28D: COLQUITT 6, GGS-3212
U.S. GYPSUM 76-3
COLQUITT COUNTY, GEORGIA
Berlin West 7½’ Quadrangle
Core Log By Paul F. Huddlestun
Posted by Thomas Thurman 13/May/2023
|
Download Huddlestun's file at right.
|
| ||
On the south side of Old Berlina Road,
1.5 miles northwest of the jct. of old Berlin Road and Perry Road,
approximately 4 miles west of Berlin, Georgia,
in Colquitt County
Latitude N 31° 04.497’
Longitude W 83° 40.885’
Elevation 225 Feet
1.5 miles northwest of the jct. of old Berlin Road and Perry Road,
approximately 4 miles west of Berlin, Georgia,
in Colquitt County
Latitude N 31° 04.497’
Longitude W 83° 40.885’
Elevation 225 Feet
Lithostratigraphic
unit and bed number Description Thickness Depth
unit and bed number Description Thickness Depth
NO CORE 130.0 0.0
LOWER MIOCENE, AQUITANIAN
CHATTAHOOCHEE FORMATION – 30 feet+
Probably lower Chattahoochee
Bed 1 Sandstone recovered: chert cemented 1.0 130.0
Fine grained sand/extremely hard
sandstone; very poor recovery (~8% core
recovery; greenish in color; overlies core
gap:
CORE GAP 12.0 131.0
Bed 2 Sand: similar to above but with some softer, 2.0 143.0
unsilicified intervals, perhaps more clayey,
quartz sand is fine- to fine/medium grained
and well sorted; poorly consolidated (~20%
core recovery; overlies core gaps:
CORE GAP 8.0 145.0
NO CORE 7.0 153.0
Bed 3 Sandstone: some chips of cherty or brittle, 0.1- 160.0
argillaceous sandstone present in top of
core run at ~160 feet; overlies:
LOWER OLIGOCENE, VICKSBURGIAN
SUWANNEE LIMESTONE - ~123 feet
Bed 4 Dolostone: appears originally to have been 10.4 160.1
pelletal, foraminiferal limestone; massive
and structureless; very hard and dense;
very poor recovery (~10%+ core recovery);
overlies:
Bed 5 Limestone: even textured, granular, 35.5 170.5
pelletal/foraminiferal, medium to coarse
grained with rare bivalve molds in the
upper few feet; mostly massive and
structureless; mostly light induration
but porous and moderately competent
(~42% core recovery); very pale orange
very pale orange (10YR 8/2);
Very hard, dense, heavy, recrystallized,
light gray pelletal/foraminiferal limestone
with inclined upper and lower contacts
from ~183 feet to ~188.5 feet; overlies “cavity”:
“CAVITY” 10.0 206.0
Bed 6 Limestone: granular, fine to medium 14.0 216.0
grained matrix, foraminiferal/miliolid
limestone with common stony algae
(rhodoliths), rare to frequent Lepidocyclina,
rare solitary coral molds and scattered
mollusk molds; gradually finer textured
downsection; massive and structureless;
mostly lightly indurated but porous and
moderately competent (~46% core
recovery); very pale orange (10YR 8/2 in
color);
Fewer rhodoliths below ~220 feet;
The echinoid Rhyncholampus gouldii at ~226 feet;
Overlies “cavity”:
“CAVITY” 22.0 230.0
Bed 7 Limestone: as above but more indurated 0.5 252.0
and more even grained; overlies core gap:
CORE GAP 8.5 252.5
Bed 8 Limestone: granular, fine to medium 13.5 261.0
grained matrix, foraminiferal/miliolid
limestone (typical Suwannee lithology),
mostly massive and structureless; lightly
indurated but porous, poor recovery in
the lower part (~48% core recovery); very
pale orange (10YR 8/2);
Dictyoconus present at ~263 feet;
Thinly layered, more micritic and chalky
from ~270 feet to ~272.5 feet;
Overlies core gap;
Core gap 8.5 274.5
LOWER OLIGOCENE, VICKSBURGIAN
BRIDGEBORO LIMESTONE – ~47 feet
Bed 9 Limestone: fine to medium grained 2.5 283.0
calcarenite, very fossiliferous with common
to abundant, very large Lepidocyclina, Pecten
anatipes present; massive and structureless;
competent (100% core recovery); grades
downward into:
Bed 10 Limestone: medium to coarse, calcarenitic, 19.5 285.5
and with granular matrix; richly fossiliferous,
Lepidocyclina-rich as above but with large
and abundant rhodoliths; the Lepidocyclina
are smaller than in overlying bed, common
molds of corals in the lower part of the Bed;
massive and structureless but rubbly
texture overall due to rhodoliths; moderate
to poorly competent (~38% core recovery);
very pale orange 10YR 8/2) in color;
overlies core gap:
Core gap 25.0 305.0
UPPER EOCENE, UPPER JACKSONIAN
OCALA GROUP – 420.6 feet
CRYSTAL RIVER LIMESTONE – 382.5 feet
Bed 11 Limestone: bioclastic; richly fossiliferous, 16.0 330.0
Lepidocyclina-coquinoid limestone, some
bryozoans and small rhodoliths, rare to
frequent Asterocyclina, rare Operculinoides,
a few Ostrea vicksburgensis; massive and
structureless; consolidated but moderately
poor recovery (~28% core recovery); grades
downward into:
Bed 12 Limestone: pelletal/foraminiferal, granular 42.0 346.0
limestone, variably well washed and porous
and micritic and pasty, mainly equigranular
sand-size, bioclastic debris, common to
common/abundant Lepidocyclina,
Asterocyclina present throughout, some
mollusk molds; mostly massive and
structureless to very thickly and rudely
layered; well consolidated to somewhat
indurated and moderately competent (~83%
core recovery;
Upper 4 feet (~346 feet to ~350 feet) is less
coarsely fossiliferous;
Asterocyclina at ~351 feet and scattered
throughout downsection;
The bivalve Spondylus present at ~356 feet;
More micritic and indurated with a few
rhodoliths at ~354 feet;
Less micritic and more well washed and
porous at ~356 feet;
More micritic, indurated and less porous at
Better washed and porous and less micritic
at ~363 feet;
Coquina of small Lepidocyclina and
common/abundant Nummulites at ~367 feet;
Frequent Operculinoides and Nummulites
and very abundant, small Lepidocyclina
at ~375 feet;
Lepidocyclina size declines and the larger
foraminifer Heterostegina is present below
~381 feet;
Overlies “cavity”:
“CAVITY” 1.5 388.0
Bed 13 Dolostone: originally a subcoquina, now 1.5 389.5
most fossils are vague but still recognized
as such – almost obliterated; massive and
structureless except for very thick and rude
layering; mostly hard and dense; thickness,
competence and depth of position not
precisely known due to poor core recovery
in overlying and underlying core runs;
brown to tan in color;
Small quartz crystals in vug at ~390 feet;
Overlies core gap:
Core gap Estimated 7 feet loss at ~391 to ~398 feet 7.0 391.0
“the driller”
Bed 14 Limestone: dolomitic, moldic fossiliferous; 1.0 398.0
stratified and competent (100% core
recovery; grades abruptly downward into:
Bed 15 Dolostone: moldic fossiliferous; massive and 7.0 399.0
structureless; hard, dense and competent
(100% core recovery); grades downward into:
Bed 16 Dolostone: sucrosic, porous and friable; 22.0 406.0 originally a subcoquina, now fossils are
moldic, vague and almost obliterated;
massive and structureless; recrystallized
but moderately coherent and competent
(~52% core recovery); grades downward
into:
Bed 17 Limestone: dolomitic, sucrosic, calcitized 11.0 428.0
and fossiliferous as above, massive
and structureless; recrystallized, coherent
and competent (100% core recovery); tan in
color; grades downward into:
Bed 18 Dolostone: mainly calcareous dolostone, 24.5 439.0
less calcareous than overlying bed, some
thin intervals are more calcareous,
otherwise the Bed is mostly dolostone;
massive and structureless; recrystallized,
coherent, and competent; tan in color;
There appears to be many small bivalve
molds at ~456 feet;
Grades downward into:
Bed 19 Dolostone: as above; (top of selenite gypsum 21.5 463.5
at ~465.2 feet) some selenite in optical
continuity throughout the Bed; massive and
structureless; recrystallized, hard, coherent
and mostly competent (~84% core recovery);
tan to brown in color; grades downward into:
Bed 20 Gypsum: selenite, granular, dolomitic, 7.0 485.0
calcareous near the base of the Bed,
fossiliferous as above; massive and
structureless; recrystallized, hard and
coherent, competent (100% core recovery);
grades abruptly downward into:
Bed 21 Limestone: slightly dolomitic, more micritic 3.5 492.0
and better fossil preservation than
overlying beds; echinoids at ~494 feet;
massive and structureless; recrystallized,
hard and competent; grades downward into:
Bed 22 Limestone: somewhat micritic and pasty, 1.5 495.5
slightly selenitic; coarsely fossiliferous,
Lepidocyclina-rich; massive and
structureless; recrystallized, hard and
competent but somewhat porous (~100%
core recovery); grades downward into:
Bed 23 Limestone, granular, calcarenitic, slightly 35.0 497.0
and variably selenitic, variably micritic and
chalky; abundantly fossiliferous to
subcoquinoid, Lepidocyclina-rich, rare
echinoids and bryozoans, rare to
frequent algae, nil to trace mollusks, fossil
preservation is moderate to poor;
Massive and structureless, fossils occur in
variable orientation – in some intervals
the fossil’s orientation are subhorizontal,
in other intervals, the fossils are randomly
oriented random; firmly; consolidated and
recrystallized but still porous; hard and
competent (100% core recovery);
The color of the core interior is very light
orange to very pale orange (10YR 9/2 –
10YR 8/2), the color of the stain on the
surface of the core ranges from pale
yellowish orange to light yellowish orange
(10YR 8/6 – 10YR 9/6) to grayish orange
(10YR 7/4); grades downward into:
Bed 24 Selenitic limestone/very calcareous selenite: 5.0 532.0
nondescript matrix with crystalline selenite in
optical continuity, recrystallized granular
texture in places, fossiliferous but most fossils
appear to be Lepidocyclina and they are very
degraded and chalky; massive and
structureless; recrystallized and competent
(100% core recovery); very light orange
(10YR 9/2), Lepidocyclina are white (N 1);
very broadly gradational downward by
decrease in selenite into:
Bed 25 Limestone: degraded, fine to coarse, very 14.0 537.0
chalky, bioclastic debris, calcarenitic,
variably selenitic – selenite comes and
goes in small concentrations, always minor,
a trace of what appears to be very fine
grained pyrite; fossiliferous with common
to abundant Lepidocyclina, very minor
mollusks and bryozoan occurrences, etc.,
fossil content diminishes below 547 feet;
Massive and structureless with fossils in
variable orientations; calcitized, partially
recrystallized and competent (100% core
recovery;
Very light orange to very pale orange
(10YR 9/2 – 10YR 8/2) in color –
mostly very light orange (10YR 9/2);
Grades downward over ~1 inch into:
Bed 26 Dolostone: slightly moldic fossiliferous, finely 2.1 551.0
crystalline with some selenite; massive and
structureless; dense, hard and competent;
light yellowish brown (10YR 7/2); grades
downward over a few inches into:
Bed 27 Dolostone: sucrosic, a trace of selenite; 2.0 553.1
abundant Lepidocyclina molds (originally
appears to have been coquinoid), massive
and structureless; recrystallized, porous and
competent (100% core recover), core surface
is jagged and rough; very pale orange to
light yellowish brown (10YR 8/2 –
10YR 7/2); grades abruptly downward into:
Bed 28 Limestone: chalky with some scattered 48.9 555.1
selenite present – mostly nil; fossil
degradation variable – at best chalky and
at worst moldic, fossil abundance variable,
Lepidocyclina apparently still are the most
common fossils present but they are
thicker and smaller in size than in the
overlying beds (more megalosphaeric
forms present?), some calcitic shell scraps
and a few pectenids present down-section,
original lithology appears to have been a
fossiliferous, finely bioclastic, granular
calcarenite;
Massive and structureless, fossil
orientation variable with some
horizontality; partially recrystallized,
calcified and competent;
Very light orange to very pale orange
(10YR 9/2 – 10YR 8/2) in color – the
interior of the core is mostly very light
orange (10YR 9/2) but the core surface is
very pale orange (10YR 8/2);
Lithology more variable below ~ 572 feet;
Selenitic limestone/very calcareous selenite
from ~576.25 feet to ~577 feet, similar to
Very gradually merges downward into:
Bed 29 Limestone: similar to Bed 28 but appears 108.5 604.0
to be more “muddy” with calcite paste
(chalky) but is still basically a degraded,
calcified bioclastic limestone on large
scales (Lepidocyclina and scattered
bivalves) and small scales (finely bioclastic
granular calcarenite); there are irregular
distributions of thin, more “muddy”
intervals; in the small pockets of well
washed bioclastic debris, there are always
velvety crusts of micro-calcite crystals that
obscure casual identification of debris’
origins; one small occurrence of selenite
was also noted;
Fossil preservation is variable but mostly
chalky and poor, with few scattered small
pockets of well washed bioclastic debris,
pectenids and Spondylus occur scattered
down the section; some larger bivalves are
present and they range in abundance from
nil to rare in the upper part and very
gradually increase in number to rare to
frequent in the lower part of the Bed;
macrofossils tend to occur in concentrations
of common to abundant;
there are possibly scattered to common
Nummulites and Operculinoides present but
the fossil preservation is mostly too poor for
certain identification in most instances, but a
few individual specimens were noted, such as
Asterocyclina;
Basically massive and structureless but
some very rude horizontal stratification is
present; partially recrystallized, calcified
and competent (100% core recovery); color
is mostly very light orange (10YR 9/2) with
some very pale orange (10YR 8/2);
A small Asterocyclina was noted in a small
pocket at ~634.5 feet;
Small algal balls (rhodoliths) and an
Operculinoides at ~645 feet;
A solitary coral preserved in selenite occurs
at ~677 feet;
Grades abruptly downward into:
UPPER EOCENE, LOWER JACKSONIAN
OCALA GROUP
WILLISTON LIMESTONE – 38.1 feet
Bed 30 Limestone: (identification of the top of the 0.5 712.5
Williston Limestone is arbitrary due to the
lack of definitive Williston lithologies); very
fine grained, chalky limestone with a small
pocket of granular/pelletal material; massive
and structureless; coherent but non-
indurated yet competent; very light orange
(10YR 9/2); grades abruptly downward into:
Bed 31 Limestone: less chalky than Bed 28, 12.0 713.0 granular/calcarenitic/angular bioclastic
matrix with large oyster shell fragments
(Crassostrea gigantissima-like) and other
platy, calcitic shell debris and fragments,
frequent Nummulites and some
Lepidocyclina and pectenids, generally
subcoquinoid; mostly massive and
structureless, generally random orientation
of fossil debris but pectenids are mostly
horizontal; consolidated and competent;
color is mostly very light orange (10YR 9/2)
with some very pale orange (10YR 8/2);
A very large oyster shell in vertical position
along with common to abundant, thin,
calcitic shell fragments at ~716 feet to
~718 feet;
Very broadly grades downward into:
Bed 32 Limestone: chalky as above, continually 5.3 725.0
granular/calcarenitic/bioclastic; macro-
fossil fragments diminish down-section,
Nummulites become conspicuous whereas
Lepidocyclina remain small;
Mostly massive and structureless but with
irregular fossil and chalky limestone
concentrations; consolidated and competent;
color is mostly very light orange (10YR 9/2)
to light yellowish brown (10YR 7/2); grades
downward into:
Bed 33 Limestone: (top of nodular gypsum) 4.2 730.3
scattered translucent nodules of gypsum,
dolomite and interstitial gypsum not
apparent; fine grained, nondescript,
interstitial calcareous matrix with small
Lepidocyclina and common to abundant
Nummulites; fossils are chalky with no
other noticeable macrofossils, massive
and structureless; consolidated and
competent (100% core recovery); color is
very pale orange (10YR 8/2); grades
broadly downward over about 1 foot into:
Bed 34 Dolostone: scattered gypsum nodules and 5.0 734.5
some interstial selenite, no bivalves or
bivalve fragments and fewer Nummulites
than in overlying Bed 33; massive and
structureless; dense, recrystallized and
competent; colors range from grayish
orange (10YR 7/4) to pale yellowish
brown and light yellowish brown
(10YR 6/2 – 10YR 7/2) to differing
shades of pale gray (N); grades
downward into:
Bed 35 Limestone: chalky, granular, finely 11.1 739.5
bioclastic, and nummulitic limestone;
the upper 1 foot of the Bed contains a few
gypsum nodules including a bed or large
nodule, 1.25 feet thick, {translucent and
pinkish gray, 5YR 8/1; the gypsum
nodule is massive and structureless with
strongly embayed upper and lower
contacts from ~740.5 feet to ~741.75
feet – no gypsum has been observed below
~741.75 feet; scattered Lepidocyclina and
a few bryozoans, macrofossil fragments
and burrows;
Finely but not completely recrystallized;
generally massive and structureless but
there are some irregular sedimentary
features that are not altogether
structureless but are not a result of
stratification, mostly random fossil
orientation; consolidated and competent
(100% core recovery);
Limestone color is mostly very light orange
(10YR 9/2) with some very pale orange
(10YR 8/2);
There is an odd lamina with abundant
microscopic black pellets or grains (pyrite?
phosphate? glauconite?) at ~750 feet;
Appears to grade downward into:
The Jacksonian/Claibornian (Upper Eocene/Middle Eocene) “contact” is obscure and indistinct at this site. Those Beds and layers above ~750.5 feet, I am confidant should be included in the Upper Eocene, Williston Limestone of the Ocala Group. Those beds below ~765 feet (including Bed 41) I am confidant should be included in the unnamed Claibornian limestone. The proper identification of the limestone lithologies between ~750.5 feet and 765 feet is uncertain to me but could possibly be correlated with the Gosport/Clinchfield interval of Alabama and Georgia and, therefore, with the Claibornian.
unnamed Claibornian limestone?
One inch of very fine grained calcarenite
(chalk) at ~750.5 feet;
Bed 36 Limestone: similar to Bed 35; structureless ~1.3 750.6
and competent; grades downward into:
Bed 37 Limestone chalk: very finely granular, 0.85 751.9
nonfossiliferous, lithologically nondescript;
massive and structureless; probably finely
recrystallized, coherent and competent
(100% core recovery); color is roughly very
light orange (10YR 9/2) with a slight cast of
yellow; grades abruptly downward into:
Bed 38 Limestone: similar to Bed 35 but with the 1.5 752.75
absence of gypsum; structureless and
competent; grades abruptly downward
into:
Bed 39 Limestone chalk: as in Bed 37 – very 4.25 754.25
finely granular limestone, lithologically
nondescript, nonfossiliferous, the surface of
core appears to be slightly quartz silty
under casual examination but probably is
not, texture coarsens a little below ~757
feet; massive and structureless; probably
finely recrystallized, coherent and
competent; very light orange (10YR 9/2);
grades downward into:
Bed 40 Limestone: very chalky, granular/ 6.5 758.5
calcarenitic/finely bioclastic, frequent to
common Nummulites but not so conspicuous
as in overlying fossiliferous beds, small
calcitic macrofossil fragments, all fossils
severely degraded;
Seven inches of translucent, light gray to
white (N6 - N9), massive and structureless
gypsum with strongly embayed upper and
lower contacts from ~763.4 feet to ~763.95
feet overlies ~1 foot of chalk (lithology;
Massive and structureless except for
gypsum and chalk layers near base of the
Bed; consolidated and competent; mostly
very pale orange (10YR 8/2) to very light
orange (10YR 9/2); grades downward into:
MIDDLE EOCENE, CLAIBORNIAN
UNNAMED CLAIBORNIAN LIMESTONE – 142.4 feet+
definite unnamed Claibornian limestone
Bed 41 Limestone: very chalky, granular/bioclastic 26.0 765.0
that is much degraded, scattered
Lepidocyclina, few obvious Nummulites,
scattered macrofossil scraps/flaky calcitic
shell fragments etc., a small echinoid at
~785 feet, scattered gypsum nodules; very,
very gradually fines down the section;
Massive and structureless, all fossils in
random orientation; finely recrystallized and
competent; very light orange (10YR 9/2)
with some very pale orange (10YR 8/2);
very broadly grades downward by fining
into:
Bed 42 Limestone: chalky and pasty, very finely 61.5 791.0
granular and very finely bioclastic, most
bioclastic particles appear to be, or have
been, angular; scattered small pockets of
somewhat coarser bioclastic debris;
common to abundant discocyclinid and
larger foraminifera occur mostly in random
orientation including some small shell
fragments; particle size and frequency of
discocyclinids and discrete biodebris
decrease very gradually down the section;
scattered gypsum nodules and layers of
various sizes and thicknesses occur
throughout the Bed; massive and
structureless; finely recrystallized,
coherent and competent (100% core
recovery); very light orange (10YR 9/2)
in color;
A small pocket of Nummulites-rich debris at
~845 feet;
Grades downward into:
Bed 43 Limestone: dolomitic with gypsum nodules, 2.5 852.5
small chalky Lepidocyclina and/or
Discocyclina; massive and structureless;
mostly recrystallized, coherent and
competent; pale orange to pale yellowish
brown 10YR 7/2 – 10YR 6/2); grades
downward into:
Bed 44 Limestone: very, very finely granular, and 38.0+ 855.0
chalky; scattered gypsum nodules from
~875 feet to ~888.5 feet. with a >1 foot
thick layer of translucent gypsum, with
strongly embayed upper and lower
contacts from roughly ~879 feet to a
little more than ~880 feet, and
containing inclusions of unincorporated
limestone; chert nodules occur at ~875 feet
to ~876.5 feet; scattered horizontal to
subhorizontal Lepidocyclina and
Nummulites, a burrow at ~887 feet;
Mostly massive and structureless but
apparently, there is some very rude stratification
in the upper part; mostly recrystallized and
competent (100% core recovery); very light
orange (10YR 9/2) with some very pale
orange (10YR 8/2);
Bottom of core at 893 feet.
____________________________ TOTA L DEPTH – 893.0 FEET
LOWER MIOCENE, AQUITANIAN
CHATTAHOOCHEE FORMATION – 30 feet+
Probably lower Chattahoochee
Bed 1 Sandstone recovered: chert cemented 1.0 130.0
Fine grained sand/extremely hard
sandstone; very poor recovery (~8% core
recovery; greenish in color; overlies core
gap:
CORE GAP 12.0 131.0
Bed 2 Sand: similar to above but with some softer, 2.0 143.0
unsilicified intervals, perhaps more clayey,
quartz sand is fine- to fine/medium grained
and well sorted; poorly consolidated (~20%
core recovery; overlies core gaps:
CORE GAP 8.0 145.0
NO CORE 7.0 153.0
Bed 3 Sandstone: some chips of cherty or brittle, 0.1- 160.0
argillaceous sandstone present in top of
core run at ~160 feet; overlies:
LOWER OLIGOCENE, VICKSBURGIAN
SUWANNEE LIMESTONE - ~123 feet
Bed 4 Dolostone: appears originally to have been 10.4 160.1
pelletal, foraminiferal limestone; massive
and structureless; very hard and dense;
very poor recovery (~10%+ core recovery);
overlies:
Bed 5 Limestone: even textured, granular, 35.5 170.5
pelletal/foraminiferal, medium to coarse
grained with rare bivalve molds in the
upper few feet; mostly massive and
structureless; mostly light induration
but porous and moderately competent
(~42% core recovery); very pale orange
very pale orange (10YR 8/2);
Very hard, dense, heavy, recrystallized,
light gray pelletal/foraminiferal limestone
with inclined upper and lower contacts
from ~183 feet to ~188.5 feet; overlies “cavity”:
“CAVITY” 10.0 206.0
Bed 6 Limestone: granular, fine to medium 14.0 216.0
grained matrix, foraminiferal/miliolid
limestone with common stony algae
(rhodoliths), rare to frequent Lepidocyclina,
rare solitary coral molds and scattered
mollusk molds; gradually finer textured
downsection; massive and structureless;
mostly lightly indurated but porous and
moderately competent (~46% core
recovery); very pale orange (10YR 8/2 in
color);
Fewer rhodoliths below ~220 feet;
The echinoid Rhyncholampus gouldii at ~226 feet;
Overlies “cavity”:
“CAVITY” 22.0 230.0
Bed 7 Limestone: as above but more indurated 0.5 252.0
and more even grained; overlies core gap:
CORE GAP 8.5 252.5
Bed 8 Limestone: granular, fine to medium 13.5 261.0
grained matrix, foraminiferal/miliolid
limestone (typical Suwannee lithology),
mostly massive and structureless; lightly
indurated but porous, poor recovery in
the lower part (~48% core recovery); very
pale orange (10YR 8/2);
Dictyoconus present at ~263 feet;
Thinly layered, more micritic and chalky
from ~270 feet to ~272.5 feet;
Overlies core gap;
Core gap 8.5 274.5
LOWER OLIGOCENE, VICKSBURGIAN
BRIDGEBORO LIMESTONE – ~47 feet
Bed 9 Limestone: fine to medium grained 2.5 283.0
calcarenite, very fossiliferous with common
to abundant, very large Lepidocyclina, Pecten
anatipes present; massive and structureless;
competent (100% core recovery); grades
downward into:
Bed 10 Limestone: medium to coarse, calcarenitic, 19.5 285.5
and with granular matrix; richly fossiliferous,
Lepidocyclina-rich as above but with large
and abundant rhodoliths; the Lepidocyclina
are smaller than in overlying bed, common
molds of corals in the lower part of the Bed;
massive and structureless but rubbly
texture overall due to rhodoliths; moderate
to poorly competent (~38% core recovery);
very pale orange 10YR 8/2) in color;
overlies core gap:
Core gap 25.0 305.0
UPPER EOCENE, UPPER JACKSONIAN
OCALA GROUP – 420.6 feet
CRYSTAL RIVER LIMESTONE – 382.5 feet
Bed 11 Limestone: bioclastic; richly fossiliferous, 16.0 330.0
Lepidocyclina-coquinoid limestone, some
bryozoans and small rhodoliths, rare to
frequent Asterocyclina, rare Operculinoides,
a few Ostrea vicksburgensis; massive and
structureless; consolidated but moderately
poor recovery (~28% core recovery); grades
downward into:
Bed 12 Limestone: pelletal/foraminiferal, granular 42.0 346.0
limestone, variably well washed and porous
and micritic and pasty, mainly equigranular
sand-size, bioclastic debris, common to
common/abundant Lepidocyclina,
Asterocyclina present throughout, some
mollusk molds; mostly massive and
structureless to very thickly and rudely
layered; well consolidated to somewhat
indurated and moderately competent (~83%
core recovery;
Upper 4 feet (~346 feet to ~350 feet) is less
coarsely fossiliferous;
Asterocyclina at ~351 feet and scattered
throughout downsection;
The bivalve Spondylus present at ~356 feet;
More micritic and indurated with a few
rhodoliths at ~354 feet;
Less micritic and more well washed and
porous at ~356 feet;
More micritic, indurated and less porous at
Better washed and porous and less micritic
at ~363 feet;
Coquina of small Lepidocyclina and
common/abundant Nummulites at ~367 feet;
Frequent Operculinoides and Nummulites
and very abundant, small Lepidocyclina
at ~375 feet;
Lepidocyclina size declines and the larger
foraminifer Heterostegina is present below
~381 feet;
Overlies “cavity”:
“CAVITY” 1.5 388.0
Bed 13 Dolostone: originally a subcoquina, now 1.5 389.5
most fossils are vague but still recognized
as such – almost obliterated; massive and
structureless except for very thick and rude
layering; mostly hard and dense; thickness,
competence and depth of position not
precisely known due to poor core recovery
in overlying and underlying core runs;
brown to tan in color;
Small quartz crystals in vug at ~390 feet;
Overlies core gap:
Core gap Estimated 7 feet loss at ~391 to ~398 feet 7.0 391.0
“the driller”
Bed 14 Limestone: dolomitic, moldic fossiliferous; 1.0 398.0
stratified and competent (100% core
recovery; grades abruptly downward into:
Bed 15 Dolostone: moldic fossiliferous; massive and 7.0 399.0
structureless; hard, dense and competent
(100% core recovery); grades downward into:
Bed 16 Dolostone: sucrosic, porous and friable; 22.0 406.0 originally a subcoquina, now fossils are
moldic, vague and almost obliterated;
massive and structureless; recrystallized
but moderately coherent and competent
(~52% core recovery); grades downward
into:
Bed 17 Limestone: dolomitic, sucrosic, calcitized 11.0 428.0
and fossiliferous as above, massive
and structureless; recrystallized, coherent
and competent (100% core recovery); tan in
color; grades downward into:
Bed 18 Dolostone: mainly calcareous dolostone, 24.5 439.0
less calcareous than overlying bed, some
thin intervals are more calcareous,
otherwise the Bed is mostly dolostone;
massive and structureless; recrystallized,
coherent, and competent; tan in color;
There appears to be many small bivalve
molds at ~456 feet;
Grades downward into:
Bed 19 Dolostone: as above; (top of selenite gypsum 21.5 463.5
at ~465.2 feet) some selenite in optical
continuity throughout the Bed; massive and
structureless; recrystallized, hard, coherent
and mostly competent (~84% core recovery);
tan to brown in color; grades downward into:
Bed 20 Gypsum: selenite, granular, dolomitic, 7.0 485.0
calcareous near the base of the Bed,
fossiliferous as above; massive and
structureless; recrystallized, hard and
coherent, competent (100% core recovery);
grades abruptly downward into:
Bed 21 Limestone: slightly dolomitic, more micritic 3.5 492.0
and better fossil preservation than
overlying beds; echinoids at ~494 feet;
massive and structureless; recrystallized,
hard and competent; grades downward into:
Bed 22 Limestone: somewhat micritic and pasty, 1.5 495.5
slightly selenitic; coarsely fossiliferous,
Lepidocyclina-rich; massive and
structureless; recrystallized, hard and
competent but somewhat porous (~100%
core recovery); grades downward into:
Bed 23 Limestone, granular, calcarenitic, slightly 35.0 497.0
and variably selenitic, variably micritic and
chalky; abundantly fossiliferous to
subcoquinoid, Lepidocyclina-rich, rare
echinoids and bryozoans, rare to
frequent algae, nil to trace mollusks, fossil
preservation is moderate to poor;
Massive and structureless, fossils occur in
variable orientation – in some intervals
the fossil’s orientation are subhorizontal,
in other intervals, the fossils are randomly
oriented random; firmly; consolidated and
recrystallized but still porous; hard and
competent (100% core recovery);
The color of the core interior is very light
orange to very pale orange (10YR 9/2 –
10YR 8/2), the color of the stain on the
surface of the core ranges from pale
yellowish orange to light yellowish orange
(10YR 8/6 – 10YR 9/6) to grayish orange
(10YR 7/4); grades downward into:
Bed 24 Selenitic limestone/very calcareous selenite: 5.0 532.0
nondescript matrix with crystalline selenite in
optical continuity, recrystallized granular
texture in places, fossiliferous but most fossils
appear to be Lepidocyclina and they are very
degraded and chalky; massive and
structureless; recrystallized and competent
(100% core recovery); very light orange
(10YR 9/2), Lepidocyclina are white (N 1);
very broadly gradational downward by
decrease in selenite into:
Bed 25 Limestone: degraded, fine to coarse, very 14.0 537.0
chalky, bioclastic debris, calcarenitic,
variably selenitic – selenite comes and
goes in small concentrations, always minor,
a trace of what appears to be very fine
grained pyrite; fossiliferous with common
to abundant Lepidocyclina, very minor
mollusks and bryozoan occurrences, etc.,
fossil content diminishes below 547 feet;
Massive and structureless with fossils in
variable orientations; calcitized, partially
recrystallized and competent (100% core
recovery;
Very light orange to very pale orange
(10YR 9/2 – 10YR 8/2) in color –
mostly very light orange (10YR 9/2);
Grades downward over ~1 inch into:
Bed 26 Dolostone: slightly moldic fossiliferous, finely 2.1 551.0
crystalline with some selenite; massive and
structureless; dense, hard and competent;
light yellowish brown (10YR 7/2); grades
downward over a few inches into:
Bed 27 Dolostone: sucrosic, a trace of selenite; 2.0 553.1
abundant Lepidocyclina molds (originally
appears to have been coquinoid), massive
and structureless; recrystallized, porous and
competent (100% core recover), core surface
is jagged and rough; very pale orange to
light yellowish brown (10YR 8/2 –
10YR 7/2); grades abruptly downward into:
Bed 28 Limestone: chalky with some scattered 48.9 555.1
selenite present – mostly nil; fossil
degradation variable – at best chalky and
at worst moldic, fossil abundance variable,
Lepidocyclina apparently still are the most
common fossils present but they are
thicker and smaller in size than in the
overlying beds (more megalosphaeric
forms present?), some calcitic shell scraps
and a few pectenids present down-section,
original lithology appears to have been a
fossiliferous, finely bioclastic, granular
calcarenite;
Massive and structureless, fossil
orientation variable with some
horizontality; partially recrystallized,
calcified and competent;
Very light orange to very pale orange
(10YR 9/2 – 10YR 8/2) in color – the
interior of the core is mostly very light
orange (10YR 9/2) but the core surface is
very pale orange (10YR 8/2);
Lithology more variable below ~ 572 feet;
Selenitic limestone/very calcareous selenite
from ~576.25 feet to ~577 feet, similar to
Very gradually merges downward into:
Bed 29 Limestone: similar to Bed 28 but appears 108.5 604.0
to be more “muddy” with calcite paste
(chalky) but is still basically a degraded,
calcified bioclastic limestone on large
scales (Lepidocyclina and scattered
bivalves) and small scales (finely bioclastic
granular calcarenite); there are irregular
distributions of thin, more “muddy”
intervals; in the small pockets of well
washed bioclastic debris, there are always
velvety crusts of micro-calcite crystals that
obscure casual identification of debris’
origins; one small occurrence of selenite
was also noted;
Fossil preservation is variable but mostly
chalky and poor, with few scattered small
pockets of well washed bioclastic debris,
pectenids and Spondylus occur scattered
down the section; some larger bivalves are
present and they range in abundance from
nil to rare in the upper part and very
gradually increase in number to rare to
frequent in the lower part of the Bed;
macrofossils tend to occur in concentrations
of common to abundant;
there are possibly scattered to common
Nummulites and Operculinoides present but
the fossil preservation is mostly too poor for
certain identification in most instances, but a
few individual specimens were noted, such as
Asterocyclina;
Basically massive and structureless but
some very rude horizontal stratification is
present; partially recrystallized, calcified
and competent (100% core recovery); color
is mostly very light orange (10YR 9/2) with
some very pale orange (10YR 8/2);
A small Asterocyclina was noted in a small
pocket at ~634.5 feet;
Small algal balls (rhodoliths) and an
Operculinoides at ~645 feet;
A solitary coral preserved in selenite occurs
at ~677 feet;
Grades abruptly downward into:
UPPER EOCENE, LOWER JACKSONIAN
OCALA GROUP
WILLISTON LIMESTONE – 38.1 feet
Bed 30 Limestone: (identification of the top of the 0.5 712.5
Williston Limestone is arbitrary due to the
lack of definitive Williston lithologies); very
fine grained, chalky limestone with a small
pocket of granular/pelletal material; massive
and structureless; coherent but non-
indurated yet competent; very light orange
(10YR 9/2); grades abruptly downward into:
Bed 31 Limestone: less chalky than Bed 28, 12.0 713.0 granular/calcarenitic/angular bioclastic
matrix with large oyster shell fragments
(Crassostrea gigantissima-like) and other
platy, calcitic shell debris and fragments,
frequent Nummulites and some
Lepidocyclina and pectenids, generally
subcoquinoid; mostly massive and
structureless, generally random orientation
of fossil debris but pectenids are mostly
horizontal; consolidated and competent;
color is mostly very light orange (10YR 9/2)
with some very pale orange (10YR 8/2);
A very large oyster shell in vertical position
along with common to abundant, thin,
calcitic shell fragments at ~716 feet to
~718 feet;
Very broadly grades downward into:
Bed 32 Limestone: chalky as above, continually 5.3 725.0
granular/calcarenitic/bioclastic; macro-
fossil fragments diminish down-section,
Nummulites become conspicuous whereas
Lepidocyclina remain small;
Mostly massive and structureless but with
irregular fossil and chalky limestone
concentrations; consolidated and competent;
color is mostly very light orange (10YR 9/2)
to light yellowish brown (10YR 7/2); grades
downward into:
Bed 33 Limestone: (top of nodular gypsum) 4.2 730.3
scattered translucent nodules of gypsum,
dolomite and interstitial gypsum not
apparent; fine grained, nondescript,
interstitial calcareous matrix with small
Lepidocyclina and common to abundant
Nummulites; fossils are chalky with no
other noticeable macrofossils, massive
and structureless; consolidated and
competent (100% core recovery); color is
very pale orange (10YR 8/2); grades
broadly downward over about 1 foot into:
Bed 34 Dolostone: scattered gypsum nodules and 5.0 734.5
some interstial selenite, no bivalves or
bivalve fragments and fewer Nummulites
than in overlying Bed 33; massive and
structureless; dense, recrystallized and
competent; colors range from grayish
orange (10YR 7/4) to pale yellowish
brown and light yellowish brown
(10YR 6/2 – 10YR 7/2) to differing
shades of pale gray (N); grades
downward into:
Bed 35 Limestone: chalky, granular, finely 11.1 739.5
bioclastic, and nummulitic limestone;
the upper 1 foot of the Bed contains a few
gypsum nodules including a bed or large
nodule, 1.25 feet thick, {translucent and
pinkish gray, 5YR 8/1; the gypsum
nodule is massive and structureless with
strongly embayed upper and lower
contacts from ~740.5 feet to ~741.75
feet – no gypsum has been observed below
~741.75 feet; scattered Lepidocyclina and
a few bryozoans, macrofossil fragments
and burrows;
Finely but not completely recrystallized;
generally massive and structureless but
there are some irregular sedimentary
features that are not altogether
structureless but are not a result of
stratification, mostly random fossil
orientation; consolidated and competent
(100% core recovery);
Limestone color is mostly very light orange
(10YR 9/2) with some very pale orange
(10YR 8/2);
There is an odd lamina with abundant
microscopic black pellets or grains (pyrite?
phosphate? glauconite?) at ~750 feet;
Appears to grade downward into:
The Jacksonian/Claibornian (Upper Eocene/Middle Eocene) “contact” is obscure and indistinct at this site. Those Beds and layers above ~750.5 feet, I am confidant should be included in the Upper Eocene, Williston Limestone of the Ocala Group. Those beds below ~765 feet (including Bed 41) I am confidant should be included in the unnamed Claibornian limestone. The proper identification of the limestone lithologies between ~750.5 feet and 765 feet is uncertain to me but could possibly be correlated with the Gosport/Clinchfield interval of Alabama and Georgia and, therefore, with the Claibornian.
unnamed Claibornian limestone?
One inch of very fine grained calcarenite
(chalk) at ~750.5 feet;
Bed 36 Limestone: similar to Bed 35; structureless ~1.3 750.6
and competent; grades downward into:
Bed 37 Limestone chalk: very finely granular, 0.85 751.9
nonfossiliferous, lithologically nondescript;
massive and structureless; probably finely
recrystallized, coherent and competent
(100% core recovery); color is roughly very
light orange (10YR 9/2) with a slight cast of
yellow; grades abruptly downward into:
Bed 38 Limestone: similar to Bed 35 but with the 1.5 752.75
absence of gypsum; structureless and
competent; grades abruptly downward
into:
Bed 39 Limestone chalk: as in Bed 37 – very 4.25 754.25
finely granular limestone, lithologically
nondescript, nonfossiliferous, the surface of
core appears to be slightly quartz silty
under casual examination but probably is
not, texture coarsens a little below ~757
feet; massive and structureless; probably
finely recrystallized, coherent and
competent; very light orange (10YR 9/2);
grades downward into:
Bed 40 Limestone: very chalky, granular/ 6.5 758.5
calcarenitic/finely bioclastic, frequent to
common Nummulites but not so conspicuous
as in overlying fossiliferous beds, small
calcitic macrofossil fragments, all fossils
severely degraded;
Seven inches of translucent, light gray to
white (N6 - N9), massive and structureless
gypsum with strongly embayed upper and
lower contacts from ~763.4 feet to ~763.95
feet overlies ~1 foot of chalk (lithology;
Massive and structureless except for
gypsum and chalk layers near base of the
Bed; consolidated and competent; mostly
very pale orange (10YR 8/2) to very light
orange (10YR 9/2); grades downward into:
MIDDLE EOCENE, CLAIBORNIAN
UNNAMED CLAIBORNIAN LIMESTONE – 142.4 feet+
definite unnamed Claibornian limestone
Bed 41 Limestone: very chalky, granular/bioclastic 26.0 765.0
that is much degraded, scattered
Lepidocyclina, few obvious Nummulites,
scattered macrofossil scraps/flaky calcitic
shell fragments etc., a small echinoid at
~785 feet, scattered gypsum nodules; very,
very gradually fines down the section;
Massive and structureless, all fossils in
random orientation; finely recrystallized and
competent; very light orange (10YR 9/2)
with some very pale orange (10YR 8/2);
very broadly grades downward by fining
into:
Bed 42 Limestone: chalky and pasty, very finely 61.5 791.0
granular and very finely bioclastic, most
bioclastic particles appear to be, or have
been, angular; scattered small pockets of
somewhat coarser bioclastic debris;
common to abundant discocyclinid and
larger foraminifera occur mostly in random
orientation including some small shell
fragments; particle size and frequency of
discocyclinids and discrete biodebris
decrease very gradually down the section;
scattered gypsum nodules and layers of
various sizes and thicknesses occur
throughout the Bed; massive and
structureless; finely recrystallized,
coherent and competent (100% core
recovery); very light orange (10YR 9/2)
in color;
A small pocket of Nummulites-rich debris at
~845 feet;
Grades downward into:
Bed 43 Limestone: dolomitic with gypsum nodules, 2.5 852.5
small chalky Lepidocyclina and/or
Discocyclina; massive and structureless;
mostly recrystallized, coherent and
competent; pale orange to pale yellowish
brown 10YR 7/2 – 10YR 6/2); grades
downward into:
Bed 44 Limestone: very, very finely granular, and 38.0+ 855.0
chalky; scattered gypsum nodules from
~875 feet to ~888.5 feet. with a >1 foot
thick layer of translucent gypsum, with
strongly embayed upper and lower
contacts from roughly ~879 feet to a
little more than ~880 feet, and
containing inclusions of unincorporated
limestone; chert nodules occur at ~875 feet
to ~876.5 feet; scattered horizontal to
subhorizontal Lepidocyclina and
Nummulites, a burrow at ~887 feet;
Mostly massive and structureless but
apparently, there is some very rude stratification
in the upper part; mostly recrystallized and
competent (100% core recovery); very light
orange (10YR 9/2) with some very pale
orange (10YR 8/2);
Bottom of core at 893 feet.
____________________________ TOTA L DEPTH – 893.0 FEET