Samuel Washington McCallie.

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

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A1 2 3 , Fe 2 3 2.78

CaO 49.60

P 2 O 5 35.45

Undetermined.- 2.62

Total 100.00

35.45, P 2 O 5 corresponds to 76.38, Ca 3 (PO 4 ) 2 .

The limestone, underlying the sandy clays, is of a white or creamy
color. It contains much siliceous material, is frequently highly fos-
silif erous, and weathers irregularly. Dr. Spencer has classed the lime-
stone as middle Miocene. The occurrence of numerous orbitolites, in

Fig. 2

Ideal Section Showing Unconformity at the Boston Phosphate Works. I. Sandy Clay Con-
taining Nodules of Phosphate. 2. Limestone Showing Irregularly Eroded Surface.

its upper layers, indicates, that it is probably the White Limestone of
the Upper Eocene. There is a marked unconformity, existing be-
tween the limestone and the overlying sands and clays. 1 Immediately
overlying the limestone, is a thin layer of sandy clays, containing
many siliceous shells of oysters. In this bed, are sometimes found nod-

1 See Fig. 2.


ules of phosphate; but they more frequently occur in the sandy clays
above, which often attain a depth of twenty feet or more.


About one mile southwest of the Toy phosphate pits, are other
similar excavations on J. B. Eason's property. The excavations are
located in a field on the south slope of a hillside, near the Savannah,
Florida & Western K. B., thirty or forty feet above the surface of
Aucilla creek. There is exposed, here, a highly siliceous, fossiliferous,
white-colored limestone overlaid by motley, sandy clays, containing
phosphatic nodules. The clays vary, in thickness, from three to
twenty feet, and are unconformable with the underlying limestone.
The following analysis may be taken, as showing the chemical compo-
sition of a fair average sample of the nodules collected :

Sand and insoluble matter ~_ 6.58

A1 2 O 3 , Fe 2 O 3 2.14

CaO 1 48.20

P 2 O 5 33.67

Undetermined 9.41

Total 100.00

33.67, P 2 O. corresponds to 73.40, Ca 3 (PO 4 ) 2 .



The deposit of phosphate on L. C. Yarnador's property is located
n lot 131, 13th district, Thomas county. It outcrops, about three
hundred yards north of the mansion-house, along the side of a low
ridge, which overlooks a small branch to the west. The outcropping
occurs about thirty feet below the top of the hill, and ten feet above
the water-level; and it may be traced, east and west, for three hundred
yards. The phosphate appears in the form of nodules, distributed
through a stratum of about six feet of brownish, sandy clays. Asso-
ciated with it, are many nodules of flint and sandstone. The cement-
ing material of the latter consists mainly of phosphate. Most of the
phosphate nodules are of a white or cream color; but there also occur
specimens of a brownish or yellowish color, due to the presence of iron.
A small number of prospecting pits, which have been sunk along the
line of outcropping of the almost horizontal phosphate-bearing stratum,
indicate, that the deposit is not of sufficient abundance, to be of any
economic value.

The analysis of two samples, taken from the deposit, showed the fol-
lowing results :


Sand and insoluble matter 6.71

Loss on ignition 3.72

A1 2 3 , Fe 2 3 2.66

CaO 48.60

P 2 O 5 34.89

Undetermined 3.42

Total 100.00

34.89, P 2 O 5 corresponds to 76.06, Ca 3 (PO 4 ) 2 .



A1 2 3 , Fe 2 3 1.14

CaO 51.17

P 2 O 5 35.96

Undetermined-. . 11.73

Total . ..100.00

35.96, P 2 O. corresponds to 78.39, Ca 3 (POJ 2 .


Several exposures of rocks, which, have been supposed to be phos-
phate, occur near the roadside, between Boston and Thomasville.
Some of the most extensive of these exposures are to be seen at the
lime-sinks, on Mrs. Mitchell's farm, seven miles east of Thomasville.
The exposure, around the pond, south of the road at this point, is made
up chiefly of large siliceous brecciated boulders, slightly phosphatic,
and weathering, on the surface, into a white, porous mass, resembling
chalk. The outcropping, at the lime-sink, on the opposite side of the
road, consists mainly of limestone, which has been used, to a limited
extent, for making lime. It is a light-colored, soft and somewhat po-
rous limestone, containing a few fossil orbitolites, pectens, sea-urchins
etc. ; and, when weathered, it presents a very irregular surface. The
entire bed carries a small percentage of phosphoric acid; but the quan-
tity is too small, to be of any value.



A siliceous deposit similar to the one, exposed at the pond, south of
the road, on the Mitchell property, occurs in a swamp on the Heard
property, six miles east of Thomasville, near the Thomasville and
Quitman road. The exposure consists of numerous boulders, im-
bedded in the wet, marshy soil. Some of these weigh many tons; but
they are usually much smaller. Their outer surface is generally white
and chalky in appearance, while within, they are compact, and fre-
quently have a greenish tint. All are phosphatic; but the percentage
of phosphoric acid is always low.


There occurs, four miles south of Boston, on Dr. Mallett's property,
lot 14) Htli district, an interesting deposit of phosphatic material. It
is exposed on a hillside, in deep gullies, along both sides of the road,
leading from Boston to Monticello. The thickness of the exposed
part of the deposit is about ten feet ; and is made up of a tough, tena-
cious, light-colored clay, in which are embedded numerous phosphatic
nodules, which vary, from one inch to a foot or more, in diameter.
The nodules are quite soft; and, when exposed a short time to the at-
mosphere, they crumble into a white, friable powder. A chemical
analysis, of what was supposed to be an average sample, gave the fol-
lowing results :


Loss on ignition 12.27

CaO 12.06

Phosphate of Al and Fe 30.45

SiO 2 45.34

Total - .-100.12

The phosphoric anhydride present is equal to 20.42 per cent., which
corresponds to 44.51 per cent, of Ca 3 (P O 4 ) 2 ; but the lime present
is sufficient to combine with only 10.25 per cent, of P 2 O 5 . This
gives 22.34 per cent, of Ca 2 (P O 4 ) 2 , the actual per cent, of the com-
mercial bone phosphate present.

Associated with the phosphatic nodules are many silicified coral
masses, some of which are more than 18 inches, in diameter. !N"a
other fossils were noticed, at this point; but, along the roadside, near
by, were seen numerous fragments of oyster shells, in the yellowish,
sandy clays, overlying the phosphate bed. No prospecting has been,
done en the property, and consequently little is known of the extent
of the phosphatic deposit. The overburden is a yellowish, sandy clay,,
about three feet in thickness.


The Mclntyre, Claypole and Mitchell properties, located from 8 to
12 miles south of Thomasville, all hare rock exposures; but an. ex-
amination proved, that they contain little or no phosphoric acid. The
outcropping consists chiefly of limestone, with an occasional thin layer
or nodule of sandstone or flint. The best exposure of these deposits is
to be seen on the Mclntyre property, where quite an outcropping oc-


curs, on a gradual sloping hillside, in an old field, near the roadside-
The limestone is usually thick-bedded; and some of the layers, which
-are semi-crystalline, have been used, to a limited extent, locally, for
building purposes, and for tombstones. It is not adapted to the lat-
ter use, by reason of its softness; but, for the former, it seems to be
"better suited, especially for retaining-walls etc. Many of the less
compact layers contain fossils, the most common being pectens, orbito-
lites, fragments of sea-urchins etc. Strewn about the field, were no-
ticed numerous pieces of silicified coral, some of which weighed several
pounds. The overlying, reddish, sandy clays are frequently uncon-
formable, and often contain oyster shells in the lower layers. These
clays are well exposed, in the deep gullies, on either side of the public
road, passing through the plantation, where they may be studied.


Further east, on Mr. J. L. Cutler's property, which is situated nine
miles south of Boston, are other rock exposures on a small tributary of
Aucilla creek. The outcropping occurs, here, in the bed of the
stream, at a small grist-mill; also along the adjacent hillsides. The
upper part of the exposure consists of siliceous, brecciated boulders,
embedded in the red clays. The outer, weathered surface of the boul-
ders is quite soft, and of a light color; while, within, they ai-e of a
greenish tint and compact, breaking with a conchoidal fracture. They
contain a small amount of phosphoric acid; but the percentage id too
low, to be of any economic value. Underlying these flint boulders, is
a light-colored, compact limestone, also slightly phosphatic. As far


as our observation extended, there appear to be no organic remains, in
either the siliceous boulders or the limestone.


South of this point, are numerous other rock exposures, in the vicin-
ity ! of lake Imonia, near the state-line. They consist of limestone,
flint and sandstone. The latter generally appears, in disconnected
masses, on the hillsides of cultivated fields, and along the shores of
ponds or small lakes. The cementing material is of a whitish color 5
and is made up chiefly of carbonate of lime and phosphate.


The topographic features of Brooks county differ but little, from
that of Decatur and Thomas counties. The surface is often rolling;
and, in places it is traversed, by chains of lime-sinks, forming beauti-
ful ponds and small lakes. The streams are numerous; and, in places
they have cut deep channels, in the clays and overlying sands. Much
of the county still retains excellent virgin forests of pine and the va-
rious hardwoods. The soil is generally fertile, and produces good
crops of cotton, corn, oats, potatoes etc. Many of the farmers have
excellent homes, and are in independent circumstances, a natural re-
sult of the varied crops, together with the fertility of the soil. There
occurs along the many streams, and about the lime-sinks, in the county,


numerous rock exposures, which were visited and tested for phosphoric


One of the most interesting of these exposures is to bo seen in the ex-
treme northwestern part of the county, on Mr. Griffin Hallaway's
property, lot W, 13th district, four miles <east of McDonald. There
appears, here, in the open piney woods, a large irregular lime-sink,
known as the Devil's Hopper, which exposes the different formations
to the depth of nearly forty feet. The two wet-weather streams, enter-
ing the sink from opposite sides, have cut deep channels, that extend
back, for several rods, and give good sections of the superficial clays
and overlying sands. At the bottom of the sink, is exposed about
twenty feet of cream-colored arenaceous limestone, which seems to be
'entirely destitute of organic remains. The different layers vary in
hardness; but all weather into a sandy, calcareous mass, containing a
small percentage of calcium phosphate. Much of this calcareous ma-
terial is soft and friable; and it could doubtless be used, with profit,
as a fertilizer on the surrounding cultivated fields. Overlying the
limestone is a grayish, sandy clay, that appears to have originated
from the weathering of the limestone. This, also, contains phosphoric
acid; but the percentage is so low, that it could hardly be used, with
profit, as a fertilizer.



On the Brice and Chapman properties, a few miles east of the Dev-
il's Hopper, occur numerous loose boulders, scattered about the culti-
vated field, which have been supposed, by some, to be phosphate.
These rocks usually appear on the hillsides, that have been washed into
gullies, and are frequently so abundant, as to interfere with the culti-
vation of the soil. They consist of sandstone and concretions of im-
pure iron ore, with slight traces of phosphoric acid. With the above ex-
ception, there seems to be no other rock exposure, of any importance,
in the northern part of the county. This appears to be mainly due to
the sluggish condition of the streams, which have not, yet, succeeded,
in cutting their channels through the overlying sands and clays. In sev-
eral wells, in this part of the county, it is reported that rock has been
struck at depths, varying from 20 to 40 feet, below the surface.

From the description, given, of the rocks thus exposed, it appears,
that they consist principally of limestone, with, however, a few excep-


One of the most interesting of these exceptions, which came under
our observation, occurs in Duke's well, in the 12th district, a short dis-
tance from Morven. There were disco vered here, at a depth of 15 or
20 feet from the surface, in a layer of sandy clay, some very peculiar,
siliceous concretions, which resemble very closely some varieties of


hard-rock phosphate. The concretions vary, from an ounce to sev-
eral pounds in weight, and are of all conceivable shapes. They are of
a beautiful snow-white color, and very similar, both in weight and
physical appearance, to casts made of plaster-of-paris.


Besides the above exposures, there are many others, along the With-
lacoochee river, that were examined. This stream, which forms the
greater part of the eastern boundary of the county, carries a considera-
ble volume of water, during the rainy season; and it has, at a few
points, cut a deep channel into the superficial deposits. The bluffs,
thus exposed, vary from 20 to 40 feet in height, and are formed prin-
cipally of stratified clays and sands. At the base of the bluffs, near
the water's edge, are frequently seen outcroppings of limestone; but
these are mostly confined to the bed of the stream; and they can be sat-
isfactorily examined, only when the river is quite low. They occur, at
various points, in the channel, as far up the river, as the Savannah,
Florida & Western R. R,. bridge, and even beyond. Just below this
bridge, within a few rods of the river, an exposure of calcareous rock
may be seen, in a large spring, located in what is now known as Wade's
Park. The spring furnishes a large volume of transparent water,
which comes up, with considerable force, through an irregular open-
ing in the rock below. Owing to the depth of the exposure from the
surface, it was found to be impractical, to make any satisfactory ex-
amination. However, judging from the small fragments, broken
from the rock, it consists mainly of soft, siliceous limestone, contain-
ing a trace of phosphoric acid.



About three miles south of Wade's Park, the same calcareous forma-
tion again appears in the bed of the river. There also oc-
curs, here, on T. J. Apain's property, lot 253, 12th district, a short dis-
tance below the mouth of Piscola creek, a deposit of marl, forming a
bed, about two feet in thickness. It outcrops, near the base of a steep
hill or bluff, which, at this point, has an elevation of about 60 feet
above the surface of the river. The marl-bed is a soft, light-colored,
highly siliceous deposit, containing many fossil pectens, barnacles,
etc., and carrying from 3 to 4 per cent, of calcium phosphate. It is
overlaid, by a thin stratum of sandstone, above which are massive, red-
dish, sandy clays, extending to the top of the hill. Beneath the marl,
is a stratum of stratified yellowish or grayish sand, that probably ex-
tends to the limestone, below. Previous to our visit, little was known
of the nature of the deposit, and no attempt had been made, to use
it as a fertilizer. It contains ample phosphoric acid, to make a val-
uable manure ; and it will no doubt produce satisfactory results, when
applied to the growing crops.



A number of other bluffs, exposing similar formations, occur at dif-
ferent points, further down the river; but none of these were exam-
ined, except one on the Roberts property, lot 77, 15th district. The
bluff, here, is about thirty feet high. Its upper part is formed of
sandy, red clays, beneath which, is an exposure of about twenty feet
of impure limestone, extending down to the water's edge. The lime-
stone is of a light color, usually quite soft, and contains many fossil
gastropods, orbitolites and pectens. It weathers into a sandy, gray-
ish, marly material, that is slightly phosphatic. In a cultivated field,
near by, on the same lot, are to be seen many siliceous nodules, which
also carry a small percentage of phosphoric acid. It is said that the
soil, where these nodules occur, is generally more productive, than
elsewhere. This increased fertility is doubtless due to the presence of
phosphate, derived from the gradual breaking down of the nodules.


An examination of a number of lime-sinks and wells, in the south-
western part of the county, reveals deposits similar to those, exposed
along the river. There is quite an outcropping of limestone, on lot 96,
J5th district; also, on the adjoining lots, owned by William Haddock.
A well, recently dug, to the depth of 65 feet, on the IJaddock property
gives, in the descending order, the following section:


Reddish, sandy clays 25 feet

Coarse sand 15 "

Bluish clay 12 "

Flint 3 "

Soft limestone 6 "

Hard limestone, with numerous orbitolites, underlying.


A few miles southeast of the above locality, on the Blalock planta-
tion, near the state-line, occur numerous siliceous boulders, which are
slightly phosphatic. These appear, in great abundance, in a sandy
hammock on an adjoining lot, owned by the Hintons, and situated just
across the state-line. The boulders, at the latter place, vary in size,
from a few ounces to many pounds; and all seem to be more or less wa-
ter-worn. They are of a light-gray color, and consist of rather coarse
sand, cemented with phosphate, which frequently makes up a high
percentage of the entire mass. The field, where the boulders occur
in such abundance, is said to have been under cultivation, for many
years; and still it produces excellent crops, without the aid of fertil-



Much of the southern and eastern portion of Lowndes county is roll-
ing, has a clay soil, and yields good crops ; while the northwestern por-
tion is more level, generally sandy, and often traversed by bays or cy-
press swamps. Along the state-line are many small lakes and ponds,
occupying lime-sinks, which are depressions produced by subterranean
streams carrying away, in solution, the underlying calcareous forma-
tions. The water, in some of these lakes, has been known to rise and
fall, or to entirely disappear, in a few hours. This phenomenon seems
to be due to the sudden stoppage, or to the opening, of subterranean
passages, through which flow the underground streams, supplying the
]akes. Lime-sinks of considerable size, now filled with water, and
forming beautiful, transparent ponds or small lakes, are said to have
had no existence, a few years ago. Instances are given, where these
depressions have actually been seen to take place, and to have been
gradually filled, by the inflowing of water, from below. The largest
of these lakes is Ocean Pond, located in the southeastern part of the
county, near Lake Park. It is a beautiful, irregular sheet of water,
covering an area of several hundred acres ; and it is well stocked, with
many choice varieties of fish, which makes it a favorite resort for the

The numerous streams of Lowndes county are usually sluggish; and,
only at a few places, have they succeeded, in cutting through
the superficial sands and clays. For this reason, our work in the
county was generally unsatisfactory; and but little knowledge was
gained, concerning the underlying geological formations. The With-
lacoochee river, which forms the western boundary of the county, was
examined at several different points between the state-line and Old


Troupville. With, but few exceptions, the banks of the stream are
low and sandy, and offer only a few opportunities, for the study of the
different formations. Just below the bridge, at Old Troupville, may
be seen, outcropping along the river bank, a stratum of argillaceous
limestone, slightly phosphatic.


This same formation again appears, a few miles further down the
river, on G. R. McRee's property, near the mouth of a small stream,
where it overlies a fossiliferous limestone. Above the argillaceous
limestone, at this point, occurs a greenish, siliceous, sandy marl de-
posit; and its associated clays are well exposed, in the narrow gorge,
cut by the small stream, that has its source near the McRee residence.
Siliceous oyster shells, and what appear to be fragments of roots, were
noticed, in the marl-bed, at one point in the region, near the river.
With this exception, no other organic remains were found in the for-
mations, overlying the limestone. A short distance from the river, and
only a few yards from the McRee branch, near an old mill-site, a bore-
hole, put down a short time previous to our visit, to the depth of
twenty feet, passed through marl and sands, containing water- worn
phosphate pebbles. The pebbles are of a dark- or light-gray color,
varying in size, from a fraction of an inch to an inch in diameter ; and
they usually run high, in phosphoric acid. An attempt, to determine
the extent and character of the bed, containing the phosphatic pebbles,
by boring, was unsuccessful. It was demonstrated, by this means,
however, that the bed lies considerably below the surface; and, con-
sequently, it can be of little economic value, by reason of its thick over-


A chemical analysis of samples of marl, taken from different points
on the property, ran from 3 to 4 per cent, of calcium phosphate.
This indicates, that the deposit is a valuable fertilizer; and it would,
no doubt, produce satisfactory results, if applied to the soil, in suf-
ficient quantities.


A short distance south of the McRee property, and just across the
river from Wade's Park, occurs quite an exposure of siliceous breccia.
It outcrops, on a slope, near a small stream, and also along the road-
side, where it appears, in the form of large, irregular boulders, in the
sandy clays. It is of a light-greenish color, and contains fragments of
oyster shells. A similar exposure occurs near the. Clyattville road,
three quarters of a mile south of Rocky Ford bridge, and also near the
mouth of Jumping Gulley creek, in the extreme southwestern part of
the county. At the latter place, it is quite abundant; and it has at-
tracted some attention, on account of its resemblance to hard-rock
phosphate. Analyses made from samples, taken from the different
places, show from 1 to 6 per cent, of calcium phosphate. ISTear the
mouth of Jumping Gulley creek, and at other points, further up the
Withlacoochee river, are several low bluffs, that expose, at their base,
impure fossiliferous limestone, overlaid by grayish and greenish sandy
clays. There were found, at one or two places, along these bluffs, small
phosphatic nodules, that appear to have been washed out of the over-
lying clays. The nodules are water-worn, compact, and of a cream
color, and are probably of animal origin. They are of rare occur-
rence, and are not considered to be of economic importance.


Besides the above siliceous and calcareous deposits, exposed along
the streams, there occur, at several places in the county, in cultivated
fields, sandstone boulders, that run high in phosphate of aluminum
and iron. These are frequently seen, in the fields and along the road-
sides, in the lake region, near the state-line; they are, also, abundant
on I. H. Freeman's property, a short distance north of Old Troupville.
The boulders vary from an inch to a foot or more in diameter, and are

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Online LibrarySamuel Washington McCallieA preliminary report on a part of the phosphates and marls of Georgia → online text (page 5 of 7)