In the 1840s, Edward Hitchcock suspected laminated sediment in North America could be seasonal, and in 1884 Warren Upham postulated that light-dark laminated couplets represented a single year's deposition.
Na década de 1840, Edward Hitchcock sospeitou que os sedimentos laminados encontrados en norteamérica poderían ser estacionais, e en 1884 Warren Upham propuxo que as parellas de capas clara-escura de sedimentos representaban un único depósito anual.