Stable isotopes, elemental distribution, and growth rings of belemnopsid belemnite rostra: Proxies for belemnite life habitat
Stable isotopes, elemental distribution, and growth rings of belemnopsid belemnite rostra: Proxies for belemnite life habitat
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箭石类箭石喙的稳定同位素、元素分布和年轮：箭石生命栖息地的代表
DOI：
10.2110/palo.2008.p08-101r
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发表时间：
2009
影响因子：
5.3
通讯作者：
M. Joachimski
中科院分区：
文献类型：
--
作者：
H. Wierzbowski;M. Joachimski
摘要对两个保存较好的箭石喙（Hibolithes beyrichi和H. hastatus）从波兰中部的Ekononian进行了研究。利用氧同位素比值计算了贝氏海鞘和黑海鞘的平均温度。hastatus分别为10°C和6°C。在高分辨率温度剖面中没有高幅度的变化，表明这些箭石生活在更深的沃茨。这种解释是兼容的belemnopsid belemnites的nektobenthic栖息地。喙部的碳同位素比值被认为是受生命分馏的影响，δ 13 C记录的显著波动是由代谢活动的变化引起的。观察到的喙部Mg：Ca比值的变化（从5 mmol·mol−1到28 mmol·mol−1）主要是一个主要信号。Mg：Ca比的温度依赖性推断为H。beyrichi的基础上的相关性与δ 18 O值;然而，没有观察到这种相关性的H。戟形。Sr：Ca比值和δ 18 O值之间没有显著的相关性。喙部的硫含量从630 ppm到4400 ppm不等，被解释为大部分与铍石方解石共沉淀。硫的极端成分被解释为在早期的海洋成岩作用期间成岩硫的掺入，这也是在这些喙的高Mg：Ca和Sr：Ca比值和低δ 13 C值的特点。结果表明，在H. beyrichi的计算值约为600，因此，H. beyrichi被认为是1.5年，假设生长带的日降水量。
Abstract Stables isotopes and elemental composition of two well-preserved belemnite rostra (Hibolithes beyrichi and H. hastatus) from the Bathonian of central Poland were studied. Average temperatures calculated from the oxygen isotope ratios of Hibolithes beyrichi and H. hastatus are 10°C and 6°C, respectively. The absence of high-amplitude variations in high-resolution temperature profiles suggests these belemnites lived in deeper waters. This interpretation is compatible with a nektobenthic habitat of belemnopsid belemnites. Carbon isotope ratios of the rostra are assumed to be affected by vital fractionation with prominent fluctuations in the δ13C records resulting from changes in the metabolic activity. Observed variations in Mg:Ca ratios of the rostra (from 5 mmol·mol−1 to 28 mmol·mol−1) are predominantly a primary signal. Temperature dependence of the Mg:Ca ratio is inferred for H. beyrichi on the basis of a correlation with δ18O values; however, no such correlation is observed for H. hastatus. No significant correlation is observed between Sr:Ca ratios and δ18O values in either taxon. Sulphur contents in the rostra vary from 630 ppm to 4400 ppm and are interpreted to be largely coprecipitated with belemnite calcite. Extreme compositions of sulphur are interpreted to result from the incorporation of diagenetic sulphur during early marine diagenesis, which is also characterized in these rostra by high Mg:Ca and Sr:Ca ratios and low δ13C values. A total number of growth rings in the rostrum of H. beyrichi is calculated at around 600, thus, an expected life span of H. beyrichi is considered to be ∼1.5 years assuming daily precipitation of growth bands.