. . "From 280 to 310 million years ago" . . . . . . . . . . "Atoka Group <Lower to Middle Pennsylvanian>, northern Fort Worth Basin, Texas : Terrigenous depositional systems, diagenesis, and reservoir distribution and quality" . . . . . "Atoka group, lower to middle Pennsylvanian, Northern Fort Worth Basin, Texas : terrigenous depositional systems, diagenesis, and reservoir distribution and quality" . "Atoka Group (Lower to Middle Pennsylvanian), northern Fort Worth Basin, Texas : terrigenous depositional systems, diagenesis, and reservoir distribution and quality" .