Conference proceeding
Integrating coral reef paleoecological and paleoenvironmental proxies to reconstruct the Holocene initiation of the Great Barrier Reef
American Geophysical Union Fall Meeting, Vol.2019
American Geophysical Union 2019 fall meeting (San Francisco, California, 09/12/2019 - 13/12/2019)
12/2019
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Abstract
The spatial and temporal pattern of the Holocene initiation of the Great Barrier Reef (GBR) from approximately 9 ka serves as an important case study of reef resilience and adaptation during a period of rapid environmental change. Work on Holocene coral reef cores have provided valuable age constraints on the timing of GBR initiation and concurrent environmental controls on growth that are evident from shifts in the reef-building communities and variations in coral skeletal isotopic ratios. Past studies have been limited by a lack of closely-spaced core transects with high-resolution dates, preventing detailed reconstructions of reef growth and paleoenvironment across various reef settings. A new dataset obtained from twelve cores drilled in three transects across different geomorphic and hydrodynamic settings of One Tree Reef, southern GBR, reveals unprecedented details of Holocene reef development. Multiple proxies preserved in the reef record from coral, coralline algae, microbialites and other reef-building biota are examined. Trace element analysis, stable nitrogen isotope analysis, mineralogy from hyperspectral imaging, and sedimentary facies data are integrated to form a temporally-constrained paleoenvironmental analysis using vertical accretion models from 85 new Uranium-Thorium and radiocarbon ages. Together this dataset reveals three distinct phases of reef development defined as: 1) fast, shallow and clear-water reef initiation from 8.3 ka until 8 ka; 2) slower, predominantly turbid-water and nutrient-rich reef growth from 8-7 ka; and 3) rapid, shallow and clear-water branching growth with reduced terrigenous influence as the reef catches up to sea level after 7 ka.fast, shallow and clear-water reef initiation from 8.3 ka until 8 ka; 2) slower, predominantly turbid-water and nutrient-rich reef growth from 8-7 ka; and 3) rapid, shallow and clear-water branching growth with reduced terrigenous influence as the reef catches up to sea level after 7 ka. To investigate the regional environmental controls on early Holocene reef development, the new results from One Tree Reef are analyzed alongside reef core data from the northern and central GBR. Through improving our understanding of past reef resilience and vulnerability during changing environmental conditions, we can refine our projections of how modern reefs will respond to increased nutrient input, rapid sea-level rise and increasing sea surface temperatures.
Details
- Title
- Integrating coral reef paleoecological and paleoenvironmental proxies to reconstruct the Holocene initiation of the Great Barrier Reef
- Creators
- Kelsey L Sanborn - University of Sydney, School of Geosciences, Geocoastal Research Group Sydney, NSW AUS AustraliaJody WebsterGregory E WebbJuan Carlos BragaMarc HumbletDirk ErlerMarcos Salas-SaavedraLuke D NothdurftMadhavi A PattersonBelinda DechnikSusan WarnerTrevor GrahamRichard J MurphyYusuke YokoyamaStephen ObrochtaJian-Xin Zhao
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2019
- Conference
- American Geophysical Union 2019 fall meeting (San Francisco, California, 09/12/2019 - 13/12/2019)
- Publisher
- American Geophysical Union
- Identifiers
- 991012978867502368
- Academic Unit
- Centre for Coastal Biogeochemistry; Faculty of Science and Engineering; Science
- Language
- English
- Resource Type
- Conference proceeding