Alamagan Island

Wikidata ID: Q478663

Lithology and Age: None ( Chorlton (2007) )       Macrostrat Geological Map Link

Geonames ID: 4041123       Getty Thesaurus of Geographic Names ID: 1006220

Mindat Loc ID: 440693


Volcanoes:

Alamagan: Andesite / Basaltic Andesite, Composite type, Stratovolcano.

brown pot Site has a full slide image.

brown pot Site has an image.

brown pot No images for this site.

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Many fabrics have a range of abundances. The range maximum (top) and minimum (bottom) are shown.

** Has full slide image available.

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
tpr11 ** 0 2 2 0 0 1 0 0 0 0 0 6 0 0 vitric, felsitic
Saipan dacitic-vitric 0 1 2 0 0 1 0 0 0 0 0 6 0 0 Marianas
tpr28 0 0 4 2 0 2 0 0 0 0 0 4 0 0 vitric, microlitic
Saipan andesitic 0 0 4 2 0 2 0 0 0 0 0 4 0 0 Marianas

Slides:

Slide Fabric Possible OriginCal. QuartzFeldspar Pyroxene Amphibole Opaques OlivineBiotite Muscovite Epidote Garnet/ Spinel Ig./Met. Rocks Sed. Rocks Grog Lithics
WD_2_7 tpr11 (Saipan dacitic-vitric) Saipan 0 2 2 0 0 1 0 0 0 0 0 6 0 0 felsitic
WD_4_11 tpr28 (Saipan andesitic) Saipan 0 0 4 2 0 2 0 0 0 0 0 4 0 0 vitric, microlitic

WD_2_7

AlamaganA1 AlamaganA1
Sherd A1 from Alamagan (NWC) (Alamagan). Slide WD_2_7 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.

Quartzose dacitic volcanic sand temper. Fine temper.


WD_4_11

AlamaganA_4 AlamaganA_4
Sherd A-4 from Alamagan (NWC) (Alamagan). Slide WD_4_11 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.

Coarse temper. Quartz-free andesitic temper sands. Probably from Saipan as orthopyroxene present.


References:

323 Mariana, reports 1-15 for MTAT, 1998 (Dickinson, W.)