The Hydro-Mars project

Red clay in a dish

Iron-rich talc from the seafloor of the East Pacific Rise

Principal Investigator

Dr Javier Cuadros

Project summary

We are studying iron- and magnesium-rich clays from hydrothermal sea floor environments around the world to better understand the nature of ancient clays on Mars.

Submarine hydrothermal sites on Earth produce jets of superheated fluids loaded with metals, known as black smokers. Clays formed in these environments are similar to ancient Martian clays.

Ancient clay minerals on the surface of Mars formed billions of years ago, when liquid water was more available. They provide a valuable record of the ancient Martian climate, as well as hydrothermal processes within the planet's crust.


We are investigating the spectral similarities of clays from Earth and Mars by comparing their infrared spectra .Clays are detected on Mars by spacecraft in orbit that peer down at the surface using infrared cameras. The NASA rover Curiosity is also in search of clays on the surface, and has unexpectedly found some at an early stage in its mission.

We are also comparing the formation temperatures of submarine clays on Earth with those on Mars. This will reveal more about the environment on Mars where the clays formed.

Understanding the environmental conditions that existed during the formation of these materials is central to revealing Mars’s geological and climate history, and the habitability of its past environments.


We have found that iron and magnesium exchange for each other in submarine clays, and that mixed-layer clays of intermediate composition and structure are very abundant on Earth.

Our research suggests that:

  • mixed-layer clays may be much more common in nature than previously thought, indicating that complex clays may be abundant on Mars
  • some Martian clays were caught in a state of arrested development, forming in short-lived or otherwise unstable aqueous conditions
  • some Martian clays formed in hydrothermal conditions that could have been suitable for the formation or sustenance of microbial life
  • analysis of colour and of light spectra is a suitable method to study iron-bearing minerals that can greatly aid investigation of Martian rocks by rovers
  • iron is distributed in the two crystallographic sites of clays following rules dictated by the size of the metal atoms in the structure; this finding solves a long-standing problem relevant to understand how they form and react.


Cuadros, J., Michalski, J.R, Dyar, M.D., Dekov, V. (2019) Controls on tetrahedral Fe(III) abundance in 2:1 phyllosilicates. American Mineralogist 104, 1608-1619

Manuel Sánchez-Marañón, Javier Cuadros, Joseph R. Michalski, Manuel Melgosa, Vesselin Dekov (2018) Identification of iron in Earth analogues of Martian phyllosilicates using visible reflectance spectroscopy: spectral derivatives and color parameters. Applied Clay Science 165, 264-276

Cuadros J, Michalski JR, Dekov V, Janice L. Bishop JL (2016) Octahedral chemistry of 2:1 clay minerals and hydroxyl band position in the near-infrared. Application to Mars. American Mineralogist, 101, 554-563.

Joseph R. Michalski, Javier Cuadros, Janice L. Bishop, M. Darby Dyar, Vesselin Dekov, and Saverio Fiore (2015) Constraints on the crystal-chemistry of Fe/Mg-rich smectitic clays on Mars and links to global alteration trends. Earth and Planetary Science Letters, 427, 215-225. 

Javier Cuadros, Joseph R. Michalski, Vesselin Dekov, Janice Bishop, Saverio Fiore, M. Darby Dyar (2013) Crystal-chemistry of interstratified Mg/Fe-clay minerals from seafloor hydrothermal sites. Chemical Geology 360-361:142-158.

Joseph R. Michalski, P.B. Niles, J. Cuadros, A.M. Balbridge (2013) Multiple working hypotheses for the formation of compositional stratigraphy on Mars: Insights from the Mawrth Vallis region. Icarus 226: 816-840.

Joseph R. Michalski, Javier Cuadros, Paul B. Niles, John Parnell, A. Deanne Rogers and Shawn P.Wright (2013) Groundwater activity on Mars and implications for a deep biosphereNature Geoscience 6: 133-138.

Javier Cuadros, Joseph R. Michalski (2013) Investigation of Al-rich clays on Mars: evidence for kaolinite-smectite mixed-layer versus mixture of end-member phases. Icarus 222: 296-306. 

Funded by

Origins, evolution and futures

We study the Earth's origins, environment and the evolution of life

Mineral and planetary sciences research

Investigating the origins and evolution of Earth and our solar system

Mineralogy collections

Explore one of the world's finest collections of 500,000 rocks, gems and minerals