passes through the city of Detroit and if the apparent intention of the framers of the ordinance had been carried out the writing of the geological history of Monroe county would have been done by the Ohio Survey. It was ascertained later that Lake Michigan extended much further south and that this east and west line would somewhere strike the western or southern shore of Lake Erie. The act of the Senate and House of Representatives of 1802, authorizing the State of Ohio to form a constitution and state government, placed the boundary "on the north by an east and west line drawn through the southerly extreme of Lake Michigan, running east, after intersecting the due ǹorth line aforesaid, from the mouth of the Great Miami, until it shall intersect Lake Erie, or the territorial line, and thence, with the same, through Lake Erie, to the Pennsylvania line aforesaid." The constitution of Ohio provided, however, that if this line should intersect Lake Erie east of the mouth of the Miami of the Lake (Maumee), then the northern boundary should be a line run direct from the southern extreme of Lake Michigan to the most northerly cape of the Miami (Maumee) Bay. The acceptance of the Ohio constitution, containing this clause, was regarded by the State as authorizing this boundary line, although not so regarded by Congress itself. This line was run in 1817 by surveyor Harris and was known as the "Harris Line." The line claimed by Michigan, namely, that drawn due east from the southerly extreme of Lake Michigan, was known as the "Fulton Line" and between them there was included the strip of land in dispute five miles broad at the west, eight miles broad at Lake Erie and about seventy miles long. Perhaps no serious differences would have occurred between the territory and state if the Erie canal from Cincinnati had not been headed for Toledo, which it would make its northern terminus with all the supposed advantages only on condition that it was a part of Ohio. The attempt to re-mark the Harris Line in 1835 precipitated trouble, the militia from each section being called out and brought almost face to face with one another. Michigan was, however, applying for admission to the union of states and was compelled by Congress to accept as its southern boundary the line claimed by Ohio. This it did most reluctantly and was given as a reward to soothe ruffled feelings, the entire upper peninsula.

4

C. Geological Work within the County.

§ 11. Previous work.

Nothing in the way of systematic geological exploration was attempted in the region covered by this report so long as Michigan remained a territory. Something was known, however, of its natural resources and the pioneers and traders had begun to utilize its economic products. The principal limestone outcrops had been located and rock removed for lime and building purposes. Quarries had been opened in the Raisin bed at Monroe and Dundee, also in the beds of Swan, Stony, Plum and Bay creeks, upon the Macon and at the head of Ottawa lake. In the region of the natural outcrops, particularly upon the "ridge," stone had been superficially quarried. Lime had been burned upon Plum Creek, at Ottawa Lake and at the Macon quarries. The bed of glass sand seven miles northwest of Monroe had been opened and found to produce a good quality of glass. Brick had been burned at Newport, Brest, Dundee and in London township, upon the Saline. The salt springs along the latter stream were known and utilized in an early day by both Indians and settlers.

§ 12. Houghton survey.

Upon the acquisition of statehood Michigan immediately established a "Geological Survey," the act of the Legislature being approved by Gov. Mason, February 23, 1837. Dr. Douglass Houghton was appointed State Geologist, with Bela Hubbard and C. C. Douglass, Assistant Geologists, and S. W. Higgins, topographer and draughtsman. During the summer following a hasty examination was made of the county by Dr. Houghton, having chiefly for its object "the determination of the rock formations, their extent and order of superposition." Under the head of the "Grey Limestone" he speaks of its outcropping edge as extending from the rapids of the Maumee to those of the Raisin, "which may without doubt, be considered identical with the mountain limestone of European geologists."*

The silicious nature of the limestone encountered in ascending the Raisin was noted and from such beds the glass sand layer was stated to have been derived by disintegration. Calcite, as "hog tooth spar" was observed at Monroe; celestite and tremolite (strontianite?) at

*1838. Report of the S. G. (first annual.) H. D. No. 24, pp. 276-317; separately, No. 14, pp. 1-39; p. 7.

Brest. The deposits of marl and the mineral springs to the south of Monroe were briefly described. Brine was stated as occurring north of a line drawn from, Monroe to Granville, Kent county, which line strikes across the county just south of its northwest corner. As an appendix to his first report, Dr. Houghton published a series of suggestions to those residents disposed to assist in the work (In Senate, February 1, 1838), and 115 questions pertaining to the bed rock, soils, water supply, subterranean forests, peat, marl, iron ore, streams, lakes and surface boulders.

The detailed study of Monroe county was assigned to the assistant Bela Hubbard and was reported upon in the Second Annual Report, February 4, 1839.*

The general topography of the surface, its springs and streams, the soils, subsoils, and timber were studied and described. The natural and artificial rock exposures were visited and the strata determined to be dipping northwest, or northwest by north, at an angle of about 5. This dip was afterwards† lessened to 15 feet to the mile, but found to vary from 10 to 20 feet.

No attempt was first made at the correlation of these strata with one another, or with those of other regions. Beds of peat and marl were located and their use in the amelioration of the natural soils repeatedly emphasized in the reports. The "Lake ridge," which cuts across the northwestern corner of the county, extending for many miles in either direction, was correctly interpreted as marking the former extension of the lakes. The abrupt change which here occurs in the topography, as well as in the character of the soil and the timber was noted and clearly understood. The surface boulders were termed "erratics" and were recognized as having been transported by some imperfectly understood agency from the north. The surface. scratches upon the limerock at Brest and Point aux Peaux were measured and found to be N. 50° E., N. 60° E., N. 65° W. They were ascribed to the "attrition of hard bodies moving in a strong current," (p. 113). In the same report (Second, p. 65), Higgins announces the completion of his topographic map of the county, but if it was ever published all trace of it seems to have been lost. It was very probably similar to his map of Wayne county which appeared the next year in the Third Annual Report.‡

*Second annual report of the State Geologist. H. D. No. 23, pp. 380-507; S. D. No. 12, pp. 264-391.

Fourth Annual Report, p. 135; H. S. and J. D. No. 11, pp. 472-607, separately H. D. No. 27, pp. 1-184; p. 135.

Annual report of the State Geologist (third, map of Wayne county); H. D. No. 27, Vol. II, pp. 206-293; S. D. No. 7, Vol. II, pp. 66-153, separately No. 8, pp. 1-120.

A still more detailed study of the geological features of the county was made by Hubbard and further reported upon in the Third Report, above referred to. The limestone was stated to occupy a horizon higher geologically than the blue limestones and shales of Cincinnati (Hudson River Group), but to be below the "black strata" (St. Clair shale), and without doubt is equivalent in position to the "Cliff limestone," of Indiana (p. 83). Three belts of rock, with quarries and outcrops, were recognized as crossing the county in a northeast and southwest direction. The most easterly, and consequently the oldest, is described as a compact limerock, light gray to blue in color, sometimes veined, sometimes oölitic, and carrying distinctive fossils. The most westerly range, highest both topographically and geologically, is somewhat sparry, geodiferous and bituminous, carry ing some fossils of a different species from the former. The middle range consists of highly silicious rock, passing into pure sandstone. The individual grains of the glass sand he recognized as consisting largely of perfect quartz crystals. The term "diluvium," or "diluvion" was applied to what is now known as the "drift," made up of "detritus of the upper portion of our coal series, which has been broken up and washed away, and in part of sands and fragments of the primary rocks, transported from a more northerly region." (p. 83). The following, quoted from page 89 of this report, is of interest since it furnishes a clear, concise statement of the views held sixty years ago, and not yet entirely discarded, concerning the origin of this "diluvium."

"It has been already remarked that in general all the rocks are covered with a mantle of clays, fine detritus of the lime and sand rocks, or loose water-worn fragments of still older rocks, swept from the north by the currents of a universal ocean and deposited during the general subsidence. Some evidences of the direction of these currents were noticed in my report of last year. Among these are the diluvial furrows and scratches on the surface of the limerock, the appearance and direction of which correspond with observations made in some of the more eastern states."

Allusion is made in the next report (Fourth p. 116), to Lyell's iceberg theory, as though the above explanation was not entirely satisfactory. In discussing the origin of the erratics he remarks that they came from the north "Whatever may have been the causes which swept these materials over the face of the rocks, whether oceanic currents or bodies of floating ice."

Owing to the inaccessibility of the reports of this first geological survey Hubbard is not generally credited with the work which he did in the way of deciphering, at this early day, the history of our great

lakes. Mention will be made of this again in connection with the glacial history of the county. The deposits from the ancient bodies. of water he termed "alluvions" to distinguish them from the "diluvion" described above, and "ancient alluvions" to distinguish them from the "recent alluvions," how forming, or having been very recently formed, as marl, peat and bog ore. The "Tertiary clays" (till) were regarded as present in Monroe and Wayne counties, as well as over two-thirds of the lower peninsula. In the Fourth Report (p. 109) Douglass identifies certain limestones in the northern part of the peninsula as Corniferous, and correlates them provisionally with those of Monguagon (Trenton) and hence also with those on the Macon. The geological formations identified and differentiated by this survey, so far as Monroe county is concerned, are shown below.

6. Recent Alluvions.

5. Ancient Alluvions.

4. Diluviums, or Erratic block group.

3. Tertiary clays.

2. Black aluminous slate.

1. Limerocks of Lake Erie.

c. Corniferous.

b. Silicious limestones, passing into sand.

a. Compact gray or blue limestone.

§ 13. Winchell Survey.

With the accidental drowning of Dr. Houghton in Lake Superior, October 13, 1845, further geological work ceased in this region and was not resumed again until the Second Geological Survey was organized by Dr. Alexander Winchell in 1859. In the meantime new outcrops had been discovered, new quarries had been opened and old ones deepened. Many wells had penetrated to the rocks, giving information in regard to the surface deposits and in regard to the rocks themselves. Much geological and palæontological work had been done in New York, and Canada, calculated to throw light upon Michigan geology. Dr. Winchell began his field work in May, 1859, with a re-examination of Monroe county, assisted by two of his students, Messrs. A. D. White and Lewis Spalding. Owing to the large amount of territory to be covered, only a short time could be devoted to this region. The First Bien