In 1889-90 Mr. S. F. Emmons published an account of observa-
tions on the gold deposits of Montgomery county, Maryland. ¹

In June, 1890, Prof. Lester F. Ward, accompanied by Prof. W. M.
Fontaine and Mr. C. S. Prosser, made a geologic trip to examine the
Newark formation. Their observations in Maryland were limited to
the vicinity of the Potomac river.

Appalachian Region.

In July, 1885, Mr. H. R. Geiger began the study of the Paleozoic
rocks in the Appalachian region along the Potomac river in western
Maryland and West Virginia. He made detailed notes on the out-
crops and carefully measured many local sections.

In 1886 and 1887 he extended his observations eastward down the
Potomac river, and for some distance southward over the Great Valley
region of Virginia.

In June, 1888, assisted by Mr. F. W. Geiger, he began work on
the Harper's Ferry quadrangle, which extends over portions of Mary-
land, West Virginia and Virginia. As a result of several months'
study, he arrived at a conclusion as to the relations of the sandstones
and associated formations in the Blue Ridge and South Mountain to
the limestones of the Great Valley.

In September, 1890, Mr. Arthur Keith began a re-examination of
the Harper's Ferry quadrangle, accompanied by Mr. R. H. Gaines
as assistant. An elaborate investigation was made of the difficult
problem of the relations of the several formations, partly crystalline
and partly sedimentary, which had puzzled geologists for so many
years. A preliminary product of Mr. Keith's studies was a paper
jointly with H. R. Geiger, read at the Geological Society of America,
on " The Structure of the Blue Ridge near Harper's Ferry, " ² and a
short notice on " The Geologic Structure of the Blue Ridge in Mary-
land and Virginia, " ³ His final publication is the Harper's Ferry
Folio, No. 10, Geologic Atlas of the United States.

¹ Trans. Am. Inst. Min. Eng., vol. xviii, pp. 391-411.

² Bull. Geol. Soc. America, vol. ii, 1891, pp. 155-164, pis. 4-5.
³ Am. Geologist, vol. x, 1892, pp. 362-368.