DATING FELDSPAR USING POST-ISOTHERMAL LUMINESCENCE AND APPLICATION TO CLIMATE-SENSITIVE PALEOENVIRONMENTS

利用等温后发光测定长石的年代及其在气候敏感古环境中的应用

• 批准号: RGPIN-2018-06422
• 负责人: Lamothe, Michel
• 金额: $ 3.72万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=656510
• 关键词: DATING; FELDSPAR; USING; POST; ISOTHERMAL

Our planet is facing a critical part of its history as modern societies need to implement adaptation strategies to rapidly changing surface environments in response to global warming. Using the past to better apprehend the future, one should take advantage of the geological record as it contains archives that can be used to interpret the resilience or sensitivity of physical environments to climate change. These archives are represented mainly by sediments and in order to be accurately interpreted, they need to be inserted in a proper time-frame, hence dated. The main objective of this research program is therein to develop new dating methodologies in the field of feldspar luminescence for assessing the chronology of climate-sensitive geological and archaeological sedimentary archives. ***The scientific approach is to focus on the luminescence properties and the phenomenology of single feldspar grains in sediments. Due to the nature of its solid-state physics, luminescence dating of feldspar shall be applicable to a large part of the last million years of Earth history. This method can therefore probe one order of magnitude deeper into geological time than radiocarbon and more than 5 times the current age range of quartz optically-stimulated luminescence, routinely used in luminescence dating. Our recent work as resulted in the development of an innovative protocol in which low-temperature IRSL following post-isothermal treatments is shown to yield ages in accordance with the stratigraphical assignment for several samples from different parts of the world. This novel approach is now possible following the development of new instrumentation in luminescence readers, most of these are now available in the Montréal laboratory as a result of a major CFI funding to the UQAM geochronology group. This innovation shall provide precise as well as accurate age determinations as no correction for fading is needed. ***The detailed methodology is two-fold. 1) In order to develop a new method, laboratory protocols have to be devised and implemented, that will investigate the phenomenology of feldspar luminescence. This research shall contribute to HQP training for laboratory-focused and physics-inclined students. 2) These innovative methodologies will then be tested and validated in climate-sensitive geological contexts: a) “warm” interglacial coastal sediments, indicators of high sea level (e.g. USA, Brazil, Morocco), b) “cold” periglacial features (e.g. Yukon, Alaska). HQP training is strongly entangled in the specific research projects for field-oriented Earth sciences students.***The novelty of this research and its upmost significance is in offering new ideas and concepts to the luminescence dating field as well as providing access to a new chronological tool for the natural sciences community involved in the science of Global Changes.

我们的星球正面临其历史的关键部分，因为现代社会需要实施适应策略来响应全球变暖，以快速改变地表环境。利用过去更好地理解未来，应该利用地质记录，因为它包含可用于解释物理环境对气候变化的韧性或敏感性的档案。这些档案主要由沉积物表示，为了准确解释，需要将它们插入适当的时间框架中，因此日期。该研究计划的主要目的是在长石发光领域开发新的约会方法，以评估气候敏感的地质和存档沉积档案的年代学。 ***科学方法是关注发光特性和沉积物中单长石晶粒的现象。由于其固态物理学的性质，长石的发光日期应适用于地球历史过去一百万年的大部分。因此，该方法可以比放射性碳深入地质时间更深地探测一个数量级，并且是石英光学刺激发光的当前年龄范围的5倍以上，该范围通常用于发光年代。我们最近作为创新方案的开发，在该方案中，根据地层分配，该方案的低温IRSL显示出了来自世界各地的几个样本的地层分配。现在，在发光读取器中开发新仪器后，这种新颖的方法现在可以使用，其中大多数是在蒙特利尔实验室中提供的，这是由于向UQAM地球人工学组提供了主要的CFI资金。这项创新应提供精度和准确的年龄确定，因为不需要褪色校正。 ***详细的方法是两倍。 1）为了开发一种新方法，必须设计和实施实验室方案，以研究长石发光的现象学。这项研究应为针对实验室和物理学的学生提供HQP培训。 2）这些创新方法将在气候敏感的地质环境中进行测试和验证：a）“温暖”“温暖”冰川间沿海沉积物，高海平面的指标（例如美国，巴西，摩洛哥，摩洛哥），b）“冷” periglacial特征（例如，Yukon，Alaska）。 HQP培训在针对现场的地球科学学生的特定研究项目中牢固纠缠。