Paulina Marsh, Oregon Tephra Dataset

This data collection describes tephra samples collected from core OSU-PMOR1907-7GP-1WPAUL-OR19-7-2G as part of a multi-proxy paleoenvironmental study of sediments at Paulina Marsh, Oregon designed to help constrain human-environmental dynamics in the northern Great Basin, U.S.A.

Six stratigraphic intervals of the core were sampled for primary or reworked tephra. A metadata spreadsheet, photographs, and core logs included in this data collection document the samples and their context.

Tephra analysis was conducted at Concord University. Resulting tephra glass geochemistry, grain size measurements, scanning electron microscopy (SEM) images, SEM image metadata, and sample preparation metadata are included in this collection.

Tephras identified among the samples include Cy from Mt. St. Helens (GVP vnum 321050) and the Paulina Creek tephra of Newberry Volcano (GVP vnum 322110). These are also known respectively as the Marble Bluff and Olema distal ash beds and occur in multiple samples. A >= 7 cm thick tephra layer containing coarse ash and fine lapilli yielded geochemistry which could not be definitively correlated to a specific known eruption and source volcano but does bear similarity to some tephras of Newberry Volcano.

本数据集收录了取自美国俄勒冈州保利纳沼泽（Paulina Marsh）沉积物岩芯OSU-PMOR1907-7GP-1WPAUL-OR19-7-2G的火山碎屑（tephra）样品，相关研究属于该区域沉积物的多代用指标古环境研究的一部分，旨在厘清美国大盆地北部的人类与环境互动关系。

本岩芯共选取6个地层段开展原生或再沉积火山碎屑样品采集。数据集附带元数据电子表格、岩芯照片及岩芯编录文件，用于记录样品及其产出背景。

火山碎屑分析工作于康科德大学（Concord University）完成。本数据集包含分析得到的火山碎屑玻璃地球化学数据、粒度测量结果、扫描电子显微镜（SEM）图像、SEM图像元数据及样品制备元数据。

本次鉴定出的火山碎屑包括圣海伦斯火山（Mt. St. Helens）产出的Cy火山碎屑（GVP vnum 321050），以及新贝里火山（Newberry Volcano）的保利纳溪火山碎屑（GVP vnum 322110）。二者分别被称为马布尔布拉夫远端火山灰层与奥莱马远端火山灰层，在多个样品中均有检出。另有一层厚度不小于7 cm的火山碎屑层，含粗火山灰与细火山砾，其地球化学数据无法与已知喷发及源火山建立明确对应关系，但与新贝里火山的部分火山碎屑具有相似性。