Carbon and oxygen isotope composition of Nautilus macromphalus:: a record of thermocline waters off New Caledonia
Carbon and oxygen isotope composition of Nautilus macromphalus:: a record of thermocline waters off New Caledonia
复制标题
DOI：
10.1016/j.chemgeo.2004.02.006
复制
发表时间：
2004-06-28
期刊：
影响因子：
3.9
通讯作者：
Sheppard, SMF
中科院分区：
文献类型：
--
作者：
Auclair, AC;Lecuyer, C;Sheppard, SMF
研究了新喀里多尼亚现代大脐鹦鹉螺（Nautilus macromphalus）壳层稳定同位素组成的控制因素。沿沿着生长线（等时线）和生长轴（时间序列）采集紧密间隔的样品。在最大生长区（-0.3ppm）和肌肉插入区（-0.4ppm），贝壳的碳同位素组成（δ（13）C =-0.3ppm ~1ppm PDB）呈下降趋势。在时间序列中记录到约千分之一的最大δ（13）C变化。在背侧和腹侧区域观察到δ（13）C值的整体个体发育下降（0.4千分之0.8千分之0.4），并且可以归因于随着年龄的代谢效应或食物来源的变化。相比之下，氧同位素组成是相当恒定的（I. I <δ（13）O < 1.3），反映了贝壳分泌物的平均温度，对应深度约为250 m。从俄罗斯下白垩统的头足类化石壳与共存的鱼鳞的比较表明，大多数头足类沉淀其壳接近氧同位素与海水的平衡。(C)2004 Elsevier B. V.保留所有权利。
This stud), investigates the controls on the stable isotope composition of shell nacreous layer of a modem Nautilus macromphalus from New Caledonia. Closely spaced samples were taken both along growth lines (isochrons) and growth axis (time series). Carbon isotope compositions (delta(13)C = -0.3parts per thousand to 1parts per thousand PDB) of the shell decrease in the domains of maximal growth (-0.3parts per thousand) and muscle insertion (-0.4parts per thousand). Maximal delta(13)C variations of about I parts per thousand are recorded in time series. A global ontogenetic decrease of delta(13)C values is observed for both dorsal and ventral areas (0.4 parts per thousand to 0.8 parts per thousand) and can be ascribed to a metabolic effect with age or to changes in the food source. By contrast, oxygen isotope compositions are quite constant (I. I < delta(13)O < 1.3) and reflect the mean temperature of shell secretion, corresponding to a depth of about 250 m. Comparison of fossil cephalopod shells with co-existing fish scales from the Lower Cretaceous of Russia suggests that most cephalopods precipitate their shells close to oxygen isotope equilibrium with seawater. (C) 2004 Elsevier B.V. All rights reserved.