WATER DEPOSITS 663 



List of Samples in Table 4 



24. Terrace gravel, Drummond, Illinois. 



25. Terrace material, Government Island, Rock Island, Illinois. 



26. Terrace gravel, Drummond, Illinois. 



27. Terrace gravel from a low terrace in Bureau creek. Bureau, Illinois. 



28. Terrace gravel from Government Island, Rock Island, Illinois. 



29. Terrace gravel from Government Island, Rock Island, Illinois. 



30. Terrace gravel, Putnam, Illinois. 



31. Terrace gravel, Putnam, Illinois. 



32. Terrace gravel, Putnam, Illinois. 



33. Somewhat cross-bedded sand in a terrace of the Mississippi, Rock Island, 



Illinois. 



34. Sand taken across the oblique lamination of the sand in a terrace. Rock 



Island, Illinois. 



35. Terrace gravel, Putnam, Illinois. 



36. Terrace sand from the Government Island, Rock Island, Illinois. 



37. Terrace material, east of Davenport, Iowa. 



Materials from single layers in terrace sands. — Eight samples were 

 taken from single layers in banks of terraces. In their mechanical com- 

 position these so closely resemble the materials taken from single layers 

 in materials deposited in glacial waters that they are chiefly interesting 

 as testifying to the similarity of the physical conditions attending their 

 deposition and to the validity of the inference that these analyses are an 

 index of physical conditions. 



List of Samples in Table 5 



38. Terrace sand from a single layer, Port Byron Junction, Illinois. 



39. Sand from a coarse layer in a terrace. Rock Island, Illinois. 



40. Sand from the coarsest part of an oblique layer in a terrace, Rock Island, 



Illinois. 



41. From the middle of an oblique layer in a terrace. Rock Island, Illinois. 



42. Sand from the finest part of a layer in the cross-bedded sand of a terrace. 



Rock Island, Illinois. 



43. Sand from a fine stratum in a terrace, Davenport, Iowa. 



44. Sand from a fine layer in oblique bedding in a terrace, Rock Island, Illi- 



nois. 



45. Sand from a homogeneous stratum of a terrace, Rock Island, Illinois. 



8ilts in terraces of the Mississippi. — Ten samples of silt, laid down 

 by the Mississippi during the waning stages of the Wisconsin ice, were 

 collected from some remnants yet left of the Wisconsin terrace in the 

 valley of the river near Clinton and Davenport, in Iowa. Number 49 

 in the analyses is a sample taken across the bedding planes in this silt. 

 All the others are taken from single layers in the deposit. There is con- 



