![Selected examples of different chemically oscillating reactions (COR) with patterns produced during the decarboxylation of malonic acid [1 M] using a solution of sodium bromate [1 M], sulfuric acid [0.33 M], sodium bromide [1 M], and phenanthroline ferrous sulfate [0.025 M]. (A) Spot proliferation pattern in a 10 cm diameter petri dish. (B) A few spots of different sizes formed within half a minute. (C) Pairs of images of a COR in a petri dish with insets taken five seconds apart showing the radial diffusion of circularly concentric spots. (D) Spots spanning from sub-millimeter (white arrows) to centimeter sizes. (E) Twinned circularly concentric spots (white dashed line shows the twin plane). A few bubbles of CO2 produced by the reaction can be seen. (F) Circularly concentric spot with short color gradients in laminations. (G) Circularly concentric spot with long color gradients in laminations. (H) Circularly concentric spot with dozens of laminations and CO2 bubbles, formed later (at ∼26 min) during another reaction. -- GeoScience World](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/01/Authigenic-biosignatures-of-microbial.png?resize=1200%2C718&ssl=1)
Ooids are small spheroidal carbonate grains that have circularly concentric and radially aligned crystals. Oolitic carbonates are commonly associated with fossils or organic matter, which has led to hypothetical formation […]
Posted inBiogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Fossils & Paleontology, Microbiology & Virology, Origin & Evolution of Life, Status Report