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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611208
• 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.

遗迹化石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。这一领域有着非常广泛的应用。洞穴代表了沉淀物动物的生存策略，它们在形状、大小和出现次数上都表现出惊人的多样性。许多遗迹化石类型出现在空间和时间上，它们的古生物学意义已经被很好地理解。遗迹化石模型提供了对古环境条件的解释，如水中溶解O2浓度、盐度和沉淀率。这项提议是利用海洋环境中的无脊椎动物(例如蠕虫、虾、海星、无脊椎动物)的洞穴，开发一种将痕迹化石与沉积温度相关联的模型，用于气候研究。 理解遗迹化石作为沉积温度的函数是至关重要的。加拿大继续向北寻找新的石油和天然气发现，一个揭示过去气候的生物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级别的资源潜力最大，以及它们的地区分布情况。这是由于气候在决定生油岩质量和储集层组成方面所起的作用。值得注意的是，行业认为遗迹分析是沉积岩解释的重要部分，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在积极参与气候变化研究，他们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遗体化石数据集，但生物数据集在很大程度上被忽略了。然而，遗迹化石组合包含重要的古生态信息。此外，大多数海洋沉积物包含丰富的生物数据，有助于更深入地了解气候变化，但关于气候，我们目前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研究低纬和高纬度遗迹化石序列之间差异的方法，以解决沉积温度的生物识别问题。拟议的研究将侧重于海洋环境。这项调查背后的理论基础是，热带(暖)和北极(冷)纬度的物理和化学参数，包括食物资源、水力能量、溶解氧含量以及氧和盐度在不同纬度的分布非常不同，因此将导致这些环境中不同的生物组合。 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适度努力的基础上。重要的是，提出的战略不是简单地确定与纬度有关的反复出现的生物组合，而是建立一个陆架到海岸线的踪迹化石特征，可以可靠地与沉积海洋水域的温度相关联。