close grained and hard, that on breaking the rock no trace of the fossil could be found. I am confident, however, that the rock is filled with organic remains, but they cannot now be sep. arated from the matrix so as to be identified. From Sioux Falls to the celebrated Pipestone quarry, the dis tance is just 40 miles, measured with an odometer. Direction a little east of north. We passed over a similar undulating prairie, with but one small tree along the route, and but one rock exposure, and that occurs about four miles south of the quarry. The rock is a very hard quartzite, composed largely of water worn pebbles, quartz, jasper, small clay nodules, chalcedony; some of the rock is a quartzose sandstone, other portions are fine grained siliceous rock. It lies in regular layers or beds, dip ping at an angle of about 5°, 30° S. of E.* On reaching the source of the Pipestone creek, in the valley of which the Pipestone bed is located, I was surprised to see how inconspicuous a place it is. Indeed, had I not known of the existence of a rock in this locality so celebrated in this region, I should have passed it by almost unnoticed. A single glance at the red quartzites here, assured me that these rocks were of the same age with those before mentioned at James and Vermilion rivers, and at Sioux Falls. The layer of Pipestone is about the lowest rock that can be seen. It rests upon a gray quartzite, and there are about five feet of the same gray quartzite above it, which have to be removed with great labor before the Pipestone can be secured. About 300 yards from the Pipestone exposure is an escarpment, or nearly vertical wall of variegated quartzite, extending directly across the valley. Each end of the wall passes from view beneath the superficial covering of the prairie. It is about half a mile in length. About a quarter of a mile farther up the valley there is another small es carpment, so that the entire thickness of the rock exposed at this point is about 50 feet. Not a tree can be seen; only a few small bushes growing among the rocks. There is a little stream of clear, pure water flowing from the rocks, with a perpendic ular fall of about 30 feet, forming a beautiful cascade. The evi, dences of erosion were very marked, and the question arosehow could all the materials which must once have existed here joined on to these walls, have been removed, except by a stream much larger and more powerful in its erosive action than the one at present flowing here? There is a slight inclination of the beds from 1° to 3°, about 15° S. of E. ar About 200 yards southeast of the quarry are five massive boulders, composed of a very coarse flesh-colored feldspathic granite, very much like that which forms the nucleus of the Black Hills. I am greatly indebted to Col. Knox, commandant of Fort Dakota, at Sioux Falls, for important facilities in my examinations. The first detailed account of the Pipestone quarry that I have been able to find, is that of Catlin, in this Journal, [1], xxxviii. In Nicollet's excellent report there is a much more careful and accurate description of the rock and the locality, but neither of these gentlemen hint at the probable geological age. The first attempt to determine the age of the rocks in which the Pipestone is located, was made by Prof. Hall, in a paper read before the American Philosophical Society not long since. In that paper he regards them as of the same age with the Huronian rocks of Canada and Lake Superior. At the time Mr. Catlin made his visit to the quarry he sent a portion of the pipestone to Prof. C. T. Jackson, of Boston, for analysis. Prof. J. gave it the name of Catlinite, with the fol lowing composition: The Pipestone layer, as seen at this point, is about 11 inches in thickness, only about 2 inches of which are used for manufacturing pipes and other ornaments. The remainder is too impure, slaty, fragile, &c. This rock possesses almost every color and texture, from a light cream to a deep red, depending upon the amount of peroxyd of iron. Some portions of it are soft, with a soapy feel, like steatite, others slaty, breaking into thin flakes; others mottled with red and gray. A ditch from four to six feet wide and about 500 yards in length, extending partly across the valley of Pipestone creek, reveals what has thus far been done in excavating the rock. There are indications of an unusual amount of labor on the part of the Indians in former years to secure the precious material. This rock has been used for many years past by the Indians of the Northwest for the manufacture of pipes, and it was formerly the custom of some of the tribes to make the locality an annual visit to secure a portion of the precious material. They placed a higher value on the rock, because, while being so firm in texture it is so easily wrought, and because they could make far more beautiful and showy pipes than from any other material known to them. Besides, this was and is now, the only locality from whence the true pipestone can be obtained, and the labor is so great in throwing off the five feet of solid quartz For ite that rests upon it, that the rock has always been rare. a mile or two before reaching the quarry the prairie is strewed with fragments that have been cast away by pilgrims. Nearly all of our writers on Indian history have invested this place with a number of legends or myths. They have rep resented the locality as having been known to the Indians from remote antiquity. All these notions, I am convinced, will disappear defore the light of a careful investigation of the facts. It is quite probable that the rock has not been known to the Indians more than eighty or one hundred years, and perhaps not even as long a period. I could not find a trace of a stone implement in the vicinity, nor could I hear that any had ever been found; and indeed nothing could be seen that would lead one to suppose that the place had been visited for a longer period than fifty years. All the excavations could have been made within that time. There are many rude iron tools scattered about, and some of them were taken out of the ditch last summer in a complete state of oxydation. Again, it does not appear that in the mounds which have been opened in the Mississippi valley so extensively, any trace of this rock has ever been found. It is well known that the pipe is the most important of the dead man's possessions and is almost invariably buried with the body, and if a knowledge of this rock had extended back into the stone age, it is almost certain that some indications of it would have been brought to light in the vast number of mounds that have been opened in the valley of the Mississippi. Pipes and other ornaments, made from steatite, have been in use among Indians from the earliest indications of their history, and they are still manufactured from this material on the Pacific coast. Now the question arises as to the age of the rocks we have attempted to describe and which include the pipestone layer. Owing to the absence of well defined organic remains, the problem becomes a difficult one. Their exceedingly close-grained, compact, apparently metamorphic character, would direct one's attention to the older rocks, perhaps some member of the Azoic series; but if the impressions seen at Sioux Falls are those of bivalve shells, we inust look higher in the scale. But in order that we may arrive at an approximate conclusion, let us look at the geology of the surrounding country. We already know that the limestones of the upper Coal Measures are exposed at Omaha City, and continue up the Missouri river to a point near De Soto, almost twenty miles farther, where they pass from view beneath the bed of the river. Overlapping them is a coarse sandstone composed of an aggregation of particles of quartz cernented with the peroxyd of iron. This assumes every color from a deep dull red to a nearly white. The layers of deposition are very much inclined and distorted. Near Blackbird hill numerous dicotyledonous leaves have been found, and many of these plants occur in a quartzite so close-grained that the lines of stratification are nearly or quite obliterated, yet the impressions are distinct. This quartzite forms a valuable quarry near Sioux City. The coal seam included in this formation, (Lower Cretaceous, No. 1) crops out forty miles up the Big Sioux, or within sixty miles of Sioux Falls. Between Sioux City and Yankton we have at least three members of the Cretaceous series. Near Fort James we find that two members of the Cretaceous series (Nos. 2 and 3) rest upon the quartzites. The surface features of the whole country, with the soil and drift, indicate that the immediate underlying rocks are of Cretaceous age. Is it not possible therefore, that the quartzites that include the pipestone bed, belong to the supra-carboniferous, Triassic perhaps, or even to an extension downward of Cretaceous No. 1? Prof. Hall, in an interesting geological memoir, read recently before the American Philosophical Society, gives an account of a tour into Western Minnesota, and many of the rock exposures which he describes must be of the same age with those noticed in this paper. He seems to have proceeded west from St. Paul to St. Peters and Fort Ridgely on the Minnesota river. From Fort Ridgely he continued west to Lake Shetek, which is not more than forty miles from the pipestone bed. Prof. Hall describes a wall of red quartzite at this locality, which he thinks is of the same age and character with that at Pipestone creek. I am convinced that not only the rock at Lake Shetek, but at many other localities which he describes with great care, are of the same age. I was informed by intelligent land surveyors in Dakota and Minnesota, that these red quartzite exposures extend very far to the north. Prof. Hall regards these quartzites as of the age of the Huronian series. His opportunities for tracing these rocks from the north and east were excellent, and his opinion is entitled to great weight. Acad. Nat. Sci. Philadelphia, Nov. 10, 1866. ART. IV.-New Classification of Meteorites, with an Enumeration of Meteoric Species; by CHARLES UPHAM SHEPARD. THE arrangement here proposed differs so widely from the two formerly put forth by me, as to be really new. The changes introduced will, I trust, appear as flowing naturally from the recent progress of the study. The localities by which the system is illustrated are such as are represented in my collection, now deposited in Amherst College. A number of localities found on my previous lists as well as upon those of others, are omitted, |