30 C. A. White on the Geology of Southwestern Iowa. 
No. 5. Compact bluish Huteelone with shes ‘petiogy - 4 ft. 
No. 6. © Yellowish and bluish marlites, - 67 
No, 7. Gray limestone with Ss concretions, - : 4 * 
No. 8. Unexposed, . = ae -  - Be 
No. 9. Compact gray li = one, - So - - 14 
No. 10. Light yellow cad oe ee 
No. 11. Yellowish siliceous atone ith finty masses, - 23 
No. 12. Yellowish earthy shale — So i ak of 
limestone, - er 
No. 13. Compact, gra fimestone: SST ae 12% 
No. 14. Yellowish earthy shale, - 225 
No. 15. Heavy ed limestone with dull fracture, - a 
No. 16. Bluish shale, - 4+“ 
No. 17. Soft, yellowish yilioadne mete, een ded veil F osuina, iy * 
No. 18. Massive, light gray limestone with dull fracture, 
No. 19. Bluish es with 9 inch band of limestone, - e 
No. 20. Compact bluish limestone with small panera BS 
No. 21. Bluish marlite, 4.5 
No. 22. Bluish, thin-bedded, fing peattied: micaceous sandstone, vy . 
Total, s1 
The localities of the two sections here given are nearly one 
hundred as apart, yet their equivalencies are very satisfacto- 
rily determined. No. 22 of the Fremont county section is re- — 
garded as SS cartel with No. 15 of the preceding one; an 
ie remainder of the Fremont county section, as “equivalent 
that portion of the preceding one between the lower por-_ 
Led of No. 6, and the top of No..15. No. 7 of the Madison 
county section is regarded as equivalent with Nos. 2 and 3 of 
that of Fremont county, both belonging to the cartio-nrgillace 
ous horizon before described. Beneath this horizon, and more 
or. less Ss 3: sila with it, there is quite a definite Fasulina hori- 
by its peculiar paleontological features. 
te Fark ge ae ee be briefly summed up thus 
usual paleontological and Lithotogseel differen- 
ces sg rona tne Coal-measure rocks and those beneath them, 
there seems to be in Iowa almost an entire absence of magne- 
_sia in the former rocks, while it prevails so largely in those of 
older date. 
i as 
_ 2. The lower Cosbmenaia: contain ‘enue ‘ali the coal of the 
state, and mposed pi nd ef nes and shales. 
