Carnets de Géologie (Dec 2004)
Stage boundaries, global stratigraphy, and the time scale: towards a simplification
Abstract
This paper examines four facets of stratigraphic terminology and usage considered faulty and proposes corrective measures. The four perfectible areas are: (1) The system of dual nomenclature requiring discrete terminologies for the superpositional and temporal aspects of rock units. (2) The premise that a GSSP establishes the base of a stage as being coincident with the top of the preceding stage rather than simply defining it as the boundary between stages. (3) The rejection of supplementary (auxiliary) sections that would broaden the knowledge of a GSSP and enlarge the area in which it is easily usable. (4) The current dual system of nomenclature for Precambrian and Phanerozoic strata is accepted, but a third system is proposed for strata formed in the last 3 to 5 Ma. In addition, the paper advocates a broader use of a limited number of conventions but warns against their proliferation; units shortened thereby would be more difficult to recognize. It points out the clear distinction between these conventions - a matter of administration and general compliance - and knowledge - a domain where free expression of opinion is indispensable -.
