Interrogating the Rock Record for Low- and High-Latitude Trace-Fossil Signatures to Better Know the Ichnological Response to Depositional Temperature

询问岩石记录的低纬度和高纬度痕迹化石特征，以更好地了解对沉积温度的地质响应

• 批准号: RGPIN-2014-04725
• 负责人: Gingras, Murray
• 金额: $ 2.7万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=566703
• 关键词: Interrogating; Rock; Record; Low; Latitude

Ichnology is the study of trace fossils, which are the preserved tracks, trails and burrows of animals in the rock record. This field has very broad application. Burrows represent survival strategies of sediment-dwelling animals and they show a surprising range in their shape, size and occurrence. Many trace-fossil types occur through space and time and their paleontological significance is well understood. Trace-fossil models provide interpretations of paleoenvironmental conditions such as dissolved O2 concentration in the water, salinity and sedimentation rates. This proposal is to develop a a model that associates trace fossils to depositional temperature for climate studies, using the burrows of invertebrates (e.g. worms, shrimp, starfish, anenomes) in marine environments. An understanding of trace-fossil occurrence as a function of depositional temperature is crucial. Canada continually looks northwards for new oil and gas discoveries, and an ichnological model that reveals past climate would be highly relevant to oil and gas exploration and development. This is because understanding changing climatic conditions helps predict what geological levels have the best resource potential and what their regional distributions might be. This is owing to the role that climate plays in dictating source-rock quality and reservoir composition. Notably, industry considers ichnological analyses to be an important part of sedimentary rock interpretation, and this would be a welcome addition to their ichnological tool belt. Canadian geoscientists have been heavily engaged, and are leaders in climate-change research. Data used for climate change analyses include geochemical and body-fossil datasets, but ichnological datasets are largely ignored. Yet, trace-fossil assemblages contain inportant paleoecological information. Moreover, most marine deposits contain abundant ichnological data that stand to contribute to a deeper understanding of climate change, but with respect to climate we presently do not know exactly how to interpret the ichnofossil distributions that we can observe in the sedimentary record. This proposal outlines an approach to investigate the differences between low- and high-latitude trace-fossil successions to address the ichnological recognition of depositional temperature. The proposed studies will focus on marine environments. The rationale behind this investigation is that physical and chemical parameters in tropical (warm) versus arctic (cold) latitudes, including food resources, hydraulic energy, dissolved oxygen content, and oxygen- and salinity-distributions are very different at different latitudes and will thus lead to different ichnological assemblages in each of those settings. The research plan considers Permian, Cretaceous, Eocene and modern datasets that will build on modest earlier efforts. Importantly, the strategy proposed is not simply to identify recurring ichnological assemblages that relate to latitude, but to establish a shelf to shoreline trace-fossil characterization that can be reliably associated with the temperature of the depositional marine waters.

技术学是对痕迹化石的研究，痕迹化石是岩石记录中保存下来的动物足迹、踪迹和洞穴。这个领域有着非常广泛的应用。洞穴代表了沉积物动物的生存策略，它们的形状、大小和出现情况令人惊讶。许多痕迹化石类型是在空间和时间中出现的，其古生物学意义已广为人知。痕量化石模型提供了对古环境条件的解释，例如水中溶解的 O2 浓度、盐度和沉降率。该提案旨在开发一个模型，利用海洋环境中无脊椎动物（例如蠕虫、虾、海星、海葵）的洞穴，将痕量化石与沉积温度联系起来，以进行气候研究。了解痕量化石的出现与沉积温度的关系至关重要。加拿大不断向北寻找新的石油和天然气发现，揭示过去气候的技术模型将与石油和天然气勘探和开发高度相关。这是因为了解不断变化的气候条件有助于预测哪些地质层位具有最佳资源潜力及其区域分布。这是由于气候在决定烃源岩质量和储层组成方面发挥的作用。值得注意的是，业界认为地貌分析是沉积岩解释的重要组成部分，这将是他们地貌工具带的一个受欢迎的补充。加拿大地球科学家一直积极参与，并且是气候变化研究的领导者。用于气候变化分析的数据包括地球化学和人体化石数据集，但技术数据集在很大程度上被忽略。然而，痕迹化石组合包含重要的古生态信息。此外，大多数海洋沉积物都包含丰富的地貌数据，这些数据有助于更深入地了解气候变化，但就气候而言，我们目前还不知道如何准确解释我们在沉积记录中观察到的地貌化石分布。该提案概述了一种研究低纬度和高纬度痕迹化石序列之间差异的方法，以解决沉积温度的技术识别问题。拟议的研究将重点关注海洋环境。这项调查背后的基本原理是，热带（暖）纬度与北极（冷）纬度的物理和化学参数，包括食物资源、水力能、溶解氧含量以及氧和盐度分布在不同纬度有很大不同，因此在每一个环境中都会导致不同的技术组合。该研究计划考虑了二叠纪、白垩纪、始新世和现代数据集，这些数据集将建立在早期努力的基础上。重要的是，所提出的策略不仅仅是识别与纬度相关的重复出现的地貌组合，而是建立一个陆架到海岸线的痕迹化石特征，该特征可以与沉积海水的温度可靠地相关联。