540 Cn KG SIEM Meal 
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line sandstones, and in a portion of the region limestones and marbles. 
The rocks of both series are closely associated with rocks of undoubted 
igneous origin. 
Clements’ gives notes on the microscopical character of certain 
rocks from the crystalline area of northeastern Alabama. ‘The rocks 
include sedimentary and igneous rocks, and others whose origin is 
unknown. The sedimentary rocks are comparatively unimportant. 
Disregarding the sedimentary rocks, the rocks as a whole have the 
characters of Archean rocks. 
Hawes’ gives notes on the microscopical characters of the Alabama 
crystalline or metamorphic rocks. 
Darton,’ in connection with a discussion of artesian well prospects 
in the Atlantic Coastal Plain region, briefly describes the occurrence 
of the crystalline rocks. The crystalline rocks, predominantly granite 
and gneiss, outcrop along a line which passes from New York City 
through Philadelphia, Baltimore, Richmond, Weldon, and Columbia, 
to Augusta, Ga., and thence through Georgia and Alabama. Westward 
they extend up the gentle slope of the Piedmont Plateau to the base 
of the Appalachians. To the east they dip below unconsolidated 
sedimentaries, and along the ocean shore, from New Jersey south, they 
are 2000 feet below the surface. 
GENERAL COMMENTS. 
As yet the broader structural problems of the crystalline and semi- 
crystalline rocks of the Appalachian region and the Piedmont Plateau 
are far from completely solved. It is certain that some of the semi- 
crystalline rocks which in former years have been called Algonkian or 
Archean are Paleozoic. It seems equally certain that in the Appala- 
chian and Piedmont Plateau region are greatly metamorphosed sedi- 
tNotes on the microscopical character of certain rocks from Northeast Ala- 
bama, by J. MORGAN CLEMENTS: Bull. Geol. Surv. of Alabama, No. 5, 1896, pp. 
RIRN7Oo 
2 Notes on the microscopic characters of the Alabama crystalline or metamorphic 
rocks, by G. W. HAwEs: Bull. Geol. Sury. of Alabama, No. 5, 1896, pp. 131-132. 
3 Artesian well prospects in the Atlantic Coastal Plain region, by N. H. DARTON: 
Bull. U. S. Geol. Surv., No. 138, 1896, pp. 18-19. 
