[7] Taylor's Memoir.
[8] Ibid.
A great class of variations due to rock character are those of surface form. The rocks have been exposed to the action of erosion during many epochs, and have yielded differently according to their natures. Different stages in the process of erosion can be distinguished and to some extent correlated with the time scale of the rocks in other regions. One such stage is particularly manifest in the Catoctin Belt and furnishes the datum by which to place other stages. It is also best adapted for study, because it is connected directly with the usual time scale by its associated deposits. This stage is the Tertiary baselevel, and the deposit is the Lafayette formation, a deposit of coarse gravel and sand lying horizontally upon the edges of the hard rocks. Over the Coastal plain and the eastern part of the Piedmont plain it is conspicuously developed, and composes a large proportion of their surfaces. As the formation is followed westward it is more and more dissected by erosion and finally removed. Near the area of the Catoctin Belt it occurs in several places, all of them being small in area. One is three miles northeast of Aldie. Here, a Newark sandstone hill is capped with gravel. This gravel is much disturbed by recent erosion and consists rather of scattered fragments than of a bedded deposit.
The materials of the Lafayette gravel are chiefly pebbles and grains of quartz, with a considerable admixture of quartzite and sandstone. The large quartz pebbles were probably derived from the large lenses of quartz in the Catoctin schist, for no other formation above water at the time contained quartz in large enough masses to furnish such pebbles. On the hypothesis that they were of local origin and merely worked over during submergence, they might be connected with the quartz veins of the Piedmont plain. That theory, however, with difficulty accounts for their well-rounded condition, which shows either beach action or long carriage. The quartz sand may well have been derived from the granitic quartzes, but that is an uncertain matter. The sandstones and quartzites are usually massive and pure white, of the variety found along Catoctin and Bull Run mountains. Other varieties of sandstone—the blue-banded type, for instance—are derived from the Weverton sandstone on the Blue Ridge. The white sandstone pebbles in the terraces along Bull Run Mountain can be traced from the ledges to the deposits. In this region, therefore, an absolute shore can be seen. In other areas along Catoctin Mountain a shore can be inferred, because the mountain projects above the baselevel plane and contains no gravel deposits. In fact, only a few points at the stream gaps are cut down to the baselevel.
Dynamic metamorphism has produced great rearrangement of the minerals along the eastern side of the Catoctin Belt, and results at times in complete obliteration of the characters of the granite. The first step in the change was the cracking of the quartz and feldspar crystals and development of muscovite and chlorite in the cracks. This was accompanied by a growth of muscovite and quartz in the unbroken feldspar. The aspect of the rock at this stage is that of a gneiss with rather indefinite banding. Further action reduced the rock to a collection of angular and rounded fragments of granite, quartz, and feldspar in a matrix of quartz and mica, the mica lapping around the fragments and rudely parallel to their surfaces. The last stage was complete pulverization of the fragments and elongation into lenses, the feldspathic material entirely recomposing into muscovite, chlorite, and quartz, and the whole mass receiving a strong schistosity, due to the arrangement of the mica plates parallel to the elongation. This final stage is macroscopically nothing more than a siliceous slate or schist, and is barely distinguishable from the end products of similar metamorphism in the more feldspathic schists and the Loudoun sandy slates. The different steps can readily be traced, however, both in the hand specimen and under the microscope.
The Weverton sandstone has suffered less from metamorphism than any of the sediments. In the Blue Ridge it has undergone no greater change than a slight elongation of its particles and development of a little mica. Along Catoctin Mountain, from the Potomac River south, however, increased alteration appears together with the diminution in thickness. What little feldspar there was is reduced to quartz and mica, and the quartz pebbles are drawn out into lenses. Deposition of secondary quartz becomes prominent, amounting in the latitude of Goose Creek to almost entire recrystallization of the mass. A marked schistosity accompanies this alteration, and most of the schistose planes are coated with silvery muscovite. Almost without exception these planes are parallel to the dip of the formation.
Metamorphism of the Loudoun formation is quite general. It commonly appears in the production of phyllites from the argillaceous members of the formation, but all of the fragmental varieties show some elongation and production of secondary mica. The limestone beds are often metamorphosed to marble, but only in the eastern belt. The recrystallization is not very extensive, and none of the marbles are coarse grained.
The metamorphism of the igneous rocks is regional in nature and has the same increase from west to east as the sediments.
In the granite it consists of various stages of change in form, attended by some chemical rearrangement. The process consisted of progressive fracture and reduction of the crystals of quartz and feldspar, and was facilitated by the frequent cleavage cracks of the large feldspars. It produced effects varying from granite with a rude gneissoid appearance, through a banded fine gneiss, into a fine quartz schist or slate. These slaty and gneissoid planes are seen to be parallel to the direction and attitude of the sediments, wherever they are near enough for comparison.
Dynamic alteration of the Catoctin diabase is pronounced and wide-spread. Macroscopically it is evident in the strong schistosity, which is parallel to the structural planes of the sediments when the two are in contact. In most areas this alteration is mainly chemical and has not affected the original proportions of the rock to a marked extent. Its prevalence is due to the unstable composition of the original minerals of the rock, such as olivine, hypersthene, and pyroxene. Along Catoctin Mountain, however, both chemical and mechanical deformation have taken place, so that the original rock structure is completely merged into pronounced schistosity. This was materially assisted by the weak lath shapes of the feldspar and the mobility of the micas.
The average dip of the schistose planes is about 60°; from this they vary up to 90° and down to 20°. In all cases they are closely parallel to the planes on which the sediments moved in adjustment to folding, namely, the bedding planes. In regions where no sediments occur, the relation of the schistose planes to the folds can not be discovered.
Parallel with the micas that cause the schistosity, the growth of the quartz and epidote lenses took place. These, too, have been deformed by crushing and stretching along Bull Run Mountain and the south part of Catoctin Mountain. From this fact, taken in connection with the folding of the schistose planes at Point of Rocks, it would appear that the deformation was not a single continuous effort.
The ratios of schistose deformation in the igneous rocks are as follows: diabase, with unstable mineral composition and small mechanical strength, has yielded to an extreme degree; granite, with stable composition and moderate mechanical strength, has yielded to the more pronounced compression.
In point of mineral wealth Loudoun ranks with the foremost counties of the State. Iron, copper, silver, soapstone, asbestos, hydraulic limestone, barytes, and marble are some of the deposits that have been developed and worked with a greater or lesser degree of success.
A large bed of compact red oxide of iron lies at the eastern base of the Catoctin Mountain, on the margin of the Potomac River. Long before the Civil War a furnace was erected here by Samuel Clapham, Sr., for the reduction of this ore, and considerable quantities of it were formerly transported moderate distances to supply other furnaces. The Clapham furnace continued in operation until all the fuel at hand was consumed and then went out of blast. Water power was supplied by the Catoctin Creek, which flows into the river immediately above the mountain. To obtain this a tunnel was cut through a spur of the mountain projecting into a bend of the creek. This tunnel, about five hundred feet long and sixty feet beneath the summit of the hill, was cut through almost a solid wall of rock, and, at that day, was considered a great work.
Magnetic iron ore has been found in certain places, and this or a similar substance has a disturbing effect upon the needle of the surveyor's compass, rendering surveying extremely difficult where great accuracy is required. In some instances the needle has been drawn as much as seven degrees from its true course. This effect is more or less observable nearly throughout the Catoctin Mountain, and has been noted elsewhere in the County.
Chromate of iron was long ago discovered along Broad Run, and, about the same time, a bed of micaceous iron ore on Goose Creek below the Leesburg turnpike. Copper ore is associated with the last-named mineral.
In 1860, the output of pig iron in Loudoun was 2,250 tons, and its value $58,000. Rockbridge was the only Virginia County to exceed these figures.
In several localities small angular lumps of a yellowish substance, supposed to contain sulphur, have been found, embedded in rocks. When subjected to an intense heat, it gives forth a pungent sulphurous odor.
Small quantities of silver ore are discovered from time to time; but the leads have never been extensively worked and many of the richest veins are still untouched.
Deposits of copper in the schists have long excited interest and led to mining operations. The amount of ore, however, appears not to have justified any considerable work.
Near the base of the Catoctin Mountain, where it is first approached by Goose Creek, marble of an excellent quality is found but has been little worked. Among the varieties at the quarry are included pure white, white and pink, blue and white, white and green, serpentinized and chloritic serpentinized marble. These marbles are of great beauty and susceptible of a good polish. The calcareous bed here is about fifty feet thick and reaches southward for three miles with increasing thickness. At its southern end it is not entirely metamorphosed into marble, but retains its original character of fine blue limestone. Northward along this range the thickness of the marble constantly diminishes and rarely exceeds ten feet. Sometimes there are two beds, sometimes only one. At Taylorstown, just south of the Potomac, the bed is about three feet thick; on the north side of the Potomac about four or five feet. Here, as elsewhere, the beds of marble are inclosed in a bluish green micaceous schist, which has been thoroughly transformed by mechanical pressure.
In the vicinity of Leesburg and north of that town, and between the Catoctin Mountain and the Potomac River, the conglomerate limestone or brecciated marble is found in abundance, associated with red shale. It is a calcareous rock, apparently formed in part of pebbles cemented together and, when burned, produces an inferior lime. It is commonly known as Potomac marble. Of this variegated marble were formed the beautiful columns in the old Representatives' chamber of the Capitol at Washington. The soil in which this rock occurs is extremely productive and valuable.
The exhibition at the World's Fair, at New Orleans, of the following specimens of Loudoun minerals claimed much interest from visiting mineraloguists:
1. Specular Iron Ore, from near Leesburg, said to be in quantity. From Professor Fontaine.
2. Chalcopyrite, from near Leesburg, said to be a promising vein. From Professor Fontaine.
The following were contributed by the "Eagle Mining Company," of Leesburg; F. A. Wise, general manager:
1. Carbonate of Copper, from vein 3' wide, developed to 25' deep. Assays by Oxford Copper Company of New York give 51 per cent of copper and 27 ounces of silver per ton.
2. Sulphuret of Copper, from vein 10" wide, developed to 50' deep. Assays by Oxford Copper Company of New York give 12-1/2 per cent of copper.
3. Iron Ore, from vein 4' wide and 50' deep. Yields 55 per cent metallic iron by assay of W. P. Lawver, of U. S. Mint.
4. Sulphuret of Copper, from vein developed 50'. Yields 11 per cent of copper and 1 ounce of silver per ton by assay of W. P. Lawver, U. S. Mint.
5. Carbonate of Copper, red oxide and glance, from vein 3' wide, developed to 25' deep. Yields 50 per cent metallic copper and 27 ounces silver per ton by assays.
6. Iron Ore, from vein 2' to 4' wide, developed 50'. Yield 55 per cent metallic iron.
7. Oxide of Copper, from Carbonate vein, developed 60' on 4' wide vein; 25' deep.
8. Sulphuret of Copper, from vein 8" to 15" wide, developed 50'.
9. Iron Ore.
10. Barytes, heavy spar, vein undeveloped.
11. Iron Ore, from 50' level of Eagle Mining Company's shaft.
12. Marble, from quarry of "Virginia Marble Company," three miles east from Middleburg. The deposit has been demonstrated to be of great extent; the marble has been pronounced of a very superior quality. Contributed by Major B. P. Noland.
13. Marble, from same as above.
14. Marble, from same as above.
17. Copper Ore, James Pinkham, from Virginia Department of Agriculture.
In the "Handbook on the Minerals and Mineral Resources of Virginia" prepared by the Virginia Commission to the St. Louis Exposition, Loudoun is credited with the three comparatively rare minerals given below. The two first-named occur nowhere else in the State.
"Actinqlite: Calcium-magnesium-iron, Amphibole,
Ca (Mg Fe)3(Si O4)3.
Specific Gravity, 3-3.2. Hardness, 5-6. Streak, uncolored.... Fine radiated olive-green crystals are found ... at Taylorstown...."
"Tremolite: A variety of Amphibole. Calcium.
Magnesium Amphibole. Ca Mg2(Si O4)3.
Specific Gravity, 2.9-3.1. Hardness, 5.6. Long bladed crystals; also columnar and fibrous. Color, white and grayish. Sometimes nearly transparent. Found in the greenish talcose rocks at Taylorstown."
Chromite, of which no occurrence of economic importance has yet been discovered in the County or elsewhere in Virginia.
"[9]On the eastern flank of the Catoctin rests a thin belt of mica slate. This rock is composed of quartz and mica in varying proportions, and this belt, on reaching the Bull Run Mountain, there expands itself, and forms the whole base of that mountain, and where the mica predominates, as it does there, it sometimes forms excellent flagging stones."
[9] Taylor's Memoir.
"Immediately at the western base of the Catoctin Mountain, a range of magnesian or talcose slates occur traversing its whole length.... In this range a vein of magnesian limestone is met with, and is exposed in several places. It however is narrow, in some places only a few feet in thickness, and being difficult to obtain is not much sought after for burning."
"Along the eastern side of the valley (Loudoun) gneiss is frequently met with on the surface, and where the larger streams have worn deep valleys, it is sometimes exposed in high and precipitous cliffs. This is more particularly the case along Goose Creek and Beaver Dam. Associated with it, however, is clay slate, not so much in rock as in soil, for it being more readily decomposed is seldom found on the surface, except as soil. These two varieties are often met with side by side in thin layers, and their combination at the surface forms a peculiarly favorable soil for agricultural purposes. The gneiss from the quartz it contains makes a sandy soil, while the clay slate gives it tenacity. This happy combination is a prevailing feature of this entire valley, and renders it one of the best farming sections in Virginia.
"Another rock that is a valuable acquisition is hornblende. This kind when first taken from the ground, is always covered as with a coat of rust. This is doubtless the fact, for the oxydasion of the iron it contains gives it that appearance, and colors the soil a reddish hue in its immediate vicinity. Wherever this rock abounds, the soil is durable and the crops are usually heavy. It is sometimes met with having a fine grain, and so very hard as to be almost brittle, though generally very difficult to break, and when broken strongly resembling cast-iron, and will sometimes ring, on being struck, almost as clearly. It was used very much formerly for making journals to run mill-gudgeons upon. When found on the surface, it is usually of a rounded form...."
However, much of the rock of the valley partakes of the nature of both hornblend and gneiss, and has been aptly termed a "hornblend gneiss rock."
Beds of magnesian or talcose slate, sometimes containing crystals of sulphuret of iron, are frequently met with in this section, and at the base of Black Oak Ridge, which is composed chiefly of chlorite slate and epidote, another bed of magnesian limestone is found. Containing about 40 per cent of magnesia, it makes an excellent cement for walls, but is of little or no value as a fertilizer.
SOILS.[10]
The soils of Loudoun vary greatly in both geological character and productiveness, every variety from a rich alluvial to an unproductive clay occurring within her boundaries. In general the soils are deep and rich and profitably cultivated.
The heavy clay soils of Loudoun are recognized as being the strongest wheat and grass soils. The more loamy soils are better for corn on account of the possibility of more thorough cultivation. However, the lands all have to be fertilized or limed to obtain the best results, and with this added expense the profit in wheat growing is extremely uncertain on any but the clay soils. The loamy soils are especially adapted to corn, stock raising, and dairying, and they are largely used for these purposes. The mountain sandstone soils, which are rough and stony, are not adapted to any form of agriculture; but for some lines of horticulture—as, for instance, the production of grapes, peaches, apples and chestnuts—or forestry they seem to offer excellent opportunities. The schist soil of the mountains, although rough and stony, is productive, easily worked, and especially adapted to apples, peaches, and potatoes. The shale and mica soils, although thin and leachy, are especially adapted to grapes, vegetables, and berries, and other small fruits. These soils should be managed very carefully to obtain the best results. They are easily worked and very quickly respond to fertilization and thorough cultivation. It is very probable that market gardening and fruit raising on these types would prove profitable. It seems, however, that peach trees are short lived on these soils. The meadow lands are low and subject to overflow, although otherwise well drained. They are best adapted to the production of corn, grass, and vegetables.
[10] For the bulk of the information appearing under this caption the author is indebted to Carter's and Lyman's Soil Survey of the Leesburg Area, published in 1904 by the United States Department of Agriculture.
That part of the County lying east of a line drawn from the Potomac River near Leesburg, by Aldie to the Fauquier line, is much more unproductive than the western portion, partly on account of an inferior soil, and partly in consequence of an exhausting system of cultivation, once so common in eastern Virginia, i. e., cropping with corn and tobacco without attempting to improve the quality of the soil. When impoverished, the lands were thrown out to the commons.
Large tracts that formerly produced from thirty to forty bushels of corn to the acre, still remain out of cultivation, though many of the present proprietors are turning their attention to the improvement of these soils and are being richly rewarded.
In this section, particularly along Goose Creek, trap-rock occurs, sometimes covering large surfaces, at other times partially covered with indurated shale, formed from the red shale of this region which has become hardened by the heat of the intruding trap. Where this rock occurs covering large surfaces, nearly level, "the soil is a dark brown colored clay, very retentive of moisture and better adapted to grass than grain.... A deficiency of lime probably occurs here, and there may be some obnoxious ingredient present. Minute grains of iron sand are generally interspersed through this rock, and as it is not acted upon by atmospheric influences, its combination may contain some acid prejudicial to vegetation. Where this rock is thrown into more irregular elevations, and is apparently more broken up, the soil is better."[11]
Near the Broad Run Bridge the soil is deplorably sterile. "In many places it is but a few inches in thickness, and the rock below, being compact, prevents the water from penetrating much below the surface, thus causing an excess of water in rainy weather, and a scarcity of it in fair weather. The red shale does not appear to decompose readily, as it is found a short distance beneath the surface, and the strata dipping at a low angle, prevents the water from freely descending into this kind of soil."[12]
[11] Taylor's Memoir.
[12] Ibid.
There is a huge belt of red land, known as "the red sandstone formation," extending from the Potomac through a part of each of the counties of Loudoun, Fairfax, Prince William, Fauquier, Culpeper, and Orange, which, with judicious cultivation, might be rendered liberally productive. Professor W. B. Rogers, in his report to the legislature of Virginia, in 1840, described it under the head of the "secondary formation in the northern district." "The general form of this area," he wrote, "is that of a prolonged triangle, extending in a direction from SSW. to NNE., having its apex at the southern extremity, and gradually expanding until it reaches the Potomac. Measured at a point on the Potomac between the mouths of Goose Creek and Broad Run, its length is about 80 miles. Its greatest breadth, as measured near the Potomac, and parallel to the road leading from Leesburg to Dranesville, is about 15 miles. This, in round numbers, gives 600 square miles for the area of this region."
Bottom lands of inexhaustible fertility and rich upland loams are commonly met with north and south of Leesburg for a considerable distance on either side of the turnpike leading from Point of Rocks, Md., at one extremity of the County to Middleburg at the other.
Limestone occurs in vast quantities throughout this zone, and there are present all the propitious elements that will be enumerated in the treatment of the soils of other areas.
The land here is in a high state of cultivation and, according to its peculiarly varying and unalterable adaptability, produces enormous crops of all the staple grains of the County.
The soil in the vicinity of Oatlands, included in this zone, is stiff and stony, except such as is adjacent to water courses, or the base of hills, where it is enriched by liberal supplies of decayed matter, which render it loamy and inexhaustible. In the main, it is of a generous quality, so pertinaciously retaining fertilizers as to withstand the washing of the heaviest rains. Still it is an anomaly that some of the richest areas in this region will not produce wheat; while, in the cultivation of rye, oats, and corn, satisfactory results are almost invariably obtained. Likewise there are but a few parcels whereon white clover does not grow spontaneously and in the greatest abundance. Than these, better pasture lands are found nowhere east of the Blue Ridge. Limestone occurs here in vast quantities.
In the Valley of Loudoun, between the Catoctin and Blue Ridge mountains, the soil is formed from gneiss, clay-slate, hornblend, greenstone, and quartz. The happy combination of these materials produces a most excellent and durable soil, containing, in fair proportions, alumina, silex, potash, lime, and other fertilizing minerals. Certain fertilizers have been successfully employed in improving its natural fertility, and when it is partially exhausted by excessive tillage, rest alone will restore it.
The Loudoun sandy loam consists of from 8 to 12 inches of a heavy brown or gray sandy loam, underlain by a heavy yellow or red loam or clay loam. Often the subsoil contains a considerable quantity of coarse sand, making the texture much the same as that of the soil. The sand of the soil and subsoil is composed of very coarse rounded and subangular quartz particles. The surface material is not a light sandy loam, but is more like a loam containing considerable quantities of very coarse quartz fragments. It is generally quite free from stones, but small areas are occasionally covered with from 5 to 20 per cent of angular quartz fragments several inches in diameter.
The Loudoun sandy loam occurs in irregular areas of considerable size in the intermediate valley between the Blue Ridge, Short Hill, and Catoctin mountains. The largest area of the type is found in the vicinity of Round Hill.
The topography of this soil in the valley varies from gently rolling to hilly, the slopes being long and gently undulating, while along the valley walls and in the uplands it is ridgy. Owing to the position which this type occupies, surface drainage is good. The light texture of the soil admits of the easy percolation of water through it, and, except where the subsoil contains considerable sand, the soil moisture is well retained. In dry weather, if the ground is cultivated, a mulch is formed, which prevents the evaporation of the soil moisture and greatly assists the crops to withstand drought.
Nearly the whole of this type is in cultivation. Where the forest still stands the growth consists chiefly of oak. The soil is easy to handle, and can be worked without regard to moisture content. It is considered a good corn land, but is too light-textured for wheat, although a considerable acreage is devoted to this crop. Corn yields at the rate of 40 or 50 bushels per acre, wheat from 12 to 15 bushels and occasionally more, and grass and clover at the rate of 1 or 2 tons per acre. The productiveness of the soil depends greatly on the sand content of the subsoil. If the quantity be large, the soil is porous and requires considerable rain to produce good yields. If the clay content predominates, a moderate amount of rain suffices and good yields are obtained. Apples, pears, and small fruits do well on this soil.
The Penn clay consists of from 6 to 12 inches of a red or reddish-brown loam, resting upon a subsoil of heavy red clay. The soil and subsoil generally have the Indian-red color characteristic of the Triassic red sandstone from which the soil is in part derived. From 1 to 10 per cent of the soil mass is usually made up of small sandstone fragments, while throughout the greater part of the type numerous limestone conglomerate ledges, interbedded with Triassic red sandstone, come to the surface. In other areas of the type numerous limestone conglomerate bowlders, often of great size, cover from 10 to 25 per cent of the surface.
This latter phase occurs in the vicinity of the Potomac River near Point of Rocks, Md., and near the Potomac, 3 miles north of Leesburg, and in these places the heavier phase of the type occurs, the clay often being very near the surface. In other parts of the County, where the limestone conglomerate is not so preponderant, or where it lies deeper and is mostly unexposed, the surface soil is deeper, often consisting of 18 inches of loam. The land is locally termed "limestone land." Near Catoctin Mountain the rocks seem to have weathered to considerable depth, there being no exposures or outcrops. Here the soil has been washed away from some of the more elevated small areas, and the heavy red clay subsoil is exposed.
In a great many places along the base of the mountain the formation of this type is somewhat complicated by the wash from the mountain, which consists principally of subangular quartz fragments, from 1 to 4 inches in diameter. This rock sometimes forms as much as 30 or 40 per cent of the soil mass. This phase is called "gravelly land," and is hard to cultivate on account of its heavy texture and stony condition, although it is inherently productive.
This type occurs in one irregular-shaped area, about 15 miles long, varying from less than 1 mile to 3 or 4 miles in width, being cut by the Potomac River just east of Point of Rocks, Md. It thus lies in the central part of the County, in the Piedmont Plateau, extending from immediately north of Leesburg, and skirting the eastern foot of Catoctin Mountain.
The general surface drainage is good, there being many small streams flowing through the type and emptying into the Potomac River. The stream beds are but little lower than the surface of the surrounding land, while the slopes are long and gentle. Excessive erosion scarcely ever occurs. The heavier phase of the type would undoubtedly be improved by tile draining, as it is usually lower lying than the lighter phase. The heavier phase bakes and cracks in dry weather much the same as the heavy limestone soils of the Shenandoah Valley, but with the lighter phases, where the soil covering is deeper, good tilth is easily maintained throughout the growing season.
Corn, wheat, clover, and grass are the crops grown, of which the yields are as follows: Corn, from 40 to 60 bushels per acre; wheat, from 15 to 25 bushels per acre, and clover and grass, from 1-1/2 to 2-1/2 tons of hay per acre.
The Penn clay is the most highly prized soil of the Piedmont region of Loudoun and brings the highest prices.
The Penn stony loam consists of from 8 to 12 inches of a red or grayish heavy loam, somewhat silty, underlain by a heavier red loam. From 10 to 60 per cent of gray and brown fragments of Triassic sandstone, ranging from 1 to 6 inches in thickness, cover the surface of the soil. The color is in general the dark Indian-red of the other soils derived from Triassic sandstone, being particularly marked in the subsoil.
This type occurs in the southeastern part of Loudoun, on the Piedmont Plateau. It occupies three small areas whose total extent probably does not exceed two and one-half square miles. It is closely associated with the Penn loam and grades gradually into that type. The only great difference between the two is the presence of sandstone fragments in the Penn stony loam.
The topography varies from gently rolling to hilly and ridgy, with slopes that are sometimes rather steep. However, the surface is not so broken as to interfere with cultivation, and the slopes are usually gentle.
The type is well drained, the slopes allowing a rapid flow of water from the surface, while the soil water passes readily through the soil and subsoil. On the other hand, the texture is sufficiently heavy to prevent undue leaching and drought.
Little of the land is in cultivation, on account of its stony character, which makes cultivation difficult. Where unimproved it is covered with a heavy growth of chestnut, oak, and pine. The land is locally called "chestnut land." In a few small areas the larger stones have been removed and the land is cultivated, corn and wheat being the principal crops. The yield of corn ranges from 20 to 35 bushels and of wheat from 8 to 15 bushels per acre. Apples and small fruits and vegetables do well.
The soil of the Iredell clay loam consists of from 6 to 18 inches of light loam, usually brown or gray, although sometimes of a yellowish color, with an average depth of about twelve inches. The subsoil consists of a heavy yellow to yellowish-brown waxy clay. This clay is cold and sour, almost impervious to moisture and air, and protects the underlying rock from decay to a great extent. Often the clay grades into the rotten rock at from 24 to 36 inches. In the poorly drained areas a few iron concretions occur on the surface. Numerous rounded diabase bowlders, varying in size from a few inches to several feet in diameter, are also scattered over the surface of the soil. Occasional slopes of the type have had the soil covering entirely removed by erosion, and here, where the clay appears on the surface, the soil is very poor. In other places, where the soil covering is quite deep, as from 12 to 18 inches, the type is fairly productive, and its productiveness is generally proportional to the depth of the soil.
The local name for the Iredell clay loam is "wax land," from the waxy nature of the subsoil, or "black-oak land," from the timber growth. A few small, isolated areas of this soil occur in the intermediate valley of the Catoctin Belt, and here the texture is much the same as that described above; but the soil usually consists of from 6 to 10 inches of a drab or brown loam, underlain by a heavy mottled yellow and drab silty clay. This phase has few stones on the surface or in the soil. The local names for this phase are "cold, sour land" and "white clay."
The greater part of the Iredell clay loam occurs in the southern or southeastern corner of the County and occupies one large, irregular-shaped but generally connected area, extending from Leesburg, in a southeasterly and southerly direction along Goose Creek to the southern boundary of the County, the most typical development of the soil being at Waxpool. The phase already described occurs in small, disconnected areas, usually quite far apart, the general relative direction of these areas being northeast and southwest. They all lie in the intermediate valley of the Catoctin Belt, and are usually near the foot of the Blue Ridge or Short Hills. The most typical development of this phase occurs just southeast of Bluemont.
Where rolling and sloping the surface drainage is good, the water passing rapidly from the surface into the numerous small streams flowing into Goose Creek, which is the main drainage way of this type. In the low, flat lands the water stands or flows very slowly from the surface. Owing to the impervious nature of the clay subsoil, underdrainage is very slow, and the land is often cold and sour.
Corn, wheat, and grass are the principal crops grown on this soil type, the average yields per acre being as follows: Corn, from 20 to 40 bushels; wheat, from 8 to 15 bushels; and grass, from 1-1/2 to 2-1/2 tons. Apples do fairly well.
The greater part of the type is tilled, while the uncultivated areas are used for pasturage and wood lots, the forest growth being black oak. In dry seasons, where the soil covering is not deep, the land bakes and cracks, and in this condition it can not be cultivated. In wet seasons the soil becomes too wet and sticky to work.
The Penn loam consists of from 8 to 12 inches of a dark, Indian-red loam, underlain by a heavier loam of the same color. This peculiar red color is distinctive of the formation wherever found, and, consequently, the type is one easily recognized. The texture of the type is very uniform, with the exception of a few small areas where the subsoil is a clay loam. The soil is locally termed "red-rock land," on account of the numerous small red sandstone fragments which occur in the soil and subsoil in quantities varying from 5 to 20 per cent of the soil mass. The soil is free from large stones or other obstructions to cultivation.
This type occurs in several large, irregular areas on the Newark formation of the Piedmont Plateau in the eastern part of the County. The areas have a general northeast and southwest trend. A few small areas occur in close proximity to the larger ones. One of the larger areas is situated just south of Leesburg, while another occurs east of Lucketts.
The topography consists of a gently rolling to nearly level plain, and there are no steep slopes or rough areas. Drainage in this type is excellent, the easy slopes allowing a gradual flow of water from the surface without undue erosion, except with very heavy rains on the steeper slopes. The loamy subsoil allows a ready but not too rapid percolation of surplus soil moisture, and never gets soggy or in a cold, sour condition. Numerous small streams extend throughout the area of this type, allowing a rapid removal of all surplus water into the Potomac River, the chief drainageway of the County. Along these streams, which in all cases have cut out beds some 10 to 30 feet below the surrounding plain, the slopes are gradual.
The original growth on the Penn loam was a forest of oak, hickory, and walnut, but at the present time nearly all of the type is cleared and farmed. The soil is not naturally very productive, but is prized on account of its great susceptibility to improvement, its quick responsiveness to fertilization, and its easy cultivation and management. The surface is smooth and regular, and the absence of stones, together with the loamy texture of the soil, makes it easy to maintain good tilth. Any addition of fertilizers or lime is immediately effective, and by judicious management the type may be kept in a high state of productiveness. Many fine farms with good buildings are to be seen on this type. The crops grown are corn, wheat, grass, clover, apples, and small fruits. Grazing, stock raising, and dairying are practiced to some extent. The land yields from 40 to 60 bushels of corn, from 10 to 15 or more bushels of wheat, and from 1 to 2 tons of hay per acre.
The soil of the Cecil loam consists of from 8 to 12 inches of a brown or yellow loam. The subsoil consists of a heavy yellow or red loam, or occasionally clay loam. The soil and subsoil are usually free from stones, but occasional areas have from 5 to 30 per cent of angular quartz or schist fragments on the surface. Often a mica-schist enters into the composition of the subsoil, giving it a soft and greasy feel.
The greater part of the intermediate valley or baselevel plain of the Catoctin Belt consists of the Cecil loam, and it occurs here as one large, connected area, inside of which are small areas of Cecil clay, Loudoun sandy loam, and Iredell clay loam. A considerable portion of the Catoctin Mountain also consists of the Cecil loam. In extent this is the most important soil type in Loudoun, covering about 33 per cent of the total area.
The Cecil loam, owing to its rolling character, is well drained throughout. Many small streams traverse it, affording ample outlets for surface water. The gently rolling areas are not generally subject to excessive erosion, but the steeper slopes wash badly, deep gullies and ditches being formed on the hillsides. Especially subject to erosion are the areas in which the subsoil contains a relatively large proportion of mica fragments. The soil and subsoil, though quite loamy, retain enough moisture in seasons of moderate rainfall to supply all growing crops.
The Cecil loam is devoted entirely to general farming. The crops grown are corn, wheat, grass, clover, vegetables, apples, and pears. The agricultural interests are further diversified by the practice of dairying and stock raising. The land is one of the best corn soils of Loudoun, being loamy and easily cultivated throughout the growing season. The average yield per acre ranges from 40 to 60 bushels. Wheat does very well, producing from 12 to 20 bushels per acre, and more in favorable seasons. Grass and clover yield at the rate of from 1 to 2 tons of hay per acre and form good grazing during a considerable part of the year. Apples and pears are grown everywhere on the type, usually in small orchards, and good yields of these fruits are obtained. Oats were at one time grown, and can be produced at the rate of from 35 to 50 bushels per acre, but the present acreage is small, the farmers claiming that this crop rapidly reduces the productiveness of the soil.
Nearly all of the type is in cultivated crops or pasture. The original timber growth was oak, hickory, and walnut; but little of this stands now, except on occasional woodlots. The Cecil loam is a soil which with careful treatment makes a fine farming land; but carelessly managed it very quickly deteriorates.
The soil of the Cecil clay consists of a heavy loam, red or brown in color, and having an average depth of 8 inches. The subsoil generally consists of a red clay, although it is sometimes a heavy clay loam. The surface is generally free from stones, though occasional small areas have a few quartz and granite or schist fragments. In the Piedmont areas small rounded diabase fragments occur on the surface. Occasionally on steep slopes or high knobs the soil covering has been washed away, leaving the heavy red clay exposed on the surface. These areas, however, are small.
The type occurs principally in the intermediate valley of the Catoctin Belt, between the Blue Ridge and the Catoctin Mountain, and on the west slopes of the Catoctin Mountain. In the valley it occupies several small, disconnected areas scattered throughout this region, while on the west slope of the mountain it is found in one of two long, broad areas, extending in a northeast and southwest direction. Three small areas occur near the southeastern corner of the County, and the type is here closely related to the Iredell clay loam.
The most typical areas of this soil occur in the Piedmont Plateau and on the gentle slopes at the foot of the Blue Ridge in the vicinity of Bluemont.
This soil type has excellent surface drainage and is well watered and drained throughout by small streams. Few of the slopes are so steep as to wash badly. The heavy clay subsoil retains ample moisture for plant growth and the soil is rarely so wet as to necessitate tile draining, although this would undoubtedly be very beneficial in the case of the heavier phases.
The whole of this soil is under cultivation and it is highly esteemed wherever found, being naturally a strong soil and susceptible of improvement. The original forest growth consisted of oak, hickory, and walnut. The land is easily improved, retentive of moisture and manure, and with careful management makes an excellent soil for general farming. Owing to its tendency to bake, crops are liable to suffer during drought.
The land produces wheat, corn, grass, clover, apples, and pears. It is a strong wheat soil, and yields from 15 to 25 bushels per acre and occasionally more. Grass and clover hay yield at the rate of 1-1/2 to 2-1/2 tons per acre, while from 40 to 60 bushels of corn per acre are usually produced in good seasons.
All things considered, the Cecil clay is best adapted to the production of wheat and grass. The more loamy phases are adapted to corn, but the type as a whole is a much better wheat land than corn land. The soil is also well adapted to apples and pears. Bluegrass grows well and makes fine pasturage, and stock raising and dairy farming are other industries to which the Cecil clay is well suited. Care has to be used in the cultivation of this soil, for if worked when too wet it dries in large, hard clods that give trouble throughout the season and interfere with cultivation for a long time afterwards.
The surface soil of the Cecil silt loam consists of 12 inches of a light gray or white silt loam. This material is underlain by a subsoil of yellow silt loam slightly heavier than the soil. The type is locally termed "white land," and is closely related to the Penn loam and the Iredell clay loam, these types surrounding and grading gradually into it. In some areas the soil is quite free from stones, while in others from 10 to 30 per cent of the soil mass is composed of small rock fragments.
The type occupies several small areas in the Piedmont region, in the southeastern part of the County. The largest of these areas lies about 2 miles east of Leesburg, and a considerable part of the type is adjacent to the Potomac River. It occupies high, rolling, ridgy, or hilly lands, and has some rather steep slopes, though in general the surface is only gently sloping.
The drainage is good, but wherever the slopes are steep erosion proceeds rapidly, making gullies and washed-out places that hinder or entirely prevent cultivation. The type is well watered by small streams which flow the year round.
Probably one-half of this type is cultivated. The remainder is covered with a growth of scrub oak, pine, and some cedar. The soil is thin and only fairly productive, and consequently is not greatly desired for agriculture. It is very easy to work, but has to be cultivated carefully to avoid washing. The crops raised are corn, wheat, grass, and some apples. Corn yields from 25 to 35 bushels, wheat from 12 to 15 bushels, and clover and timothy hay from 1 to 2 tons per acre. Small fruits and vegetables do well.
Although naturally a thin soil, the Cecil silt loam is fairly well adapted to the production of the crops just named. Of the small fruits, peaches, plums, and berries do best. On the whole the type is considered much better adapted to wheat than to corn. It is limed and fertilized to a considerable extent, and responds well to such applications.
The Cecil mica loam consists of 12 inches of a friable, micaceous yellow or yellowish red loam, underlain by a yellow or yellowish-red loam, whose mica content increases with the depth until at 24 to 30 inches the subsoil is little more than a mass of small mica flakes which gives it a loose texture. Occasionally the subsoil is a clay loam for several inches before grading into the unweathered mica particles.
On the surface there is from 5 to 40 per cent of angular quartz fragments, ranging from 1 to 6 inches in diameter, some being much larger.
The Cecil mica loam occurs as one long, narrow strip, occupying the lower, gentle eastern slopes of the Catoctin Mountain. The southern end of the strip begins a short distance north of Leesburg, and extends in a northeasterly direction to the Potomac River, opposite Point of Rocks, Md.
The topographic features of the Cecil mica loam consist of gentle and occasionally steep rolling slopes. The surface is well drained and on the steeper slopes the soil washes badly and deep gullies are formed. In a season of moderate rainfall the soil and subsoil retain considerable moisture, but in dry weather crops suffer from drought.
No farms are found entirely on the Cecil mica loam, but those farms of the Piedmont, extending up the mountain slopes, generally include some of this soil. Such areas are often farmed, but more generally used as woodlots. Where cultivated the yields are scant, except where the soil is heavily fertilized. Corn yields from 10 to 30 bushels per acre and sometimes more, and wheat from 6 to 12 bushels per acre. The type is best adapted to forestry, chestnut orcharding, and grape growing.
The soil of the De Kalb stony loam consists of a yellow or gray sandy loam of coarse texture, having an average depth of 12 inches. The subsoil consists of a heavy yellow sandy loam to a depth of 24 inches or more, where it rests upon a mass of sandstone fragments. These sandstone fragments and bowlders occur in varying quantities throughout the soil and subsoil. Where the fewer stones are found the soil is not so sandy, but a light loam, yellow or brown in color, underlain by a deep yellow loam subsoil.
The De Kalb stony loam is a mountain soil, occurring in long, parallel bands of varying width, extending in a general northeast and southwest direction, and mainly occupies the crests and slopes of the Blue Ridge and Short Hill mountains. It also occurs in smaller areas on the crest and east slope of Catoctin Mountain.
On the Blue Ridge and Short Hills the De Kalb stony loam covers the whole of the mountains, and here the physiography consists of long, sharp, rock-crested ridges, with steep, rugged slopes and occasional cliffs and huge ledges. There are occasional benches on the mountain sides, and here there is an accumulation of two or three inches of a black mold, resting on the broken sandstone fragments, and covered with a growth of locust, oak, and berry vines.
Owing to the steep and rugged surface of this soil, together with its stony character, superficial drainage is rapid and thorough, the water rushing in torrents from the mountain slopes, while as a result of the loose texture and the large number of stone fragments in the soil the water passes rapidly through it, and there is never an excess of moisture in the soil or subsoil.
On account of the steep and stony nature of the De Kalb stony loam little of the type can possibly be cultivated. The soil is naturally a very thin one, and is not capable of producing fair yields except in its less stony phases.
The principal growth on the type is chestnut, oak, and some pine. Probably 95 per cent of the type is uncultivated, and is valuable only for the timber growth it supports. Where cultivated the average yields per acre are as follows: Corn, from 10 to 20 bushels; wheat, from 6 to 10 bushels. Apples and especially peaches do fairly well on the mountain phase where not too stony.
The greater part of the De Kalb stony loam is not adapted to agricultural purposes at all, and it is not likely that the land will ever be valuable except for forestry. It is locally termed "mountain land," and is the poorest agricultural soil of the County.
The Porters clay consists of from 6 to 12 inches of a brown or reddish-brown loam, underlain by a heavy red loam or clay loam. The type consists of fairly rough mountain land, and is very stony, having from 15 to 60 percent of small and large schist fragments on the surface, some of which are several feet in diameter. The soil is light and easy to work wherever it is not so stony as to interfere with cultivation.
This soil is a strictly mountain type and not of great extent. It follows the crest and part of the east slope of the Blue Ridge Mountains for several miles, extending in a northeasterly direction and ending at the areas of sandstone formation.
The type is well drained throughout, while the texture of the subsoil is sufficiently heavy to retain considerable moisture through quite extended dry spells. The steeper slopes are uncultivated, and hence are not subject to erosion.
A considerable proportion of this soil type is under cultivation, especially on the broad mountain top. Those areas not cultivated are covered with a heavy growth of oak, hickory, locust, and walnut. Corn and wheat can be grown on the type with fair yields, but little of the latter is grown on account of the stony nature of the land. Corn yields from 20 to 35 bushels, wheat from 8 to 15 bushels, and grass and clover from 1 to 2 tons per acre. Irish and sweet potatoes give good yields, and fine apples and peaches are produced. Peaches are liable to winterkill, and the crop is uncertain for this reason. This type is peculiarly adapted to fruit growing, and especially to the production of apples.
The Meadow of Loudoun is usually a brown silty or sandy loam, with a depth of several feet. The type occurs in narrow bands along the larger streams, forming a bottom or low terrace a few feet above the mean water level. The nature of the soil depends greatly on the surrounding soils, as it is formed from sediment of the wash from these types and partakes of their textural characteristics to some extent.
The type, while low and flat, is generally well enough drained for cultivation, although this is somewhat hindered by overflows; consequently the land is chiefly used for grazing. The soil is alluvial in origin, being built up by successive overflows of the streams. Little of the type is forested. Where cultivated it is generally used for corn, which yields from 50 to 75 bushels an acre. Little wheat is grown, although the soil is capable of producing fair yields of this crop. It also produces from 2 to 3 tons of hay per acre, and affords excellent pasturage. The crops are somewhat uncertain, however, on account of overflows which sometimes occur after the planting season, though in the case of the River the danger from flood is usually past before the time for corn planting. Where the areas are in grass the floods usually do little damage. Productiveness is in a great measure maintained by the addition of the sediments left by the overflow waters.
Flora.—Records of the days of early settlement point to a scarcity and an inferiority of large timber in Loudoun (then Prince William) and contiguous counties. The responsibility for this condition has been traced to the hunters who frequented this region prior to its settlement and wantonly set fire to the forests in order to destroy underbrush, the better to secure their quarries. A comparatively dense and vigorous new growth followed the discontinuance of this pernicious practice.
At the present time, after the encroachment of field and pasture for nearly two centuries, a large portion of the county's area is still under forest cover. The stand, in the main, is somewhat above average size and quality.
The total value of forest products cut or produced on farms in 1899 was $51,351. This includes only the wood, lumber, railroad ties, etc., which the farmers cut in connection with their ordinary farming operations. The reports of persons making lumbering or wood cutting their principal business are not included.
The trees common to Loudoun are four varieties of the white oak, i. e., common, swamp, box, and chestnut-leaved, the latter, however, appearing only along the margin of the Potomac River; black, Spanish, and red oak, chestnut oak, peach or willow oak, pin oak; and in the eastern parts of the county, black jack, or barren oak, and dwarf oak, hickory, black and white walnut, white and yellow poplar, chestnut, locust, ash, sycamore, wild cherry, red flowering maple, gum, sassafras, persimmon, dogwood, red and slippery elm, black and white mulberry, aspin (rare), beech, birch, linn, honey-locust, sugar maple, sugar nut, yellow and white pine, hemlock, and red cedar.
Among the smaller trees and shrubs are the white thorn, maple-leaved or Virginia thorn (suitable for hedging), hawthorn, wild May cherry, or service berry, water beech, fringe tree, red bud, black alder, common alder, sumach, elder, laurel, witch-hazel, hazel-nut, papaw, chinkapin, burnish bush, nine bark, button-bush, honeysuckle, several varieties of the whortleberry or huckleberry, and wild gooseberry.
A few of the brambles met with are the greenbrier, high blackberry, dewberry, or low blackberry, and raspberry.
A list of the vines and creepers would comprise the fox grape, three varieties; pigeon, or raccoon grape, chicken grape, a wild bitter grape, sarsaparilla, yellow parilla, poison-vine, or poison-oak, clematis, trumpet-flower, and wild potato vine.
The medicinal herbs found in Loudoun are the rattlesnake root, Seneca snakeroot (also called Virginia snakeroot), many varieties of mint, liverwort, red-root, May apple, butterfly-weed, milk weed, thorough-stem, trumpet-weed, Indian-physic, lobelia inflata, and lobelia cardinalis, golden-rod, skunk-cabbage, frost-weed, hoar-hound, and catnip.
The injurious plants with which the careful farmer must contend are the wild garlic, tribby weed, dog fennel, two varieties of the common daisy, oxeye daisy, St. John's wort, blue thistle, common thistle, pigeon-weed, burdock, broad and narrow-leaved dock, poke-weed, clot-bur, three-thorned bur, supposed to have been introduced from Spain by the Merino sheep, Jamestown or "jimson" weed, sorrel, and, in favorable seasons, a heavy growth of lambs quarter and rag-weed.
Of introduced grasses, Loudoun has red clover, timothy, herd's-grass, orchard-grass, and Lucerne to which last little attention is now given. Native grasses are the white clover, spear grass, blue grass, fox-tail and crab grass, the two last-named being summer or annual grasses. Several varieties of swamp or marsh grass flourish under certain conditions, but soon disappear with proper drainage and tillage.
Although some of the wild flowers of Loudoun merit the attention of the florist, as a whole they have no commercial value or significance and, for this reason, an enumeration of the many varieties has not been thought expedient.
Fauna.—Wild ducks, geese, and turkeys, pheasants (English and Mongolian), partridges and woodcock are among the game fowls of Loudoun, and eagles, crows, buzzards, owls, and hawks among the predatory. The usual list of songbirds frequent this region in great numbers and receive some protection under the stringent fish and game laws in force here.
Red and gray foxes, raccoons, opossums, woodchucks, squirrels, hares and smaller animals are quite general.
In pioneer days the county abounded in the larger species of game common to the forests of North America. Among these were the beaver and otter, buffalo, deer, wolf, wild-cat, panther, bear, fox, and elk or wapiti (Cervus canadensis), noble herds of which ranged the mountain sides and valleys of this section.
TRANSPORTATION FACILITIES.[13]
Good roads, always of immeasurable importance to the farmer, were early made necessary by the tremendous crops of marketable products harvested from Loudoun lands. Though this need, in time, became imperative the roads were never hastily and imperfectly constructed; they were built with an eye single to permanence and with due allowance for generations of unintermittent and augmentative traffic.
These roads yielded their promoters modest dividends, but with the completion in 1832 of the Chesapeake and Ohio Canal, bordering the county just across the Potomac, transportation to and from Washington (Georgetown) and Alexandria was materially cheapened and the earnings of the turnpike companies suffered a corresponding decrease, the income, in many cases, being barely sufficient to defray the expense of maintenance. Tolls are now collected at only two points, in the County.