Possible organosedimentary structures on Mars

Abstract

: This study, using the Microscopic Imager (MI) of NASA Rover Exploration Mission's (REM) ' Opportunity', aims to explain the origin of laminated sediments lying at Meridiani Planum of Mars, and of the strange spherules, known as blueberries, about which several hypotheses have been formulated. To this purpose, images of the sedimentary textures of layers and fragments captured by REM have been analysed; sediments that NASA has already established as ' pertinent to water presence '. Our study shows that such laminated sediments and the spherules they contain could be organosedimentary structures, probably produced by microorganisms. The laminated structures are characterized by a sequence of a thin pair of layers, which have the features of skeletal/agglutinated laminae and whose basic constituents are made by a partition of septa and vacuoles radially arranged around a central one. The growth of these supposed organosedimentary masses is based on the 'built flexibility' of such a basal element ; it may be a coalescing microfossil formed by progressive film accretion (calcimicrobe), in a variety of geometrical gross forms, such as a repeated couplet sequence of laminae or domal mass and large composite polycentric spherule, both in elevation. The acquired structural and textural data seem to be consistent with the existence of life on Mars and could explain an origin of sediments at Meridiani Planum similar to that of terrestrial stromatolites. The Martian deposits, probably produced by cyanobacterial activity, and the embedded blueberries could represent a recurrent and multiform product of colonies with sheath forms, resembling in shape those of the fossil genus Archaeosphaeroides (stromatolites of Fig Tree, South Africa).

Opportunity Rover's image analysis: Microbialites on Mars?

“…In this paper, a tangle of microspherule and intertwined filaments (Table 1, samplings, textures shown on Figs. 1-3, 5-7) has been evidenced on the Martian sediments (also described in an our previous work [21]:) a textural pattern that is also present in living microbialites as well in recent and fossil stromatolites [12-14, 45, 46] (Figs. 5-7).…”

Structural parallels between terrestrial microbialites and Martian sediments: are all cases of ‘Pareidolia’?

“…Stromatolites, Dendrolites, Thrombolites and Leiolites) with gradual transition between them (Riding 2008(Riding , 2011. In particular, we have already highlighted (Rizzo & Cantasano 2009Bianciardi et al 2014) that the widespread Fig. 1.…”

Microbialites at Gusev Crater, Mars.

“…In this paper, a tangle of microspherule and intertwined filaments of microspherules has been evidenced on the Martian sediments photographed by the Spirit rover: a textural pattern that is also present in living microbialites as well in recent and fossil stromatolites [18][19][20]. Both the textures, from microbialite images (Earth) or from analyzed MI images (Mars), are multifractals, as revealed by the two straight lines present in the log-log plots ( Figure 5).…”

“…Rizzo observed by a qualitative visual inspection that images of Martian outcroppings (selected frames from images obtained by Opportunity and Spirit rovers) presented features resembling terrestrial stromatolites/microbialites [18][19][20]. Recently, we performed a fractal morphometric quantitative analysis of the Martian outcroppings explored by the Rover Opportunity revealing evidences of the presence of microbialites at Meridiani Planum [21].…”