Regular readers of this blog will remember my many references to Chickies Rock in Lancaster County.   This 110-foot high quartzitic rock  is located north of Columbia and can easily seen crossing the Susquehanna River.  The rock is arch-shaped being folded up by the giant collision between Africa and North America that occurred during the construction of Pangaea some 350 million years ago.  At Chickies Rock, trained eyes will find ripple marks, cross–bedding and a fossil that actually has made this location a famous site.  It is the finding of this fossil and the story behind Scolithus linerais that composes this blog.

The finding of a fossil is always a cool experience.  You are the first person to ever see that particular specimen and you probably know, each specimen is unique in appearance.   Some of you have probably experienced that feeling while fossil hunting.  Just think now if you find a fossil that has never been described before and you know that your find could be very important.

This is the case of Samuel S. Haldeman.  Samuel was born on the homestead just at Locust Grove, now Bainbridge, Lancaster County in 1812.  His father was a  great business man having interests in furnaces, a grist mill and .    He attended a classic school in Harrisburg and then spent two years at DickinsonCollege, although he did not receive a diploma.

The Haldeman homestead at Locust Grove as it appears today.

After his marriage in 1835 to Mary A. Hough of Bainbridge, he moved to a new residence at the base of Chickies Rock, Marietta. Not only did he design the stately home built by his father, he laid out the grounds with native specimens of trees and shrubs gathered from the surrounding woods, and some foreign varieties, all of which were planted with his own hands.

For a time he managed a saw mill. In 1836 Henry D. Rogers, having been appointed state geologist of New Jersey, sent for Haldeman, who had been his pupil at Dickinson, to assist him. A year later, on the reorganization of the  Pennsylvania Geological Survey, Haldeman was transferred to his own state, and was actively engaged on the survey until 1842, preparing five annual reports, and personally surveying the counties of Dauphin and Lancaster.   In 1840 he began the publication of his monograph on the “Fresh-Water Univalve Mollusca of the United States,” in which he described the Scolithus linearis, a new genus and species of animal fossil, the most ancient organic remains in Pennsylvania. During the year 1842/3, he gave a course of lectures on zoology at the Franklin Institute.

Samuel Haldeman circa 1850

In 1852, Haldeman was appointed professor of the natural sciences in the University of Pennsylvania. In 1855 he went to DelawareCollege, where he filled the same position. While there, he also lectured on geology and chemistry in the state agricultural college of Pennsylvania. In 1869, he returned to the University of Pennsylvania as professor of comparative philology. He remained there until his death, which occurred at Chikckies Rock, Pennsylvania.

Scolithus specimen found in the York area

Haldeman was an earnest advocate of spelling reform. He was a member of many scientific societies, was the founder and president of a Philological Society, and one of the early members of the National Academy of Science.

Samuel loved many aspects of the natural sciences.  He built and lived in a mansion at the north end of Chickies Rock.  He studied the plants living there and discovered Scolithus fossils.  Not certain of its origin, Samuel sent a letter to Charles Darwin in an attempt to identify the specimen.  Although I haven’t seen the correspondence or even sure if a letter still exists, historians have stated “that the fossil is Scolithus, a worm borrow of an ancient animal.”  Samuel continued his communication with Charles, helping Charles write the final pages of the classic “The Origins of Species.”  It was determined that Scolithus was a relatively short lived species of only several million years.  The age was placed on the Precambrian and Paleozoic era boundary, on today’s geologic time scale as 545 million years.  Because of its short life span was a species, any rock containing Scolithus can be dated at 545 million years old.  This is known tov a geologist as an index fossil, used as a dating tool.

Samuel Haldeman in his later years

Samuel died in September, 1880 at his mansion.   He left behind 200 publications covered six disciplines he had studied.  Samuel Stehman Haldeman gave his life to his scholarly pursuits, and his influence, though largely unnoticed, is astounding. Many of the most famous and influential scholars of the past were directly influenced by Haldeman both personally and professionally. Haldeman was able to aid in progressive research on many fronts, both scientific and linguistic. The fact that Haldeman was constantly on the cutting edge of every field he studied suggests that he was a man who challenged convention, a man who truly thought for himself. Samuel Haldeman was not only one of the greatest American scholars, but also one of the greatest American thinkers.

Samuel’s mansion he designed and his father built at the north end of Chickies Rock where he died in 1880.

What brought this blog to mind was that I finally visited the HaldemanMansion in Bainbridge this past Sunday.  I was the speaker at the Annual Meeting of the Haldeman Mansion Preservation Society and had a chance to see some of Sanuel’s specimens in his collection.  I even assisted members with identifying several of the artifacts they had questions about.  This society has done much work on the mansion and are still looking for funding to do more, for example, installing a new roof.   This is a great place to visit during the summer when they have open houses and appreciate some of the history of a great person in our local history.

The largest mining district in YorkCounty was undoubtedly the Dillsburg magnetite deposit located about one mile east of this quiet borough.  The area holds a wealth of history as well as some of the current events in local geology.  In fact, the Dillsburg area contained another iron field west of town, in what is today known as Dogwood Hollow in SouthMountain.  These mines were the site of valuable limonite ore in the mid 19^th century.  A drive back Dogwood Hollow heading toward CampTuckahoe will show you some of the large dump piles and pits that once flourished.

Location of the magnetite mines east of Dillsburg

The credit for finding the rich magnetite ore east of town goes to local resident and farmer, Abraham Mumper.  During his spring plowing on his farm in 1847, Abraham brought up large black rocks that appeared to be something he never noticed before.  The mineral was identified as rich grade mineral known as magnetite.   Although the chemistry of the ore was higher in sulfur, the percentage of iron wqas higher than the limonite ore on the opposite side of town.   Important to the development of the magnetite ore, it was a known fact that iron masters knew that a mixture of magnetite and limonite for their furnaces produced a better grade of boiler plate iron.  The mixture of ores did not allow the iron to crack.  The quality was desirable for the manufacture of wood stoves and firebacks.

Abraham opened his mine on his farm, which today was located on the west side of Ore Bank Road.  Wow, what a name for a road in a mining district.   “Ore” is the material removed from the Earth and “Bank” was the name given to a mining operation for many of the mines were simply dug into a hillside.  Abraham’s brother, John also got into the action by opening his own mine just north of Abraham’s,  Much of the ore was found very close to the surface just the use of shafting was not required.  The Abraham Mumper mine (which become the Underwood mine and largest producer in the district), sometimes often could produce 30-40 tons of ore a day.

Both the Abraham and John Mumper mines flourished and of course, peaked interest in the remaining lands adjacent to the Mumper farm.  At John’s operation, the ore was followed to depth requiring mine shafts and drifts to be developed.  A two-foot thick magnetite body was encountered 26-feet down, said to be one of the wealthiest ore bodies recovered in this area.  This find also was the base for one of the comedy stories in local mining history.  John Logan, a local attorney owned property on the east side of Ore Bank Road, but not believing that any magnetite was found on his farm, Mr. Jogan sold his land.  Following the discovery of the large John Mumper ore body, John Logan crawled back to the land owner wanting to buy his property back.   Well, John got his wish but paid considerable more for the property.  Mr. Logan and a fellow miner Mr. Longnecker teamed up and developed a shaft which also found the same ore body was that encountered by John Mumper.  This find perhaps took the edge of the foulest story of land purchasing deal.

Abraham Mumper built and lived in this Old York Road residence for many years.

It is said that Ore Bank Road was originally built as an access to wagon the ore into Dillsburg and then transported by rail to furnaces.  This is what separated this ore field to most of the others in southeastern Pennsylvania.  Other mines were built very close to working furnaces so that transportation did not have to be dealt with.  Here at Dillsburg, the ore was not associated with a local furnace and that the ore  was being purchased by various furnace owners.   Later, a railroad was built into the Dillsburg magnetite mining district that would run two to three trains a week.  Today, with observant eyes, you can trace bits and pieces of the railroad bed the whole way over to the northeastern corner of the district near Meadowview and Mumper Lane.

John Mumper built and lived in this Mumper Lane residence.

After Abraham death in 1868, An Alexander Underwoods, a son-in-law of Abraham’s, purchased the mine.  Although Alexander wqas an attorney from Mechanicsburg, he understood the wealth of the ore on the Mumper Farm and modernized the operation.  He hired the Wrightsville Iron Company who developed shafts to further extract the magnetite.   In the meantime John Mumper hired McCormick and Company to take over the mining.  The McCormick’s used their ore in furnaces in the Harrisburg area and in PerryCounty.

Abraham Mumper’s tombstone at the Wolgamuth Church of the Brethren on Old York Road.

Although approximately 9 other mines were opened in this 0.75 square mile area, no production outdid the Underwood and McCormick mines.  A total of 1.5 million tons of ore were removed from 1847 and 1908, when the final operation closed.  The other mines included the Smyser, King (McClure), Bell, Price (Cox), Grove, Altland and Jauss.  Most of the operations included shafts but constant sizeable ore bodies were not found.  As in today’s economy, the area also saw  periods of low demand and production.  The Panic of 1873 was the largest such downfall where the mines were temporary closed.  It was not until 1876 that the economy rebounded.  By the turn of the century much of the ore bodies had been removed. The last two operations were the King and Jauss mines on the east side of the district.

The Price (Cox) mine as it appears in 2013.

In fact, one of the most historic moments of the district occurred near the end of production.  In August, 1906, renown inventor Thomas Edison was invited to travel to the Jauss mine in hopes that he would invest in the operation.  Mr. Edison was involved in iron mining and cement manufacturing in central New Jersey.  Mr. Edison and his son were escorted to the mine by local historian John Morris.  Although Thomas Edison did not invest in the Jauss mine, he did hire John Morris to serve as a mining engineer for a number of his mining ventures.

The Mumper (McCormick) mine is 2013

The area has set dominant since 1908. when the Jauss Mine closed its doors.  However, with World War II coming unto the scene, the Federal Government set geologists out to re-evaluate abandoned mine properties for possible future mining.  Two gentleman,  Neumann and Hotz associated with the U.S. Bureau of Mines were assigned the Dillsburg magnetite area.  Two different phases of core drilling were conducted in 1944 – 1948 and other mineable magnetite bodies were located  with the boundaries of the district.  Their work also proofed that the ore was developed in sandstone and limestone trapped between two bodies of diabase (an igneous rock formed by magma within the Earth).  No development of these ore bodies were ever engaged.

Today, much of the area remains overgrown in either mature forests or secondary =growth caused by recent logging.  Also, in two cases residential housing as encroached very close to abandoned mines.  In fact, one of the mine shafts was exposed in the spring of 2009 in a front yard of a house.  It is not sure if the soil over the shaft subsided because of heavy precipitation  or recent earthquake activity.  The mining district received some public attention in 1976 when the newest edition of “Mineral Collecting in Pennsylvania” book was released listing the Logan-Longnecker mine as a site for varios minerals including nice magnetite and feldspar crystals and a rather rare mineral for the state, datolite.

It is hoped by this writer athat a small portion of the Dillsburg Magnetite District can be preserved by a park or preservation group.  I have been researching this area since 1975 and have come to appreciate its history, minerals and more recently the Dillsburg earthquake swarm that was centered in the southern limits of the district.

Whenever I start my Earth Science class at MessaihCollege, I start with a brief “History of Geology” section.  Covering what folks believed 400 years ago is a good way to set the tone for what we will be studying the remainder of the semester.  Now I have stated before that I believe the first geologists were prehistoric people, who sought the best rock for the manufacturing of their stone tools.  If the quarry site was too far to travel, they found a way to trade for the rock.

The birth of modern geology is said to have started in the 18^th century.  The introduction of new concepts and thoughts about the Earth was a brave thing to do.  Why is that?  Because the believeth of Neptunism, the thought that everything on our planet was formed as a result of the Great Biblical Flood and that the Earth was only 6,000 years old.  Any other theory introduced conflicting Neptunism was enough for you to be imprisoned and maybe put to death.  One pre-modern day geology person was James Ussher (1581-1656).  James was born in Ireland and found his life in knots, often getting in trouble with the archbishops of the church with his conflicts, both personal and cultural.  In an attempt to get on the good side of the religious leaders, James wrote a book titled “Annalium pars postieror” published in 1654.  In this book, James advanced the Neptunism theory by stating that the Earth was created on the night fall preceding October 25, 4004 B.C. Did this advancement actually get him on the good side and mke him one of the early science leaders,?  That question will never be answered.

James Ussher postulated the Neptunism theory

So the era of scientific discovery was introduced by several people, but James Hutton (1726-1797) was known as the father of geology.  As so many of the early advancers in the science, these folks were educated in many other fields.  For example, James Hutton was educated in soils, was a physician, geologist, naturalist, chemical manufacturer and  practiced experimental agriculture.  His many travels to in Scotland, western Europe and the United   States allowed him to make observations on many rock exposures, where he created detailed notes.  He concluded that the Earth was alive and should be considered a super organism,  He also recognized that rocks were composed of the destruction of bodies, animals, vegetables and minerals of more ancient formations.

James Hutton recognized that the rock strata took many years to form and introduced uniformitarianism

In 1785, James completed a 25-year writing of a multi-volume piece title “Theory of the Earth: or an investigation of the Laws observable in the composition, dissolution and restoration of land upon the Globe”  This publication was read in two separate parts to the Royal Society of Edinburgh.  Here James Hutton introduced a concept known as uniformitarianism.  Mr. Hutton believed that the same processes working on the Earth today have been working on the planet for many years.  In short and as he put it, “The present is the key to the past.”

The last person mentioned here was Charles Lyell (1797-1875) who was born in Scotland and later became a British lawyer.  He had a interest in geology and liked  Hutton ‘s theory.  With travels through Europe, North America and South America, Charles, like James Hutton made his own observations on rock exposures and wrote a book “Principles of Geology” which popularized the uniformitarianism theory.  The book was first published in 1830-1833 in multi volumes.  Charles also made the statement about the theory “The future will resemble the past.”  Charles also became close friends with another theory setter names Charles Darwin and the two collaborated on the thoughts of uniformitarianism and evolution.  And into the future we go with scientific discovery!!!

Charles Lyell supported Hutton’s theory and wrote “Principles of Geology”

You may ask why I am bringing this up now in the blog?  How does this “the present is the key to the past” involve our area?  Just like another theory not to be introduced until 35 years after Charles Lyell’s death known as continental drift, no geologist today cannot interpret the history of our little section of Earth unless we  believe and study the processes.

When you travel to the seashore for vacation, check out the movement of the waves and how the sand on the bottom moves around.  These waves have been working this way for millions of years.  You can actually see the sand forming ripple marks on the bottom near the low tide zones; you can see sea shells gathered along the low tide zone and where two directions of waves are coming into the shore, cross-bedding is taking place where one layer of sand is being deposited on top of another layer.

Modern day ripple marks at Fort Myers Beach, FL

We care observe these same features around here without going to the beach.  The only difference is that these features locally are millions of years old, BUT we can understand how they were formed because we can see the “in progress” processes at the beach.  Ripple marks are well preserved on the northern side of Chickies Rock in LancasterCounty.  You will have to park near the pumping station along Pa. Rte. 441 and walk down to the north end of Chickies Rock.  These are some of the best in the area.

Ripple marks at Chickies Rock with Lancaster County Parks naturalist Mary Ann Schlegel taking measurements

Go fossil collecting into the Appalachian Mountains and find layers of rock containing a wide assortment of fossils all jumbled up.  This zone represents the low tide zone of an ancient seashore.  Crossbedding can be observed in the abandoned sand quarry behind the Harley Davidson plant in York, although the quarry is owned by Kinsley Construction and permission should be sought.

Mudrcracks found in the Valley Quarry- Fairfield, Adams County

What other feature can we compare the modern look to the ancient look?  Picture a ballfield infield. When it rains, puddles of water will lie in the low areas until it evaporates.  After the water dries up, the sun warms the area and makes the dirt crack.  These are called mud cracks.  Mud cracks can also form along a stream where water pooling in a hole will dry up and then hit by the Sun.

Crossbedding found in quartzite behind the Harley Davidson plant in York

While walking the beach, you may occasionally see a small stream flowing off the mainland into the ocean.  Carefully examine the sand on the bottom where the ocean and stream come together.  You may see a sprinkling a larger well rounded pebbles lying among the sand.  This environment is called a delta and although what we see at the beach is a small-size example, deltas can be large scale.  Take for example, the Susquehanna River flowing into the Chesapeake Bay.  The current of the Susquehanna River is strong enough to carry larger pieces of rock, but when it flows into the bay, the flow rate decreases and the larger rocks are dropped to the bottom.

Chickiies Formation conglomerate at Rocky Ridge County Park that may have been a delta about 600 million years ago

What we have learned in the past 400 years is that our Earth operates on cycles.  For example, rocks evolve through a cycle of change through compaction, heat and pressure and lithification to form different rocks; volcanoes erupt for a period of time than become quiet for a long period; earthquakes are common in an area and then become quiet; and, even our atmosphere goes through changes and returns to an earlier stage eventually.

For those of you that enjoy history, you may have traveled to Hopewell Furnace in ChesterCounty or Pine Grove Furnace in CumberlandCounty.  These two classic sites are remarkably preserved showing how a 19^th century industry flourished.  By visiting such sites, one gets an understanding how amount of work and various resources were required to successfully produce iron ore and finished products.  In most cases, furnaces were built very near their required resources:  iron ore, limestone for flux and chestnut trees that would produce adequate charcoal to produce the heat in a furnace.  The best preserved example of a furnace complex in YorkCounty is found at Margaretta Furnace located west of East Prospect in LowerWindsorTownship.  Although many of the original buildings have been destroyed and some modernization has been done, remnants of this complex still stand today.

The furnace was built by Samuel Slaymaker of Lancaster in 1823 and put into operation in 1825.  His nephews, Henry Y. and Samuel Slaymaker succeeded his ownership and began a large businesses.  Iron ore was found around the area and taken from various mines or “banks” as they were called in the 19^th century and will be described later in this blog.  The furnace was in operation about 9 months of the year.  Each week, 30 tons of iron was made, or about 1,100 tons annually. The furnace was in operation about 9 months of the year.  Each week, 30 tons of iron was made, or about 1,100 tons annually.  Samuel Slaymaker eventually moved to York and became involved in other local furnace interests.  Henry continued the business on his own for many years and even constructed the “ironmaster’s house” which still stands today.  Eventually, the business failed and was closed in 1843.  Henry moved to Davenport, Iowa where in died in the 1880’s.  The furnace was started again by some of the leading employees, Messrs. Curen and Connelly and Dr. Barton Evan, who formed a partnership until 1847.  Not much production is listed after this date and was reportedly owner by Mr. Himes of New Oxford in 1886.

1876 map showing the Margaretta Furnace area

With the good pig iron, a foundry was built and in 1828 Woodstock Forge was erected about 1.5 miles east on Cabin Branch Creek.  At the foundry, a number of tem-plate stove plates, iron kettles, skillets and various types of hollow wares were produced here.

Pine Grove Furnace as it appears today. Margaretta Furnace looked similar as this one during its heyday.

For the charcoal, about 8,000 cords of wood were required annually.   John E. Beard, ex-county commissioner and his brother, Henry, together hauled 14,000 cords in five successive years.  At one time, the firm owner 1,900 acres, showing just how large an operation it truly was.

Artists drawing of a common furnace complex

Persifor Frazer of the Pennsylvania Geologic Survey reported on all of the region’s iron mines in the 1870’s.  IN his one classic report of 1876, he reported the following about the iron banks that worked in the Margaretta Furnace area.  W. G. Case Bank was opened by Curren and Evans and opened around 1853 and was worked by them for 2 or 3 years.  The property owner by Jacob Keller was then leased to Mr. Eagle, of Marietta, who worked it for about 2 years.  Mr. Case of Columbia then brought the property of 198 acres, including the bank for several months.  The ore exposed about 10 feet below the surface was a shelly limonite.

Frazer’s 1876 map showing the iron banks near Margaretta Furnace.

The James Curren Bank was opened in about 1846 by Eckert & Guilford, owners who worked it for a s short time and sold it to Georege Heindle, who worked it 3 or 4 years and sold it to John Givens.  John Givens, after working it about the same length of time, sold it to James Curren of Wrightsville.  It laid idle for 10 years of more (prior to 1876).

The Daniel Leber Bank was opened in 1875 and was leased to Skills & Fry.  The ore was a hard, compact limonite.  The ore was removed by windlass.

John Emig Bank 1 was fallen shut in 1876 and was last worked  around 1869.

John Emig Bank 2 is very old and has been idle since 1871.  There is no machinery there and the buildings are in a state of decay.  The shaft was reportedly 110 feet deep and blasting was required to loosen the limonite ore.  It had been leased to Hildebrand of West Chester, but the lease had long since expired.

George Keller’s Shaft was opened around 1866 and was first leased to Wrightsville Iron Company.  It was afterwards leased to Skills & Fry, of Lancaster, but their lease was expired in 1876.  Two shafts were dug, the one 70 feet deep and the other 30 feet deep.  The ore was reportedly closed to surface, but had to be blasted to become loosened.

Reuben Burg’s Bank was opened in 1873 but no information on by who.  Ore was found about 30 feet below the surface in a shaft.

John Small Bank was originally owned by Mr. Slaymaker but purchased  by Mr. Small in 1962.  Mr. Small’s son worked the bank himself for 2 years.  The water was pumped and the ore washer was driven by horse power.  The teams hauling the ore to the shipping station are owned by J. Hoke, who charged $0.90 per ton for hauling.  Much of the ore was not used at Margaretta Furnace, but shipped to Harve de Grace, Maryland and used by Whitaker & Sons.   The ore was used for the manufacturing of foundry iron and is sold for $4.00 per ton at the canal.

Margaretta Furnace Banks were opened by Mr. Slaymaker.  Hanh & Himes purchased the nearest bank to the furnace in 1852 and still being worked by Himes in 1876, who also was residing in the ironmaster’s house.  The ore contained 45% metallic iron, an average composition of iron ore for those days.  About 200 tons of ore was removed each week.  All of the ore was taken to the Tidewater and SusquehannaCanal and cost $2.00 a ton to haul.  The iron made at the furnace was foundry and it was used for hollow ware and sold it to the Baltimore market.

John Keller Bank was open in 1868 by Mr. Keller himself.  Some 1,000 tons of ore had been removed, all within the first 6 months of operation.

DR. JH. W. Barcroft Bank was originally owner by H. J. Slaymaker and has been opened for 34 years.  It was leased to J. Eagle, of Marietta who suspended work there in 1870.  The ore ironically was used shipped to Emig’s Station near Hellam and then shipped for use in Mr. Eagle’s furnaces at Chickies, LancasterCounty.  Musselman & Watts also mined ore from here and reportedly removed 10,000 tons.

Christian Barley Bank was opened about 1870 and Mr. Brillinger was the leasse.  It was occasionally worked over a 2 year period with about 400 tons of hematite ore removed.

Samuel Hengst Bank was open in about 1870 by Stahm, Keller & Leon, who worked the bank for about 3 years.  About 3,050 tons of brown hematite ore was removed.

A picture showing the main house and mill at Margaretta Furnace circa 1920. Thanks to Elizabeth Senft.

This blog was just a quick glimpse back into the past at a lost industrial center.  A drive through the area is interesting as you spot some of the banks that are located close by the public roads. The trailer park today occupies the “heart” of the complex, but the ironmaster’s house and mill still stand.  This would be an excellent subject for a local historical group to organize a self-guided brochure on Margaretta Furnace and historical markers.  Find a book on local ghost stories and a tale about the spirit of Margaretta Furnace might be included.

Like most sciences, geology is not an exact science.  Much of the understanding of how the Earth System works and why it operates the way it does is dependent upon many scientists’ thoughts or theories.  Thankful for these scientists, we have evolved as far as we did in this understanding of how our landscape has developed through repetitive cycles of crustal collisions and riftings.  But this series of theories was not easy to come by, and matter of fact, still written in stone.  Remember theories are ideas supported by evidence that are acceptable to the science world.  These theories are always open for discussion and change.  When I was a college student and reading a research paper on an area I was working in, the author’s paper started out by saying:

“If you don’t accept my thoughts disclosed in this paper, write your own.”

One of the largest controversies in geology in southeastern Pennsylvania is centered on what is today known as the Martic Line or Martic Fault.  This geologic structure is easily traced on a geologic map from at least Maryland into eastern Pennsylvania where it connects with the Doe Run Fault near Philadelphia.  In York County, the Martic Line is found at the southern end of Long Level at the Susquehanna River, runs through the north edge of Dallastown and Jacobus, about 1 mile north of Jefferson and occupies one of the long sections of Lake Marburg in Codorus State Park.   If one would stand on the Black Rock Road bridge at the western end of the state park and look east, you are looking along the Martic Line.

What makes the Martic Line so intriguing? On a geologic map, the structure stands out.  The Martic Line divides the metamorphic rocks to the south and generally sedimentary rocks to the north.  Phyllites, slates and schists making up the Marburg and Octoraro formations are separated with limestone of the Conestoga Formation.  Even a non-science brain would ask why is there such a sharp division there between metamorphic and sedimentary rocks?

A section of the geologic map of York County by George and Anna Stose (1944) showing the Martic Line near Dallastown.

We have to go back into history a short distance to introduce this Martic Line controversy.  What helps to make this such a controversy is the lack of good rock exposures to study.  First of all, faults are not uncommon, particularly in a region like ours that has gone through major continental collisions and separations.  Often, we have a good rock exposure like in a quarry to do our examination and measurement of a fault to interpret what occurred there.  However, for the Martic Line is poorly exposed along its line of existence.  Even from its type site at Martic Forge in Lancaster County, there is not a good exposure to study.  The best exposure is found along the Enola Low Grade Bike Path in Provenance Township near Quarryville, Lancaster County. More details about that later.

Stose and Jonas (1939) map of the geology of York County showing the Martic Line south of Hanover, now the location of Lake Marburg.

The recognition of the Martic Fault was first published by Eleanora Bliss Knopf and Anna I. Jonas in 1929.  These two females were laying the foundation for women in geology and had graduated from Bryn Mawr College in Bryn Mawr, PA.  Their professor was Florence Bascom, who was nationally recognized as the first woman in geology.  Florence not only has a crater on the Moon named for her but also an asteroid.  Her life is worth its own blog sometime.

Eleanora and Anna recognized in the Coatesville area that a group of rock formations known as the Glenarm Series was sitting on top of a slightly metamorphosed limestone known as the Conestoga Formation.  They believed that the Glenarm Series metamorphic rocks (schists) were much older than the Conestoga Formation rocks.  Eleanora and Anna’s thinking about the age of these two rock units is what created a separate argument with Florence Bascom.  Eleanora and Anna believed the Martic Fault could be traced from at least Virginia eastward to Coastesville where it connects with the Doe Run Fault which continues into New Jersey.  They also hypothesized that the rocks of the Glenarm Series were moved approximately 20 miles to the northwest over younger-aged rocks.  Well, let me tell you, this published work generated a bunch of controversy (that is only an editorial note since there was not way I was around here yet).

One of the leading non-believers in the controversy was J. Hoover Mackin who published an article in the Journal of Geology in 1935.  He presented evidence not supporting the Martic Fault theory.  Many supporters against the theory also rose to the top.  Was it  because these two trend-setting females came up with an idea on their own and women weren’t too well accepted into the geologic world yet?  In their two classic woprks in York County geology, George Stose and Anna Jonas Stose identified this structure as the Martic Overthrust.  (See an earlier blog regarding George and Anna’s life together).  So this debate continued for many years.  Various publications and field trip guides centered on this controversy with no “clear-cut” decisions.  Researchers used a variety of tools to attempt to provide conclusive evidence such as geomagnetic work, the degree of metamorphism across the “line” and the structural orientation in the rock.  I would have loved to be present for some of these classic discussions on a field trip – that would have been a classic to have recorded.

Since the turn of the century, thinking among the geologic world began to change on the origin of the Martic Line.  Further research involving the theory of plate tectonics and establishing a picture of how our landscape evolved placed the Martic Line has the edge of what has now been called terranes.  Terranes are pieces of the Earth crust that had a origin separate that that on our continent and later attached itself onto our landmass.  Different terranes have been identified in the Mid-Atlantic states by geologists.  More recent dating procedures have been conducted by Gale Blackmer of the Pennsylvania Geologic Survey across the Martic Line to determine the age and degree of metamorphism.

Don Wise (2006) map showing the terranes of our region.

Today, the Martic Line is widely accepted as a low-angle fault known as a thrust fault.  Many maps label the structure as the Martic Fault.   In the mid 2000’s, Don Wise, a former professor geology at Franklin and Marshall College and now at Amherst College in Massachusetts, created a new regional map of southeastern Pennsylvania and eastern Maryland showing the various terranes.  Using this theory, the Martic Fault has a definite role in the history of plate tectonics in our region.

It is surprising to me that a number of residents have heard of the Martic Fault.  This stemmed from the April, 1984 earthquake centered near Martic Forge, Lancaster County.  While being interviewed about the earthquake, Dr. Charles Scharnberger of Millersville University was asked by a media writer if a faults occur in this area.  Dr. Scharnberger responded yes we have the Martic Fault.  The reporter mis-interpreted that the Martic Fault was the key player in the origin of the earthquake.  The readers of the article believed that the Martic Line was active and the center of earthquake activity which is totally a false statement.  The earthquake was actually along another fault not directly associated with the Martic Line.

THe Enola Low Grade Railroad bike trail exposure showing the Martic Fault. The Octoararo SChist is on top of the Conestoga Formation limestone. Dr. Charles Scharnberger, my dear friend and field trip host poses for the photographer.

Finally, if anyone would like to view the Martic Fault, travel to the Enola Low Grade Bike Trail in Providence Township just west of Quarryville, Lancaster County.  On the west side of the path just north of the Sawmill Road bridge (mile marker 3.8), there is a large rock exposure.  If you examine this outcrop, the Octoraro Schist lies on top of the Conestoga Formation limestone.  This is the best exposure of the Martic Fault known in Pennsylvania.

This post is almost like a fairy tale in a sense, but it’s written with pride, as it is a story about two geologists who laid the foundation for recent geologic exploration in southeastern Pennsylvania. This is a cool human interest story.

Let’s introduce two people to set the stage. George W. Stose was born in Chicago, Ill., in 1869 and graduated from Massachusetts Institute of Technology in 1893 with a degree in civil engineering. He spent a year in graduate work in geology. Receiving a civil engineering degree prior to becoming a geologist seemed to be common in preparation for geologic training.

In 1894, George was hired by the U.S. Geological Survey as a field assistant in geology, which paid $50 per month. His first research occurred in Colorado. He worked continuously for the U.S.G.S. until 1941, when he was 72. He was reemployed by the same agency in 1942 to conduct additional mineral exploration in Virginia during World War II. This position ended in 1943.

George continued to prepare reports for the federal government until 1953, panning a period of 60 years. What a remarkable career! He suffered a heart attack in 1953 and a cerebral hemorrhage in 1955. He died at his home in Arlington, Va., in 1960.

George Stose in his office at the USGS (courtesy of the USGS Library)

Anna I. Jonas was born in Bridgeton, N.J., in 1881. She went to Bryn Mawr College outside of Philadelphia for her undergraduate and graduate work, earning her Ph.D. in 1912. Anna assisted in the college’s Geology Museum and geological laboratories when there.  Anna studied under Florence Bascom, the grande dame of American geology. Florence’s success story (she was one of the first women to receive a P.h.D in geology) is worth a blog post in itself. Search for her on the Internet to see all of her achievements. 

Anna shared her knowledge of geology with various institutions, including the American Museum of Natural History, geological surveys of Pennsylvania, Maryland and Virginia, and the United States Geological Survey, from which she retired in 1954. She died in 1974 in Ocean View, N.J.

A young Anna Jonas at Bryn Mawr College (courest of Bryn Mawr Archives)

Now that you know a little about George and Anna, you’re ready to learn their connection to southeastern Pennsylvania. George started to conduct geologic research within the Appalachian Mountains and South Mountain of Maryland and Pennsylvania in the early 1900s. He spent a good amount of time in Adams County conducting research, including the “then-rich” copper deposits near Blue Ridge Summit. George was reassigned to investigation of important mineral deposits in southern Virginia but returned to the region around 1919 to continue his work.

Anna started her career-long investigations in southeastern Pennsylvania in or around 1916. Her first several reports were co-authored with classmates from Bryn Mawr College. Her early reports began to get her name and reputation out into the scientific world, including George Stose. As fate had it, George and Anna probably met professionally and realized they shared interests in geology and southeastern Pennsylvania. Their first published article appeared in 1922. It described Lower Paleozoic rocks in the region.

George and Anna became one of the closest-working geologic teams. I learned many years ago that in physics similar poles do not attract. Well, this is true when you look at the personalities of George Stose and Anna Jonas. From what I have read, George was a great observer in the field but also was a great cartographer and illustrator. He seemed to be a quiet, laid-back person who did what needed to be done to complete the research. 

Anna was the eye of the storm. Much has been written about this controversial figure. She always said what was on her mind, no matter her colleagues’ reactions. Her field notes were some of the best by far, among some of the most detailed notes ever taken. 

Anna also had the ability to take a good observation a bit further than was warranted. Her colleagues’ notes and field maps became modified by ideas, so that Anna’s published maps tended to become somewhat schematic cartoons.

George and Anna Stose. This believed to be one of the only pictures showing the couple.

With their span of published reports from 1922 to 1944 dealing with Adams, York and Lancaster counties, George and Anna laid the foundation for future investigators. Because George and Anna were the first geologists studying this region, they had the honor of giving names to the different rock units. These include the Conestoga, Peters Creek and Cocalico formations, to name a few. They also named many of the faults and folds found in the region. Their work was monumental and still used today for reference.  As a budding geologist in the 1970s, I read their classic works, two in particular — “Geology and Mineral Resources of York County” (1939) and “Geology of the Hanover-York District” (1944), which helped me grasp the complexity of our geology.Combining George’s ability as an illustrator and Anna’s field interpretations, their publications certainly did lay the foundation.

I guess George and Anna got tired of meeting for coffee after work to discuss their day’s fieldwork. In 1938, they married so that the talk around the supper table could be all geology.  With Anna’s remarks, I wonder how many words George got in about his thoughts. The York County geology report referenced above was the first publication prepared by Stose and Stose. Some of their publications are referenced as “Anna Stose and George Stose,” while others were “George Stose and Anna Stose.”  I wonder what criteria was used to determine whose name went first.

What is remarkable about the Stoses’ research is its accuracy and foresight. Think back to the 1920’s and 1930’s in York County.  The amount of construction we see today here wasn’t occurring in those days. There were limited rock exposures to examine. Not even Interstate 83 existed.  Yes, there was the Northern Central Railroad running north and south across the county and the Western Maryland railroad running in a east to west direction.  But still, Stose and Stose had limited exposures to work from plus the technology from their day to today is as different as George’s and Anna’s personalities.

Chickies Rock taken from York County by Stose and Jonas (1939)

Present day picture taken of Chickies Rock from the same location

If you read one of their county or quadrangle reports, pay attention to the geologic history section. Talking about being ahead of one’s time! George and Anna’s description included a hint of continental drift (today known as plate tectonics). Remember, the theory of continental drift was introduced by Alfred Wegener in 1909 but was not really considered by geologists to be an acceptable theory until 1954, the year that George Stose retired. Was this part of Anna’s personality always pushing the “envelope” to take an idea to the next level?

I love to pore through one of their publications on local geology and look at the pictures. For example, their picture of Chickies Rock in Lancaster County was taken on the York County side of the Susquehanna River. Just where exactly did they stand to get that shot? Another example is a picture of a faulted hill in the area of Jacobs Mill west of Spring Grove.  I looked at that picture trying to identify its precise location.  I had a special interest in that photograph as the church my wife ministers is located within that area. There is a log-cabin style house, power lines and a small creek on the picture to help orient ourselves. I showed the picture to several long-time members of the church, asking them: “Does this landscape look familiar?” 

No one could really help!  One day when my wife was coming home, she recognized the log house sitting along a hillside similar to the Stose’s picture. Sure enough, there was the creek and power lines along with the correctly shaped hillside.  Wow, right here is my heroes George and Anna stood to take the picture.

There are many photographs taken by George Stose on the U.S. Geological Survey’s Photograph Library.  Go to www.usgs.gov and search for “Stose photographs”.  It is interesting to see just how many places in Adams, York or Lancaster counties that look familiar. Also if you can find a copy of their report, look at the their drawings of quarries (some of which are still in operation or at least visible).  Their detail is remarkable showing folds and faults.  I have included a drawing from Stose and Stose (1944) for Zinn’s Quarry on Zinn’s Quarry Road in West Manchester Township.  Below the drawing is a present view of the same wall.  Can you find the features illustrated?

Drawing by Stose and Stose (1944) of a wall at Zinn’s Quarry.

Present day picture of the wall at Zinn’s Quarry

Apparently both George and Anna were camera-shy. Pictures of them individually or together are few and far between. I guess their interest was in the rocks instead of themselves.

In any case, George and Anna Stose did remarkable work, and I wish I could bring them back to life just to say thank you for their observations and thoughts. I can almost hear a conversation between George and Anna about their individual interpretations or in some cases Anna’s “convincing” comments, when she’s free to speak her mind.

A jade necklace worn by Anna Jonas Stose

A real gem – George Stose’s Brunton compass

George and Anna are buried together in the Overlook Cemetery in Bridgeton.  Preparing for a paper at the 2012 Northeastern Section Meeting of the Geological Society of America meeting held in Hartford, CT, I needed a photograph of the grave marker.  Using today’s technology, I contacted a funeral home from Bridgeton and ask if someone could go to the cemetery and get me a picture of the grave site.  Within a week I had a picture in my possession.

George and Anna Jonas Stose’s grave marker in Overlook Cemetery in Bridgeton, NJ