Fig. S2. Sedimentary geochemistry used to infer the provenance of Permian–Triassic marine sandstones related to the SE Gondwana active continental margin, South Island, New Zealand
posted on 2019-02-13, 15:32authored byAlastair H.F. Robertson, Romesh Palamakumbura
Photomicrographs of sandstones. (a)–(f) From the Permian–Triassic succession exposed at Parapara Peak, Takaka Terrane, Western Province. (a) Large, rounded grain of microcrystalline quartz (translucent; central) set in smaller angular to sub-rounded quartz grains, together with some plagioclase; GPS WSG 84 E24 82605 N60 40305; viewed under plane polarized light (PPL); Parapara section, Flowers Formation; Western Province. (b) Foliated siltstone lithoclast (partially recrystallized) within detrital grains of mostly quartz and plagioclase (as in a). The brown mineral is neomorphic biotite; viewed under PPL; Flowers Formation; Parapara section. (c) Large, sub-angular grain of altered feldspar (orthoclase) within smaller mostly angular to sub-angular grains, including common polycrystalline (detrital metamorphic) quartz; viewed under crossed nicols; Flowers Formation; Parapara section. (d) Upper left: polycrystalline quartz grain; centre right: large uniform monocrystalline quartz grain, of probable plutonic rock origin; note the incipient cleavage development picked out by neomorphic biotite; viewed under crossed nicols; Flowers Formation; Parapara section. (e) Large detrital grain of monocrystalline quartz showing incipient recrystallization at the edges, together with recrystallization of finer-grained quartz and biotite; viewed under plane crossed nicols; Flowers Formation; Parapara section. (f) Rounded monocrystalline quartz which cracked prior to final deposition; note the incipient cleavage picked out by biotite; Walker Formation; Parapara section.