RE: Visual logging observations lol........I rest my case!! Perhaps if anyone was to answer your post as written, it would come from a 40 year drilling guy with one years of experience any you would both be confused. It seems somewhat Gerald McBoingBoingish.
But, if I am "picking up what you are laying down" I'll also give that a whirl from my perceived interpretation of the post. Drilled samples are caught and presented to the wellsite geologist at 5 foot intervals for his examination and then his ability to identify the rock chips, classify them, sort them and describe them for all of their characteristics and log them on paper, charted as an electronic log in a long linear continuous scrolled paper from hole bottom up to the casing shoe. So, much like a ship with radar in a busy shipping channel or anchorage, the radar will identify objects but show little other identifying markers, but in daylight on a clear day, a more descriptive picture will be shown of the exact same layout. An electronic log will show certain well parameters that are beneficial for the well history records and aid in production work, ie: gamma ray to place casing perforation shots in the correct intervals while geologists strip log will be an ongoing description of all rock formation make up and characteristics as they naturally exist as true lithography or maybe called a stratigraphic chart or description............if that helps in what you are searching for.........