COPROLITIC MACRINITE: EXAMPLES FROM THE CRETACEOUS NO. 6 COAL OF THE SHENGLI COALFIELD, INNER MONGOLIA

Coprolitic macrinite has been recognized in coals at least as old as the Mississippian coals of western Kentucky. Based on several samplings, the Lower Cretaceous No. 6 coal of the Shengli Formation, Inner Mongolia, has notable examples of the maceral form. The location is known as the site of the Wulantuga Ge-rich coal, one of three coals in the world mined as Ge ore. The host trees may have been standing and alive at the time of the insect infestation. The fecal pellets in the elongated chamber and the surrounding wood attained fusinite or semifusinite reflectance in the same charring episode. While both the fecal pellets and the fusinite/semifusinite originated from the same woody plant tissue, their paths to the similar-reflectance inertinites seen in the coal underwent significant diversions prior to the charring. For the coprolitic macrinite, the path to the maceral was through the digestive tract of an arthropod, possibly Collembola. The pathways and not the final reflectance are the keys to the maceral type; the charring did not erase the pre-charring history of the fecal pellets.