This content was translated by an AI-powered translation tool.
It may contain inaccuracies due to the limitations of machine translation.
Copyright © DongA Science. All rights reserved.
Science study reports first discovery of native sulfur deposits in Gale Crater’s Gediz Vallis after 3.1–2.8 billion years of preservation
This week’s cover of the international journal 'Science' features a photo of natural sulfur (S) deposits found by NASA’s Mars rover Curiosity in Gediz Vallis within Gale Crater on Mars. It is the first time that elemental sulfur in a neutral state, rather than sulfates or sulfides, has been identified on Mars.

Scott Van Bommel’s team at Washington University in St. Louis, together with NASA researchers, analyzed the natural sulfur deposits discovered on Mars and published their findings in Science on June 28 (local time).

The team examined the bright rock pile that Curiosity found on the floor of Gediz Vallis using the Alpha Particle X-ray Spectrometer (APXS) and cameras. The rocks were shown not to be previously known sulfur-rich sedimentary rocks or sulfate minerals, but instead to consist of almost pure elemental sulfur.

The rocks were clustered in a depositional area of about 2,100 square meters (㎡). Some rocks were broken by the rover’s wheels, exposing interiors that were not covered by dust or sand, where the characteristic pale yellow color of sulfur and a glassy, resinous luster were observed.

Because there are few other rock fragments or sediments inside and outside the rocks, and they have a porous structure, the team interpreted the sulfur deposits as having formed in place rather than being transported from elsewhere. They estimate that sulfur erupted from the subsurface about 3.1–2.8 billion years ago and was then buried and preserved beneath overlying sediments.

The surface of Gale Crater shows little evidence of high-temperature volcanic or hydrothermal activity, so the discovery of pure sulfur deposits is considered unexpected.

The researchers suggest that sulfur–oxygen–hydrogen vapors or fluids originating from magma were trapped in a cold subsurface cryosphere and later released as Gediz Vallis was eroded and pressure decreased, leaving behind elemental sulfur.

The team explained, "Further observations and comparative studies are needed to understand the conditions under which elemental sulfur formed on Mars and was preserved for billions of years."

<Reference>
– doi.org/10.1126/science.adu5501