| Autor: |
Andréa G. Grottoli, Leila Chapron, Dana Gava, John W. Olesik |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
|
| Zdroj: |
Geochemistry, Geophysics, Geosystems, Vol 21, Iss 12, Pp n/a-n/a (2020) |
| Druh dokumentu: |
article |
| ISSN: |
1525-2027 |
| DOI: |
10.1029/2020GC009245 |
| Popis: |
Abstract Elemental proxies are used to reconstruct oceanic conditions that predate modern records. Such proxies have been established in corals, but few attempts have been made in sclerosponges. However, their wide distribution and slow growth make sclerosponges good candidates for multicentury recorders of local oceanographic conditions. Here, we investigated the elements P, Pb, and Ba (standardized to Ca) in the accretionary skeleton of two sclerosponge species, Acanthocheatetes wellsi (high‐Mg calcite) collected from Palau and Saipan, and Astrosclera willeyana (aragonite) collected in Saipan. All specimens were stained in situ and left to grow on the reef for two years. We measured these elements in (1) 2‐year bulk skeletal samples to explore the effect of local environmental conditions and mineralogy on the skeletal composition and (2) at high resolution to determine the temporal variability of these elements and evaluate their potential as paleo‐proxies. We found that for A. wellsi, bulk P/Ca was higher and Pb/Ca lower in Palau than in Saipan suggesting that these elements vary in response to the local seawater elemental composition. In Saipan, bulk P/Ca was higher in A. wellsi compared to A. willeyana, which is most likely due to differences in mineralogy. At high resolution, only P/Ca signatures appeared to be moderately reproducible within and among species suggesting that sclerosponges are recording seawater P/Ca. In Saipan, A. willeyana P/Ca variability also correlated with temperature suggesting that variation in seawater P concentrations co‐varied with temperature. Additional study is needed to determine if sclerosponge P/Ca is a reliable proxy of seawater nutrient variability. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
