Site: Tumon Bay

Island: Guam Lithology: Composite high island ( Nunn et al. (2016) )

Lithology and Age: Cenozoic sedimentary rocks ( Chorlton (2007) ) Macrostrat Geological Map Link

Near/In Geonames ID: 4038719 Wikidata ID: Q25185570 Getty Thesaurus of Geographic Names ID: None

Mindat Loc ID: None

In:

Guam Island Wikidata ID: Q16635

Mariana Islands Wikidata ID: Q153732

Note that to see the 'Geology' layer (layer options in top right corner) you may have to zoom out.

Fabrics:

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.	Quartz	Feldspar	Pyroxene	Opaques	Ig./Met. Rocks	Lithics/ Region
tpr20	0	0	3	3	3	6	vitric, microlitic
Guam lithic andesiitic	0	0	1	1	1	5	Marianas
tpr8	5	4	2	2	2	2	microlitic, felsitic
Saipan hybrid quartzose	4	3	1	0	1	1	Marianas

Slides:

Slide	Fabric	Possible Origin	Cal.	Quartz	Feldspar	Pyroxene	Amphibole	Opaques	Olivine	Biotite	Muscovite	Epidote	Garnet/ Spinel	Ig./Met. Rocks	Sed. Rocks	Grog	Lithics
WD_7_23	tpr20 (Guam lithic andesiitic)	Guam	0	0	2	1	0	2	0	0	0	0	0	5	0	0	vitric
WD_6_17	tpr8 (Saipan hybrid quartzose)	Saipan	4	4	2	1	0	1	0	0	0	0	0	2	0	0	microlitic, felsitic

WD_7_23

guam_488 — Sherd 488 from Tumon Bay (Guam). Slide WD_7_23 from Dickinson Collection, Bishop Museum. x4 Magnification PPL (left) XPL (right). Scale bar: 0.5mm. High resolution image or full slide in VIMIPO (user: Guest pwd: Guest). Imaged by K. Hardy and M. Leclerc, ANU.

Moderately sorted andesitic volcanic sand temper of probable fluvial origin composed of subangular to subrounded grains of fine to coarse sand rich in glassy volcanic rock fragments.