a distance of three-fourths of a mile, rock can be struck with a probe and appears at frequent intervals in the bed of the stream. A small amount of the rock has been removed upon the place of Peter Suzore. It is a tough, compact rock of a grayish drab color. The most important quarry in the eastern part of the county is the one now being operated by the Monroe Stone Company. This is located in the southern part of Frenchtown, about two miles north of the city of Monroe, claim 64, North River Raisin. It lies between the Lake Shore and Michigan Central tracks and is connected with the Pere Marquette by means of a switch, so that the shipping facilities are all that could be desired. The quarry was opened in September, 1895, since which time work has been actively pushed and an immense amount of rock crushed and marketed. The stripping averages about two and one-half feet varying but little toward the east and west. Two hundred feet to the south it equals four feet in thickness while one hundred feet north it equals three feet. The upper layer is glaciated above, as is uniformly the case in the county. For fourteen feet the rock is thin bedded, the strata varying in thickness from two inches at the top to ten inches below, and is shattered and broken so as to have no value for building purposes. It is a dark drab dolomite, of fine grain and even texture, breaking with rough conchoidal fracture and sharp edges. Thin, wavy carbonaceous films traverse the rock. Between the strata are layers of a soft putty-like clay which hardens upon exposure. These sometimes reach a thickness of two inches and represent surface material brought in by percolating waters. A good view of the bed as seen upon the west wall of the quarry is shown in Plate IV. At the base of these beds there is a thin stratum of breccia made up of angular fragments of a deep blue dolomite, another which is finely laminated and further, fragments of oölite, all contained in a drab, dolomitic matrix. Beneath this lies a bluish gray layer, streaked and mottled with a deeper blue coloring substance. Two large sink holes were encountered in the quarry, which at the time of examination was in the form of a semicircle, with a radius of about 130 feet. These holes were well like openings with a diameter of six to ten feet, containing at the bottom a mass of irregular fragments, cemented with crystallized calcium carbonate. The following analyses of the rock from the upper and main beds were kindly supplied by Mr. K. J. Sundstrom:

To the south of the city of Monroe there have been opened several quarries of more or less importance, chiefly in the immediate vicinity of Plum Creek. Some of these furnished building stone and lime in an early day to the French settlers of the region. The main excavations are upon the north side of the creek and lie upon adjoining divisions of claim 498, belonging to Alexander T. Navarre and Mrs. Mary T. Navarre. The stripping consists of a stony, yellowish brown clay, from three and one-half to five feet thick, deepening mainly towards the west. In the northeastern part of the irregular excavation two fairly well defined folds intersect one another, one bearing N. 45° E. and the other N. 60° W. From these ridges the rock dips in four directions from two to five degrees. In the A. T. Navarre quarry the dip is approximately one to two degrees toward N. 61° W. Here four beds may be recognized, the upper of which is termed the "white bed." This is a gray to creamy white dolomite, six to seven feet thick, thin bedded and fissured above, but thicker toward the base. Many loose pieces of this bed are in the clay stripping, softened upon the surface to a mealy powder. At the lower part this bed passes into a nine to ten inch stratum, which is very compact, even grained, somewhat laminated, and sparingly streaked with blue. The rock is brittle, gives sharp edges and coarse, conchoidal fracture. Owing to its higher specific gravity it is known in the quarry as the "lead bed." Beneath this lies a two foot "gray bed," made up of a fossiliferous, light drab dolomite, carrying some films of carbonaceous material. The lowest bed exposed in the quarry at the time of the visit is the so called "blue bed." This is a compact heavily bedded dolomite, inclining to drab on fresh fracture but having a decided bluish surface upon standing. Struck with a hammer the slabs give out quite a ringing sound. The individual strata have very rough upper sur

faces, covered with black carbonaceous deposit. The blue color is not so marked in the portion of the quarry belonging to Mrs. Navarre and the bed not so sharply separated from the overlying one. A local deposit of brecciated material similar to that found in the sink holes of the Monroe Stone Company quarry, was observed at one place. Upon the south side of the creek the rock lies very near the surface and a linear excavation extends for a considerable distance parallel with the stream. It is here that the bed of oölite, previously described, appears. Above it is a creamy dolomite, becoming somewhat blue, while beneath is a compact, laminated bed, streaked horizontally with a rusty brown. Judging from the alteration in the mottled dolomite seen in the Little Sink quarry this bed is of the blue streaked variety. These beds underlie those above described, as well as those in the quarries north of the city.

One-half mile down stream a large quarry has been opened between the two railroad tracks by the Michigan Stone and Supply Co., the owners of the Woolmith quarry. The excavation is in the form of an irregular rectangle about 450 by 125 feet. At the time of the visit it was well filled with clear blue water so that the strata could not be examined. Toward the north side the depth is said to be thirty-two feet, penetrating a lower series of beds than are seen elsewhere in the county. The rock was used entirely for road purposes and a crusher was operated in connection with the quarry. For five years no work has been done here, owing, it is reported, to the damage done to neighboring houses by the blasting. The ledges exposed above the water are thin-bedded fissured dolomites, of a light color. In the stone pile at the crusher there are seen fragments of a compact, fossiliferous, drab dolomite; another of a bluish color and conchoidal fracture and a third blue shaly rock, friable and carrying carbonaceous seams. The former foreman says that the strata are very much disturbed in this quarry and “run every way."

During periods of low water in the Raisin, rock is quarried directly from the bed opposite the city and for a distance of three to four miles above, at frequent intervals. The lower beds thus exposed consist of gray and drab dolomites, the latter finely laminated. A view of these layers is shown in Plate VIII, but was not taken at the lowest stage of the water. Opposite claims 65 and 88 (North River Raisin) the rock is a creamy yellow dolomite, in some