File talk:Shale gas production USA.svg

Some notes on the updated version

The EIA spreadsheet as of July 2019 is somewhat different from that as of August 2016, not only in containing the more recent data but also in the number and selection of the formations listed. While the 2016 sheet contained data of the Antrim Shale of the Michigan Basin, the 2019 sheet does not (wherein it is probably included in the ‘Rest’). Instead, the 2019 sheet contains data of the Niobrara and Codell Formations of the central Rocky Mountain region as well as of the Permian of Texas and New Mexico, and the Mississippian of Oklahoma. These changes probably are due to a change in significance of these four plays. While the Antrim Shale apparently has lost significance, the three other plays have gained significance over the last three years. --Gretarsson (talk) 00:50, 20 August 2019 (UTC); subsequently modified 15:48, 20 August 2019 (UTC)