The transition from the Archean to the Proterozoic Eon marks a fundamental change in environments and processes on the early Earth. There is also a push to abandon the chronometric definition of the boundary at 2500 Ma, and establish a chronostratigraphic definition that will bring Precambrian stratigraphic nomenclature into line with the Phanerozoic, requiring the definition of a Global Boundary Stratotype Section and Point (GSSP). Candidates for defining the A-P boundary associated with global ocean and atmospheric evolution are the Great Oxidation Event and the Huronian Glaciation. An alternative proposal involves a transitional period, from 2600-2300 Ma, that records global changes in mantle rheology and chemistry. However, there is currently no consensus as to what event or proxy should be used to define the A-P boundary or at which location it should be defined. We call for papers that document changes in Earth systems that took place between the Neoarchean and Paleoproterozoic