ASSOCIATED UNIDENTIFIED STRUCTURES

A common structure associated with the horizontal, regularly-oriented structures are spherical features (Figure 9.1-9.6) that are uniform in diameter, but whose populations show wide ranges in size from 5 to 40 mm in diameter. Unlike most inorganic concretions in the Clarens Formation, these spheres show no internal textures of any kind. They generally have smooth exteriors, but locally display rough, ornamented surfaces consisting of small, 3-4 mm humps (Figure 9.3, 9.4). At one locality, one humped horizontal cylinder 20 mm in diameter is also preserved (Figure 9.4) among the humped spheres. The spheres occur both in isolation (Figure 9.4) and in large masses, where their abundance is typically sufficient to form column-like structures 0.2-0.3 m in diameter (Figure 9.5). In some exposures, the vertical distribution of the spheres shows a very sharp upper boundary (Figure 9.6). In thin-section, the spherical features show no distinctive textural characteristics with the exception of some irregular mottles of fine- and very fine-grained massive quartz sand grains.