Paleoclimate reconstruction of the Prince Creek Formation, Arctic Alaska, during Maastrichtian global warming
Paleoclimate reconstruction of the Prince Creek Formation, Arctic Alaska, during Maastrichtian global warming
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马斯特里赫特全球变暖期间阿拉斯加北极地区 Prince Creek 组的古气候重建
DOI：
10.1016/j.palaeo.2019.109265
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
F. Longstaffe
中科院分区：
文献类型：
--
作者：
Susana Salazar;P. McCarthy;Andrés Ochoa;S. Fowell;F. Longstaffe
位于北极阿拉斯加(~82-85°N)的上白垩统(马斯特里赫特)太子河组保存了一系列冲积古土壤，用于估算年平均降水量(MAP)、年平均温度(MAT)和大气水氧同位素组成。对于太子溪组，最高的MAP估计在1,000至3,900 毫米/年之间，最低的范围在350至1,200 毫米/年之间。由稳定碳同位素分析得出的降水变率发生在104年的时间尺度上。MAP值与之前从化石花粉、土壤学特征、土壤类型、植被组成、沉积学指标和夹具估计得出的解释一致，表明降雨量大、湿度高。尽管MAT指标存在相当大的不确定性，但我们的数值与之前从古植物学数据中获得的暖月平均温度是一致的。膨润土层中蒙脱石的δ-18O聚集在~+5.0VSMOW值附近。由膨润土蒙脱石计算出的大气水的δ18O为~−23‰(VSMOW)，假设年平均温度为6.3VSmow°C，这比从靠近布鲁克斯山脉的较年轻地层中的成壤菱铁矿计算出的大气水略缺18O。与阿拉斯加德纳利国家公园下坎特威尔组(~°N古纬度)的年代地层对比表明，与阿拉斯加中部相比，晚白垩世古北极的降水速率更高，18O的贫化程度更高。这些数据与以前的研究一致，这些研究表明，地球变暖和潮湿，以及加强的水文循环，加强了潜热输送，从而增加了降雨效应。
The Upper Cretaceous (Maastrichtian) Prince Creek Formation of Arctic Alaska (~82–85°N paleolatitude) preserves successions of alluvial paleosols that are used to estimate mean annual precipitation (MAP), mean annual temperature (MAT) and meteoric water oxygen isotope composition. For the Prince Creek Formation, the highest MAP estimates range between 1000 and 3900 mm/yr and the lowest range between 350 and 1200 mm/yr. The precipitation variability, derived from stable carbon isotope analysis, occurs on a time scale of 104years. MAP values agree with previous interpretations from fossil pollen, pedological features, soil types, vegetation composition, sedimentological indicators and CLAMP estimates that suggest high precipitation amounts and high humidity. Despite the considerable uncertainty with MAT proxies, our values are consistent with warm month mean temperatures obtained previously from paleobotanical data. Theδ18O of smectite from bentonite beds clusters around ~+5.0‰ (VSMOW). Theδ18O of meteoric water calculated from bentonitic smectite is ~−23‰ (VSMOW), assuming a mean annual temperature of 6.3 °C, which is slightly more18O-depleted than meteoric water calculated from pedogenic siderite in stratigraphically younger beds closer to the Brooks Range. Chronostratigraphic correlation with the lower Cantwell Formation, Denali National Park, Alaska (~64°N paleolatitude), suggests higher precipitation rates and highly18O-depleted precipitation in the Late Cretaceous paleo-Arctic compared to central Alaska. These data are consistent with previous studies that suggest a warmer and moister greenhouse Earth and an intensified hydrological cycle that enhanced latent heat transport, resulting in increased rainout effects.
影响因子：
--
作者：
Jung, Claudia;Voigt, Silke;Frank, Martin
通讯作者：
Frank, Martin
影响因子：
4.3
作者：
Lunt, Daniel J.;Farnsworth, Alex;Wrobel, Neil
通讯作者：
Wrobel, Neil