Samuel Washington McCallie.

A preliminary report on a part of the phosphates and marls of Georgia online

. (page 6 of 7)
Online LibrarySamuel Washington McCallieA preliminary report on a part of the phosphates and marls of Georgia → online text (page 6 of 7)
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generally of a brown or gray color; they rarely appear in beds. Where
they are found in large numbers, they are said to have a marked ef-
fect on the productiveness and durability of the soil.


Echols county is comparatively level, has a sandy soil, and still re-
tains, in its eastern part, extensive forests of long-leaf pine. The in-
habitants, who are few in number, are chiefly engaged in the lumber
and turpentine business. These industries were formerly quite profi-
table; but, at present, they have become less remunerative, by the rea-
son of the exhaustion of the timber, and the reduction, in price, of the
lumber and turpentine. Farming is confined mainly to the western
part of the county, where the greater part of the timber is now ex-
hausted, and the soils are best adapted to agricultural purposes.




Fig. 3

The streams are few; and, having but little currant, they have rarely
succeeded in cutting through the superficial sand and clays. The ex-
ceptions to this general rule occur along the Allapacoochee creek and
the Allapaha river, near the state-line. Along the latter stream, south
of Statenville, are a number of bluffs, varying in height from 20 to 30
feet. They are mostly confined to the east bank, and usually lie op-
posite low, flat palmetto lands. One of the highest of the bluffs is
located about half a mile south of Statenville, on the right bank of the
river. It has a height of about thirty feet, and presents the follow-
ing geological section:

The phosphate pebbles vary
in size from a mustard seed to
half an inch or more in diame-
ter. They are of a dark-gray
or jet-black color; and usually
they have a smooth enameled
surface, which readily distin-
guishes them from other peb-
bles. They appear to be pretty
evenly distributed throughout
the entire stratum of sand; but
they make up only a small
percentage of the entire mass.
A similar exposure occurs
on the east bank of the river, in a deep gully, a few rods below the
bridge at Statenville. There is to be seen, here, underlying the phos-
phatic sand and calcareous deposit, a bed of limestone, the upper lay-

- ^= - 3

Section through Rocks along the West
Bank of the Allapaha River, Half a Mile be-
low Statenville. I. Massive Sands. 2. Red-
dish, Coarse Sand. 3. Yellowish Sand In-
terstratified with Thin Layers of Clay.





ers of which, consist of a soft, calcareous material, or marl, about three
feet in thickness. It contains many fragments of sea-urchins, with
other fossils, and with numerous phosphate pebbles. Below the marl-
bed, is a stratum of argillaceous limestone, two feet thick, made up of
a number of thin, compact layers, between which occur phosphatic peb-
bles. This stratum is followed, in turn, by a compact, heavy bedded,
siliceous limestone, forming the bed of the river. There appears, here,
a slight unconformity, existing between the superficial sands and the
deposits below. 1 These calcareous deposits, containing phosphate
pebbles, outcrop at several points along the river between Statenville
and the state-line. They are well exposed on W. T. Green's property,
lot 189, 16th district, and, also, on the Fresco tt property, further up
the river. The section, indicated in the figure below, occurs at the
mouth of a small stream, on the Green property, a few hundred yards,
from the state-line.

Fig. 4

Section through the Rocks on W. T. Green's Property, i. Sandy Clays. 2. Limestone.
3. Phosphate Pebbles in Calcareous Matrix.

The total thickness of the layers of phosphate, at this point, as seen
in the above section, is only about 22 inches. They consist of phos-
phate pebbles, cemented into a hard, compact mass, by a cream-col-

1 See Fig. 4.


ored, calcareous matrix, which also frequently runs high in phosphoric

A chemical analysis of the pebbles, which constitute, probably, 30
per cent, of the phosphatic mass, gives the following results :

Sand and insoluble matter 6.38

Xioss on ignition 12.64

Al/) 3 , Fe 2 3 3.39

CaO _ - 44.67

P.O. . 26.78

Undetermined . .__ 6.14

Total- - 100.00

26.78, P 2 O 5 corresponds to 58.38, Ca 3 (POJ 2 .

The limestone, underlying the phosphate at this point, is compact,
more or less sandy, and weathers into irregular cavities. It is slightly
phosphatic; and it frequently contains nodules of flint; but rarely does
it contain organic remains.

A few miles west of the Allapaha river, the same deposits again out-
crop, along the banks of Allapacoochee creek. The best exposures, on
this stream, are to be seen at the Swilley and the Kersey bridges, where
the deposits are exposed, in bluffs, from 15 to 20 feet high. At the lat-
ter place, there occurs, overlying the phosphatic sands and conglomer-
ate, a tough, greenish, laminated clay, with thin layers of sand, con-
taining phosphatic pebbles. A remnant of this clay was noticed at
one or two points on the Green property; and it shows up well, at the
bluff at the mouth of the small creek, which enters the river, just above
Statenville. The exposure, at the Swilley bridge, consists mainly of
sands with pebbles of phosphate. Associated with the phosphate, tare
numerous fragments of bone, sharks' teeth and fossil shells, the latter


being especially abundant, in the lower beds, which are usually highly

Specimens of the pebbles, collected at the Swilley bridge, show the
following chemical composition:

Sand and insoluble matter 16.35

A1 2 3 , Fe 2 3 3.65

CaO 39.37

P 2 O 5 26.22

Undetermined 14.41

Total- ___100.00

26.22, P 2 O 5 corresponds to 57.23, Ca 3 (PO 4 ) 2 .

The extent of the area, underlaid by the deposit of phosphate, could
not be definitely determined. However, it seems quite likely, that it
underlies much, if not all, of the area between the Allapaha river and
the creek, from the state-line, as far north as Staten-
ville. This conclusion is based upon the similarity of the deposits, on
the two streams, together with the fact, that some of the small
branches, between the above streams, expose, at different places along
their course, outcroppings of the upper beds of the deposit. The
banks of both the Suwannee river and Toms creek were examined, at
different points, with the view to locating the deposit further east ; but,
at no place, was there noticed any indication, whatever, of its presence.
Along the former stream, occur at several places near the state-line,
exposures of limestone, which is fossiliferous, and often slightly phos-
phatic. The banks are usually low and sandy, and rarely present op-
portunity, for studying the underlying formations.



Much of the western part- of Charlton county, and a considerable
portion of the southern part of Ware and Clinch counties, are covered
by the Okefenokee Swamp. This is an extensive cypress swamp, ly-
ing partly in Florida and partly in Georgia. It has a length of about
40 miles, and varies, in width, from five to twenty miles. The total
area is 500 square miles. The greater part of this area, which has an
elevation of about 90 feet above sea-level, is covered, during the most
of the year, by water, from a few inches to several feet in depth. The
surplus water, supplied to the swamp from all sides, by an almost in-
definite number of small streams, ultimately finds an outlet through
the Suwannee and St. Mary's rivers, one flowing, south, to the Gulf of
Mexico, and the other, east, into the Atlantic Ocean. The surface
of the swamp, with the exception of the places, where the water is sev-
eral feet deep, is covered by a luxuriant growth of aquatic plants,
whose decaying bodies and leaves form, on the bottom, a layer of veg-
etable material or peat, from one to ten feet in thickness. Besides the
herbaceous aquatic plants, there are, also, in places, extensive forests of
cypress, which is now being utilized, by the Suwannee Canal Company
in the manufacture of lumber. The above Company, which pur-
chased the greater part of the swamp from the State of Georgia, in
1891, at a cost of $65,000, has recently constructed a canal, connect-
ing the swamp with the St. Mary's river, at a point a few miles south
of Trader's Hill. The total length of the canal, including the part
extending into the swamp, is several miles. It is from 10 to 40 feet
deep, and about 30 feet wide. The company had two objects in view
in constructing the canal; first, the conveyance of the cypress timber
to the mills, located at the head of the canal; second, the drainage of


the swamp, and the reclaiming of an extensive area of land, for agri-
cultural purposes.

The following geological section, taken from the canal near the mill,
gives an idea of the formations, which probably underlie much of the
swamp area.

Fig. 5

Cross-section of the Suwannee Canal, near the Okefenokee Swamp, I. Soil. 2. Light-
Colored Sands. 3. Dark Sands. 4. Yellow Sands.

The surface of Charlton county is unusually low and level, and pre-
sents rarely, but slight variations, in its topographical features. The
St. Mary's and the Satilla rivers, forming the eastern boundary, are
both tidal rivers, and, only at a few places, have they succeeded, in cut-
ting through the superficial deposits, and exposing the underlying
formations. The bluffs, which are few in number, are generally low,
and are formed mainly of sand, interstratified with thin layers of clay.
There occur, however, at some points along St. Mary's river, both
above 'and below Trader's Hill, bluffs several feet in height, where the
underlying formations may be examined.


The most interesting of these bluffs is to be seen at Camp Perry, on
the St. Mary's river, at the south end of the Savannah, Florida &


"Western R. R., about two miles below Trader's Hill. The entire
thickness of the deposit, occurring here, including the exposure on the
river-bank and in the railroad-cut 'above is about 40 feet, consisting of
sands, clays, limestone and marl. 1 The marl-bed, which outcrops just
above the water's edge, has an exposure of about five feet, and consists
of a mass of small, loose>, compact shells, with a greenish clay matrix.
With the exception of the unconsolidated condition, the deposit resem-
bles very closely the Coquina beds, near St. Augustine. The lime-
stone appears in layers, from three to eight inches thick, and is quite

compact, showing but lit-

Fig. 6

tie indication of organic
remains. Similar deposits
are reported to occur, at a
number of points along
the river above Trader's
Hill; but, owing to 'the
swollen condition of the

Cross-section at Camp Perry, i. Massive Sands. , n ?

nver, at the time of our

2. Motley, Jointed Clays. 3. Yellowish, Lamin-

ated Clays. 4- Reddish Clays, Containing Cavities visit > Jt W&S foUnd i

Filled with Sand. 5. Greenish, Stratified Sands. Slble to examine these

6. Shell Marl. 7. Limestone. DOSUreS


Camden county, which lies in the extreme southeastern corner of
the State, has extensive salt marshes, along the eastern border; and,
only far inland, along the Big and Little Satilla rivers, are there op-

1 See Fig. 6.


portunities offered, for the study of the different geological formations,
in natural exposures. These rivers frequently traverse wide and fer-
tile bottoms, that produce extensive crops of rice; and, only occasion-
ally, do the bluffs attain a sufficient height, to give a geological section
of more, than a few feet in thickness. In the vicinity of Owen's
Ferry and Burnt Fort, are to be seen, at various points along the Sa-
tilla river, bluffs, or steep banks, from 20 to 30 feet in height. The
Bluffs are made up of sands and stratified clays, with an occasional
layer of either mud-stone or clayey limestone. The latter generally
outcrops, just above the surface of the water, and consists of a number
of layers, from 3 to 8 inches in thickness, separated by thin beds of
bluish or white-colored clay. As far as our observations expended, the
calcareous layers appear to be entirely free from organic remains; but
they carry a small amount of phosphoric acid.


Several miles further up the river, on Mr. Jas. P. King's estate, oc-
curs an extensive marl-bed. The property, on which the deposit is
located, is situated six miles south of Atkinson; and, of kte years, it
has become quite a popular resort, for fishing parties, whose attention
is usually attracted, by the peculiar appearance of the deposit. The
principal exposure occurs, at the base of a bluff, on the left bank of the
river, a few hundred yards north of the mansion-house. The bluff,
which is about 30 feet in height, shows the following geological sec-


Soil li feet

Bluish clays ._ 2 "

Motley, sandy clays 10 "

Light-colored, sandy clays 5 "

Yellowish, sandy clays 4 "

Laminated blue clays 2 "

White sand , 1 "

Blue clay -... 2J "

Marl 2 "

At the time of our visit, only about two feet of the marl-bed was ex-
posed above the surface of the water; however, detached fragments
of the bank, below this level, show, that the bed attains a thickness,
at this point, of four feet or more. The deposit consists almost entirely
of small bivalve shells, with a sandy clay matrix. Associated with the
shells, are fragments of bones, and what appear to be the remains of
the carapaces of turtles and crabs. The marl has been used, to a lim-
ited extent, by Mr. King, as a fertilizer, on various crops; and it is said
to have given very satisfactory results. It is evidently of much value,
locally, as a fertilizer; however, it could not probably be transported to
any distance, with profit. Another outcropping of the deposits occurs
about a mile further up the river; but it here seems to be diminished
in thickness, and also contains more sand and clay.


In the eastern part of the county, along "White Oak creek, are other
marl deposits. These can be best examined, during low tide, at the
trestle, crossing the creek, near White Oak station. The banks of the


creek, at this point, are almost eight feet high, and are formed of
greenish and light-colored sandy clays, that overlie the marl, forming
the bottom of the stream. The marl deposit, which contains numer-
ous fossil shells and fragments of bone, is of unknown thickness and of
a grayish color; and it contains a high percentage of calcium car-
bonate. Phosphoric acid is present through the entire mass; but it is
especially abundant in the bones and in the small, dark-colored parti-
cles, which seem to be of animal origin. The bed of the stream, in
places, is frequently strewn with fragments of bones, that have been
washed out of the marl-beds. This has led to the belief, that there oc-
curs, somewhere along the creek large deposits of bones, which are
available for phosphate. A diligent search, however, has, so far,
failed to reveal any such deposit.

A chemical analysis of samples of bones, collected, gives the follow-
ing results:

Sand and insoluble matter 1.37

A1 2 3 , Fe 2 3 1.67

CaO 51.15

P 2 O 5 32.57

Undetermined 13.34

Total 100.00

32.57, P 2 O. corresponds to 71.00, Ca 3 (PO 4 ) 2 .


Glynn county differs but little, topographically, from Camden. It
has, along its coast, extensive salt marshes, made classic by the poems


of Sidney Lanier. Further inland, are large tracts of low, swampy
lands, which, when properly drained, bring crops of cotton and corn,
without the aid of fertilizers. The western portion of the county is
frequently undulating; has a sandy soil; and is generally well tim-
bered, with long-leaf pine. The streams, especially the j\ltamaha,
forming the northern boundary, often have wide, fertile bottoms, that
yield large crops of rice.


At the time of our visit to the county, numerous reports were cur-
rent, concerning the recent discovery of phosphate, at different places,
along College creek and Turtle river, two small tidal streams, a few
miles west of Brunswick. Both these streams were visited, at several
points, and the reports were investigated. College creek, so called,
on account of the land, in its immediate vicinity, having been orig-
inally granted to Kev. Geo. Whitfield, by the Countess of Notting-
ham, for endowing a college, is, more properly speaking, a slough, or
narrow ravine, containing but little water, during low tide. Its
banks are frequently precipitous; and, on the Livingstone property,
they attain a height of about ten feet. There is exposed here, along
the bank, just above the surface of the water, at low-tide, a bed of
argillaceous limestone, which has frequently been taken for phos-
phate. The bed is exposed along the stream, for a quarter of a mile,
or more. It is made up of many thin layers, that break up, when
exposed to the atmosphere for a short while, into small, regular blocks,
the surface of which, when freshly broken, is of a dark-blue color ; but,


often, exposure gradually changes this to a pale yellow. Chemical
analysis shows,, that it contains only a trace of phosphoric acid, and can
be of no commercial importance, as a fertilizer. Immediately overly-
ing the limestone, is a bed of sandy marl, about six feet in thickness.
Its upper layers are made up largely of greenish sands, containing-
numerous fossil shells, fragments of bones, and sharks' teeth; while the
lower layers are of a light color, consist chiefly of calcium carbonate,
and are even more fossiliferous. In the lower part of the bed, were
found, associated with the fragments of bones, a few phosphatic peb-
bles, which showed, by chemical analysis, the following composi-

Sand and insoluble matter 3.17

Loss on ignition 10.61

A1 2 3 , Fe 2 3 . . 1.71

CaO _, 49.55

P 2 O ? 32.34

Undetermined - 2.62

Total- ..100.00

32.34, P 2 O 5 corresponds to 70.50, Ca 3 (PO 4 ) 2 .

The whole marl deposit contains phosphoric acid; but it is usually
low, varying from a half to two per cent. It, however, seems to be
sufficiently abundant, throughout the entire bed, to make the deposit
of value, locally, as a commercial fertilizer. With the exception of
the occurrence of limestone, the deposit along Turtle river was found
to be similar to that, exposed along College creek. A like deposit is
also said to be found along the Satilla river. This statement could
not be verified, on account of the swollen condition of the river, dur-
ing the time of our visit.


Besides these calcareous deposits, there are also others, to be seen, at
various points, in the cuts and drain-ditches, along the Florida Central
& Peninsular K. K. in the southwestern part of the county. These
consist largely of oyster shells, which form beds, from a few inches to
three feet in thickness. They are frequently encountered in wells and
other excavations, only a few feet beneath the surface.


Mclntosh county, like the counties lying further south, has a very
irregular coast-line, indented by numerous sounds and inlets, separat-
ing the main land from numerous low, marshy islands. Inland, the
surface is generally low and level, with a sandy soil. The Altamaha
river, which forms its southern boundary, is ..the only stream of any
importance in the county. It usually flows through wide bottoms or
swamps, and offers but little opportunity, to study the different geo-
logical formations, along its low, sloping banks.


The only natural exposures of any consequence, that were examined
in the county, occur along the headlands, near the mouth of Sapelo
river, a few miles north of Diarien. There are to be seen, here, at
several points, long stretches of bluffs, from 20 to 30 feet high. The


most noted of these bluffs are known as Belleview, Crescent and South-
erland. They are formed almost entirely of sand, some of the layers
of which have become indurated, and have resisted, to a great extent,
the action of the waves, and are now seen, to form step-like shelves,
projecting from the face of the bluffs. While examining these bluffs,
our attention was c'alled to a deposit of bog iron ore, in an old rice field,
belonging to Mr. James "Walker, on the Sapelo river, near Crescent
bluff. The deposit forms a more or less continuous bed, about 8 inches
thick, extending over an area of less than an acre in extent. Beneath
the bog ore, is a layer of dark-colored marsh mud, containing small,
irregular masses of vivianite, a hydrous iron phosphate. When first
dug up, it is very soft, and of a light color; but, after exposure to the
atmosphere, for a short time, its color changes to a deep blue. This
deposit of vivianite is local, and including its matrix, is only a few feet
in thickness. It is of no economic importance.



The result of our investigations, in the various counties, lying along
the Georgia-Florida state-line, demonstrates, to a considerable degree
of certainty, two very important economic facts. First, that there
do not likely exist, anywhere along the state-line, with the excep-
tion, probably, of Thomas county, deposits of phosphate, of sufficient
extent and purity, to be mined with profit, for the manufacture of
commercial fertilizer, at its present market value. Second,, that all
these counties contain more or less extensive beds of marl, or low-
grade phosphate, a valuable natural fertilizer, that might be used to a
great extent, in replacing the more costly artificial manures. It seems
difficult to understand, why the planters of these counties, who are al-
ways desirous of raising good crops, without the use of expensive arti-
ficial fertilizers, have not, before now, tested the merits of these de-
posits. The explanation appears to be due, to a great extent, to the
want of knowledge, concerning the mode of occurrence, physical ap-
pearance and the nature of marl, and the manner of applying it to the
soils. It has been further suggested, that the cheapness of land and
the abundance of virgin soil, which needs no artificial stimulant, for a
few years, have, also, caused the farmers to be slow, about seeking out
natural fertilizers. In many instances, it has been found cheaper, to
purchase and clear up new lands, rather than to attempt to build up
the old to its former fertility, by the use of costly artificial manures.
Fortunately for the future welfare of that part of the State,, this con-



dition of things, on account of the gradual increase in the price of
lands, and the growing scarcity of virgin soils, seems to be drawing rap-
idly to a close; and the time will soon arrive, when the planters will,
of necessity, be driven to the use of natural manures, or the final
abandonment of large areas of land, which are now becoming rapidly
exhausted, under the present mode of cultivation. There can be lit-
tle doubt, but that there exists in many, if not all, of the above coun-
ties, deposits of marl, more or less extensive, and equal, in many re-
spects, to the Greensand beds of New Jersey. In only a few instances,
have they been tried on growing crops; but, in all cases, they are re-
ported to have produced beneficial results. Our work, both in the
field and in the laboratory, was necessarily preliminary in its char-
acter, and gave only general results. The true economic value of
these deposits can be definitely determined, only by making a num-
ber of practical field-tests. If some of the leading farmers, in this sec-
tion, can be induced to give these marls a thorough trial, there is little
doubt but that the results, in many cases, will prove to be satisfactory,
and will finally lead to their general use, as a fertilizer. The impor-
tance, to the farmer, of the discovery of valuable marl deposits in
South Georgia, can hardly be overrated. It would enable him, not
only to restore thousands of acres of land, exhausted by long cultiva-
tion, to their original fertility; but also to greatly increase the pro-
ductiveness of all other lands, with much less expense, than is now be-

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Online LibrarySamuel Washington McCallieA preliminary report on a part of the phosphates and marls of Georgia → online text (page 6 of 7)