The Lower Cretaceous McMurray Formation of the Western Canada Sedimentary Basin has been the subject of numerous studies, with emphasis on its stratigraphic framework and sedimentological models. However, due to the stratigraphic complexity of the paleo-depositional system, which comprises fluvial and marginal-marine strata, it remains a challenging area of research. There is ongoing debate surrounding the depositional model of the most volumetrically significant and economically relevant units in the formation, with some suggesting that channel-belt deposits are predominantly fluvial in origin, while others argue that they are estuarine in origin, with some tidal influence. To gain insight into these issues, we present a comprehensive review of the McMurray Formation paleo-depositional system, focusing on three key aspects. First, we provide a detailed analysis of facies characteristics, including regional mapping results and trace fossil analysis. Second, we summarize the chronology of stratigraphic and depositional models developed for the McMurray Formation over the last 100 years. Third, we discuss the McMurray conundrum and present supporting information for the two widely accepted depositional models for the McMurray Formation channel-belt deposits. Proposed analogues and some of the associated critiques are discussed for each depositional model, and some future research directions are recommended. The complex nature of the McMurray Formation and the ongoing debates surrounding its depositional models emphasize the need for continued research and a multidisciplinary approach to better understand the McMurray paleo-depositional system.

中文翻译：

---

麦克默里组的早白垩世演化：为更好地了解古沉积系统而进行的回顾

加拿大西部沉积盆地的下白垩统麦克默里组一直是众多研究的主题，重点是其地层框架和沉积学模型。然而，由于由河流和边缘海地层组成的古沉积系统的地层复杂性，它仍然是一个具有挑战性的研究领域。围绕地层中最具体积意义和经济相关性的单元的沉积模型一直存在争论，一些人认为河道带沉积物主要起源于河流，而另一些人则认为它们起源于河口，受到一些潮汐影响。为了深入了解这些问题，我们对麦克默里组古沉积系统进行了全面回顾，重点关注三个关键方面。首先，我们对相特征进行了详细分析，包括区域测绘结果和遗迹化石分析。其次，我们总结了过去 100 年来为麦克默里组开发的地层和沉积模型的年代学。第三，我们讨论了麦克默里难题，并提供了麦克默里组河道带沉积的两种广泛接受的沉积模型的支持信息。对每个沉积模型提出的类似物和一些相关的批评进行了讨论，并推荐了一些未来的研究方向。麦克默里地层的复杂性质以及围绕其沉积模型的持续争论强调需要继续研究和采用多学科方法来更好地了解麦克默里古沉积系统。