ILLUSTRATIONS 



Plate I. Fairview Dome, Sierra Nevada, from the north 436 



II. A, Parallel veins of calcite, Great Basin; B, Biotitic granite, showing garnet 



surrounded by lenticular areas deficient in iron-bearing minerals 700 



III. Photomicrographs of metamorphic textures 704 



IV. Textures of limestones and marble 796 



V. Textures of metamorphosed marbles 810 



VI. Photomicrographs of limestone and marbles 814 



VII. Photomicrographs of iron-bearing rocks 836 



VIII. A, Unaltered Newark conglomerate from Virginia, after Keith; B, Schist conglom- 

 erate from Felch Mountain district, Michigan 858 



IX. Photomicrographs of sandstone and quartzites 872 



X. Photomicrographs of graywackes 888 



XI. Photomicrographs of pelites _ 902 



XII. A, Vein quartz, Banner mine, California; B, Secondary galena and blende in ores 



from Missouri 1 156 



XIII. Iron-ore deposits in pitching troughs 1196 



Fig. 1. Change of volume resulting from solution, and relations of solution and pressure 78 



2. Quantitative relations between solution and temperature 80 



3. Triangular cross sections of pore space 132 



4. Spheres packed in the most compact manner possible 133 



5. Relations of level of ground water to topography and to surface drainage 410 



6. Effect of unequal heating of the surface of a rock _ 434 



7. Ideal horizontal section of the flow of ground water from one well to another 570 



8. Ideal vertical section of the flow of ground water from one well to another 571 



9. Ideal vertical section of the flow of ground water entering at one point on a slope and 



issuing at a lower point _ 573 



10. Ideal vertical section of the flow of ground water entering at three points and issuing 



at a single point 574 



11. Ideal vertical section of the flow of ground water entering at many points along a 



slope and issuing at a single point at a lower elevation 575 



12. Ideal section illustrating the chief requisite conditions of artesian wells 577 



13. Part of a thin section of a quartz-schist showing liquid- and gas-filled cavities of a 



secondary nature; Black Hills, South Dakota 620 



14. Enlargement of feldspar fragment 626 



15. Enlargement of hornblende fragment 626 



16. Clastic quartz penetrated by serpentine 643 



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