TY - JOUR
T1 - Assessment of coral δ44/40Ca as a paleoclimate proxy in the Great Barrier Reef of Australia
AU - Chen, Xuefei
AU - Deng, Wenfeng
AU - Zhu, Hongli
AU - Zhang, Zhaofeng
AU - Wei, Gangjian
AU - McCulloch, Malcolm T.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - The Ca isotopic composition (δ44/40Ca) in a Porites spp. coral from the Great Barrier Reef was analyzed at monthly intervals for two consecutive years. It was found that variations in skeletal δ44/40Ca values over the 2-year period are slightly greater than the analytical precision of the measurements, although other coralline geochemical records (i.e., δ13C, δ18O, δ11B and Sr/Ca ratios) show remarkable variations. To evaluate the potential of δ44/40Ca as a paleoclimate proxy in corals, we compared δ44/40Ca with other well-established indicators, and found that δ44/40Ca values show little relationship to δ18O, Sr/Ca, δδ18O, or δ11B values, thus suggesting that the influence of seawater temperature, seawater pH and river inputs on skeletal δ44/40Ca is limited or overwhelmed by other factors. However, skeletal δ44/40Ca values are significantly related to δ13C values (r = 0.46, p < 0.05; n = 27), thus indicating that Ca isotopic fractionation in corals is subjected to vital effect. The strong influence of biogenic factors on δ44/40Ca in corals, limit the applicability of coral δ44/40Ca to paleoclimate reconstruction.
AB - The Ca isotopic composition (δ44/40Ca) in a Porites spp. coral from the Great Barrier Reef was analyzed at monthly intervals for two consecutive years. It was found that variations in skeletal δ44/40Ca values over the 2-year period are slightly greater than the analytical precision of the measurements, although other coralline geochemical records (i.e., δ13C, δ18O, δ11B and Sr/Ca ratios) show remarkable variations. To evaluate the potential of δ44/40Ca as a paleoclimate proxy in corals, we compared δ44/40Ca with other well-established indicators, and found that δ44/40Ca values show little relationship to δ18O, Sr/Ca, δδ18O, or δ11B values, thus suggesting that the influence of seawater temperature, seawater pH and river inputs on skeletal δ44/40Ca is limited or overwhelmed by other factors. However, skeletal δ44/40Ca values are significantly related to δ13C values (r = 0.46, p < 0.05; n = 27), thus indicating that Ca isotopic fractionation in corals is subjected to vital effect. The strong influence of biogenic factors on δ44/40Ca in corals, limit the applicability of coral δ44/40Ca to paleoclimate reconstruction.
KW - Calcium isotopic composition
KW - Geochemical proxy
KW - Porites coral
UR - http://www.scopus.com/inward/record.url?scp=84964933320&partnerID=8YFLogxK
U2 - 10.1016/j.chemgeo.2016.04.024
DO - 10.1016/j.chemgeo.2016.04.024
M3 - Article
AN - SCOPUS:84964933320
SN - 0009-2541
VL - 435
SP - 71
EP - 78
JO - Chemical Geology
JF - Chemical Geology
ER -