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Two boreholes were drilled through coralgal sequences in the barrier-reef edge of the mid-Pacific island of Tahiti, and their bases were radiometrically dated at 10.23 ([+ or -]0.05) and 13.77 ([+ or -]0.05) ka (thousand calendar years). The sequences are composed mainly of the reef-edge Acropora gr. danai-robusta and Hydrolithon onkodes assemblage, occasionally replaced by reef-slope tabular Acropora-Neogoniolithon or domal Porites-Lithophyllum assemblages. The response of reef growth to sea-level rise has varied according to the framework type, and vertical accretion rates have ranged from 9.3 to 20.6 mm [multiplied by] [yr.sup.-1]. From a general trend of long-term, continuous, sea-level rise tracked by growth, the reef-edge coralgal assemblages have experienced two distinct changes controlled by the antecedent paleotopography and internal reef processes. During the past 13.8 k.y. at Tahiti, there is no evidence of any reef-drowning event primarily caused by global glacio-eustatic perturbations as has been recorded in the Caribbean.

Thick laminar to columnar stromatolitic growths encrust typical high-energy coralgal reef communities in a French Polynesian outer-reef edge. The reef communities accumulated during vertical growth from 5870 plus or minus 100 yr B.P. to the present, at depths never exceeding 5 m below mean sea level. Oxygen and carbon isotope records and high calcification rates of stromatolite-encrusted corals strongly suggest that for about the past 6000 yr, the local environmental conditions were optimal for reef development. Accordingly, stromatolites can grow in healthy Holocene reefs. Because similar stromatolites have been recorded in other Cenozoic reefs, we suggest that microbial structures may have played a more prominent role in Cenozoic reef growth than is currently recognized.

A study on stromatolites associated with coralgal communities in Holocene high-energy reefs has been disputed. Although the study presented an interesting sequence of coral and lithified carbonate crusts from a core hole drilled in a barrier reef near Tahiti, French Polynesia, there were several shortcomings. The arguments include issues such as lack of support for the hypothesis that the submarine crusts are laminated organosedimentary structures, lack of identification and illustration for some crust contents and the comparison between the subsurface micritic crusts and surface-growing stromatolites. A reply to the arguments is also presented.

Offers a reply to the article written by the authors in 1997, which relates to the continuous record or reef growth over the past 14 k.y. on the mid-Pacific of Tahiti. Indication that issues were raised concerning the reliability of the study of biological associations in drill cores from Tahiti; Indepth look at the response to the issues raised.