Aeolian studies of Lake Michigan’s coastal dunes have yet to elucidate what factors control their episodic activity over the past 5000 years. High lake levels exposing sand along with increased storminess is generally accepted for high perched dunes. This hypothesis, however, remains poorly tested for low perched dunes along the southeast Lake Michigan coastline. Here, small lakes in the lee of dune complexes contain aeolian sand and various biological proxies. Age and sedimentation rate models from Gilligan Lake cores guide analysis of aeolian sand, charcoal, pollen, and diatoms at high resolution (1 cm [10.4 yr/cm]) during the high-water Algoma Phase (3.1–2.4 ka) of the upper Great Lakes. The diatoms record a transition from a deep, more acidic lake to a shallower, more alkaline lake with fewer wetlands. This transition is accompanied by a stepped increase in the amount of aeolian sand. There is a weak correlation (R² 0.5, p < 0.01) between increasing abundances of charcoal chunks and sand. Peaks of sand follow peaks in charcoal threads and sheets, suggesting fire played a role in removing vegetation, presaging the landscape for increases in storminess. Arboreal pollen records a transition from a mesic forest Fagus-Acer-Quercus-Abies assemblage suggestive of moister conditions to one richer in mesic hardwoods tolerant of drier conditions. Together, the environmental proxy data record a shallowing lake concomitant with increasing aeolian sand, suggesting that drought-like conditions along the coastline conditioned the landscape for renewed aeolian activity. Once initiated, increased storminess and shoreline erosion maintained dune activity through increased sediment supply.

密歇根湖沿岸沙丘的风成研究尚未阐明在过去 5000 年中是什么因素控制了它们的情节活动。高湖水位暴露沙子以及增加的暴风雨通常被高位沙丘所接受。然而，对于密歇根湖东南海岸线的低栖息沙丘，这一假设仍然没有得到很好的检验。在这里，沙丘背风处的小湖泊含有风积沙和各种生物代理。来自 Gilligan Lake 岩心的年龄和沉积速率模型在高水位 Algoma 阶段 (3.1–2.4 ka) 期间以高分辨率 (1 cm [10.4 yr/cm]) 指导风积沙、木炭、花粉和硅藻的分析五大湖。硅藻记录了从较深、酸性更强的湖泊到湿地较少的较浅、碱性更强的湖泊的转变。这种转变伴随着风积沙量的阶梯式增加。² 0.5, p < 0.01) 在增加木炭块和沙子的丰度之间。沙子的山峰紧随木炭线和床单的山峰，这表明火在去除植被方面发挥了作用，预示着暴风雨的增加。树栖花粉记录了从暗示潮湿条件的中型森林Fagus - Acer - Quercus - Abies组合到更丰富的中型硬木耐受干燥条件的过渡。总之，环境代理数据记录了一个变浅的湖泊，伴随着风沙的增加，这表明沿海岸线的干旱条件使地貌适应了新的风沙活动. 一旦开始，增加的风暴和海岸线侵蚀通过增加沉积物供应来维持沙丘活动。