Extended, High-Temperature Cooling of Lava Tube Interiors: Analog for Venus
Mentor 1
Lindsay McHenry
Start Date
28-4-2023 12:00 AM
Description
This project is analyzing lava samples from lava tubes from the Northeast rift Zone located within the 1843 lava flow off the slopes of Mauna Loa, Hawaii. X-ray diffraction is used to determine their mineralogical composition. The data collected contrasts the surface with the interior. When exposed to high temperatures in an oxidizing environment over periods of weeks to months in a published laboratory experiment, the mineral olivine (common in basalt) develops a thin veneer of hematite, which can mask its spectral signature. On Earth, it is challenging to locate a region that can sustain Venus-like conditions. That is due to the natural environment of Earth, the surface temperature is much cooler. The demand for a site that could sustain basalts cooling at extended, high-temperatures is critical. Venus is difficult to study remotely (thick atmosphere) and the extreme temperatures at the surface (~475°C) and atmospheric pressures (~90 bars) makes the surface uninhabitable and difficult to study using landers or rovers (Fegley et al., 1995). The interior of a recently formed lava tube could provide the adequate environment for slow cooling basalts in contact with extended, high-temperatures. Therefore, the objective is to determine if Lava tube interiors are an adequate analog for Venus. If there is a trend in specular hematite coating on interior surfaces of lava tubes, then it indicates that it is a good match for experimental results under Venus temperature conditions (Filiberto et al., 2020). If the surface layer is hematite-bearing and lacks olivine, but the interior contains olivine, then we might be able to study high-T weathering processes on Earth, in this environment. Preliminary results show that hematite is present in both the exteriors and interiors, but testing additional samples will help determine if this trend is ubiquitous.
Extended, High-Temperature Cooling of Lava Tube Interiors: Analog for Venus
This project is analyzing lava samples from lava tubes from the Northeast rift Zone located within the 1843 lava flow off the slopes of Mauna Loa, Hawaii. X-ray diffraction is used to determine their mineralogical composition. The data collected contrasts the surface with the interior. When exposed to high temperatures in an oxidizing environment over periods of weeks to months in a published laboratory experiment, the mineral olivine (common in basalt) develops a thin veneer of hematite, which can mask its spectral signature. On Earth, it is challenging to locate a region that can sustain Venus-like conditions. That is due to the natural environment of Earth, the surface temperature is much cooler. The demand for a site that could sustain basalts cooling at extended, high-temperatures is critical. Venus is difficult to study remotely (thick atmosphere) and the extreme temperatures at the surface (~475°C) and atmospheric pressures (~90 bars) makes the surface uninhabitable and difficult to study using landers or rovers (Fegley et al., 1995). The interior of a recently formed lava tube could provide the adequate environment for slow cooling basalts in contact with extended, high-temperatures. Therefore, the objective is to determine if Lava tube interiors are an adequate analog for Venus. If there is a trend in specular hematite coating on interior surfaces of lava tubes, then it indicates that it is a good match for experimental results under Venus temperature conditions (Filiberto et al., 2020). If the surface layer is hematite-bearing and lacks olivine, but the interior contains olivine, then we might be able to study high-T weathering processes on Earth, in this environment. Preliminary results show that hematite is present in both the exteriors and interiors, but testing additional samples will help determine if this trend is ubiquitous.
