Oceanography, Sedimentology and Acoustic Mapping of a Bryomol Carbonate Factory in the Northern Gulf of California, Mexico

Authors

J. Halfar, Universität Stuttgart - Germany
M. Strasser
Bernhard Riegl, Nova Southeastern UniversityFollow
Lucio Godinez-Orta, Centro Interdisciplinario de Ciencias Marinas - La Paz, Mexico

ORCID

0000-0002-1637-4125

ResearcherID

F-8807-2011

Document Type

Article

Publication Title

Geological Society, London, Special Publications

ISSN

0305-8719

Publication Date

2006

Abstract

Bryomol carbonates, composed of bryozoans and molluscs, are found in non-tropical shelf and upper slope settings where they are sensitive indicators of oceanographic conditions. Few modern bryomol carbonate settings have been investigated to date, despite their importance in the Phanerozoic rock record. Furthermore, no detailed facies mapping and long-term oceanographic observations have been undertaken in modern bryomol settings, even though this is important for accurately interpreting facies, climate and oceanography from fossil bryomol carbonates. A bryomol carbonate factory on the western margin of the northern Gulf of California, Mexico was selected for an integrated high-resolution in situ oceanographic monitoring, acoustic seafloor mapping, sediment and bryozoan growth morphology study. Molluscan- (28%), bryozoan- (25%) and barnacle- (14%) dominated carbonate production takes place under normal saline warm-temperate eutrophic conditions, with average near sea surface temperatures of 20°C. Even though temperatures are unusually warm for the formation of bryomol carbonates, they develop as a result of prevailing eutrophic conditions (average chlorophyll-a contents of 2.2 mg chl-a m⁻³). Eutrophic conditions provide ample food to heterotrophic calcifiers and largely exclude faster-growing phototrophic organisms by drastically restricting the depth of the euphotic zone and, therefore, water clarity. Thus, the presence of high amounts of nutrients can generate cool-water-type carbonate assemblages at temperatures where a warm-water association would be expected.

DOI

10.1144/GSL.SP.2006.255.01.13

Volume

255

First Page

197

Last Page

215

Comments

©The Geological Society of London 2006

NSUWorks Citation

J. Halfar, M. Strasser, Bernhard Riegl, and Lucio Godinez-Orta. 2006. Oceanography, Sedimentology and Acoustic Mapping of a Bryomol Carbonate Factory in the Northern Gulf of California, Mexico .Geological Society, London, Special Publications : 197 -215. https://nsuworks.nova.edu/occ_facarticles/693.