资源环境科技发展态势分析平台

Cave ice is an understudied component of the cryosphere that offers potentially significant paleoclimate information for midlatitude locations. This study investigated a recently discovered cave ice deposit in Strickler Cavern, located in the Lost River Range of Idaho, United States. Field and laboratory analyses were combined to determine the origin of the ice, to limit its age, to measure and interpret the stable isotope compositions (O and H) of the ice, and to investigate its glaciochemistry. Results indicate that the ice forms through snow densification, freezing of infiltrating water, and refreezing of meltwater. Radiocarbon dating revealed that an similar to 30-m-thick deposit of layered ice and organic matter accumulated over the past several centuries. In contrast, a 3.5-m-tall ice stalagmite began forming almost 2000 yr ago. Stable isotopes in the stalagmite and in the layered ice generally have slopes that parallel the local winter meteoric water line; however, delta O-18 and delta H-2 values are offset to the right of this line, indicating the influence of sublimation. Values of delta O-18 are lower in older ice, signaling cooler temperatures during the Little Ice Age. Calcium is the most abundant element in the ice, followed by Na, Mg, and K. Principal component analyses revealed a group of elements related to the local bedrock, a second group reflecting regional transport of mineral dust, and a third group suggestive of eolian transport from a mining dust source. Future work should build upon this foundation to further exploit the significant paleoenvironmental information archived in Strickler Cavern.