The biotic and sedimentologic evolution of the Cambrian

5亿年前的“寒武纪大爆发”是地球生命的转折点：海洋动物的进化出现，产生了贝壳、针状体、骨骼，有时甚至是软组织的化石，以及新的微生物和藻类。这种新的复杂生物群在海洋领域引起了深刻的生态革命。沉积物由于挖洞、消化、排泄、有机结合和细菌腐烂等过程而发生了根本性的变化。第一批后生动物礁出现了。我的小组将继续以跨学科的方式研究这些现象，结合沉积学和古生物学的方法，以便更全面地探索这一令人兴奋但仍然神秘的地球历史。壮观的南落基山脉将是我们的天然实验室。室内实验室包括广泛的分析技术，从光学显微镜到使用同步加速器x射线荧光的元素映射。通过沉积特征、古生态属性和地球化学资料，研究了前寒武纪晚期至早古生代热带碳酸盐岩礁、砂滩、潮滩、陆架和泻湖环境中古沉积物的起源、演化和有机沉积过程。在短短的5000万年时间里，这些相继形成的碳酸盐岩台地既有鲜明的对比，又有惊人的相似之处。我们将重新考虑长期以来的相解释和假设，并制定标准来区分海啸和风暴产生的床，以及地震开裂和干燥。化石的地层分布将使岩性单元的高分辨率时间相关性成为可能，并将有助于揭示这些岩石中捕获的多样化、灭绝、系统发育和区域和全球变化的时代模式。这个广泛的跨学科数据集将使我们能够解释寒武纪古气候、古海洋学、海平面和沉积，以及阐明这些岩石积聚的巨大大陆架和内陆海的构造历史。

The `Cambrian Explosion' half a billion years ago was a turning point for life on Earth: the evolutionary appearance of animals in the sea, which gave rise to fossils of shells, spicules, skeletons, even sometimes soft tissues, plus new kinds of microbes and algae. This new and complex biota caused profound ecological revolution in the marine realm. Sediment changed fundamentally due to processes of burrowing, digestion, excretion, organic binding and bacterial decay. The first metazoan reefs appeared. My group will continue to investigate these phenomena in an interdisciplinary way, by combining sedimentological and paleontological approaches in order to explore more fully this exciting yet still mysterious episode of Earth History. The natural laboratory for us will be the spectacular southern Rocky Mountains. The indoor laboratory includes a wide range of analytical techniques from optical microscopy to elemental mapping using synchrotron X-ray fluorescence. The origin and evolution of ancient sediments and organo-sedimentary processes in various tropical carbonate reef, sand shoal, tidal flat, shelf and lagoonal environments will be studied from the preceding latest Precambrian through early Paleozoic time via sedimentary features, paleoecological attributes and geochemical data. In a short span of time-just some 50 million years-these successive carbonate platforms show dramatic contrasts yet also remarkable similarities. We will reconsider long-held facies interpretations and assumptions, and develop criteria to differentiate tsunami- versus storm-generated beds, and earthquake cracking from desiccation. The stratigraphic occurrence of fossils will permit high-resolution temporal correlation of lithological units and will help reveal patterns of diversification, extinction, phylogeny and times of regional and global change captured in these rocks. This wide-ranging and interdisciplinary dataset will allow us to interpret Cambrian paleoclimate, paleoceanography, sea level and sedimentation, as well as elucidate the tectonic history of the vast continental shelves and inland seas in which these rocks accumulated.