Page:Popular Science Monthly Volume 84.djvu/190

186 Omaha village situated below the mouth of the Big Sioux river. A short distance upstream from the last mentioned point he examined strata which, by means of their fossils presumably, he refers to the Chalk division of the Floetz, or Secondary, rocks of northern France and southern England. This is the earliest definite recognition of beds of Cretacic age in America. It preceded by a decade and a half the separation, by John Finch, of the newer Secondary rocks from the Tertiary section in the Atlantic states, and Lardner Vanuxem's and Samuel Morton's references of the same deposits to the Cretaceous age. Thus also was another great succession of one of our main geologic periods discovered in a then remote part of our continent years before it was recognized in the East.

At the mouth of the Big Sioux river Nuttall fell in with an old trapper who described to him the great falls which blocked navigation at a distance of 100 miles up that stream, and who told him of the famous Indian pipestone quarries beyond.

The analogy established by Nuttall between the general Carbonic section of Iowa and the upper Mississippi valley and that of northern England was one of the important geologic discoveries in America. Its great significance was pointed out by Owen a couple of decades later. Its historical value grows with the advancing years. In the final recognition of a standard Carbonic section for this continent the sequence displayed in the Mississippi basin must prevail, since it is now generally conceded that the Appalachian succession of strata can never be considered as the typical development.

So conspicuously botanical in character are Nuttall's services to science that one can but wonder under what circumstances he could have obtained his keen insight into matters geological. Elias Durand said of him immediately after his death that "No other explorer of the botany of North America has personally made more discoveries; no writer on American plants, except perhaps Asa Gray, has described more new genera and species." Lists of his published memoirs and papers quite generally omit all reference to his recorded geological observations, probably because their importance could hardly be fully appreciated by writers in other fields of science. In the present connection our main interest centers on the transplanting so early to the interior of the American continent of Williams Smith's novel ideas concerning fossils. Brief reference to some of the early events in Nuttall's life seem to offer a clue.

Nuttall was born in Yorkshire, England, in the mountain limestone belt, and near the scene of Martin's famous labors on the Carbonic fossils of Derbyshire. He was early apprenticed to the printer's trade and after a few years removed to London. There he followed his trade until, at the age of 22, he set out for America, in 1808. He appears to