206 W. A. Tarr — C.one-in-Cone. 



which the writer has come from his past and recent 

 studies. Future studies will call for much revision and 

 possibly the discarding of parts or all of these sugges- 

 tions. 



The suggestion made here is that cone-in-cone structure 

 has been formed through a combination of pressure, more 

 or less localized, and solution. Contributing factors are 

 both the radial and parallel arrangement of the crystals 

 of calcite composing the structure, and the cleavage of 

 the original carbonate. 



Evidence of movement — The fibrous calcite constituting 

 a layer of cone-in-cone is often banded horizontally. 

 When the structure is developed in such a layer these 

 bands are displaced by the cone-in-cone. This displace- 

 ment is analogous to a fault, but careful study showed 

 that the layer has not been faulted along a plane ; it is 

 the cone which has moved. Another proof of such move- 

 ment is the occurrence of the cones within each other. 

 A large cone (fig, 10) may contain a small one which 

 has penetrated the large one, yet has not displaced the 



Fig. 10. 



Fig. 10 — Shows small cone penetrating large cone which does not show 

 any evidence of displacement in the large cone. 



outer surface of the large cone. The inward movement 

 may amount to from one quarter to one half an inch in 

 a cone which is two to two and one half inches high. 



Evidence of solvent action — The last statement in 

 regard to movement also furnishes proof that some 

 material has been removed through solvent action. The 

 small inner cone could not have moved inward without 

 displacing the material of the larger cone. As there is 

 no external evidence of such displacement the cone must 



