Mercuryi

Regional Level Types
Mercury	Planet

The planet nearest the Sun.

Mineralogical data is mostly from infra-red spectroscopic measurements.

Note: beside common species/groups like feldspar, plagioclase, pyroxene, and olivine (and maybe graphite), the listed minerals are more like proposals rather than 100%-confirmed finds.

Radar features (imaging by the Mercury Dual-Imaging System with Wide-Angle Camera with 8 filters from 433 to 996 nm, within the MESSENGER, aka MErcury Surface Space ENvironment GEochemistry, spacecraft):

1. Radar-bright areas, heavily cratered, may contain some impact-derived excavated materials (impact ejecta) - near the equator.

2. Dark plains - located west to the Caloris Basin; volcanic plains younger than the Basin interior. Likely built of oligoclase basalts.

3. Caloris Basin - a site with intrusive and extrusive volcanic features.

The results of the imaging are in the form of reflectance spectra, showing absorption features (Vilas et al., 2014 & 2016). In general, the imaging revealed the presence of vents, pyroclastics, and other extrusive volcanism signs. There are Mg-rich orthopyroxene and olivine; Ca-, Na- and Mg-rich clinopyroxene; K-feldspar; Na-bearing plagioclase; small amounts of both pyrope and grossular are possible. Rutile is most likely present, but perovskite is also likely.

Quite recently a sulphide mineralization at the Dominici crater (see the sublocality) was suggested. Calcium sulphide (likely oldhamite) is predicted to be the major lithophile sulphide on the planet (Villas et al., 2014 & 2016).

The resurfacing magmas had low to intermediate silica saturation.

Remote sensing suggests that the reason for the relatively dark hue of the planet's surface is due to a low-reflectance material within impact craters and their ejecta. The infrared spectroscopy suggests the presence of carbon, in an amount 1-3 wt.% greater than the surrounding. The theory's author's (Peplowski et al., 2016) confirm the presence of graphite, mixed with volcanic, as a remnant of the planet's graphite crust, that would float over the magma ocean in Mercury's early history. The competing theory is that the darkening material was brought by comets (Syal et al., 2015). Further studies (Denevi et al., 2016) seem to confirm the first theory.

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Mercury_(planet)
Wikidata ID:	Q308

Localities in this Region

References