Precipitation and diagenesis of hot spring deposits/Evolution of carbonate successions on isolated oceanic islands

我的研究计划将集中在(1)控制方解石、文石和蛋白石-A沉淀的因素，(2)微生物在文石、方解石和蛋白石-A沉淀中所起的作用，以及(3)广泛的白云岩化成功的起源。研究目标1和目标2将通过对温泉/间歇泉矿床的详细研究来实现，而研究目标3将以开曼群岛第三纪白云岩为基础，并与来自艾伯塔省的泥盆纪白云岩和中国的前寒武纪白云岩进行比较。 温泉/间歇泉矿床：未来五年，人们的注意力将集中在云南省中国发现的泉水系统上。该地区的构造活动与印度板块和欧亚板块之间的碰撞有关，产生了许多泉水，其特点是水温高达100℃，pH值在2至9之间，水成分多变。因此，它们是评估控制矿物沉淀和微生物垫分布的因素的理想自然实验室。从这些泉水中获得的信息将与我从冰岛、新西兰、肯尼亚裂谷和加拿大西部研究的泉水系统中获得的数据相结合。尽管这项研究的重点是泉水系统，但这项研究将侧重于与所有碳酸盐矿床相关的问题--例如，控制文石而不是方解石沉淀的因素，微生物在降水中所起的作用，以及控制软体微生物保存的因素。 开曼群岛第三纪白云岩的演化：这项研究将集中于形成布拉夫群(时代为渐新世-上新世)的白云岩的成因，以解释在地球表面附近的低温和低压制度下如何形成普遍存在的白云岩化序列。这项研究对各时代白云岩的成因，特别是白云岩如何演化成为优质油气藏具有重要的意义。在接下来的五年里，从开曼群岛白云岩发展出来的假说将与阿尔伯塔省中东部格罗斯蒙特组的泥盆纪含沥青白云岩和中国的前寒武纪白云岩进行测试。通过研究不同年龄和不同地理位置的白云岩，应该可以确定共性，然后可能导致更好地了解白云化过程。

My research program will focus on (1) factors that control calcite, aragonite, and opal-A precipitation, (2) the role that microbes play in the precipitation of aragonite, calcite, and opal-A, and (3) the origin of pervasively dolomitized successons. Research goals 1 and 2 will be achieved by the detailed study of hot spring/geyser deposits, whereas research goal 3 will be based on the Tertiary dolostones of the Cayman Islands with comparisons being made to the Devonian dolostones of Alberta and Precambrian dolostones from China. Hot Spring/Geyser Deposits: Over the next five years, attention will be focused on spring systems found in Yunnan Province in China. Tectonic activity in this area, related to the collision between the Indian and Eurasian plates, gives rise to numerous springs that are characterized by water temperatures up to 100°C, pH values between 2 and 9, and variable water compositions. As such they are ideal natural laboratories for assessing the factors that control mineral precipitation and the distribution of microbial mats. Information obtained from these springs will be integrated with data that I have already obtained from spring systems that I have studied in Iceland, New Zealand, the Kenyan Rift Valley, and western Canada. Although focused on spring systems, this research will focus on questions that are pertinent to all carbonate deposits – including, for example, the factors that control aragonite as opposed to calcite precipitation, the role that microbes play in precipitation, and the factors that control preservation of soft-bodied microbes. Evolution of Tertiary dolostones of the Cayman Islands: This research will focus on the origin of the dolostones that form most of the Bluff Group (Oligocene – Pliocene in age) with the view of explaining how pervasively dolomitized successions originate under the low temperature and low pressure regimes near the surface of the earth. This study has important implications for the origin of dolostones of all ages and, in particular, the manner in which they evolve to become excellent hydrocarbon reservoirs. Over the next five years hypotheses developed from the Cayman dolostones will be tested against the bitumen-bearing Devonian dolostones in the Grosmont Formation of east-central Alberta and Precambrian dolostones from China. By examining dolostones of different ages and from different geographic locations it should be possible to identify commonalities that may then lead to a better understanding of the dolomitization process.