Site: Tuam

Island: Tuam

Slides:

IL_1_100

Tuam clay. This is a potential clay source of tpr179a. No inclusions except for oxides.

IL_2_5

Lapita style. The pale brown clay contains remnant shelly fragments, up to 0.3 mm in length. Volcanic rock fragments contain mainly plagioclase crystals and tiny feldspar grains up to 0.5 mm in length. Subrounded ferruginized clasts and angular feldspar grains are about 0.2 mm in length. Contains wavy layers of red brown clay.

IL_2_1

Sio style sherd. "CAUTION: Section less than 30microns. Pyroxene crystals are angular and about 0.4 mm in diameter. They are unaltered and show prominent cleavage traces. Volcanic rock fragments essentially contain ferruginized glass, feldspar crystals and small plagioclase laths. Opaques, rounded red brown clay clasts, ferruginized fossil fragments and feldspar grains are minor components. The clay is dark brown.

IL_2_8

Lapita style. CAUTION: Section less than 30microns. This sample contains colourless to pale green pyroxene crystals (10%) up to 0.4 mm in length. Angular feldspar grains are up to 0.3 mm in length and there is less than 5%. There are rare grains of volcanic rock fragments up to 0.4 mm across, elongate to rounded ferruginized clasts of clay up to 2 mm in length, and carbonate shell fragments, about 0.5 mm across.

IL_2_7

Lapita sherd. CAUTION: Section less than 30microns. This sample is similar to 8/1 but contains more and larger shelly fragments and fewer and smaller pyroxene grains. Volcanic rock fragments are up to 0.8 mm in length and consist of small feldspar crystals and opaque particles set in a glassy groundmass.

IL_2_6

Lapita sherd. CAUTION: Section less than 30microns. This sample has reddish brown clay containing pyroxene crystals up to 0.5 mm in length. Feldspar grains up to 0.5mm in length, show growth rings. Volcanic rock fragments are composed mainly of glass with minor feldspar crystals. Opaque grains are up to 0.2 mm across.

IL_2_4

Type Y style. Contains high levels of amphibole. The amphibole is green to brown and the blades and prisms range from 0.1 to 0.5 mm in length. The angular amphibole grains make up about 10% of the sherd. Plagioclase (<10%) occurs as large rectangular crystals which show growth rings. Some of the grains are partly sericitized. Other plagioclase crystals are small and angular. Magnetite (<1%) .

IL_2_3

Type Y style. This sherd contains quartz, feldspar, amphibole, pyroxene, magnetite, spinel, rock fragments, ferruginized clay clasts and relict shells. The quartz and feldspar grains (10%) are generally angular and 0.2 mm in length. Amphibole blades (<5%) are green to brown, and less than 0.2 mm across. Magnetite (5%) occurs as rounded grains. Pale green pyroxene crystals are rare. Spinel is an accessory mineral occurring as angular grains up to 0.2 mm.

IL_2_2

Sio style. CAUTION: Section less than 30microns. in diameter. Volcanic rock fragments (<10%) are up to 0.5 rnn across and contain feldspar microlites, opaques and altered glass. Angular pyroxene crystals are accessory. Elongate and rounded pellets are devoid of inclusions. The sherd also contains some large (up to 2 nm in length) ferruginized fragments which also contain opaques and plagioclase. These may be broken pot fragments. Opaque minerals.

References:

Prehistoric exchange in the Vitiaz Strait, Papua New Guinea (Lilley, I.)