GRGC: Developing an Absolutely-Dated Holocene Tree-Ring Chronology from Subfossil Huon Pine in Tasmania for Paleoclimatic and Isotopic Studies

这项为期3年的提案旨在资助继续开发一个连续的、绝对确定时间的全新世树木年轮年表，该年轮年表来自澳大利亚塔斯马尼亚州西部收集的活的Huon松树和亚化石原木。迄今为止的进展包括建立了两个绝对年代的休恩松年轮年表，从现在开始追溯到2000多年前，从这些年轮序列中重建了公元前300年以来塔斯马尼亚温暖季节的温度，建立了两个漂浮的4- 6000年BP范围的亚化石树木年轮年表，以及在斯坦利河洪泛平原挖掘了105个新的亚化石休恩松木材。其中6个新原木的放射性碳测年表明年龄在4- 7000年BP之间，另外两个原木的测年时间在30000年BP之间。后两个，每个包含几百个环，是迄今为止发现的最古老、保存完好的亚化石原木之一，证明了塔斯马尼亚岛存在着末次冰河期可恢复的休恩松木。因此，延续到晚更新世的连续的树木年轮年表的发展是非常现实的可能性。这次收集的大量木材和新收集的木材最终将用于同位素分析，并可能将高精度放射性碳校准曲线延伸到最后一个冰河期。在接下来的三年里，我们将对现有的亚化石木材进行处理，将现有的树木年轮年表延长到过去，并继续在塔斯马尼亚西部地区收集更多的Huon松木亚化石。此外，我们将为塔斯马尼亚岛开发新的和扩展的气候重建，包括可能将暖季温度重建追溯到公元前2000年。

9310093 Cook This 3-year proposal is for funding to continue the development of a continuous, absolutely-dated Holocene tree-ring chronology from live Huon pine trees and sub-fossil logs collected in western Tasmania, Australia. Progress to date includes the development of two absolutely-dated Huon pine annual tree-ring chronologies extending back over 2,000 years from the present time, the reconstruction of warm-season Tasmanian temperatures since 300 BC from one of these series, the development of two floating, sub- fossil tree-ring chronologies in the 4-6,000 years BP range, and the excavation of 105 new sub-fossil Huon pine logs from the Stanley River flood plain. Radiocarbon dates of six of these new logs indicates ages of 4-7,000 yrs BP, plus two other logs with dates in the 30,000 yrs BP range. The latter two, each containing several hundred rings, are among the oldest, well-preserved, sub- fossil logs yet discovered anywhere and are proof that recoverable Huon pine wood from the last glacial epoch is present in Tasmania. Consequently, the development of a continuous tree-ring chronology extending back into the late-Pleistocene is a very real possibility. The bulk wood from this collection and the proposed new collections will eventually be used for isotopic analyses and the likely extension of the high-precision radiocarbon calibration curve back into the last glacial epoch. Over the next three years, we will process the sub-fossil wood now in hand, extend the existing tree-ring chronology back in time, and continue to collect more sub-fossil Huon pine wood from area in western Tasmania. In Addition, we will develop new and extended climatic reconstructions for Tasmania, including the probable extension of the warm-season temperature reconstruction back to 2,000 BC.