History of Lehigh county, Pennsylvania and a genealogical and biographical record of its families, Vol. I, Part 3

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 3

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BRUNSWICK CONGLOMERATE.

Toward the border of the Triassic belt the shales give way to pebble rocks, breccias, and conglomerates. The soil of this type of material is somewhat paler red than that of the shales, and is strewn with numerous well rounded hard pink quartzite pebbles, left behind on the weath- ering away of the solid rock. Locally also ledges of the conglomerate are exposed on hillsides, and present a peculiar porous appearance, owing to the removal of limestone pebbles by the action of the weather, leaving the red mud cement and the pebbles of the harder rocks standing out in relief.

These pebble-bearing beds have evidently been deposited at the mouths of rivers flowing into the valley where the muds were accumulating in Triassic times. But the size of the pebbles- many over 3 inches, and occasional 2-foot bould- ers, together with their well-rounded condition and arrangement in definite strata, interleaved with fine sandy mud, makes their transportation by simple water action seem improbable, and it is not unlikely that they were carried down the streams by cakes of floating ice, broken from glaciers which perhaps occupied the upper ends of the valleys of the Appalachian mountains, which were then much higher than at present. But since these high mountains collected most of the moisture from the winds blowing in from the west, the climate of the plain below must have been comparatively dry-in fact, many geol- ogists have regarded it as practically like that of a desert,-which is also in agreement with the

evidence of the fossils which are found in the beds.

The fossils of the Triassic of this region com- prise reptiles known both from their footprints preserved in many strata, as well as from actual bones and teeth (and it should be noted at this point that one of the first finds of these remains in this country was made in Lehigh county, at a point about one mile southwest of Hosensack, by a Dr. Shelley about 1850, the animal being named by Isaac Lea Clepsyaurus pennsylvani- cus) ; fishes of types at present inhabiting shallow fresh water lakes; small crustaceans, also shal- low water forms; and fossil plants, chiefly cy- cads and conifers, found both as leaf and stem impressions and in the form of petrified wood.

DIABASE OR TRAP ROCK.

Some time after the Triassic sediments had been deposited igneous activity began to assert itself, and basic magmas found their way between the beds and along fissures in the strata, render- ing these harder and changing their red color to a dull gray, and ultimately solidifying into the form of trap. This rock, being very resistant, forms several ridges near the south border of the county, on which however, there are but few ledges of solid rock, but instead great quantities of enormous rounded boulders. These boulders have been formed by the action of rain water, penetrating downwards along cracks in the rocks, and gradually decomposing the blocks, the corners being rounded off the most rapidly be- cause exposed to the water on several sides at once.

PLEISTOCENE ROCKS.

The rocks of Pleistocene age are neither wide- spread nor thick in Lehigh county and belong entirely to the Glacial Drift.

GLACIAL DRIFT.

Although the main ice sheet that so profoundly changed the topography of northeastern Penn- sylvania failed to reach Lehigh county, there is evidence, however, of an earlier ice-sheet to be found in the many places in the limestone valley west of Allentown and occasionally glacial boulders are found on the tops of the slate hills.

The glacial drift consists of quartzite and sandstone boulders of variable size up to a foot or more in diameter that are found in the fields . at many points. Nowhere is the deposit thick and the evidence of the former ice-sheets are the nu- merous boulders of foreign material, entirely un-

GEOLOGY.

like any of the rocks of the immediate region, that are found in the soils. These boulders and cobbles seem from their composition to have been derived entirely from the rocks of Blue moun- tain and beyond. Some of them show glacial striæ well developed.

RECENT ROCKS.

The deposits of the Recent age consist of the soils, the talus that has been collected at the foot of the steep slopes of Blue mountain and other less rugged hills, and the alluvium deposited by the larger streams in their flood plains. The lat- ter are worthy of more than passing mention.

RECENT ALLUVIUM.

Along the Lehigh river and in a few of the smaller streams there are deposits of sand, gravel, and boulders brought down in times of floods and deposited by the streams along their valleys. The areas covered by them are in some places, as much as one-half mile wide but in most instances considerably less. Some of the deposits seem to be as much as 30 or 40 feet in thickness.

GEOLOGICAL STRUCTURE OF LEHIGH COUNTY.

The structure of the rocks of the great lime- stone valley and the hills bounding it on either side is far from simple. In general the strata dip to the north so that in crossing the valley from south to north one successively encounters young- er rocks ranging from the pre-Cambrian gneisses on the south to the Ordovician Martinsburg shales on the north. Folds and faults interfere with this general order in many places and the true structure is only determined with difficulty.

Several systems of folds occur with their axes running in different directions. Most of the major and many of the minor folds have a north- east-southwest direction but some have their axes at almost right angles to the general trend. Some of the larger folds involve thicknesses of 3,000 to 4,000 feet of strata although most are of much less magnitude. Near Hokendauqua many complicated folds involving 50 to 100 feet of strata are well exposed, while small crumplings are numerous. In that region many of the folds are overturned and some have passed into thrust faults.

The faults of the region are likewise numerous and complicate the structure considerably. They are mainly normal strike faults although thrust strike faults and normal dip faults are also pres- ent. The throw is sometimes several thousand

feet. Faults are the cause of certain areas of slates that extend into the limestones. The larg- est of such slate areas is Huckleberry Ridge, a few miles west of Allentown, that has been caused by a fault of considerable displacement that has brought the slate into the belt of lime- stone.

HISTORICAL GEOLOGY.

As stated on a previous page the science of Geology has at the present time made such prog- ress that it is now possible for us to read the his- tory of past geologic ages by correctly interpret- ing the phenomena observed in the rocks them- selves. In the following pages an attempt is made to unravel the geologic history of the region now included within Lehigh county. . Naturally, some of the explanations given are based upon observations that have been made in other places in the State and adjoining states.

GEOLOGIC EVENTS OF PRE-CAMBRIAN TIME.

The record of pre-Cambrian geology is ex- tremely complicated and also somewhat obscure in most places. For these reasons it is necessary to deal mainly in generalizations.

The rocks of this age are the crystalline rocks composing the South mountain of the southeast- ern portion of the county. As stated in a pre- ceding page they are largely of igneous origin but mixed with them are many sediments that accumulated beneath the waters of the ocean. The abundance of igneous rocks might seem to indicate a period of great volcanic activity al- though not necessarily so because of the great length of time involved in the period. How- ever, the crust of the earth in the eastern por- tion of the United States seems to have been weaker then than now, thus permitting more igneous material to be extruded.

All of the igneous material did not come to the surface at the same time because we find many places where one igneous rock has cut through another older igneous rock. If volcanic cones through which the igneous matter issued ever existed they have long since been destroyed by erosion.

The sedimentary rocks of pre-Cambrian time consist of graphite, schists, garnetiferous gneisses, and marbles. They were originally mud, sand, and calcareous deposits formed in the bottom of the ocean near the shore of a continental land mass that furnished the detritus which was car- ried by streams to the ocean. They were laid down in horizontal beds but at the present time have been so greatly disturbed, altered, and

HISTORY OF LEHIGH COUNTY, PENNSYLVANIA.

eroded that it is impossible to determine the act- ual conditions that prevail during their forma- tion.

Subsequent to the deposition of the sediments above described and the extrusion of igneous rocks in the area now constituting the southeast- ern part of the county, these rocks were subjected to intense squeezing which resulted in the rocks being broken and displaced in certain places and elsewhere thrown into folds. In this compres- sion and resulting movements so much heat was generated that many of the mineral particles be- came plastic and moved in such a way as to bring their long diameters perpendicular to the direction of the compressive force while other minerals broke down and their atoms united to form new minerals. The cause of this compres- sion was primarily the result of shrinkage of the earth's crust.

GEOLOGIC EVENTS OF CAMBRIAN TIME.

At the beginning of the Cambrian period a continental land mass lay to the southeast of the Lehigh county district, and probably included extensive areas now beneath the waters of the Atlantic Ocean. This region formed a part of a great inland sea that extended over the entire Appalachian mountain district and a consider- able part of the region lying to the west. Into this sea the rivers from the continent brought sediment of all kinds which they dropped near the margin.

The first materials formed on top of the pre- Cambrian rocks were deposits of sand and gravel which now constitute the Hardyston formation. The coarse pebbles present in some layers indi- cate that the edge of the continent was close and some swift streams emptied into the sea near where we now find this formation. Since swift streams mean steep slopes, we may conclude that the continent near its northwest margin was fairly steep. In the places where the deposits consisted of fine sand, such as are seen on Lock Ridge, boring worms seems to have been abun- dant.

Soon the streams seem to have lost their ability to carry coarse materials into the sea as is shown by the deposits of shaly limestones (Leithville formation) overlying the sandstone. This check- ing of the stream velocity was caused in one of several ways, but which way cannot be deter- mined. The land adjacent to the sea may have been worn low by the streams; the land may have sunk with respect to the sea; or the streamns may have shrunk in size due to climatic condi- tions. All that we can determine is that fine

mud and calcareous oozes were the only ma- terials deposited during this period in the region now included in Lehigh county.

The same change continued and finally prac- cally no mud from the land was carried into the region. The deposits formed were entirely cal- careous and constitute the Allentown limestone. The water was shallow as is shown by wave marks observed in many places near Allentown and Bethlehem. The water was evidently not adapted for many forms of life but one form, Cryptozoon proliferum, seems to have thrived and its remains are abundant in the limestones near Allentown. It resembles a coral in many respects.

GEOLOGIC EVENTS OF ORDOVICIAN TIME.

During the first part of the Ordovician the sea covering this region continued much the same as during the close of the Cambrian except probably the water was deeper. Limestones were formed either by chemical precipitation of calcium carbonate from the sea water or from the calcareous shells and skeletons of animals. The Beekmantown and Jacksonburg limestones represent this period. Fossils of several kinds indicate that conditions were favorable for ma- rine life.

Somewhat later, probably through an uplift of the region by which the streams were given greater slope and velocity, mud from the land was carried in to be mixed with the calcareous oozes. These conditions gave rise to the Naza- reth cement limestone. Through a continuation of the same movements, soon mud from the land increased to such an extent as to mask all cal- careous deposits. The Martinsburg shales were formed at this time.

The close of the Ordovician was marked by great folding of the rocks previously formed. Strata originally horizontal were folded as though they were paper, in many places, while in other regions the rocks were broken. The com- plicated folds seen near Coplay and elsewhere owe their form mainly to these compressive forces that were so active at the close of the Ordovician, although these rocks were at a still later period again squeezed and made to assume new positions.

As a result of these compressive forces the rocks themselves, were changed ; one of the great- est changes being the formation of slate from the mud shales of the Martinsburg deposits.

GEOLOGIC EVENTS OF SILURIAN TIME.

The Silurian rocks of Lehigh county consist of the coarse conglomerates and sandstones of

GEOLOGY.

Blue mountain. Their coarse character indi- cate that the adjacent continent again had swift streams emptying into the inland sea carrying pebbles of large size. In all probability these de- posits were formed over the entire county but have been removed by stream action over all but the extreme northwestern margin.

Following the deposition of the Shawangunk formation deposits of shales and limestones were formed but no traces of these now occur in Le- high county. To the northwest of Blue moun- tain they are well represented.

GEOLOGICAL EVENTS OF POST-SILURIAN AND PRE-TRIASSIC TIME.

A long interval of time, from the Silurian to the Triassic period is not represented by any rocks in Lehigh county. This is probably due to the fact that the region was above the sea dur- ing the time and constituted a part of the conti- nental land mass.

To the northwest of this region the sea con- tinued for a long time and great deposits of shale, limestone, and sandstone were formed dur- ing the Devonian period. Later during the Car- boniferous period sandstone, shale, and coal were formed over great areas in the region now known as the Anthracite Coal Fields.

Following the Carboniferous period of depo- sition the region again became unstable and yield- ing to the intense strains to which it had been subjected, the originally horizontal rock strata were thrown into folds. The Appalachian mountains were formed as the result of this ac- tion in the place where the inland sea had ex- isted for such a long time previously.

In Lehigh county the movements accompany- ing the formation threw the Shawangunk rocks into the steeply dipping position they now have and further folded the Ordovician, Cambrian, and pre-Cambrian rocks which had previously been deformed.

GEOLOGIC EVENTS OF TRIASSIC TIME.

During the Triassic period a portion of the continent lying to the southeast of the Appala- chian mountains was depressed to such an ex- tent that it was covered with water at intervals, forming a series of bays, low-lying valleys, or estuaries extending from the Connecticut river valley to North Carolina. In these bodies of fresh water, deposits of shales, sandstones, and occasional limestones were formed. The red shales and sandstones of the extreme southeast- ern corner of the county were formed at this time.

For millions of years, ever since the pre-Cam- brian, there had been no igneous actions in the eastern part of the United States. Near the close of the Triassic period, or soon after, however, much igneous matter pushed its way to the sur- face in or near the region where the Triassic de- posits had accumulated and dikes and sheets of lava were formed from New England to North Carolina. These lavas are all dark in color and are mainly diabase. They are commonly called "trap rock." These rocks are present in several places in the southeastern corner of the county.

GEOLOGIC EVENTS OF POST-TRIASSIC AND PRE- PLEISTOCENE TIME.

Triassic deposition ended in this region by an uplift and again the entire area embraced within Lehigh county became land. Since all land masses lying above sea-level are constantly being worn away, following this uplift the region be- gan to be lowered by erosion. This continued until during the Cretaceous period the whole Appalachian region had been reduced practically to sea-level. Across this plain the streams meandered powerless to cut their channels deeper or to remove the decomposed rocks.

Toward the close of the Cretaceous period the Appalachian mountain region again was uplifted and the streams again renewed their work of destruction and transportation. They deepened their valleys and transported the loosened waste rock to the ocean. In this process the softer rocks were worn away first and at the present time the only remnants of this Cretaceous plain in Lehigh county are seen in the flat-topped ridge of Blue mountain. The South mountain hills have been reduced in elevation only slightly but enough to destroy the flat tops which they formerly had.

GEOLOGIC EVENTS OF PLEISTOCENE TIME.

During the Pleistocene or Glacial period a great change in climate took place in the north- eastern part of the North American continent re- sulting in the accumulation of an immense ice sheet that covered all of the northeastern por- tions of the United States and Canada. The ice sheet advanced and retreated several times de- pending upon the climate. At one time it ad- vanced to a point in the limestone valley several miles west of Allentown while at a later time it advanced to within a few miles of the present county. During the first advance the ice carried boulders of various kinds which were strewn over the surface as the ice melted and during the sec-

HISTORY OF LEHIGH COUNTY, PENNSYLVANIA.

ond advance the water resulting from the melting of the ice swelled the streams to such proportions that they overflowed their banks and deposited much clay, sand and gravel in many places. Many of these deposits are present in Lehigh county especially near Ironton and Slatington.

GEOLOGIC EVENTS OF RECENT TIME.

Since the final disappearance of the North American ice sheet the ever-present forces of Nature have been at work and have accomplished much in. the disintegration and transportation of materials from higher to lower regions. The hills are wasting away, the valleys of the streams are being cut deeper and wider, and the whole region is being lowered. If the land remains station- ary with respect to the sea, it is only a question of time until the present hills will be destroyed and the region again reduced to a plain as it was during the Cretaceous period.

MINERAL RESOURCES OF LEHIGH COUNTY.

Within the limits of Lehigh county are both varied and valuable mineral deposits that have contributed much to its development. Some of them have been exhausted or for various reasons cannot at the present time be utilized but others are now being exploited to a greater degree than ever before. These will be described briefly below.

BUILDING STONE, CRUSHED STONE, ETC.

In all probability the first of the natural re- sources to be used was stone for building pur- poses and before the advent of railroads all the stone used for construction was obtained in the region. The gneisses, quartzites, and limestones were all used and quarries of small size were opened in many places. At the present time lit- tle stone is quarried within the county for build- ing purposes but instead numerous quarries in the genisses and limestones furnish great amounts of crushed rock for ballast and for paving.

LIME.

In the early history of the county when agri- culture was almost the sole occupation, those regions where the soils were richest were most thickly populated. It soon developed that the limestone soils were fertile for only a few years after clearing them of timber, and their fertility could only be restored by permitting fields to lie fallow for several years. But even this method of farming did not suffice for many years and eventually the limestone soils produced so small

a yield of grain that they were almost useless. The farmers in the limestone valley near Allen- town were called "Drylanders" which term im- plied their poverty.

Toward the close of the eighteenth century, the farmers of eastern Pennsylvania began to experiment with lime as a fertilizer and soon proved its value for the limestone soils. Lime- stone was abundant and kilns were erected in great number throughout the region. The ruins of many of these can still be seen. Farmers erected kilns and hauled limestone for miles to their farms where they burned it and spread the lime over the fields.

Within recent years the use of lime as a ferti- lizer has again declined, owing to the introduc- tion of other kinds of fertilizers and new methods of farming, yet nevertheless considerable lime- stone is still burned in the county. Most of it is used for plastering purposes but some is still sold for fertilizing purposes.

Limestone has been also extensively quarried in many places for use as a flux in local iron furnaces.

CEMENT.

The cement industry of Lehigh county which has grown to such proportions as to make it the most valuable manufacturing industry of the region owes its growth to the presence of the Nazareth Cement Limestone described on a pre- vious pages. Quarries and mills are located near Coplay, Cementon, Egypt, Ormrod and Fogelsville.

The first Portland Cement made in the county was made by the Coplay Cement Com- pany which was organized in 1867. This was the predecessor of the Coplay Cement Manufactur- ing Company and some of the first kilns construct- ed can still be seen in the latter company's prop- erty on the right bank of the Lehigh River a short distance above Coplay.

Several other companies were organized be- tween 1870 and 1880 and with a few excep- tions the cement production of Lehigh county has shown an increase each year. The product has also greatly increased in quality while the price has rapidly fallen.

The supply of cement rock in the county is so great that the industry will doubtless continue to be of the greatest importance for many years to come.

SLATE.

The slate industry of Lehigh county has long been one of the most important industries of the region. The almost universal use of slate for

GEOLOGY.

roofing purposes all through the county is evi- dence of the activity of the local quarries situ- ated near Slatington, as is also the continuous line of slate quarries extending from the Lehigh river westward for several miles. The slate con- stitutes a part of the Martinsburg formation previously described.

The first slate quarried in the county is said to have been taken out in 1828, but not until 1849 was any considerable quarrying started. The Washington quarry of Slatington was opened in the latter year and in 1851 the town of Slatington was laid out by the Lehigh Slate Company.

CLAY AND KAOLIN.

Clay deposits formed by the disintegration of the limestones and gneisses or transported by the ice sheet which formerly covered part of the region has been worked in many places. The material is mainly used in the manufacture of common brick. At the present time several brick yards are in operation in or near Allentown.

Clay of good quality has also been found in connection with many of the deposits of iron ore but seldom has it been utilized.

Kaolin, formed by the decomposition of the feldspar of the gneisses, occurs in many places in the South mountain hills but always mixed with impurities, which can only be removed by wash- ing. On the south side of Lock Ridge a com- pany has for several years been engaged in the mining and washing of the kaolin. The product is fine and white and adapted to many uses.

SAND AND GRAVEL.

The ice sheet which covered part of the region during the Pleistocene period brought down great quantities of sand and gravel which were drop- ped when the ice melted. Deposits formed in this manner have long been worked between Bethle- hem and Allentown.

Along the Lehigh river and some of the minor streams deposits of sand dropped by the streams during seasons of flood have also been utilized. A good deposit of this character that has been extensively worked is located along the left bank of the Lehigh river a short distance below Slat- ington.

In the disintegration of the gneiss of South mountain kaolin and quartz have been formed. The quartz occurs in the form of angular frag- ments mixed with the kaolin. The rotten rock is dug in several places, screened to remove the undecomposed fragments of rock, and hauled to

many points for use in plastering or for mould- ing purposes. There are many deep sand pits in the south slope of South mountain between Al- lentown and South Bethlehem.

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History of Lehigh county, Pennsylvania and a genealogical and biographical record of its families, Vol. I, Part 3

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