Fabric Code: tpr436

Ata vitric

Clinopyroxene and orthopyroxene. Rare grains of cumulus microgabbro (pyroxene-plagioclase igneous rock coarser grained internally than volcanic rock).

Sites:

Mineral and Rock Abundances

None (0) Minor (1) Few (2) Common (3) Frequent (4) Major (5) Very Dominant (6)
0% 0-5% 5-15% 15-30 % 30-50% 50-70% 70-100%

Name Cal. QuartzFeldspar Pyroxene Amphibole Opaques OlivineBiotite Muscovite Epidote Garnet/ SpinelIg./Met. Rocks Sed. Rocks Grog Lithics/ Region
Max 0 0 4 3 0 0 1 0 0 0 0 5 0 0 vitric, microlitic
Min 0 0 4 2 0 0 1 0 0 0 0 4 0 0 Tonga

Representative slides:

Slide Site Possible OriginCal. QuartzFeldspar Pyroxene Amphibole Opaques OlivineBiotite Muscovite Epidote Garnet/ Spinel Ig./Met. Rocks Sed. Rocks Grog Lithics
WD_72_21 ‘Ata (‘Ata) Ata 0 0 4 2 0 0 1 0 0 0 0 5 0 0 vitric, microlitic
WD_72_20 ‘Ata (‘Ata) Ata 0 0 4 3 0 0 1 0 0 0 0 4 0 0 vitric, microlitic

WD_72_21

Eua_Ata1 Eua_Ata1
Sherd Ata1 from ‘Ata (‘Ata). Slide WD_72_21 from Dickinson Collection, Bishop Museum. x4 Magnification PPL (left) XPL (right). Scale bar: 0.5mm. High resolution image in VIMIPO (user: Guest pwd: Guest). Imaged by K. Hardy and M. Leclerc, ANU.

Vitric fabric. Some orthopyroxene.


WD_72_20

Eua_Ata2 Eua_Ata2
Sherd Ata2 from ‘Ata (‘Ata). Slide WD_72_20 from Dickinson Collection, Bishop Museum. x4 Magnification PPL (left) XPL (right). Scale bar: 0.5mm. High resolution image in VIMIPO (user: Guest pwd: Guest). Imaged by K. Hardy and M. Leclerc, ANU.

Vitric fabric.


References:

222 'Ata, Tonga, 2002 (Dickinson, W.)