Holocene Lake Level and Climate Change Inferred from Marl Stratigraphy of the Cayuga Lake Basin, New York
Holocene Lake Level and Climate Change Inferred from Marl Stratigraphy of the Cayuga Lake Basin, New York
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根据纽约卡尤加湖盆地泥灰岩地层推断的全新世湖水位和气候变化
DOI：
10.2110/jsr.68.569
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发表时间：
1998
影响因子：
2
通讯作者：
H. T. Mullins
中科院分区：
文献类型：
--
作者：
H. T. Mullins
摘要为了评估美国东北部全新世气候的稳定性，我们使用了一系列12个放射性碳测年的沉积物岩心（长达15 m）来确定纽约州中部卡尤加湖盆地下的全新世地层。这些岩芯含有丰富的厚湖泥灰岩（> 30% CaCO 3），用于重建世纪至千年规模的湖平面变化，从而重建古气候。最古老的沉积物恢复（> 11.2 ka）由粉红色的，冰前粘土，沉积在Iroquois冰湖之间~ 12.5和11.3 ka。在现代卡尤加湖的北部和南部都发现了Killarney-Younger Dryas年龄（11.2-10.3 ka）的湖泊沉积物（非泥灰岩），表明在这一著名的寒冷气候阶段，湖泊水位相对较高。在短暂的全新世高温期（~ 9-4 ka）之后，卡尤加湖盆地的特点是广泛沉积泥灰岩，局部含有高达90%的CaCO 3。这些泥灰岩记录了一个广泛的，第一阶的升温-降温趋势，整个高温，气候最佳的约7万年。这种长期趋势与格陵兰岛的日射数据和冰芯记录一致，可能是米兰科维奇轨道强迫的反应。整个手指湖地区的湖泊水位相对较高，在全新世高温，这意味着一个整体温暖和潮湿的气候与传统的看法中全新世干旱。然而，芬格湖地区的高温气候和湖泊水位并不稳定;相反，它们的特点是世纪至千年尺度的显著变化，这意味着短期的气候变化。泥灰岩沉积在卡尤加湖盆地停止在~ 3.4万年时，湖泊水位下降，全球降温设置在年底的高温。然而，有一个短暂的返回到温暖和潮湿的气候在~ 1 ka，在中世纪温暖期之前的人类活动的影响。
ABSTRACT A series of 12 radiocarbon-dated sediment cores (up to 15 m long) were used to define the Holocene stratigraphy beneath the Cayuga Lake basin in central New York State in order to evaluate the stability of Holocene climate in the northeastern United States. These cores contain an abundance of thick lacustrine marls (> 30% CaCO3) that were used to reconstruct century- to millennium-scale changes in lake levels and, thus, paleoclimates. The oldest sediments recovered (> 11.2 ka) consist of pink, proglacial clays that were deposited in Glacial Lake Iroquois between ~ 12.5 and 11.3 ka. Lacustrine sediment (non-marl) of Killarney-Younger Dryas age (11.2-10.3 ka) was recovered both north and south of modern Cayuga Lake, indicating relatively high lake levels during this well-known cold-climate phase. Following a brief ( The Holocene Hypsithermal period (~ 9-4 ka) in the Cayuga Lake basin was characterized by widespread deposition of marl that locally contains as much as 90% CaCO3. These marls document a broad, first-order warming-cooling trend throughout the Hypsithermal, with the climatic optimum at ~ 7 ka. This long-term trend is consistent with insolation data as well as ice-core records from Greenland, and likely was a response to Milankovitch orbital forcing. Lake levels throughout the Finger Lakes region were relatively high during the Holocene Hypsithermal, implying an overall warm and wet climate in contrast to the traditional view of mid-Holocene drought. However, Hypsithermal climate and lake levels in the Finger Lakes region were not stable; rather they were characterized by significant century- to millennium-scale variability, implying short-term climate changes. Marl deposition in the Cayuga Lake basin ceased at ~ 3.4 ka when lake levels dropped as global cooling set in at the end of the Hypsithermal. However, there was a brief return to a warm and wet climate at ~ 1 ka, during the Medieval Warm Period prior to the onset of anthropogenic effects.