Rock magnetic fingerprint of Mt. Etna volcanic ash: the dataset

This dataset refers to the article: "Rock magnetic fingerprint of Mt. Etna volcanic ash" by the same authors, published in Geophysical Journal International, https://doi.org/10.1093/gji/ggac213.

A detailed rock magnetic study was conducted on ash samples collected from different products erupted during explosive activity of Mount Etna, Italy, in order to test the use of magnetic properties as discriminating factors among them, and their explosive character in particular.
Samples include tephra emplaced during the last 18 ka: the benmoreitic Plinian eruptions of the Pleistocene Ellittico activity from marine core ET97-70 (Ionian Sea) and the basaltic Holocene FG eruption (122 BC), the Strombolian/Phreatomagmatic/sub-Plinian eruptions (namely, the Holocene TV, FS, FL, ETP products, and the 1990, 1998 eruptions) collected from the slope of the volcano, and the Recent explosive activity (lava fountains referred to as “Ash Rich Jets and Plumes”, or ARJP) that occurred in the 2001-2002 period, related to flank eruptions.
A full set of rock magnetic experiments were carried out to determine the magnetic mineralogy and the magnetic grain size at the Institute for Rock Magnetism at the University of Minnesota, including First-Order Reversal Curves (FORCs), hysteresis loops and backfield DC demagnetization remanence curves (DCD or Backfield curves) at room temperature on Princeton Measurements Corporation (Princeton, NJ) Vibrating Sample Magnetometers (VSMs).
Low temperature (LT) experiments were conducted on Quantum Design (San Diego, CA) Magnetic Properties Measurement Systems (MPMS-XL and 5S). LT experiments were carried out by measuring the magnetic remanence on warming from 10 K to room temperature (300 K) after cooling in a 2.5 T field (field cooled remanence, FC), as well as after cooling in zero field and applying a saturation isothermal remanent magnetization (SIRM) of 2.5 T at 10 K (zero-field cooled remanence, ZFC). A room temperature (RT) 2.5 T SIRM was also applied at 300 K and the remanence was measured upon temperature cycling to 10 K and back (RTSIRM). AC susceptibility as a function of temperature and frequency (1, 10, 100 Hz or 1, 5, 32, 178, 1000 Hz) was also measured for selected specimens from the three groups of samples.
Room temperature susceptibility measurements as a function of field amplitude (10, 20, 40, 80, 120, 200, 400 A/m) were carried out on the Late Pleistocene samples using a Magnon susceptibility system. Saturation magnetization on warming between room temperature and 700°C (Ms-T) was measured on selected specimens using a horizontal Curie balance with Argon gas circulation to limit oxidation processes during heating. Likewise, magnetic susceptibility on warming between room temperature and 700°C (X-T) was measured on a Kappabridge KLY-2 (Brno, Czech Republic) using fields of 300 A/m and 920 Hz. Ms-T and X-T curves are collectively referred to as thermomagnetic curves.

本数据集关联于同一作者发表于《国际地球物理杂志》（Geophysical Journal International）的论文《埃特纳火山灰的岩石磁学指纹》（Rock magnetic fingerprint of Mt. Etna volcanic ash），DOI链接为https://doi.org/10.1093/gji/ggac213。

研究团队针对意大利埃特纳火山爆发活动中采集的不同喷发产物火山灰样品开展了详细的岩石磁学研究，旨在验证磁学性质能否作为区分不同喷发产物及判别喷发特征（尤其是爆发式喷发特征）的依据。

样品涵盖过去18 ka以来的火山碎屑沉积：包括取自爱奥尼亚海深海岩芯ET97-70的更新世埃利蒂科（Ellittico）活动的碧玄岩质普林尼式喷发产物，以及全新世公元前122年的玄武质FG喷发产物；另包含从火山斜坡采集的斯通博利式/射汽岩浆喷发式/次普林尼式喷发产物（即全新世TV、FS、FL、ETP样品，以及1990年、1998年喷发产物），还有2001-2002年发生的与侧翼喷发相关的近期爆发活动产物——即被称为“富灰射流与羽流”（Ash Rich Jets and Plumes, ARJP）的熔岩喷泉产物。

美国明尼苏达大学岩石磁学研究所使用普林斯顿测量公司（Princeton Measurements Corporation, 普林斯顿, 新泽西州）的振动样品磁强计（Vibrating Sample Magnetometers, VSMs）在室温下开展了全套岩石磁学实验，以测定磁性矿物组成与磁晶粒尺寸，实验包括一阶反转曲线（First-Order Reversal Curves, FORCs）、磁滞回线以及反向直流退磁剩磁曲线（Backfield DC demagnetization remanence curves, 简称DCD或反向场曲线）。

使用量子设计公司（Quantum Design, 圣迭戈, 加利福尼亚州）的磁学性质测量系统（Magnetic Properties Measurement Systems, MPMS-XL和5S）开展低温实验：包括在2.5 T磁场中冷却后，于10 K至室温（300 K）升温过程中测量磁剩磁（场冷剩磁, Field Cooled Remanence, FC）；以及零场冷却后，在10 K下施加2.5 T的饱和等温剩磁（Saturation Isothermal Remanent Magnetization, SIRM），随后升温过程中测量的剩磁（零场冷剩磁, Zero-Field Cooled Remanence, ZFC）。此外还在300 K下施加室温2.5 T SIRM，并在循环升降温至10 K的过程中测量剩磁（RTSIRM）。针对三组样品中的部分标本，还测量了随温度和频率（1、10、100 Hz 或 1、5、32、178、1000 Hz）变化的交变磁化率。

使用Magnon磁化率系统对晚更新世样品开展了随场振幅（10、20、40、80、120、200、400 A/m）变化的室温磁化率测量。针对部分标本，使用通氩气以抑制加热过程中氧化反应的水平式居里天平，测量了室温至700℃升温过程中的饱和磁化强度（Ms-T曲线）。同样，使用捷克布尔诺的Kappabridge KLY-2磁化率仪，以300 A/m场强和920 Hz频率，测量了室温至700℃升温过程中的磁化率（X-T曲线）。Ms-T与X-T曲线统称为热磁曲线。