Paul J. Wallace Matthew W. Loewen Don Swanson Adam J R Kent Robin M Tuohy 2016 <div class="abstract svAbstract " data-etype="ab"> <p id="sp0005">Concentrations of H₂O and CO₂&nbsp;in olivine-hosted melt inclusions can be used to estimate crystallization depths for the olivine host. However, the original dissolved CO₂concentration of melt inclusions at the time of trapping can be difficult to measure directly because in many cases substantial CO₂&nbsp;is transferred to shrinkage bubbles that form during post-entrapment cooling and crystallization. To investigate this problem, we heated olivine from the 1959 Kīlauea Iki and 1960 Kapoho (Hawai&lsquo;i) eruptions in a 1-atm furnace to temperatures above the melt inclusion trapping temperature to redissolve the CO₂&nbsp;in shrinkage bubbles. The measured CO₂&nbsp;concentrations of the experimentally rehomogenized inclusions (⩽590 ppm for Kīlauea Iki [n=10]; ⩽880 ppm for Kapoho, with one inclusion at 1863 ppm [n=38]) overlap with values for naturally quenched inclusions from the same samples, but experimentally rehomogenized inclusions have higher within-sample median CO₂&nbsp;values than naturally quenched inclusions, indicating at least partial dissolution of CO₂&nbsp;from the vapor bubble during heating. Comparison of our data with predictions from modeling of vapor bubble formation and published Raman data on the density of CO₂&nbsp;in the vapor bubbles suggests that 55-85% of the dissolved CO₂&nbsp;in the melt inclusions at the time of trapping was lost to post-entrapment shrinkage bubbles. Our results combined with the Raman data demonstrate that olivine from the early part of the Kīlauea Iki eruption crystallized at &lt;6 km depth, with the majority of olivine in the 1-3 km depth range. These depths are consistent with the interpretation that the Kīlauea Iki magma was supplied from Kīlauea&rsquo;s summit magma reservoir (&sim;2-5 km depth). In contrast, olivine from Kapoho, which was the rift zone extension of the Kīlauea Iki eruption, crystallized over a much wider range of depths (&sim;1-16 km). The wider depth range requires magma transport during the Kapoho eruption from deep beneath the summit region and/or from deep beneath Kīlauea&rsquo;s east rift zone. The deeply derived olivine crystals and their host magma mixed with stored, more evolved magma in the rift zone, and the mixture was later erupted at Kapoho.</p> </div> application/pdf 10.1016/j.gca.2016.04.020 en Geochemical Society Magma transport and olivine crystallization depths in Kīlauea’s East Rift Zone inferred from experimentally rehomogenized melt inclusions article