Abstract The Archean era (4 to 2.5 billion years ago, Ga) yielded rocks that include the
oldest conclusive traces of life as well as many controversial occurrences. Carbonaceous …

Water plays a critical role in erosion and sediment transport and this relationship is most
evident in the hyperarid Atacama Desert of Northern Chile, a region characterized by …

Transient appearances of oxygen have been inferred before the Great Oxygenation Event
(GOE)[∼ 2.3 billion years (Ga) ago] based on redox-sensitive elements such as Mo and S …

The nine editions of Stable Isotope Geochemistry have appeared over a time span of nearly
50 years. The first edition (1973) appeared as a slim book of 135 pages. Due to the rapid …

The NASA Mars 2020 rover mission will explore an astrobiologically relevant martian site to
investigate regional geology, evaluate past habitability, seek signs of ancient life, and …

Raman spectroscopy is widely used to evaluate the nature and potential origins of
carbonaceous matter in Earth's oldest rocks and minerals. It is also the tool that will be used …

The Martian surface is cold, dry, exposed to biologically harmful radiation and apparently
barren today. Nevertheless, there is clear geological evidence for warmer, wetter intervals in …

The disappearance of mass-independent sulfur isotope fractionation (S-MIF) within the c. 2.3-
billion-year-old (Ga) Rooihoogte Formation has been heralded as a chemostratigraphic …

Return of samples from the surface of Mars has been a goal of the international Mars
science community for many years. Affirmation by NASA and ESA of the importance of Mars …

Archean sulfide and sulfate minerals commonly exhibit anomalous ratios among four stable
sulfur isotopes, 32S, 33S, 34S, and 36S. These anomalous relationships, referred to as …