible due to the difference in pleochroism
xpl 2 mm
xpl 2 mm
ppl 8 mm
xpl 8 mm
No.9
LL2.6
Loch Lomond
Grt zone
ppl 2 mm
xpl 2 mm
Sericitisation & retrograde Chl
ppl 8 mm
Hydrous alteration
xpl 8 mm
Grt smash-up
No.10
LL2.6-2
(Same locality as No.9)
ppl 8 mm
xpl 8 mm
Straight inclusion trails in the western Grt
No.11
LL3.1
Loch Lomond
Grt zone
ppl 2 mm
xpl 2 mm
Ab sericitisation (N)
Mca → Chl (centre)
ppl 8 mm
xpl 8 mm
No.12
LL3.1-2
(Same locality as No.11)
ppl 8 mm
xpl 8 mm
No.13
Z.C.7
Crd-And schist
Near Methlick, Aberdeen
And zone
ppl 8 mm
An apparent difference in colour in the N and S
xpl 8 mm
Confusing mica pattern in the SW
ppl 2 mm
Crd?
xpl 2 mm
ppl 8 mm
Crd?
xpl 8 mm
xpl 8 mm
Possible sector trilling (six sectors)
ppl 1 mm
xpl 1 mm
Pl (?) with an inclusion N of centre; a grain with potentially four quadrants to the right of it
ppl 1 mm
xpl 1 mm
Pl with concave boundaries
xpl 0.3 mm
ppl 1 mm
Moderate-high relief phase in centre
xpl 1 mm
ppl 1 mm
Yellow pleochroic halo just right of centre (⇒ Crd)
ppl 1 mm
No more pleochroic halo
xpl 1 mm
ppl 1 mm
xpl 1 mm
ppl 2 mm
xpl 2 mm
ppl 1 mm
xpl 1 mm
Mca collision
ppl 1 mm
xpl 1 mm
Symplectites
No.14
10177 (aka G152)
St-Grt schist
Above Cornescorn, Glenesk
St zone
ppl 1 mm
xpl 1 mm
ppl 2 mm
St
xpl 2 mm
Unusual extinction
xpl 2 mm
ppl 2 mm
Bt → Chl
xpl 2 mm
ppl 2 mm
Tur
xpl 2 mm
xpl 2 mm
ppl 2 mm
Tur
xpl 2 mm
ppl 2 mm
Tur length cutting through Bt
ppl 2 mm
xpl 2 mm
ppl 5 mm
St and Grt
xpl 5 mm
No.15
7105 (aka F318)
Sil-Crd gneiss
Loose block near Ellon, Aberdeenshire
Sil zone
ppl 2 mm
xpl 2 mm
ppl 1 mm
xpl 1 mm
Symplectite
xpl 1 mm
ppl 2 mm
xpl 2 mm
Polysynthetic twins pinching out in one direction (= Crd)
ppl 5 mm
xpl 5 mm
Sector trilling in Crd
xpl 5 mm
ppl 1 mm
Dark green oxides?
xpl 1 mm
ppl 5 mm
xpl 5 mm
ppl 2 mm
xpl 2 mm
ppl 2 mm
Fibrolite ?
xpl 2 mm
ppl 1 mm
xpl 1 mm
No.16
LD20
Retrograde Grt-Mica pelite
Eastern Glenelg, Lewisian [above GGF]
Grt zone
ppl 0.3 mm
xpl 0.3 mm
ppl 8 mm
xpl 8 mm
ppl 2 mm
xpl 2 mm
No.17
M00563
Barrovian schist
Ky zone
ppl 2 mm
xpl 2 mm
Pseudomorph ?
ppl 8 mm
xpl 8 mm
Ky → shimmer aggregate ?
xpl 8 mm
Centre grain: straight extinction (speckled)
ppl 2 mm
Ky with a reaction rim
xpl 2 mm
ppl 1 mm
xpl 1 mm
xpl 1 mm
ppl 2 mm
xpl 2 mm
ppl 1 mm
ppl 1 mm
xpl 1 mm
ppl 2 mm
St
xpl 2 mm
ppl 8 mm
(Section flipped to be "upside-down")
xpl 8 mm
xpl 2 mm
("Ah")
ppl 8 mm
xpl 8 mm
No.18
M00522
Barrovian schist
Sil zone
ppl 2 mm
xpl 2 mm
Epitaxial growth: Sil on Bt
ppl 8 mm
xpl 8 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
ppl 2 mm
xpl 2 mm
Sericitisation
No.19
Z.C20
Silica-poor hornfels
Belhelvie, Aberdeen
ppl 8 mm
xpl 8 mm
ppl 2 mm
Pleochroic centre grain: green
ppl 2 mm
Pink
xpl 2 mm
Maximum birefringence
ppl 1 mm
ppl 1 mm
Pleochroism ?
xpl 1 mm
xpl 1 mm
Pink birefringence ?
No.20
CD.43
St-Ky schist
Buchan Coast
Sil zone
ppl 8 mm
xpl 8 mm
Clump pseudomorph / porphyroblast ?
ppl 2 mm
xpl 2 mm
Ms pseudomorphing Ky ? (Simple twin)
xpl 2 mm
ppl 8 mm
xpl 8 mm
ppl 2 mm
Ky
xpl 2 mm
Simple twin NE of centre
No.21
128119 (aka Super 12)
Bed of R. Acklrock [?], near Tomintoul
Chl zone
ppl 2 mm
xpl 2 mm
ppl 8 mm
xpl 8 mm
No.22
Super 80
Braemar, Scotland
Ky zone
ppl 2 mm
xpl 2 mm
(The crack looks like it has Christmas lights)
ppl 8 mm
xpl 8 mm
xpl 8 mm
ppl 2 mm
xpl 2 mm
Ky? Cpx?
xpl 2 mm
ppl 1 mm
xpl 1 mm
xpl 1 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
No.23
SS 03
Diopside rock [irrelevant]
Glencoe, Scotland
ppl 8 mm
xpl 8 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
No.24
SS S7 (aka R489)
Hbl-Bt-Chl schist
Glen Dorvel, Cowal
Bt zone
ppl 2 mm
xpl 2 mm
Ep (Kermit green)
Some CaCO₃ (peach)
xpl 2 mm
Extinct Ep
ppl 1 mm
xpl 1 mm
xpl 1 mm
ppl 1 mm
xpl 1 mm
xpl 1 mm
ppl 1 mm
xpl 1 mm
xpl 1 mm
Elongate inclusion with inclined extinction (and very high birefringence)
ppl 1 mm
Reaction rim
xpl 1 mm
Rim composed of Ep ?
xpl 1 mm
ppl 1 mm
Ab w/ Ep inclusions (?)
xpl 1 mm
xpl 0.3 mm
ppl 8 mm
Fabric wrapping around Ox
Qz pressure shadow?
xpl 8 mm
ppl 2 mm
xpl 2 mm
ppl 1 mm
Cassiterite?
xpl 1 mm
ppl 1 mm
xpl 1 mm
ppl 8 mm
ppl 8 mm
xpl 8 mm
ppl 8 mm
High relief accessory mineral visible
No.25
Super 1
Glen Clova, Forfarshire
Sil zone
ppl 8 mm
xpl 8 mm
ppl 2 mm
St next to Grt
xpl 2 mm
xpl 2 mm
ppl 2 mm
Hydrous alteration
xpl 2 mm
ppl 2 mm
Fibrolite
xpl 2 mm
xpl 2 mm
ppl 2 mm
Sil (fibrous and incipient prisms)
xpl 2 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
ppl 2 mm
Bt → Chl
xpl 2 mm
ppl 2 mm
xpl 2 mm
xpl 2 mm
xpl 1 mm
Lamellar twins
ppl 8 mm
