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How did Charles Lapworth resolve the dispute over the Cambrian and Silurian systems?

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Ordovician paleogeography — Ordovician Period The distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the Ordovician Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.

The dispute between Adam Sedgwick and Roderick Murchison arose because their respective Cambrian and Silurian systems, both named in 1835, were expanded until they overlapped, creating a contentious boundary disagreement.12

In 1879, English geologist Charles Lapworth resolved this conflict by proposing the Ordovician System as a separate, intervening system to define the disputed interval of strata. Lapworth identified this distinct sequence of rocks—which had been inconsistently classified as either Upper Cambrian or Lower Silurian—by utilizing graptolite fossils to establish the order of the strata. Although his proposal faced resistance in Britain for several years, it eventually gained widespread international acceptance as the standard solution to the geological feud.132