CHAPTER 16. — HUMAN REMAINS IN THE LOESS, AND THEIR PROBABLE AGE.

  Nature, Origin, and Age of the Loess of the Rhine and Danube.
  Impalpable Mud produced by the Grinding Action of Glaciers.
  Dispersion of this Mud at the Period of the Retreat of the
     great Alpine Glaciers.
  Continuity of the Loess from Switzerland to the Low Countries.
  Characteristic Organic Remains not Lacustrine.
  Alpine Gravel in the Valley of the Rhine covered by Loess.
  Geographical Distribution of the Loess and its Height above the Sea.
  Fossil Mammalia.
  Loess of the Danube.
  Oscillations in the Level of the Alps and lower Country required to
     explain the Formation and Denudation of the Loess.
  More rapid Movement of the Inland Country.
  The same Depression and Upheaval might account for the Advance
     and Retreat of the Alpine Glaciers.
  Himalayan Mud of the Plains of the Ganges compared to
     European Loess.
  Human Remains in Loess near Maestricht, and their probable
     Antiquity.

NATURE AND ORIGIN OF THE LOESS.

Intimately connected with the subjects treated of in the last chapter, is the nature, origin, and age of certain loamy deposits, commonly called loess, which form a marked feature in the superficial deposits of the basins of the Rhine, Danube, and some other large rivers draining the Alps, and which extend down the Rhine into the Low Countries, and were once perhaps continuous with others of like composition in the north of France. [Note 35]

It has been reported of late years that human remains have been detected at several points in the loess of the Meuse around and below Maestricht. I have visited the localities referred to; but, before giving an account of them, it will be desirable to explain what is meant by the loess, a step the more necessary as a French geologist for whose knowledge and judgment I have great respect, tells me he has come to the conclusion that "the loess" is "a myth," having no real existence in a geological sense or as holding a definite place in the chronological series.

No doubt it is true that in every country, and at all geological periods, rivers have been depositing fine loam on their inundated plains in the manner explained above in Chapter 3, where the Nile mud was spoken of. This mud of the plains of Egypt, according to Professor Bischoff's chemical analysis agrees closely in composition with the loess of the Rhine.*

     (* "Chemical and Physical Geology" volume 1 page 132.)

I have also shown when speaking of the fossil man of Natchez, how identical in mineral character and in the genera of its terrestrial and amphibious shells is the ancient fluviatile loam of the Mississippi with the loess of the Rhine. But granting that loam presenting the same aspect has originated at different times and in distinct hydrographical basins, it is nevertheless true that during the glacial period the Alps were a great centre of dispersion, not only of erratics, as we have seen in the last chapter, and of gravel which was carried farther than the erratics, but also of very fine mud which was transported to still greater distances and in greater volume down the principal river-courses between the mountains and the sea.