The Washington Formation is a coal, sandstone, and limestone geologic formation in West Virginia. It preserves fossils dating back to the Permian period.
The Washington Formation is a coal, sandstone, and limestone geologic formation in West Virginia. It preserves fossils dating back to the Permian period. (en)
The Washington Formation is a coal, sandstone, and limestone geologic formation in West Virginia. It preserves fossils dating back to the Permian period. (en)