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 …

Desert soil surfaces are generally covered with biological soil crusts, composed of a group
of organisms dominated by cyanobacteria, lichens, and mosses. Despite their unassuming …

uring the spring of 1960, an uncle showed me a 'petrifying spring'near Plaxtol in Kent
Dwhere twigs had been encased in a calcareous jacket. A twig was collected and having …

Investigation of travertine accumulations throughout central Italy and the west-central US
has shown that the carbonate is precipitated in response to both inorganic and organic …

A new occurrence of conical and branched pseudocolumnar stromatolites in Archean
dolostones in the Pilbara region, Australia, contributes significant new morphologic …

This paper provides a critical review of advances made in understanding of sedimentary
environments, geochemical processes, and biological systems that contributed to the …

Stromatolites document microbial interactions with sediments and flowing water throughout
recorded Earth history and have the potential to illuminate the long-term history of life and …

Publisher Summary This chapter summarizes the sedimentary characteristics of non-marine
environments. Non-marine evaporite deposits are common features of modern arid closed …

Abstract The Paleoproterozoic (2.5–1.6 Ga) Era is a decisive time in Earth and life history.
The paleobiological record (microfossils, stromatolites, biomarkers and isotopes) illustrates …

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 …