Phyllosilicate-poor palagonitic dust from Mauna Kea Volcano (Hawaii): A mineralogical analogue for magnetic Martian dust?

Author:

Morris, R.V., Golden, D.C., Ming, D.W., Shelfer, T.D., Jorgensen, L.C., Bell, J.F. III, Graff, T.G., Mertzman, S.A.

Title:

Phyllosilicate-poor palagonitic dust from Mauna Kea Volcano (Hawaii): A mineralogical analogue for magnetic Martian dust?

Periodical:

Journal of Geophysical Research

Year:

2001

Volume:

106

Pages:

5057-5083

Subject:

Mauna Kea volcano Mars Exploration Rover Trace elements Geomagnetism

Summary:

A collection of dust samples from the upper slopes of Mauna Kea volcano (Hawaii) was studied by X-ray diffraction (XRD), X-ray fluorescence (XRF), visible and near-IR reflectance spectroscopy, Mossbauer spectroscopy, magnetic properties methods, and transmission electron microscopy (TEM). The dust samples are spectral analogues of Martian bright regions at visible and near-IR wavelengths. Simulation of the Mars Pathfinder Magnet Array (MA) experiment was performed on Mauna Kea Volcano in areas with phyllosilicate-poor palagonitic dust and with copies of the Pathfinder MA. On the basis of the magnetic properties of dust collected by all five MA magnets and the observation that the Pathfinder MAs collected dust on the four strongest magnets, the value for the saturation magnetization of Martian dust collected in the MA experiments is revised downward from 4 plus or minus 2 Am(super 2) / kg to 2. 5 plus or minus 1.5 Am(super 2) /kg. Comparison of the magnetic properties of bulk Mauna Kea palagonitic dust to those for dust collected by MA magnets shows that the MA magnets extracted (culled) a subset (25-34 wt %) of composite magnetic particles from bulk dust.

Label:

Geology

Collection:

Periodicals