Skeletal correlates of coral density banding and an evaluation of radiography as used in sclerochronology
Skeletal correlates of coral density banding and an evaluation of radiography as used in sclerochronology
复制标题
珊瑚密度带的骨骼相关性和硬化年代学中使用的射线照相术的评估
DOI：
10.3354/meps110029
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发表时间：
1994
影响因子：
2.5
通讯作者：
Ps Davis
中科院分区：
文献类型：
--
作者：
M. Tissier;B. Clayton;B. Brown;Ps Davis
骨骼相关的密度带模式上看到的珊瑚骨骼的射线照相的理论分析，比较射线照相和骨骼，和建模的骨骼切片的巨大的印度太平洋珊瑚Pontes lutea和分支的加勒比海珊瑚Pontes porites。射线照相术比以前认识到的珊瑚骨骼更精细。衰减X射线束的单个骨骼元素的路径长度的微小变化，包括薄至3至10 μ m的差异，可以在X射线照片上产生对比度以及骨骼体积密度的变化。年高/低密度带型分别与相对厚/薄的骨骼元素的面积相关。二次密度的变化，在射线照片上看到的“细”带，被发现与珊瑚壁的位置垂直于骨骼切片或dissepiments的长轴。骨骼切片的建模表明，密度带记录中的误差可能是由于（1）骨骼切片不遵循殖民地的生长轴，以及（2）珊瑚石取向的变化产生的密度变化不是任何生长记录的一部分。使用射线照相作为一种工具，证明在珊瑚骨骼的生长记录进行了严格审查。提出骨骼生长记录由骨骼元素的粗细和间距模式组成。通过分析实际骨骼而不是通过放射线照相术来说明这些模式，可能被证明是确定珊瑚生长记录的一种非常准确的方法。
The skeletal correlates of density band patterns seen on radiographs of coral skeletons is investigated by theoretical analysis of radiography, comparison of radiographs and skeleton, and modelling of skeletal slices of the massive Indo-Pacific coral Pontes lutea and the branching Caribbean coral Pontes porites. Radiography resolves finer detail of the coral skeleton than has previously been recognised. Small changes in path length of individual skeletal elements attenuating an X-ray beam, including dissepiments as thin as 3 to 10 pm, can generate contrast on radiographs as well as variations in skeletal bulk density. The annual high/low density band pattern was found to be correlated with areas of relatively thick/thin skeletal elements respectively. Secondary density variations seen on radiographs, 'fine' bands, were found to be correlated with the position of corallite walls oriented perpendicular to the the long axis of the skeletal slice or dissepiments. Modelling of skeletal slices showed that errors in the density band record may be introduced by (1) skeletal slices not following the growth axis of the colony, and (2) changes in corallite orientation which generate density variations that are not part of any growth record. The use of radiography as a tool for demonstrating growth records in coral skeletons is critically reviewed. It is proposed that the skeletal growth record consists of patterns of thickeninglthinning and spacing of skeletal elements. The illustrations of these patterns by analysis of the actual skeleton, rather than by radiography, may prove to be a very accurate method of determining growth records in corals.