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

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 outcrops 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 Maryland, 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," and a short notice on "The Geologic Structure of the Blue Ridge in Maryland and Virginia.' 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, pls. 4-5.

Am. Geologist, vol. x, 1892, pp. 362-368.

2

In July, 1892, Mr. C. D. Walcott, the present director, made an examination of the Blue Ridge and South Mountain region and definitely determined the Cambrian age of its quartzites. A statement of the results of this investigation was set forth in two papers, one entitled "Notes on the Cambrian Rocks of Pennsylvania and Maryland from the Susquehanna to the Potomac," and the other "The Geologist at Blue Mountain, Maryland." "

2

In 1892 Mr. Keith, having continued his studies of South Mountain and Blue Ridge geology into Virginia, prepared a report on the “Geology of the Catoctin Belt." This report describes the Blue Ridge, South Mountain and Catoctin belts from northern Virginia through Maryland into Pennsylvania. It treats of the character of the rocks and their alteration, the general geologic relations and structures, and reviews the geomorphic development of the region.*

In the coal fields of western Maryland two investigations were made. In 1886 Prof. I. C. White made an examination of the coal fields of West Virginia, in which incidentally some study was made of the coal basins of Western Maryland. The results of these and some later observations by Professor White were published by the survey in a report entitled "Stratigraphy of the Bituminous Coal Field in Pennsylvania, Ohio and West Virginia.'

In the autumn of 1894 a party was organized under the direction of Mr. Bailey Willis for the mapping of the Piedmont quadrangle, which covers the southern part of Garrett county, Maryland. The geologic work was done by Messrs. N. H. Darton and J. A. Taff. The product is the Piedmont folio, No. 28, Geologic Atlas of the United States, which was published in 1896.

Coastal Plain.

In July, 1883, the Potomac Division of Geology was organized, in charge of W J McGee, for the purpose of studying the Coastal Plain

1 Amer. Jour. Sci. 3d series, vol. xliv, pp. 469-482.

2

Nat. Geog. Mag., vol. v, pp. 84-88; Sci. Am. Supp., vol. xxxvii, pp. 14,75314,754.

3 Fourteenth Ann. Rept. U. S. Geol. Survey, part ii, 1894, pp. 285-395, pls. xix-xxxix.

Bull. U. S. Geol. Survey No. 65, 1891, 212 pages, plates and maps.

region adjacent to the Potomac river in the District of Columbia, Maryland and Virginia. Mr. McGee at once began making observations in the vicinity of Washington and the immediately adjoining portions of Montgomery and Prince George's counties, Maryland, and in this and several years following he made numerous local trips which threw much new light upon the obscure problems of the general relations of the Coastal Plain formations.

In 1884 he also made several trips westward over the adjoining provinces, one journey extending along the Potomac river to its

source.

In July and August, 1885, he made a short trip with Profs. W. M. Fontaine and Lester F. Ward along the Potomac formations in Maryland and Virginia.

2

A

The first publication of the results of Mr. McGee's observations in the vicinity of Washington was in the report of the Health Officer of the District of Columbia for the year ending June 30, 1885.' more extended memoir followed, entitled, "Three Formations of the Middle Atlantic Slope." In this paper there was defined the Columbia, Appomattox (now Lafayette) and Potomac formations, and some account was given of their distribution and relations in eastern Virginia, District of Columbia and Maryland. An account of the Columbia formation was also given to the American Association for the Advancement of Science in 1888.*

In July, 1886, Mr. McGee made a trip to the region about the head of Chesapeake Bay to determine the prospects for an artesian water supply for the Fishing Battery Station. Facilities for this trip were given by the officials of the United States Fish Commission. On a short subsequent visit to the region Mr. McGee was accompanied by Prof. Lester F. Ward, who gave special attention to the Potomac formation and its plant remains. The results of Mr. McGee's observations were published in a paper entitled "The Geology of the Head of Chesapeake Bay."

1 Pages 19, 20, 23, 25, Washington, 1886.

2 Am. Jour. Sci., 3d series, vol. xxxv, pp. 120-143, 328-331, 367-388, 448-466, pls. ii, vi, vii.

3 Proc. Am. Assoc. Adv. Sci., vol. xxxvi, pp. 221-222.

7th Ann. Rept. U. S. Geol. Survey (for 1885-86), 1888, pp. 537-646, pls. 56-71.