History of Lehigh county, Pennsylvania and a genealogical and biographical record of its families, Vol. I, Part 2

Author: Roberts, Charles Rhoads; Stoudt, John Baer, 1878- joint comp; Krick, Thomas H., 1868- joint comp; Dietrich, William Joseph, 1875- joint comp; Lehigh County Historical Society
Publication date: 1914
Publisher: Allentown, Pa. : Lehigh Valley Publishing Co.
Number of Pages: 1158

USA > Pennsylvania > Lehigh County > History of Lehigh county, Pennsylvania and a genealogical and biographical record of its families, Vol. I > Part 2

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Series Duration in years

S Recent 20,000

Miocene

3,400,000

Carboniferous 3 Pennsylvanian Mississippian .

GEOLOGY.

Many small streams originate in these hills and join the larger creeks in the limestone valleys but none of them cut entirely through the ridge. The hills therefore form the watershed between two drainage systems. With few exceptions all the streams which head in the southeastern slopes of these hills belong to the Schuylkill river drainage system, while the streams on the north- western slopes constitute a portion of the Lehigh river drainage system.

The South mountain hills owe their height and their rugged character to the fact that the rocks composing them resist the destructive agents of the atmosphere and water much better than the rocks underlying most of the county. Their rocky slopes bear evidence to the wearing action which they are now undergoing, but the process of disintegration of such firm rocks is a slow one.

Limestone Valleys .- In striking contrast topo- graphically to the South mountain hills are the limestone valleys. In comparison the latter are almost flat. The Little Lehigh, the lower course of the Jordan, and the upper part of the Saucon creeks drain the principal limestone areas of the county. These creeks flow slowly because of the slight differences in elevation, and have extremely crooked courses. Meandering streams are char- acteristic of flat regions.

The surfaces of the limestone valleys might be characterized as rolling. The hills are low, well- rounded, and in the main so covered with soil that few rocks are seen. The elevations of the uplands in these broad valleys range from 300 to 400 feet above sea level, but along some of the larger streams the elevations are considerably less than 300 feet. The Jordan and Little Lehigh creeks have an elevation of only about 220 feet at their junction with the Lehigh River.

The low elevations of the limestone valleys and their characteristic features are due entirely to the fact that the limestones are worn away readily by water due to their ease of solubility.

Slate Hills-The Slate Hills tract comprises practically all of the townships of North White- hall, Washington, Lowhill, Heidelberg, Lynn, and Weisenberg. The region is rugged in com- parison with the limestone valley to the south and greatly dissected by streams. Most of the hills are flat-topped, attain an elevation of 600 to 800 feet above sea level, and are surrounded by narrow steep-sided valleys. The streams have cut their valleys about 200 feet below the tops of the hills. On account of the steep slopes nearly all the main roads follow the streams or the sinuous flat-topped stream divides. On the flat uplands there is a clayey-soil covering several feet in depth, while along the steep slopes the soil is

well-filled with fragments of disintegrated slate.

The slate hills owe their characteristics to the fact that the rock composing them is only slight- ly soluble and disintegrates mainly by frost ac- tion. The streams have cut their valleys almost as deep as they can at present, but have done very little work in widening them.

Blue Mountain .- Blue mountain, the crest of which forms the northwestern boundary line of Lehigh county, is the most striking topographic feature of the region. On a clear day this moun- tain can be seen from almost all parts of the county, and is greatly admired because of its rugged character, and its even sky-line unbroken for many miles. Its greatest elevation in Lehigh county is in the extreme northwestern corner of the county where the three counties of Berks, Le- high, and Schuylkill join. Here the ridge has an elevation of 1,642 feet above sea level. Bake Oven Knob, about eight miles farther northeast, between Lehigh and Carbon counties, is another prominent point in the ridge. It has an eleva- tion of 1,560 feet above sea level. The greater portion of the ridge rises to the height of 1,400 to 1,500.

Blue mountain is a narrow ridge with north- east-southwest trend, and is composed of ex- tremely resistant siliceous sandstones and con- glomerates dipping steeply to the northwest. The top of the ridge owes its even sky-line to the fact that erosion at one time planed the entire region, regardless of the kind of rocks, to base level. Later the region was elevated and the weaker rocks have now been extensively worn away leaving the hard rocks of Blue mountain the only remnants of the former plain.

At Lehigh Gap the Lehigh river breaks through Blue mountain in a narrow valley which is called a "water gap." Some early writers be- lieved that the gaps in the Blue mountain through which the Delaware, Lehigh, and Schuyl- kill rivers flow, were produced by an earthquake shock which had split the rocks. This is plainly not the case. The gaps have been cut by the rivers themselves during long ages. Their nar- row character is due to the fact that the rocks are so resistant that the streams have accom- plished little in widening their valleys. How ever, the rocks of Blue mountain are gradually going to pieces, as is plainly shown by the numer- ous blocks of loose rock that cover the slopes.

RELATION OF THE PHYSIOGRAPHY TO THE ECONOMIC DEVELOPMENT OF LEHIGH COUNTY.

It is generally recognized among geographers that the physiography of a region is of the

HISTORY OF LEHIGH COUNTY, PENNSYLVANIA.

greatest importance in the determination of the occupations of the people and in its industrial de- velopment. Certainly in Lehigh county we have many examples of its effects.

When the first settlers entered Lehigh county they found the entire region covered with forests which they at once began to remove in order that they might cultivate the soil. Naturally they first cleared the lower-lying more level portions of the county and these were found in the lime- stone valleys where agriculture was alone fol- lowed for many years. Later the slate hills were brought under cultivation but the steeper slopes there retarded the development of that district for many years. Much later some portions of South mountain were cleared but the steep slopes that permit the soil to be removed as fast as it forms are so unfavorable for agricultural purposes that the greater portion of these hills are still covered with timber. Lastly, Blue Mountain in this section is so rugged that no at- tempts have ever been made to farm it. Agri- culture, therefore, is confined to the limestone valleys and the slate hills of the county.

The original forests of Lehigh county were at first regarded as a hindrance in the development of the region and in the regions best suited for agriculture, the timber was destroyed before its value was appreciated.

Consequently, for many years almost all the timber furnished by the county has come from the South mountain hills and Blue mountain. But since a timbered country cannot furnish a livelihood permanently for many people the more elevated and rugged portions of the county have always been thinly populated. Some mining operations that have been carried on at various times in the South mountain hills have slightly increased the population but to no great extent.

In the settlement of the region the main roads followed the limestone valleys where the grades were gentle, and there is where the first towns were built, and that is where we still have the largest towns and cities. A few towns have later been built in the slate hills on account of the slate and cement industries, but no towns are found in the more rugged portions of the county.

When railroads were built the easiest paths were naturally sought and the result is shown by the number of railroads in the limestone val- leys compared with those in the other physi- ographic districts. The Perkiomen Railroad is the only line that crosses South Mountain in Le- high county and it passes through the highest part of the mountain by means of a tunnel. The only railroad lines that cross Blue Mountain do so in the narrow gaps cut by the streams. Trol-

ley lines are not so dependent upon gentle slopes as are steam railroad lines and yet they too are mainly confined to the limestone valleys.

In the present stage when agriculture is being replaced in importance by manufacturing, we again see the influence of the physiography. The establishments must be within easy reach of the railroads and so the various manufacturing in- dustries are almost all confined to the limestone valleys. The question of supplies of water has also determined the location of the largest in- dustrial plants and since the streams of any con- sequence are found in the lower-lying portions of the county, there alone is where most of them could carry on their operations.

Other illustrations of the same character might be cited, but it is not considered necessary to mul- tiply examples. Man justly prides himself upon his ability to overcome obstacles in Nature but in the last analysis it is apparent that he is guided and controlled in his various activities by Nature at every turn.

DESCRIPTIONS OF THE GEOLOGICAL FORMA- TIONS OF LEHIGH COUNTY.

The rocks appearing at the surface in Lehigh County belong to five of the great geologic per- iods named in the table given on a preceding page. Since the rocks of some of these periods are of quite different character, we further di- vide them into various formations to which geo- graphic names have been applied.

The geologic column of Lehigh county, is given in the following table arranged with the oldest rocks at the base. In the descriptions which follow each series will be described. beginning with the oldest.

Period.

Formation.

Recent

River Alluvium.

Pleistocene

Glacial Drift.

Triassic

Brunswick Conglomerate.

Silurian

Shawangunk Conglomerate.

[ Martinsburg Shales.

Nazareth Cement Limestone.

Ordovician

Jacksonburg Limestone.

Beekmantown Limestone.

Allentown Limestone.

Cambrian

Leithsville Limestone.

Hardyston Quartzite.

Pre-Cambrian

Gneisses and schists.

PRE-CAMBRIAN ROCKS.

The pre-Cambrian rocks of Lehigh county occur in the southeastern corner of the county in the townships of Hanover, Salisbury, Upper Saucon, Upper Milford, Lower Milford, and

§ Brunswick Shale.

GEOLOGY.

Lower Macungie. They constitute the highest elevations in this section of the county. South mountain which extends from South Bethlehem to Shimersville and beyond owes its present ele- vation to the fact that it is composed of these rocks which have resisted the wearing action of the atmosphere and water better than the adjoin- ing rocks.

In the absence of any fossils it is not possible to determine whether these rocks belong to the Algonkian or Archean, so they are usually group- ed under the more general term of pre-Cambrian.

The rocks are completely crystalline, are varied in their mineralogical composition, and present many different phases in different localities. They belong to the class of rocks called gneisses and have been formed by the metamorphism of rocks that were originally for the greater part igneous but in part sedimentary. Most of them consist primarily of feldspar, quartz, hornblende, mica and pyroxene with subordinate amounts of epidote, magnetite, pyrite, ilmenite, allanite, molybdenite, graphite, corundum. As the rocks decompose the minerals, kaolin, limonite, pyrolu- site, hematite are formed. In some places the dark-colored minerals predominate while in other localities the rocks consist almost entirely of the light-colored minerals. In most of the rocks, however, both light and dark-colored con- stituents are present and roughly arranged in light and dark bands. During the process of metamorphism there was a tendency for like min- erals to segregate which is responsible for the banding which is very prominent in many places.

The size of the mineral particles varies from about 1-16 to 1/4-inch in diameter in most of the rocks. Here and there one encounters dikes of pegmatite that have cut through the other crystal- rocks and are extremely coarse. The individual crystals of the pegmatite may be several inches in diameter.

In two places in the county gneisses containing considerable graphite occur. These localities are in the top of South mountain about one mile east of Emaus and about one mile east of Vera Cruz Station. These graphite bearing gneisses were undoubtedly sedimentary deposits originally.

The crystalline rocks of the county have been divided into five formations which have received names of Pochuck Gneiss, Byram Gneiss, Losee Gneiss, Pickering Gneiss, and Franklin Forma- tion, but lack of space does not permit individual descriptions of each of these varieties.

The economic deposits of the pre-Cambrian gneisses in order of importance are iron ore, building stone, paving and ballast stone, kaolin,

sand, pyrite, manganese ore, corundum, mica, and graphite. These have been found in many places and the numerous abandoned mines and prospect pits on South mountain bear evidence of the active search made for economic deposits. These will be described more fully on a later page.

CAMBRIAN ROCKS.

The rocks of Cambrian age of Lehigh county represent two distinct types-quartzites and lime- stones. The quartzites belong to the formation that has received the name of Hardyston ; while the limestones belong to two formations-Leiths- ville shaly limestone, and the Allentown dolomitic limestone.

HARDYSTON QUARTZITE.

The Hardyston formation overlies the gneisses of South mountain, and is composed of varied materials. In many places the basal portions con- sists of an indurated soil formed from the decay- ed portion of the underlying gneiss, in which are angular pieces of quartzite with an occasional rounded quartz pebble. The indurated kaolin is of a light green color in most places resembling serpentine but in a few places it is stained by iron oxide to such an extent that it resembles red jasper. This old soil bed is seldom more than four feet in thickness. It forms a gradation between the gneiss and the overlying sandstone or quartzite and may equally well be classified with either.

Above the indurated soil stratum occur beds of siliceous rocks ranging from conglomerates with pebbles an inch or more in diameter to quartzites in which the individual grains of quartz cannot be distinguished. The basal beds are stained with iron, a rusty brown in most places, but the upper strata are so white that they furnish excellent building stone. In some places kaolin derived from the adjacent gneiss forms a prominent constituent of the lower strata.

The most unusual phase of the formation oc- curs along the northwest flank of South Moun- tain near Emaus where secondary changes have converted the rock into a ferruginous chert, chert breccia, or brown iron ore. In the altera- tion which has been produced by ascending and descending waters along a fractured zone all traces of bedding planes have been obliterated. Great masses of this rock occur a short distance northeast of Emaus where broken blocks cover extensive areas. The Indians made use of this rock in the manufacture of their arrow heads,

HISTORY OF LEHIGH COUNTY, PENNSYLVANIA.

and several of their old work shops have been located in the vicinity of Emaus.

The Hardyston formation has yielded few fossils in this region, the only ones being a few spines of the trilobite Olenellus about one-half mile southwest of Old Zionsville, and specimens of the borings of a marine worm called Scolithus linearis. The latter are abundant in Lock Ridge near Alburtis.

The formation is about 150 feet thick in the region of Bethlehem, but increases slightly in thickness toward Macungie.

LEITHSVILLE SHALY LIMESTONE.

Overlying the quartzite and sandstones of the Hardyston formation is a considerable thickness of shales and shaly limestones with occasional strata of compact thick-bedded dolomitic lime- stones, in which there are many nodules of black to gray chert. They outcrop at the base of the South mountain hills and are in many places en- tirely concealed from view by the talus of the more resistant gneiss and quartzite which out- crop at higher levels. Fossils seem to be entirely absent, suggesting a chemical origin for the lime- stones. The thickness of the strata of this for- mation is about 1,500 feet.

ALLENTOWN LIMESTONE.

The Allentown formation is composed of mas- sive beds of dolomitic limestones, white to gray in color. Outcropping to the north of the Leithsville strata and farther from the steep slopes of South mountain there are many excel- lent exposures of the formation in the southern portion of the great limestone valley. The rocks of this formation are well exposed along the little Lehigh and Jordan creeks in the vicinity of Al- lentown, and extend from there in a broad belt in a southwesterly direction beyond the borders of the county.

The limestones are so soluble that caverns are common in the regions where these rocks occur, and many houses and even towns make use of these underground passages in the disposal of their sewerage.

The only abundant fossil thus far recognized in this formation is Cryptozoon proliferum. It occurs in rounded heads varying in diameter from I inch to 11/2 feet. Closely associated with these fossils are layers of oolite. In most cases a band of oölitic limestone several inches in thick- ness underlies the stratum containing the col- onies of Cryptozoon proliferum.

The thickness of the Allentown limestone is apparently about 3,000 feet, but the absence of any continuous section across the entire forma-

tion, and the presence of several strike faults, render the exact determination of the thickness impossible.

ORDOVICIAN ROCKS.

The rocks of Ordovician age in Lehigh county consist of limestones and shales or slates. The limestones belong to three formations-Beekman- town Limestone, the Jacksonburg Limestone, and the Nazareth Cement Limestone. The shales constitute the Martinsburg formation, which is so extensively developed in the northwestern por- tion of the country.

BEEKMANTOWN LIMESTONE.

The lowest member of the Ordovician period in this region is the Beekmantown formation that is well exposed in several places along the Lehigh river in the vicinity of Coplay. Lithologically it is a heterogeneous limestone composed of small irregular bodies of light and dark material. Some shaly layers are also present. Some of the layers consist of almost pure CaCO3 and have been used in the manufacture of cement while interbedded strata are dolomitic. In general, the dolomitic layers are whiter than the others and can be readily detected in quarry openings.

Fossils have been found in the rocks of this formation at many points in the vicinity of Beth- lehem and Coplay. They are not very well pre- served, but yet it has been found possible to de- termine the following forms:

Helicotoma sp. Liospira (?) sp. Syntrophia lateralis.

Protowarthia rossi.

Ophileta complanata. Eccyliopterus volutatus.

Dr. E. O. Ulrich, who made the determina- tions, considers the formation to be the equiva- lent of the Beekmantown of New York. The thickness of the formation is about 1,500 feet.

JACKSONBURG LIMESTONE.

Gray shaly limestones immediately underlying the cement rock constitute the Jacksonburg for- mation. The formation, although only about 100 feet thick, is of great economic importance because of the extensive use made of these lime- stones in the manufacture of Portland cement. Magnesium is either very low, or altogether lack- ing, and the rock is therefore well suited for mixing with those shales that are deficient in lime in order to get the correct composition for the best grade of cement. Fossils are not abundant although they have been found in several places. The following species have been determined

GEOLOGY.

from quarries near Nazareth, Northampton county :

Receptaculites occidentalis, Plectambonites sp. Pachydictya sp. Fragments of crinoids.

Dr. E. O. Ulrich considers the fauna the ap- proximate equivalent of the Black River of New York.

The formation is well developed along the Le- high river a short distance northwest of Cop- lay.

NAZARETH CEMENT LIMESTONES.

The Nazareth formation, consisting of a gray to black shaly limestone that has been so exten- sively utilized in the manufacture of cement in the Lehigh Cement District, outcrops along the north side of the limestone valley extending from the Delaware river to the Schuylkill river. In this narrow belt are located many of the largest cement mills of the country and only a few years ago 90 per cent. of the cement product of the United States was manufactured here, while at present the district contributes about one-third of the total product.

The Nazareth limestone is not continuous and its absence in certain localities is explained by its passage into shales that are not separable from the overlying Martinsburg shales. The maxi- mum thickness is probably about 500 feet. The crumpling which it has undergone by which bed- ding planes have been obliterated in many places render the determination of the thickness some- what indefinite. Mesotrypa quebecensis has been found in several places in this formation together with fragments of other fossils.

MARTINSBURG SHALES.

The difficultly soluble black shales of the Mar- tinsburg formation bound the limestone valley on the north as do the slightly soluble gneisses and quartzites on the south side. Near the base of the formation the shales have become suffici- ently metamorphosed to permit certain strata to be used for roofing slates, and several slate quar- ries were formerly worked in this part of the Martinsburg shales in the vicinity of Nazareth and Bath, in Northampton county, and near Laurys in Lehigh county. The middle portion of the formation contains many interbedded lay- ers of dark-colored sandstones and no workable slate, while the upper part consists of shales alone and contains many extensive slate quarries in the vicinity of Slatington.

These shales contain considerable pyrite in

certain places and where the shales have weath- ered they are colored a rusty brown by iron oxide that was probably derived from pyrite. The presence of small quantities of pyrite is of inter- est in the determination of the origin of the brown iron ores of the limestone valley.

SILURIAN ROCKS.

Rocks of the Silurian period are sparingly rep- resented in Lehigh county. All that do occur are present in Blue mountain and belong to a single formation termed the Shawangunk for- mation.

SHAWANGUNK CONGLOMERATE.

The Shawangunk formation consists of quartz- ites and siliceous conglomerates that form the Blue mountain of Pennsylvania and its continu- ation, the Kittatinny mountain of New Jersey, and Shawangunk mountain of New York. These names have been used in the different states for the continuations of the same range. The formation receives its name from the last named portion of the range. The strata now in- cluded in this formation were formerly classified as the Oneida and Medina formations and as such they are described in the various reports of the Second Pennsylvania Geological Survey. Re- cent investigations in New York have shown the presence of an eurypterid fauna of Salina age thus proving the much more recent age of the beds. Although few fossils have thus far been reported from this formation in Pennsylvania there is no doubt of its stratigraphic continuation with similar strata carrying the Salina fossils at Otisville, New York.

The Shawangunk formation consists primarily of a conglomerate in which small quartz pebbles are cemented together by siliceous material. Cer- tain layers are very fine-grained, passing into a quartzite while occasionally strata are observed in which the pebbles are fully an inch in diameter. The resistant character of the rocks of this for- mation are shown by the high ridge formed by the outcropping beds. This formation is well exposed in Lehigh Gap where it has a thickness of about 1, 125 feet. It dips steeply to the north beneath younger beds and does not reappear at the surface.

TRIASSIC ROCKS .*

The rocks deposited during the Triassic period in eastern North America are characterized by their intense red color, which appears prominent-

*The description of the Triassic Rocks has been written by Edgar T. Wherry.

HISTORY OF LEHIGH COUNTY, PENNSYLVANIA.

ly in fields, roads, and railroad cuts. These beds cross the southern end of Lehigh county, and comprise both shale and conglomerate, together with diabase or trap rock, which is to be regarded as an igneous intrusion.

BRUNSWICK SHALE.

The bulk of the Triassic in the region under consideration is a thinly laminated, dull-red mud rock, usually classed as a shale, although fre- quently containing enough sand grains to deserve the name sandstone. The surfaces of some lay- ers are marked with ripple-marks, sun-cracks, and rain-drop impressions, proving the deposition of the beds in shallow water. The absence of marine fossils indicates that the water was fresh, and it is believed that the deposits were formed by rivers which periodically overflowed their banks, as did the Nile, Mississippi, and Ganges until civilized man got them under control.

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History of Lehigh county, Pennsylvania and a genealogical and biographical record of its families, Vol. I, Part 2

Author: Roberts, Charles Rhoads; Stoudt, John Baer, 1878- joint comp; Krick, Thomas H., 1868- joint comp; Dietrich, William Joseph, 1875- joint comp; Lehigh County Historical Society Publication date: 1914 Publisher: Allentown, Pa. : Lehigh Valley Publishing Co. Number of Pages: 1158

Author: Roberts, Charles Rhoads; Stoudt, John Baer, 1878- joint comp; Krick, Thomas H., 1868- joint comp; Dietrich, William Joseph, 1875- joint comp; Lehigh County Historical Society
Publication date: 1914
Publisher: Allentown, Pa. : Lehigh Valley Publishing Co.
Number of Pages: 1158