Imagens das páginas

Table showing the proportion (in decimals) of prairie and timber in each township in the Mineral Point land district.

Range 1, west of 4th

Range 2, west of 4th


Range 3, west of 4th


Range 4, west of 4th


Range 5, west of 4th


Range 6 and 7, west of

4th meridian.











| Prairie.




[blocks in formation]


Fr. 1 & 2


Fr. 2 & 3



Frac. 3

[ocr errors]

1.00 .00

[ocr errors]
[merged small][ocr errors][merged small][merged small][merged small]






[ocr errors]

1.00 .66

8 and 9

Fr. 8&9


2.97 | 5.03



189 15.11

2.01 | 2.99



1.48 4th meridian. | 4th meridian. | 4th meridian | 4th meridian, | 4th meridian| 4th meridian, | of 4th Imerid.



Range 1. east of 4th meri- | Range 2, east of | Range 3, east of | Range 4, east of | Range 5, east of | Range 6, east of | Range 7, east of | Range 8, east dian.

T'nship. Prairie. Timber. Prairie. Timber. Prairie. Timber. Prairie. Timber. Prairie. Timber. Prairie. Timber. Prairie. Timber. Prairie. Tim'r.

[ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][ocr errors][ocr errors][ocr errors][ocr errors][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][ocr errors]

4.57 |

3.43 | 3.05 | 4.95 | 3.55 | 4.45 | 2.34 | 5.66 | 3.10 | 4.90 |



5.55 |





Total 39.48 prairie, and 67.52 timber; equal to about three-eighths prairie and five-eightbs timber. NOTE.-All tracts of land covered with a small growth of oak, standing from ten to twenty feet apart, called in the west "oak openings," have been set down in the foregoing table as timber; and at least three-fourths, if not four-fifths, of all the timbered country is of this description,

No. V.


To David Dale Owen, M. D., principal agent to explore the mineral lands

of the United States. Sir: Having, at your complimentary solicitation, been appointed your assistant in the late survey of the mineral lands of the United States, and having been charged by you with those duties most agreeable to my former pursuits, viz: the physical department, including, especially, the barometrical observations, the measured altitudes, and the geological sections, it is with peculiar pleasure that I submit to you the following

the lateed by you.ay departmenudes


The subjects to which my attention was chiefly directed, and which will mark the heads or divisions of this report, are as follow :

1. A comparison between the rocks of the lead or mineral region, and those of Ohio, Indiana, and Kentucky, called the “cliff limestone," showing their probable identity.

2. Several sections of strata (the height and thickness being determined by the barometer) with drawings.

3. The altitudes of table-lands, hills, mounds, and mountains, determin. ed by barometrical observations, with a chart.

4. The result of numerous observations and calculations on the elements of terrestrial magnetism, including the dip, declination, and force or intersity, of the magnetic needle at several places between Cincinnati and the region surveyed, and in that region itself, accompanied by two charts; together with some remarks on the practical uses of these elements of magnetism.

5. Surveys of a few of the earthwork antiquities of Wiskonson, with drawings.

6. Some observations on the climate and meteorology of the Upper Mississippi.

7. Acknowledgments and concluding remarks.



From the examinations which we have lately made, I am of opinion that the limestone containing the chief deposites of the lead in lowa, Wiskon. sin, and Illinois, is a part of a stratum of great extent in our own country, and, possibly, is geologically identical with rocks found in other continents.

The following appear to me to be some of the synonymes by which our own geological writers have intended to designate this stratum :

“Galeniferous limestone,” Featherstonhaugh.
“ Cornutiferous limestone,” Eaton.
“ Magnesian limestone,” 'Keating and Shepherd.

“ Mountain limestone,” Ohio reports.
« Metalliferous limestone."

“ Cliff limestone." This last name I intended, in my report on the geology of Ohio, to be merely a provisional one, like the numerical distinctions used by Professor Rogers: it was adopted from the inhabitants on the Miami, above Dayton, in Ohio.

In Major Long's “Expedition to the Source of the St. Peter's," in 1823, there is a very interesting article on this rock by Mr. Keating. These ob servations were descriptive of the geological formation on the « Wassamon," ten or twelve miles northeast of the present town of Galena. The external characters there sketched by him apply very generally to this formation; they are, in substance, briefly as follows:

Horizontally stratified structure, crystalline, sandy, or gravelly; cellular, cells sometimes filled with crystallized carbonate of lime, contains much white hornstone, (flint or chert,) often in flattened nodules, lying in horizontal strata; organic remains rather uncommon, consisting of terebratulites, encrinites, and madriporites, (Linn.)

These characters, it is remarked by Mr. Keating, are similar to those of the carboniferous or mountain limestone of Messrs. Cony beare and Phillips, or the metalliferous limestone of other geologists; similar, also, to zechstein and rauchwacke of Thuringen, described by Mr. Friesleben. But Mr. Keating is not of opinion that the limestone of the “ Wassamon” is identical with those foreign rocks, for he believes it to be “of a much later formation,” and "to be connected with an oõlite observed between Prairie du Chien and St. Anthony."

The politic limestone, at and above Prairie du Chien, is not a real oõlite ; and we found it to be older than, and below, the cliff stone of the “ Wassamon." Mr. Keating seems to have taken the impression that the rocks of Wiskonsin are above the coal formation, and reasons accordingly. He observes, (page 197 :) “It is probably connected, as we have already intimated, with the limestone situated above the coal-fields of Wheeling and Zanesville; it extends over those parts of Ohio and Indiana where salt has been found.” Our investigations, you know, have led us to an opposite conclusion, viz: that the rocks of the lead region are below the coal. Mr. Keating seems to have been aware that his conclusions, drawn from so rapid and so slight an examination, might not be correct, as appears by the following remark: “Let it be remembered that we only offer this as a suggestion to the future investigator of our western limestone, in order that he may turn his attention to the subject with more favorable opportunities for observation than those afforded us by a transient visit through the country." The following conclusion of Mr. Keating does credit to the science of geology in general, and to the author in particular: “If, as Mr. Friesleben has described it, the zechstein presents specks of galena or sulphuret of lead; if, as Mr. Conybeare states, the galena is seen occurring in strings in the magnesian limestone of Nottingham and Durham; if it has occasionally been found in the conglomerate beds associated with this formation, especially near Mendip hills, in England; if it contains veins of sulphate of barytes at the Huddlestone qnarry, near Sherburne, between Ferrybridge and York; if it is traversed by veins of sulphate of barytes, near Notting. ham and Bramham moor, &c.-may it not then be asked, whether these considerations do not render it probable that the great lead deposite in the west is in this limestone? And is it not likely that all that has been worked 2 an alluvion has been detached from this formation? These are questes upon which, in the present state of our acquaintance with the western time stone, we must profess ourselves unable to give any decided opinion : BCL from various circumstances which we need not dwell upon, we should 13cline to consider the lead ore as probably existing in an older lim stone, which we think underlays this, and which may be connected withi e carboniferous or mountain limestone of Messrs. Conybeare and Phillips, o sit the metalliferous limestone of other geologists."

Situated as was Mr. Keating at the moment of making these observations in the centre of one of the most productive lead regions in the world, we veins of lead ore probably beneath his feet, it will be thought surprising, by those not acquainted with geology, that he did not make the discovery. Flis failing to do so is attributable, not to a want of skill or industry on hispert, but to the want of time and opportunity to make the necessary examinations.

Since the time in which Mr. Keating wrote this article, geologists hare become less confident in geological identities and correspondences in coninries remote, than they were at a previous period; and the principles laid lown by Professor Phillips, in a late publication, will, I presume, ILI rich eneral concurrence. Aster giving a table of the order and superposition if “the British stratified rocks," he proceeds to observe, “ that the series ai trata classed in the preceding table is always recognisable, wholly or a.. ially, in every part of the British islands; that is to say, the stratified as 'ccurring in any situation, can be referred to their respective types in be eneral table. But the local variations are considerable ; sereral of the tratified rocks are only of limited extent; even whole formations, as the ölitic formation, change their characters, or, as the millstone grit, are esirely extinct in particular regions, where the groups above and below them ire complete. This being the case, it is evident that such subdivisions are too minute and variable to be employed between British and foreign series of strata; we must be satisfied with comparing formations, and, in some cases, omit even these, and look only to the succession of primary, secondo ary, and tertiary classes of rocks.

“ This examination has been made in almost all parts of the world ; 10where, indeed, except in Europe, and certain portions of the other continents, completely, yet everywhere sufficiently to establish the truth of the following propositions : · "1st. The series of British strata represents very well the succession of stratified rocks in Europe, parts of Africa, Asia, and North America; this agreement is most strict in those parts which are nearest to the British islands, and becomes more vague and indefinite as the distance increases, &c.

“ 2d. In all parts of the globe, where a considerable extent of country has been examined, stratified rocks have been found,” &c.

It seems to follow, from the first of these propositions, that, instead of jumping at once from the examinations of a rock in one locality, to the correspondence with a rock or formation in a very remote country, we ought first to trace, as far as possible, the continuity, correspondence, order, and zuperposition of the rocks in our own, or any other country examined.

If, as many have supposed, the lead-bearing limestone of the Mississip is identical with the magnesian limestone of Great Britain, it onght to Oc.

« AnteriorContinuar »