Identification of Carbonate-Rich Outcrops on Mars by the Spirit Rover

Ancient Carbonate Minerals on Mars The historical presence of liquid water on Mars together with a CO 2-rich atmosphere should have resulted in the accumulation of large deposits of carbonate minerals. Yet, evidence for the presence of carbonates on the surface of Mars has been scarce. Using data collected by the Mars Exploration Rover, Spirit, Morris et al. (p. 421, published online 3 June; see the Perspective by Harvey) now present evidence for carbonate-rich outcrops in the Comanche outcrops within the Gusev crater. The carbonate is a major outcrop component and may have formed in the Noachian era (∼4 billion years ago) by precipitation from hydrothermal solutions that passed through buried carbonate deposits. Thus, it is likely that extensive aqueous activity under neutral pH conditions did occur on Mars. Substantial carbonate concentration in martian outcrops implies extensive aqueous activity in the past. Decades of speculation about a warmer, wetter Mars climate in the planet’s first billion years postulate a denser CO2-rich atmosphere than at present. Such an atmosphere should have led to the formation of outcrops rich in carbonate minerals, for which evidence has been sparse. Using the Mars Exploration Rover Spirit, we have now identified outcrops rich in magnesium-iron carbonate (16 to 34 weight percent) in the Columbia Hills of Gusev crater. Its composition approximates the average composition of the carbonate globules in martian meteorite ALH 84001. The Gusev carbonate probably precipitated from carbonate-bearing solutions under hydrothermal conditions at near-neutral pH in association with volcanic activity during the Noachian era.

[1]  D. Ming,et al.  Evidence for Calcium Carbonate at the Mars Phoenix Landing Site , 2009, Science.

[2]  D. Ming,et al.  Geochemical properties of rocks and soils in Gusev Crater, Mars: Results of the Alpha Particle X-Ray Spectrometer from Cumberland Ridge to Home Plate , 2008 .

[3]  John F. Mustard,et al.  Orbital Identification of Carbonate-Bearing Rocks on Mars , 2008 .

[4]  H. McSween,et al.  Petrogenesis of high‐phosphorous Wishstone Class rocks in Gusev Crater, Mars , 2008 .

[5]  D. Ming,et al.  Iron mineralogy and aqueous alteration from Husband Hill through Home Plate at Gusev Crater, Mars: Results from the Mössbauer instrument on the Spirit Mars Exploration Rover , 2008 .

[6]  William H. Farrand,et al.  Spirit Mars Rover Mission to the Columbia Hills, Gusev Crater: Mission overview and selected results from the Cumberland Ridge to Home Plate , 2008 .

[7]  R. Gellert,et al.  Quantitative in situ determination of hydration of bright high‐sulfate Martian soils , 2008 .

[8]  Jeffrey R. Johnson,et al.  Hydrothermal processes at Gusev Crater: An evaluation of Paso Robles class soils , 2008 .

[9]  J. Grant,et al.  Structure, stratigraphy, and origin of Husband Hill, Columbia Hills, Gusev Crater, Mars , 2008 .

[10]  D. Ming,et al.  Detection of Silica-Rich Deposits on Mars , 2008, Science.

[11]  A. Steele,et al.  Comprehensive imaging and Raman spectroscopy of carbonate globules from Martian meteorite ALH 84001 and a terrestrial analogue from Svalbard , 2007 .

[12]  A. F. C. Haldemann,et al.  Pyroclastic Activity at Home Plate in Gusev Crater, Mars , 2007, Science.

[13]  William H. Farrand,et al.  Rocks of the Columbia Hills , 2006 .

[14]  Rebecca Castano,et al.  Geology of the Gusev cratered plains from the Spirit rover transverse , 2006 .

[15]  D. Ming,et al.  Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars: Spirit's journey through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills , 2006 .

[16]  William H. Farrand,et al.  Geochemical and mineralogical indicators for aqueous processes in the Columbia Hills of Gusev crater, Mars , 2006 .

[17]  B. Hapke,et al.  Mineralogy of Martian atmospheric dust inferred from thermal infrared spectra of aerosols , 2005 .

[18]  V. Hamilton,et al.  Evidence for extensive, olivine-rich bedrock on Mars , 2005 .

[19]  M. Darby Dyar,et al.  Spectroscopic evidence for hydrous iron sulfate in the Martian soil , 2004 .

[20]  Steven W. Squyres,et al.  The new Athena alpha particle X‐ray spectrometer for the Mars Exploration Rovers , 2003 .

[21]  U. Bonnes,et al.  Athena MIMOS II Mossbauer spectrometer investigation , 2003 .

[22]  R. Clark,et al.  Discovery of Olivine in the Nili Fossae Region of Mars , 2003, Science.

[23]  J. Bandfield,et al.  Spectroscopic Identification of Carbonate Minerals in the Martian Dust , 2003, Science.

[24]  H. Graber,et al.  Impact of flow distortion corrections on turbulent fluxes estimated by the inertial dissipation method during the FETCH experiment on R/V L'Atalante , 2003 .

[25]  Steven H. Silverman,et al.  Miniature thermal emission spectrometer for the Mars Exploration Rover , 2002, SPIE Optics + Photonics.

[26]  A. Treiman,et al.  Hydrothermal Origin for Carbonate Globules in Martian Meteorite ALH84001: A Terrestrial Analogue from Spitsbergen (Norway) , 2002 .

[27]  David C. Catling,et al.  Alteration Assemblages in Martian Meteorites: Implications for Near-Surface Processes , 2001 .

[28]  D. Ming,et al.  An experimental study on kinetically‐driven precipitation of calcium‐magnesium‐iron carbonates from solution: Implications for the low‐temperature formation of carbonates in martian meteorite Allan Hills 84001 , 2000 .

[29]  B. Dale,et al.  The thermal springs of Bockfjorden, Svalbard: II: selected aspects of trace element hydrochemistry , 1999 .

[30]  H. Wiesmann,et al.  The age of the carbonates in martian meteorite ALH84001. , 1999, Science.

[31]  David C. Catling,et al.  A chemical model for evaporites on early Mars: Possible sedimentary tracers of the early climate and implications for exploration , 1999 .

[32]  M. Ramsey,et al.  Mineral abundance determination: Quantitative deconvolution of thermal emission spectra , 1998 .

[33]  Harry Y. McSween,et al.  A possible high-temperature origin for the carbonates in the martian meteorite ALH84001 , 1996, Nature.

[34]  A. Treiman.  A petrographic history of martian meteorite ALH84001: Two shocks and an ancient age , 1995 .

[35]  D. Mittlefehldt,et al.  ALH84001, a cumulate orthopyroxenite member of the martian meteorite clan , 1994 .

[36]  W. Griffin,et al.  The lower crust and upper mantle beneath northwestern Spitsbergen: evidence from xenoliths and geophysics , 1987 .

[37]  J. Kasting,et al.  The case for a wet, warm climate on early Mars. , 1987, Icarus.

[38]  S. Gaffey,et al.  Spectral reflectance of carbonate minerals in the visible and near infrared (0.35–2.55 um): Anhydrous carbonate minerals , 1987 .

[39]  J. Gooding.  Chemical weathering on Mars - Thermodynamic stabilities of primary minerals /and their alteration products/ from mafic igneous rocks , 1978 .