div class=ts-pagebuttonPage 1button div class=ts-image a href=https:reader042vdocumentinreader042viewer20220221195e090093974d8f017422fe3fhtml5page1jpg target=_blank amp-img class=ts-thumb alt=Page 1: pubsusgsgov · Dr-ni Middle and Lower Devonian rocks Predominantly shale Hamilton Group in upper part and shale limestone and sandstone in lower part Silurian rocks undivided src=https:reader042vdocumentinreader042viewer20220221195e090093974d8f017422fe3fhtml5thumbnails1jpg width=142 height=106 layout=responsive amp-imga divdiv