Figure 4 in Identification of fossil worm tubes from Phanerozoic hydrothermal vents and cold seeps

Figure 4. 'West Fork Satsop River tubes', Oligocene, Washington State, USA. A, B, WFSR-3B and WFSR JLG 459C, respectively, tubes in hand specimen showing wavy nature and smooth tube walls. C, D, WFSR 3A-1; C, transverse section of tube showing multilayered brown walls of varying thickness; D, detail of tube wall where a potential preserved fibrous tear occurs, revealing frayed fibre endings (white arrow). Scale bars: A = 10 mm; B = 5 mm; C = 300 µm; D = 100 µm.