more than two hundred miles towards the west, and is covered here and there with strata of shale, or aluminous slate, sometimes penetrated with bitumen (often mistaken for coal) and in which I never found any organic remains, and with a stratum of a peculiar sandstone, which has an earthy aspect, passing sometimes into hornstone or chert, and is characterised by Gorgonia antiqua (Goldf.) and an undetermined Flustra. About six miles west from Nashville it is covered with the above mentioned shale, upon which follows a stratum of Encrinital limestone, and the already mentioned sandstone, forming the Harpeth Ridge. (This stratification is more fully described in another part of this Report.) The same stratification composes all the high lands west of Sparta, and continues nearly uninterrupted, except where it is cut through by currents, from the Harpeth to beyond Tennessee river. It is in this sandstone, which as I have already mentioned, passes sometimes into chert or hornstone, that the rich deposites of iron ore (hydroxide of iron) are found, which supplies the numerous furnaces of Dickson, Stewart, Hickman and Perry counties. Tennessee river has cut its way through all these upper strata till it has reached in some parts the limestone strata of the vicinity of Nashville, while the edges of the strata are visible on both sides of the river. (1) They are entirely lost at no great distance west of Tennessee river. Indeed about ten miles west of it, in Perry county, a more recent formation (1) No place can be more interesting for the study of the stratification than where the edges of these various strata are exposed to the decomposing influences of the air and water. Among the detritus of these strata, and its water worn fragments, I found a large number of very interesting organic remains, most of them similar to those that occur in Eifel, near the Rhine in Europe, which place furnished a great part of the palaeontological stores from which Dr. Goldfuss composed his excellent work on petrifactions. There is no doubt that these strata, which are particularly visible near the Tennessee river, in Perry county, are posterior to the grauwacke group (as will be seen in the detailed geological description of that part of the State,) they form the upper part of the stratification which composes Middle Tennessee, and are anterior not only to the coal measures, but also to the silicious strata which form the Harpeth ridge and other high lands; they are therefore intermediate between the grauwacke and the coal measures; they are separated by a great number of strata from the grauwacke; nevertheless the fossils which are found in them are very similar to those described by Dr. Goldfuss as occurring at Eifel in the grauwacke group. To make this more evident, we will enumerate only a few organic remains which are put down by De la Beche in his Manual,' as occurring in the grauwacke group, and which are found, in the interior of America, in the superior strata of a series which seen in other respects equivalent to the upper transition of the Continental Europeans, aud mountain limestone of the English geologists. E* covers them, which is composed of marl (1) and ferruginous sandstone the former being characterized by Grypha, Ostres, and other organic remains which characterize some strata of the cretaceous group (green sand,) and which are mostly identical with those that are found in New Jersey in similar strata. This series, covered with strata of clay, lignite, and a diluvial deposite, continues to the Mississippi river, where, near Randolph, at the elevation known by the name of the Chickasaw Bluff, a similar stratification is visible. Travelling southward, this cretaceous formation continues perhaps till near Walnut Hill, where, near Vicksburg, Miss. a more recent formation makes its appearance, abounding in Dentalia, Arca, and other fossils characterizing the supercre Cyathophillum ceratites, Bensberg, Eifel, Goldf. secundum, Eifel, Goldf. Astrea porosa, Eifel, Bensberg, Goldf. On the glædes in Per ry county, Tenn. Catenipora escaroides, Lam. Eifel, Norway (Goldf.) Ratosta (Fischer,) Perry co. Tenn. Eddyville, Ky., oolitic limestone." labyrinthica. Calamopora favoso-in the glades of Perry co. Tenn, gothlandica, Eifel, Goldf. basaltica, Eifel, Gothland, Goldf. spongites," Bensberg, Swed. Go. Aulopora serpens, Eifel, Goldf. Christiana, Brong, These zoophytes, as I mentioned above, are only a few of those that I found in the American strata; they are associated with several genera of Radiata, amongst which the Asterias occurs; Conchifera and a few Mollusca also, among the latter I found a Natica, and a few gene-. ra of Trilobites. This zoological difference between the American superior transition and that observed in Europe, is certainly remarkable. The grauwack group, which in Europpe, as appears from the above list, is rich in fossils, is destitute, or at least poor in organic remains in E. Ten. while we find those characterizing that formationin a more recent series. (1) This marl, which is also found in several places in the States of Alabama and Mississippi, and is generally known by the name of rotten limestone, has an earthy appearance, interspersed with minute particles of mica, and grains of green sand, sometimes so small as to be perceptible only by the aid of the magnifying glass. It is soft, and when exposed to the atmospheric influence disintegrates, crumbles to dust, and forms a more or less plastic paste with water. Its contents Earthy matter, insoluble in acid, composed of green sand and particles of white silvery mica, 51 34 Carbonaceous matter, 2 Alumina, water, and loss, 13 -100 The places where it crops out, and where it is not sufficiently mixed taceous group. As I am but slightly acquainted with that State, I shall not draw the line beyond the limits of Tennessee in that direction. If we now return again to Nashville, and draw a line from that place towards the north, we will find a continuation of the strata of Middle Tennessee for a great distance. From Nashville to Clarksville we have the same stratification as in Davidson county, (see my 1st and 2d reports.) No important alteration takes place till at Eddyville, Kentucky-the limestone is oolitic and is characterised by Stylina, Syringopora and Bellerophon hiulcus, the last of a large size (between five and six inches.) I am not well acquainted with the country from that place to the Ohio and Mississippi rivers, all that I have seen of it is covered with deep alluvium. More eastwardly in Gallatin county, Illinois, the oolitic limestone exists, and near Smithland, at the mouth of Cumberland river, we have again strata similar to those of Middle Tennessee, which strata continue when we cross the Mississippi river above the Tyawappita bottom. An extensive range of the oolitic limestone is found towards the north of that bottom, which, near Maramec river, in Jefferson county, abounds in Stylina and Syringopora, similar to those of Eddyville. But travelling from Commerstown, at the head of Tyawappita bottom, in a north west course through Cape Girardeau and Madison counties, we have again rocks similar to Middle Tennessee as far as the high grounds in Madison county near the village of St. Michael, or, as it is at present called, Frederickstown, where the St. Francis river takes its origin. The rocks at that place, as well as those of Washington county, in the same State, are generally sienitic, (1) which at several places passes into the most beautiful red porphyry, which formation begins near the lead mines known by the name of Mine la Motte. with soil, are remarkable for sterility, and are called glades; but when properly mixed with soil it is very beneficial to agriculture. Of this fact the farmers in Pennsylvania are well convinced, and hundreds of loads are taken from New Jersey, where similar marl exists, to improve their farms. The same is the case with the farmers of Maryland, who send at great expense to the Eastern Shore for that substance. We have inexhaustible quantities of it in the Western District, but are yet too rich to husband properly our ground. (For more information on marl, see my 3d Geological Report to the 21st General Assembly, in October, 1835.) (1) This sienitic is generally composed of reddish felspar, small particles of greenish black hornblende (amphibole,) and quartz. The felspar being most abundant, and some parts assuming a beautiful red color, (approaching to bright blood red,) forms a splendid ornamental rock; it passes into a magnificent porphyry, equal, if not superior in beauty to the fine Swedish porphyry. This sienitic contains small veins of magnetic iron ore, and in its vicinity are found large deposites of this ore. In Washington, the adjoining county, the famous Iron Mountain is found. Extensive tracts of trappean rocks occur there at many places, which must be considered as subordinate to the sienitic In order to make these geological views of the whole State of Tennessee more intelligible, I have given a map, on which all the formations are marked by different colors, and a section of the strata in the directions mentioned above. From these preliminary remarks, it will be perceived that the strata. in the vicinity of Nashville, and those prevailing through Middle Tennessee, belong to an old group of rocks, which the English geologists call carbonaceous limestone or mountain Jimestone and old red sandstone, while the continental Europeans consider it as the upper part of the transition. They do not nevertheless, coincide exactly (judging from the imbedded organic remains) with those observed in Europe; f in the same stratum in which some of the different genera of Trilobites occur, I found the Asterias (A. antiqua, nobis) (1) which is found according to Defrance in the supercretaceous strata, and according to Alberti in the Muschelkalk. Another proof that the rocks of Middle Tennessee, and in fact of the central part North America, differ from those observed on the old continent, is the peculiarity of the stratum of sandstone which sometimes covers a stratum of limestone, often entirely composed of fragments of Encrenites, and where this limestone is wanting, a slaty clay or aluminious slate, of which I have spoken in the report on Davidson county takes its place. This sandstone has sometimes an earthy aspect, and resembles the tripoli of Europe; in fact some part of this sandstone is entirely made up of species of Gorgonia, particularly the and porphyry. That this trap is posterior to the formation of the sienitic and porphyry can be seen at several places, and it is displayed no where more interestingly than in the vicinity of Mine la Motte, in Madison county. The sienitic in that place is rent asunder, and the crevice, which is from two to four feet wide, is filled up with basaltic matter, We can yet see how the rock was formerly connected together-as, where we find on one side an indentation, we find on the other side a corresponding projection, at other places the fragments which have been torn from the mass are found enclosed in the bassaltic matter which fills the rent. This sienitic formation is covered at that place with a stratum of grey silicious sandstone. The time which I could spend there was too short to enable me to examine properly this spot, so interesting for the geological knowledge of this sienitic, and its subordinate trap. (1) I found this Asterias, resembling more or less those living at present on our coast, in the limestone near Big Harpeth river in Davidson county, Tennessee. It is associated in this limestone with Ceriopora Goldf. Calamopora Goldf. Spirifer and Terebratula. This stratum is the lowest which is visible in that section of country, and is the same as those in the vicinity of Nashville, where it contains Orthoceratites, and Isotellus, and where it rests on the strata which contains Conotubularia, nobis, and consequently belongs to the upper transition series. My description of the A. antiqua was published in the "Transactions of the Geological Society of Pennsylvania," vol. 2, page 232, G. antiqua Goldf. Retepora and Flustra; it contains also, but very rarely, Terebratula. This sandstone, which deviates very much from any port. I have seen or of which I have read, was described in my first re of Neither do these strata belong to the true grauwacke series; part our State exhibits grauwacke alternating with limestone, containing. most of the usual accidental intermixtures, and having a stratification approaching to the vertical. This is the formation which composes the country between the Smoky, Unaka and Cumberland mountains. This grauwacke group, which is here and there covered with horizontal strata, equivalent to those of Middle Tennessee, (except that, besides the usual fossils found there, they contain also, the Maclurites gigas, in some places the rock being characterized by it, while it is of very rare occurrence in the limestone of Middle Tennessee,) is lost. under the eastern slope of Walden's ridge, and may in some places in the Sequatchee Valley, be seen covered with the strata of Middle Ten nessee... In the present, as yet, infant State of Tennessee, the greatest part of it being yet covered with forest, no strata of any consequence having been penetrated to quarry the rocks for building stone, it is difficult to study properly its formations and their characteristic fossils. We have no important excavations in which the stratifications can be observed, and petrifications obtained. Our ravines, slopes of mountains and banks of rivers are covered with forest trees. The fossils, which we can now collect, are those which have come to light by the disintegration of the rocks, occasioned by long exposure to the action of water and air, by which, when they are of a calcareous nature, they are often mutilated, and cannot be recognized. This nevertheless is not always the case, for unlike the organic substances of other countries, those which we find in our old strata, are often of a silicious nature, and have therefore been able to withstand the decomposing effect of the above named agents, which would not have been the case if they had been composed of carbonate of lime. 1835. This fact seems not yet to be known in Europe; for the Rev. W. Buckland, in his valuable work on geology and mineralogy (one of the Bridgwater treatises) says, vol. 2, page 313, American edition.-"No fossil Stelleridans have yet been noticed in strata more ancient than the Muschelkalk." Now, not only have I found the Asterias antiqua in limestone, which is separated from the muschelkalk by Millstone grit and shale, Coal measures, Exeter red conglomerate, Gypseous red sandstone, but I have found several other Stelleridans, belonging to other genera, in limestone near the Tennessee river, which is characterized by Trilobites, calceola sandalina, and other fossils of the European grauwacke series. |