Inferring sediment transport using Large Benthic Foraminifera

composition, taphonomy and geochemical proxies

Thomas Fellowes, Jordan Gacutan, Daniel L. Harris, Ana Vila-Concejo, Bradley Opdyke, Maria Byrne, Jody M. Webster

Research output: Contribution to conferenceAbstract

Abstract

Coral reef geomorphological processes are responsible for landform evolution, habitat change and sediment dynamics. Understanding reef sediment transport allows insight into antecedent processes and future landform responses. Large Benthic Foraminifera (LBF) live in the algal rim and deposit tests (shells) which are transported by hydrodynamics (eg. waves, currents). Due to well-defined source areas, LBF tests may act as a ‘tracer’ to infer sediment transport pathways. We analysed surficial (n=74) and down-core (n=97) samples from two sand aprons at One Tree Reef, in the southern Great Barrier Reef (Australia). LBF tests (Baculogypsina sphaerulata and Calcarina spp.) exhibited increased abrasion (rs=0.60, p<0.001) with cross-reef lagoonward transport. Transport trends were consistent with wave direction and refraction. Down-core and surficial sediments were spatially consistent suggesting transport conditions have prevailed for the last 3 ka. While the effectiveness of LBF as tracers has been proved in this and other studies, low abundance remains a limitation. We propose elemental ratios using LBF tests as a novel proxy for determining sediment transport pathways. LBF test analysis (n=40) revealed decreased Mg/Ca and increased Sr/Ca with lagoonward transport. Mg/Ca (R2=0.83, p<0.001) and Sr/Ca (R2=0.32, p<0.001) ratios were significantly correlated against abrasion, suggesting a link with test alteration. This novel proxy is rapid, requires minimal materials and provides quantitative measures for LBF test alteration.
Original languageEnglish
Pages100
Number of pages1
Publication statusPublished - Jul 2016
Externally publishedYes
Event13th International Coral Reef Symposium - International Convention Center, Honolulu, United States
Duration: 19 Jun 201624 Jun 2016
https://sgmeet.com/icrs2016/

Conference

Conference13th International Coral Reef Symposium
Abbreviated titleICRS
CountryUnited States
CityHonolulu
Period19/06/1624/06/16
Internet address

Fingerprint Dive into the research topics of 'Inferring sediment transport using Large Benthic Foraminifera: composition, taphonomy and geochemical proxies'. Together they form a unique fingerprint.

  • Cite this

    Fellowes, T., Gacutan, J., Harris, D. L., Vila-Concejo, A., Opdyke, B., Byrne, M., & Webster, J. M. (2016). Inferring sediment transport using Large Benthic Foraminifera: composition, taphonomy and geochemical proxies. 100. Abstract from 13th International Coral Reef Symposium , Honolulu, United States.