- GeoRef, Copyright 2006, American Geological Institute.
On behalf of the INQUA Commission on Genesis and Lithology of Quaternary Deposits, a questionnaire consisting of about 150 questions concerning the methodology of investigations of tills was distributed in the formerly glaciated countries of Europe and North America in 1974. The 210 replies representing more than 750 investigators of tills (geologists, geographers, pedologists, engineering geologists and soils engineers) are summarized and discussed, considering the field and laboratory equipment used, and the procedures of field and laboratory investigations of tills. Particular attention is paid to the particle-size determinations and their boundaries, where a tendency is noticeable towards a general agreement on the clay-silt-sand size boundaries. Though the methods and equipment used vary considerably among the specialists of different professions and different countries, surprisingly few major differences exist between Europe and North America.