Fabric Code: tpr191a

Manus andesitic placer

Quartz-free andesitic tempers occur as moderately sorted, fine to medium-grained, subangular to subrounded volcanic sand. Plagioclase feldspar, clinopyroxene, and hornblende are the principal mineral grains, with varied volcanic rock fragments and opaque iron oxides the only other grain types present. The volcanic rock fragments are nearly all microlitic (pilotaxitic to hyalopilitic) or vitric, with internal textures suggestive of the groundmasses of andesitic rocks.

Fabric Class:

Pyroxenic Opaque: Dominated by pyroxenic inclusions with opaques.

Andesitic Arc: Dominated by andesite and basalt lithic fragments, with microlitic, felsitic and vitric textures, and the andesite minerals (plagioclase, clinopyroxene and sometimes hornblende).

Sites:

Ceramic Wares

Admiralty Transitional (2300 - 1900 BP)

Admiralty Historical (800 - 0 BP)

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.	Quartz	Feldspar	Pyroxene	Amphibole	Opaques	Olivine	Biotite	Muscovite	Epidote	Garnet/ Spinel	Ig./Met. Rocks	Sed. Rocks	Grog	Lithics/ Region
Max	1	0	2	4	2	4	0	0	0	0	0	1	0	0	microlitic, vitric
Min	0	0	2	4	2	4	0	0	0	0	0	1	0	0	Bismarck

Representative slides:

Slide	Site	Possible Origin	Ware	Cal.	Quartz	Feldspar	Pyroxene	Amphibole	Opaques	Olivine	Biotite	Muscovite	Epidote	Garnet/ Spinel	Ig./Met. Rocks	Sed. Rocks	Grog	Lithics
WD_41_6	Manus (Manus)	Manus	Admiralty Historical (800 - 0 BP)	0	0	2	4	2	4	0	0	0	0	0	1	0	0	vitric, microlitic

WD_41_6

Quartz-free andesitic temper sand. Coastal placer sand present. Pyroxene > Hornblende.

References:

145 Manus, Admiralty, PNG, 1997 (Dickinson, W.)

150 Mussau, Manus, New Hanover, New Ireland, PNG, 1997 (Dickinson, W.)