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

遗迹学是对遗迹化石的研究，遗迹化石是岩石记录中保存下来的动物的足迹、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，它们在形状、大小和发生率方面表现出令人惊讶的变化。许多遗迹化石类型贯穿空间和时间，它们的古生物学意义已被很好地理解。微量化石模型提供了对古环境条件的解释，如水中溶解的O2浓度、盐度和沉积速率。该提议是利用海洋环境中无脊椎动物（如蠕虫、虾、海星、海葵）的洞穴，开发一个将遗迹化石与沉积温度联系起来的模型，用于气候研究。了解作为沉积温度的函数的遗迹化石的出现是至关重要的。加拿大不断向北寻找新的石油和天然气发现，揭示过去气候的遗迹学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所起的作用。值得注意的是，工业界认为遗迹学分析是沉积岩解释的重要组成部分，这将是他们遗迹学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，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体化石数据集，但遗迹学数据集在很大程度上被忽视。然而，遗迹化石组合包含着重要的古生态信息。此外，大多数海洋沉积物包含丰富的遗迹学数据，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地解释我们在沉积记录中观察到的遗迹化石分布。这一建议概述了一种方法来调查低纬度和高纬度的痕迹化石序列之间的差异，以解决沉积温度的遗迹学识别。拟议的研究将侧重于海洋环境。这项调查背后的基本原理是，热带（温暖）与北极（寒冷）纬度的物理和化学参数，包括食物资源，水力能，溶解氧含量，氧气和盐度分布在不同的纬度是非常不同的，因此将导致不同的遗迹组合在这些设置。该研究计划考虑二叠纪，白垩纪，始新世和现代数据集，将建立在适度的早期努力。重要的是，提出的战略是不简单地确定反复出现的遗迹组合，涉及到纬度，但要建立一个大陆架海岸线痕迹化石特征，可以可靠地与沉积海洋沃茨的温度。

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.