262 The Philippine Journal of Science 1914 



TEXT FIGURES 



Fig. 1. Outline map of central Luzon, showing situation of the Bulacan 

 iron-ore mining region with respect to Manila. 



2. Stratigraphic column for the Bulacan iron-ore region. 



3. Geologic sections through the iron-ore region, diagrammatic in part: 



(a) Post-Miocene sedimentaries ; (b) Miocene sedimentaries ; (c) 

 granite; (d) effusives with intrusives; (e) intrusives with eflfu- 

 sives. 



4. Geologic section through ore body at Camaching, along an east-west 



line; diagrammatic in part: (a) Miocene shales, tuffs, and elastics; 



(b) altered wall rock; (c) iron ore; (d) intrusives; (e) blocks of 

 limestone in ore; (/) limestone and elastics; (h) effusives; length 

 of section, about 200 meters. 



5. Geologic section through ore body at Montamorong, along a north- 



east-southwest line; diagrammatic in part: (a) Granite; (6) in- 

 trusives; (c) altered wall rock; (d) iron ore; (e) effusives; length 

 of section, about 100 meters. 



6. Geologic section through ore body at Hison, along an east-west 



line; diagrammatic in part: (a) Granite; (6) intrusives; (c) 

 altered wall rock; (d) iron ore; (e) effusives; (/) limestone, 

 shale, and sandstone; length of section, about 200 meters. 



