A large (~10 cm X 15cm) "antique" glass-mounted thin section through a concretionary nodule ("bullion") shows dozens of small planispirally coiled and chambered shells clustered randomly together. The shells are in various orientations with respect to the plane of the section. In most, the inner whorls appear clear, with sediment or secondary mineral-fill in the outer (body chamber) portion. The irregularly shaped surrounding rock matrix is very dark in contrast. The roughly rectangular cover slip shows a thin rim of amber coloured adhesive. On the right side of the section, a scale graduated in millimetres indicates the overall size. A small circular label in the lower right reads, "JAMES LOMAX - PETROLOGIST" around the outer margin and, "MOSES GATE - BOLTON" in the centre. In the upper right, a small typed label ("No. 2.") is affixed. The section was likely produced sometime in the late 1800's or early 1900's.
A close-up view of the thin section showing details of the very small coiled goniatite shells.
Historic Lomax #thinsection of a classic marine "bullion" concretion from the Upper #Carboniferous (~310 MYA) of Lancashire, UK, reveals dozens of tiny #fossil juvenile & embryonic ("ammonitella") #goniatite shells in an organic-rich carbonate matrix. #MolluscMonday #ammonoid #cephalopods