Direct Intercalibration of Astronomical and Radioisotopic Time Scales: 40Ar/39Ar Dating of Tephra in Neogene Mediterranean Sections

9903078 Deino该项目旨在比较基于沉积记录中反映的天文频率的地质时标与基于40 Ar/39 Ar方法的地质时标。 该项目将利用地中海地区新近纪地层中有节奏的年代确定的火山灰层。 用40 Ar/39 Ar方法测定这些灰烬的年龄将能够直接与天文年龄进行比较，而不是使用地磁极性转换等间接定年层位。 定年和旋回地层建模将与乌特雷奇大学和阿姆斯特丹大学的研究紧密结合。 该项目的一个重要成果将是评估上新世和中新世地球气候在多大程度上受到由于偏心率、岁差和地球轨道不均匀性而引起的日照变化的调制。

9903078DeinoThis project aims to compare geologic time scales based on astronomicalfrequencies reflected in the sedimentary record with those based on the40Ar/39Ar method. The project will make use of readily dated volcanic ashlayers intercalated with rhythmically bedded Neogene strata in theMediterranean region. Dating of these ashes by 40Ar/39Ar methods willenable direct comparison with astronomical ages, rather than usingindirectly dated horizons such as geomagnetic polarity transitions. Datingand cyclostratigraphic modelling will be closely integrated with researchat the Universities of Utrech and Amsterdam. An important product of theproject will be evaluation of the extent to which Earth's climate in thePliocene and Miocene has been modulated by variations of insolation due toeccentricity, precession, and obliquity of Earth's orbit.