Figure 7. (A) Cylindrical carbonate chimney #3, lying on its 

 side, dragged from same location as conical chimneys (see 

 fig. 2). We have no indication which end is the top or 

 bottom of the chimney, but for sampling purposes the top and 

 bottom were arbitrarily chosen. (B) End view of cylindrical 

 chimney; note internal cavity with its well-rounded, open 

 plumbing tube that runs parallel to the main chamber. Scale 

 is 6-inch ruler. (C) Cross-sectional cut of the smaller of 

 the two ends of cylindrical chimney; burrowing animals 

 produce grooves in dense carbonate lithology. See table 1 

 and text for detailed description of chimney. Scale is 6- 

 inch ruler. (After Schroeder et al. 1987). 



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