CONSHOHOCKEN PLASTIC CLAYS 483 



Number 6 is an abandoned iron mine, overgrown. 



Number 7 is a sand pit apparently about 20 feet deep. 



Number 8 is a large clay pit, where several shafts have been sunk recently around 

 the border of the pit, showing fresh exposures. These show a layer of yellow 

 sand, clay, and pebbles at the top, varying from two to eight feet, vinderlying 

 which is a bed of varying thickness consisting of variegated, red, red and gray 

 mixed, and black clay, containing many pebbles. Beneath this is a clay, red, 

 gray, black, and dove-colored, running to a depth of 40 to 50 feet. The clays are 

 not regularly banded, but the colors are irregularly intermixed. The black clay 

 which predominates toward the bottom contains large quantities of charcoal or 

 lignite, fragments of limbs and twigs varying in size from a fraction of an inch to 

 several inches in diameter. No leaves nor bark were observed. 



Number 9 is a large pit containing clayj sand, and gravel in different portions. 

 Large quantities of iron ore were removed from this opening a number of years 

 ago. At the west end is a deposit of clean, sharp sand about 20 feet deep that has 

 been quarried for foundry purposes. Near the middle of the opening is a shaft 

 about 25 feet deep showing alternating layers of sand and light-colored clay ; east 

 of that a few yards the clay disappears, and the material is coarse sand and fine 

 gravel ; a few yards farther on is an opening in the variegated red clay. All of 

 these sections are at about the same level, but none of them go through either the 

 sand or clay, so the thickness is not known. About 50 yards south is a large 

 marble quarry, where the limestone extends to the surface and has been quarried 

 to a depth of 100 feet or moi'e. 



Number 10 is an abandoned brick yard where variegated and white clays were 

 worked. It is now overgrown. 



. Number 11 is a small pit where white clay and white sand occur together. The 

 white clay is overlain by five to eight feet of yellovy sandy loam which contains 

 fragments of quartz and pieces of red and brown hematite. The shaft penetrates 

 about 15 feet into the white clay, but how much thicker it is could not be ascer- 

 tained. Between number 11 and number 12 a thick deposit of white clay is re- 

 ported. 



Numbers 12 and 13 are old iron mines, from both of which considerable red 

 and red variegated clay has been removed, but both mines are now abandoned. 



Number 14 is an old iron mine from which white sand has been removed. 



Number 15, a few yards farther south, shows two to five feet of brownish sandy 

 clay at the top, banded blue and gray clay underneath, 20 feet or more in thick- 

 ness. It shows a faint schistose structure in places as though it was decayed 

 schist. About a quarter of a mile north of the last mentioned opening is a large 

 iron mine. 



Number 16, one of the largest openings on the hill is an ore pit, froin which 

 large quantities of clay were taken, and between the iron mine and the clay bank, 

 number 14, there is an old marble quarry. 



Number 17 is a short distance northeast of Lafayette hill, on the farm of Mr 

 George Rapine. It is a shaft in the light and red variegated plastic clay which 

 has been mined to some extent for use in the Barren Hill terra-cotta works. 

 Some exploitation has been done here, but the report of it is too indefinite to give 

 a correct estimate of the extent of the bed. The owner states that the clay follows 

 a narrow east-and-west belt, and a short distance north exploitation pits showed 

 nothing but sand. 



