div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=ha-6-1-oklahoma-geological-ha-6-sheet-1-of-4-explanation-the-stratigraphic-nomenclaturehtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: HA 6 1 - Oklahoma Geological SurveyogsoueduMAPSHA1-12HA6plate1pdfMAP HA-6 Sheet 1 of 4 EXPLANATION The stratigraphic nomenclature and age determinations used herein are those loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader034vdocumentsusreader034viewer20220428015adb15967f8b9add658d8367html5thumbnails1jpg width=140 height=200 divdiv