Photomicrographs of thin sections of the Orahiri Limestone. The scale line on No. 5 corresponds to approximately two milimetres in each thin section. (1) Moderately sorted, sandy (45 per cent), mixed polyzoan-algal-echinodermal biosparite. Member A, Section S11. Sample taken from one of the hard bands of the banded limestone at this locality. (2) Moderately sorted, sandy (25 per cent), polyzoan-echinodermal biosparite. Facies B1, Section Sll. (3) Sorted, slightly sandy (< 10 per cent), echinodermal-polyzoan biosparite. Facies B3, Section S4. Although the overall appearance is not one of good sorting, each species of grain tends to be rather well sorted. (4) Glauconitic, mixed polyzoan-foraminiferal-algal-molluscan packed biomicrite. Facies B4, Section Sl8. The matrix of this rock is calcite-mud. (5) Slightly sandy (< 10 per cent), fragmental polyzoan packed biomicrite. Facies Cl, Section S11. One large molluscan fragment is present (top centre). (6) Coarsepolyzoan packed biomicrite. Facies C3, Section Sll. Note the preservation of the larger, more delicate polyzoan structures as compared with No. 5.

Transactions of the Royal Society of New Zealand : Earth Sciences, Volume 8, Issue 1, 16 July 1970, Plate 3

Photomicrographs of thin sections of the Orahiri Limestone. The scale line on No. 5 corresponds to approximately two milimetres in each thin section. (1) Moderately sorted, sandy (45 per cent), mixed polyzoan-algal-echinodermal biosparite. Member A, Section Sll. Sample taken from one of the hard bands of the banded limestone at this locality. (2) Moderately sorted, sandy (25 per cent), polyzoan-echinodermal biosparite. Facies 81, Section Sll. (3) Sorted, slightly sandy (< 10 per cent), echinodermal-polyzoan biosparite. Facies 83, Section S 4. Although the overall appearance is not one of good sorting, each species of grain tends to be rather well sorted. (4) Glauconitic, mixed polyzoan-foramini-feral-algal-molluscan packed biomicrite. Facies 84, Section SlB. The matrix of this rock is calcite-mud. (5) Slightly sandy (< 10 per cent), fragmental polyzoan packed biomicrite. Facies Cl, Section Sll. One large molluscan fragment is present (top centre). (6) Coarsepolyzoan packed biomicrite. Facies C 3, Section Sll. Note the preservation of the larger, more delicate polyzoan structures as compared with No. 5.