Microbialite fabrics and diminutive skeletal bioconstructions in lower Norian Summit Point reefs, Oregon, United States

Martindale RC, Corsetti FA, Bottjer DJ, Senowbari-Daryan B (2012)

Publication Language: English

Publication Type: Journal article

Publication year: 2012

Journal

Palaios Society for Sedimentary Geology (SEPM)

Book Volume: 27

Pages Range: 489-508

Journal Issue: 7

DOI: 10.2110/palo.2012.p12-001r

Abstract

Microfacies analysis of five patch reefs from the Martin Bridge Formation (Upper Triassic/Norian, Summit Point, Oregon, United States) reveals that microbialite fabrics dominate reef construction versus corals or other large metazoans. Other reef bioconstructors include characteristic Late Triassic branching corals and diminutive calcifiers (solenoporacean red algae, foraminifera, and sponges). The patch reefs exhibit dense growth fabrics and had elevation above the seafloor, making them ecological reefs or true reefs. Robust binding and encrusting organisms inhabited higher-energy areas, whereas red algae, followed by phaceloid coral colonies, inhabited zones of decreasing water energy, defining a subtle zonation consistent with wave energy in the paleoenvironment. The dominance of microbial fabrics and diminutive bioconstructors make the Summit Point reefs distinct among Upper Triassic reefs from northeastern Panthalassa. Summit Point was originally identified as a Dachstein-type reef (e.g., high diversity, dominated by corals and sponges, massive bedding, large reef cavities). However, the dominance of microbial fabrics over larger metazoans, the (comparatively) modest faunal diversity, and lack of abundant, multigenerational epibionts or cements clearly differentiates the Summit Point reefs from the Dachstein reefs of northern Europe. The Summit Point reefs do, however, bear a striking resemblance to some Middle Triassic (Anisian) reefs from the Tethys, particularly with the abundance of microbialite fabrics and diminutive, binding or encrusting bioconstructors.

Authors with CRIS profile

Baba Senowbari-Daryan Naturwissenschaftliche Fakultät

Involved external institutions

University of Texas at Austin US United States (USA) (US) University of Southern California (USC) US United States (USA) (US)

How to cite

APA:

Martindale, R.C., Corsetti, F.A., Bottjer, D.J., & Senowbari-Daryan, B. (2012). Microbialite fabrics and diminutive skeletal bioconstructions in lower Norian Summit Point reefs, Oregon, United States. Palaios, 27(7), 489-508. https://dx.doi.org/10.2110/palo.2012.p12-001r

MLA:

Martindale, Rowan C., et al. "Microbialite fabrics and diminutive skeletal bioconstructions in lower Norian Summit Point reefs, Oregon, United States." Palaios 27.7 (2012): 489-508.

BibTeX: Download