"Gray shale, Little Conewago Creek", York Co., Pennsylvania, USA; Triassic [details]
"Shale, Little Conewago Creek", York Co., Pennsylvania, USA; Triassic [details]
"Shale, Little Conewago Creek", York Co., Pennsylvania, USA; Triassic [details]
"Shale, Little Conewago Creek", York Co., Pennsylvania, USA; Triassic [details]
"Shale, Little Conewago Creek", York Co., Pennsylvania, USA; Triassic [details]
"Shale, Little Conewago Creek", York Co., Pennsylvania, USA; Triassic [details]