1. A well logging method of plotting the variation with depth of a characteristic of the earth formation adjacent a borehole to a higher vertical resolution than that of the output of a well logging device passed through the borehole to initially measure said characteristic, comprising the steps of: (a) for each of a succession of depths in the borehole, producing a corresponding initial well logging measurement of said characteristic of the earth formation adjacent the borehole at said depth derived from a well logging device which is passed through the borehole and has a selected vertical response range and a selected vertical response characteristic, (b) storing, in a computer storage device, a selected variation of said characteristic with depth along the borehole, (c) generating new well logging measurements for said depths in the borehole by operating computer circuits to apply the vertical response characteristic of the well logging device to said stored selected variation of the characteristic with depth along the borehole, (d) operating computer circuits to compare the initial and the new well logging measurements, and (e) modifying said selected variation of the measured characteristic with depth along the borehole by operating computer circuits in accordance with the comparison to produce thereby a modified variation with depth which conforms more closely to the initial logging measurements, and plotting said modified variation of the measured characteristic of the earth formation versus depth in the borehole to thereby produce a plot having higher vertical resolution than that determined initially by the extent of the vertical response range of the well logging device, said plot approximating the variation of the measured characteristic of the earth formation with depth in the borehole more closely than a plot of the initial well logging measurements versus depth in the borehole.