...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Estuarine Coastal and Shelf Science >Morphological variations of crossed-lamellar ultrastructures of Glycymeris bimaculata (Bivalvia) serve as a marine temperature proxy
【24h】

Morphological variations of crossed-lamellar ultrastructures of Glycymeris bimaculata (Bivalvia) serve as a marine temperature proxy

机译：Glycymeris bimaculata（Bivalvia）的交叉层状超微结构的形态学变化作为海洋温度的代表

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Bivalve shells are among the most promising archives for high-resolution seawater temperature reconstructions. However, despite major research advances in bivalve sclerochronology over the past decades, estimating water temperature from shells remains a challenging task. This is largely because the most frequently used and widely accepted temperature proxy in bivalves, i.e., the shell oxygen isotope (delta O-18(shell)) value, also requires knowledge of changes in delta O-18 of the water (delta O-18(water)) in which the bivalve lived, which is rarely available for ancient environments. According to a few recent studies, the size and shape of individual biomineral units (BMUs) of the shell ultrastructure may serve as an independent temperature proxy that is also less vulnerable to diagenetic changes than isotope chemical proxies. However, the crossed-lamellar ultrastructure, which occurs in ca. 90% of all mollusk species, has hitherto not been investigated. Here, we evaluate the potential use of morphological properties of the BMUs in Glycymeris bimaculata as a proxy for water temperature. For this purpose we introduce a suitable preparation technique (immersion for 2 m in 0.001 vol% formic acid followed by 20-30 m in 3.5 vol% H2O2) and an automated image processing technique that tremendously speed up ultrastructure analysis (5 s versus one to 2 h image processing time with automated and manual methods, respectively) and increase the robustness of BMU measurements. Glycymeris is a particularly useful target taxon, because it is a cosmopolitan genus with evolutionary roots in the Upper Cretaceous, and some species of Glycymeris can attain a lifespan of more than two hundred years, which allows for long-term, high-resolution paleoclimate reconstructions. As in other previously studied ultrastructures, larger and more elongated BMUs formed in warmer water permitting temperature estimates with an error of 2.3 degrees C (1 s). Since the new temperature proxy is unaffected by other environmental variables, including salinity, it can potentially be applied to (modern and fossil) specimens from brackish environments.
机译：双壳贝壳是高分辨率海水温度重建中最有前途的档案之一。然而，尽管在过去的几十年中双壳类年代学研究取得了重大进展，但从贝壳中估计水温仍然是一项艰巨的任务。这主要是因为在双壳类动物中最常用和被广泛接受的温度替代物，即壳氧同位素（δO-18（壳））值，还需要了解水的δO-18（δO-双壳类动物生活的地方18（水），这在古代环境中很少见。根据最近的一些研究，壳超微结构的单个生物矿物单元（BMU）的大小和形状可以充当一个独立的温度代理，与同位素化学代理相比，它不易受成岩变化的影响。然而，交叉层状的超微结构，发生在约。迄今为止，尚未对所有软体动物物种中的90％进行过调查。在这里，我们评估潜在的使用BMUs在Glycymeris bimaculata中作为水温的替代物的形态特征。为此，我们介绍了一种合适的制备技术（在0.001体积％的甲酸中浸入2 m，然后在3.5体积％的H2O2中浸入20-30 m）和一种自动图像处理技术，该技术极大地加快了超微结构分析的速度（5 s比1 s降低了）。使用自动和手动方法分别需要2小时的图像处理时间），并提高了BMU测量的稳定性。甘草是一个特别有用的目标分类群，因为它是一个世界性的属，其进化根源于上白垩纪，某些甘草可以达到200多年的寿命，从而可以长期，高分辨率地进行古气候重建。 。像其他先前研究的超微结构一样，在温暖的水中形成的更大，更细长的BMU允许温度估计，误差为2.3摄氏度（1 s）。由于新的温度替代不受其他环境变量（包括盐度）的影响，因此可以潜在地应用于咸淡环境中的（现代和化石）标本。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号