These Rocks are weathering,Hence, releasing sulphur
Sulphur comes in contact with air and is converted into sulphates.
Sulphates are taken up by plants and microbes, and converted into organic forms.
The organic form of sulphur is then consumed by the animals through their food and thus sulphur moves in the food chain.
When the animals die, some of the sulphur is released by decomposition while some enter the tissues of microbes.
A COMIC STRIP BYPARTH AGGARWAL 8th-I
There are several natural sources such as volcanic eruptions, evaporation of water, and breakdown of organic matter in swamps, that release sulphur directly into the atmosphere. This sulphur falls on earth with rainfall.