Code for "Revisiting the boron systematics of aragonite and their application to coral calcification"

The isotopic and elemental systematics of boron in aragonitic coral skeletons have recently been developed as a proxy for the carbonate chemistry of the coral extracellular calcifying fluid. With knowledge of the boron isotopic fractionation in seawater and the B / Ca partition coefficient (KD) between aragonite and seawater, measurements of coral skeleton δ11B and B / Ca can potentially constrain the full carbonate system. Two sets of abiogenic aragonite precipitation experiments designed to quantify KD have recently made possible the application of this proxy system. However, while different KD formulations have been proposed, there has not yet been a comprehensive analysis that considers both experimental datasets and explores the implications for interpreting coral skeletons. Here, we evaluate four potential KD formulations: three previously presented in the literature and one newly developed. We assess how well each formulation reconstructs the known fluid carbonate chemistry from the abiogenic experiments, and we evaluate the implications for deriving the carbonate chemistry of coral calcifying fluid.

近年来，文石质珊瑚骨骼中的硼同位素与元素系统学特征已被开发为珊瑚细胞外钙化液（extracellular calcifying fluid）碳酸盐化学的代用指标（proxy）。若已知海水中硼的同位素分馏效应，以及文石与海水间的硼钙分配系数（partition coefficient, KD），则通过测量珊瑚骨骼的δ¹¹B与B/Ca比值，即可约束完整的碳酸盐体系。近年来，两项旨在定量KD的非生物成因文石沉淀实验，使得该代用指标体系的应用成为可能。然而，尽管已有多种KD模型被提出，但目前尚无一项综合分析同时涵盖两类实验数据集，并探讨其在珊瑚骨骼解译中的应用意义。本研究评估了四种可行的KD模型：其中三种已见于既往发表的研究，另一种为本次研究首次提出。我们将评估各模型从非生物实验中还原已知流体碳酸盐化学特征的能力，并探讨其在反演珊瑚钙化液碳酸盐化学方面的应用价值。