628 PROCEEDINGS OF THE NEW YORK iMIOE'l'lNd 



2. Laiuiiiation planes. 



3. Bedding planes. 



4. Vesicles (in igneous rocks only). 

 II. Secondai-y forms. 



1. Secondaiy pores. 



A. Pores resulting from leaching and solution. 



B. Pores resulting from recrystallization. 



2. Solution openings. 



A. Isolated cavities. 



B. Tubular channels. 



C. Sheet openings. 



3. Mechanical eroded reservoirs. 



A. Tubular channels. 



B. Pocket openings. 



C. Sheet openings. 



4. Fracture openings. 



A. Irregular openings. 



a. Desiccation cracks. 

 h. Contraction fissures. 

 c. Tortion fractures. 

 (1. Shearing breaks. 



e. Vibration fractures. 



f. Explosion ruptures. 



B. Joints. 



a. Vertical joints. 

 6. Horizontal joints. 



c. Parallel joints.. 



d. Intersecting joints. 



e. Joint breccias. 



C. Faults. 



«. Single fault planes. 

 h. Parallel fault planes. 

 c. Irregular faults. 

 (I. Intersecting faults. 

 c. Fault breccias. 



5. "\'ein contacts. 



6. Igneous contacts. 



7. Shearing planes. 



8. Cleavage planes. 



9. Foliation and schistosity planes. 



Most of the forms enumerated are not limited to any particular class of 

 rock, but may he found in the stratified, metamorphic. and igneous types. 

 The vesicles of igneous rocks, however, have no exact counterjiart in stratified 

 rocks, although the pores containing included v^'ater of sedimentation approach 

 them in nature. Solution channels are likewise usually, although not neces- 

 sarily, found only in sedimentary rocks, foliation and schistosity are mainly 

 features of igneous or metamorphic roc'ks, while lamination, as the term is 

 here used, is a feature of stratified rocks. 



