20080868 Ver 2_Stratigraphy Study_20150417

PotashCorp
Helping Nature Provide
April 15, 2015
Federal Express
Ms Karen Higgins
401 and Buffer Permitting Unit Supervisor
NC DENR — Division of Water Resources
512 N. Salisbury St, #942 -E
Raleigh, NC 27604
Dear Ms. Higgins:
PotashCorp - Aurora
APR 1 7 2015 1�
The NC Division of Water Quality (now Division of Water Resources) issued to PCS Phosphate
(PCS) 401 Certification No. 3771, DWQ #2008 -0868 version 2 0 on January 15, 2009, for our
mine expansion in Beaufort County Language within the second paragraph of Condition 9 of
the Certification, talking about the 1,145 -foot wide mining corridor through the narrowest
portion of the Bonnerton Non- Rivenne Wet Hardwood Forest states:
"A detailed strat;igraphy study shall be done on both sides and throughout the area to be
mined in order to determine the presence, extent and permab>lity of any aquitards and
aquicludes (mainly clay- based) within the mining corridor." Condition 9 also states
"Additional written approval is needed from DWQ before this stratigraphic study is done
or restoration is initiated."
Enclosed are two copies of a plan by Groundwater Management Associates, Inc titled "Site
Investigation Plan, Bonnerton Strattgraphy Study, PotashCorp- Aurora, Beaufort County, North
Carolina ". PCS requests written approval of the plan from DWR so that we can proceed with the
plan as soon as possible If you have any questions, please call me at (252) 322 -8249, or email at
jfumess @pcsphosphate.com.
Sincerely,
41,C c 7-ilt, rw
ffre C. Furness
Senior Scientist
Enclosure
1530 NC Hwy 306 South, Aurora, NC USA 27806 T (252) 322 -4111
PotashCorp I www potashcorp com

Pc: David May — DWR, Washington
w /encl.
23-01-004-29
w /encl.
T.L. Baker
w /encl.
M. Brom
w/o encl.
S. Jordan
w/o encl.
J. Pierce
w/o encl.
R. Jenner
w /encl.
T. Cvetan
w /encl.
D. Jordan
w /encl.

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp - Aurora
Beaufort County, North Carolina
�
PotashCorp_
AURORA
Prepared For:
PotashCorp Aurora
1530 NC Highway 306 South
Aurora, North Carolina 27806
Prepared By:
Groundwater Management Associates, Inc.
4300 Sapphire Court
Suite 100
Greenville, North Carolina 27834
GMA
Ca
GROUNDWATER MANAGEMENT ASSOCIATES, INC.
GMA Project #43626
March 24, 2015

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
Table of Contents
1.0
Introduction .............................................................. ..............................1
2.0
Scope of Work ........................................................... ..............................1
3.0
Local Geologic Setting .............................................. ..............................2
4.0
Site Investigation Plan ............................................. ..............................5
5.0
Conclusions and Recommendations ......................... ..............................6
6.0
Plan Certification ...................................................... ..............................7
7.0
List of References ..................................................... ..............................8
Figures
Figure 1. PotashCorp Site Facilities Map
Figure 2. Bonnerton Mining Corridor
Figure 3. Biotic Communities Map for Modified Alternative L, Bonnerton Tract
Figure 4 Expanded View of Mining Corridor and Non- Riverine Wet Hardwood Forest Areas
Figure 5. General Geologic Section — PCS Phosphate
Figure 6. Existing PotashCorp Boring Location Map — Bonnerton Tract
Figure 7. Proposed Boring and Monitoring Well Location Map
Page i

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
1.0 Introduction
PotashCorp — Aurora (PCS) operates a phosphate mining operation near the town of Aurora
in Beaufort County, North Carolina. The mining operation has been active since 1965 and it
provides the raw material used for processing in the PCS Aurora chemical facilities. Fertilizers
are the primary product from the Aurora site. Mining of the phosphate ore is accomplished
by open pit mining methods.
PCS will soon begin relocating its mining operations from the current area of mining to the
Bonnerton tract (Figure 1).
The North Carolina Department of Environment and Natural Resources Division of Water
Resources (NCDENR -DWR) requires that a detailed stratigraphic study be done on both sides,
and within, a 1,145 -foot wide mining corridor at the Bonnerton Tract (Figure 2).
The purpose of this requirement is to determine the presence, extent, and permeability of
any aquitards and aquicludes (confining layers) within the mining corridor. This information
will be used to develop a plan for the restoration of each of these confining layers and shall
be included with a re- vegetation plan in order to ensure that pre - mining hydrology is re-
established in the mining corridor. A site investigation plan must be provided to NCDENR -
DWR for written approval before the stratigraphic study is initiated. PCS requested that GMA
to develop a site investigation plan to address requirements of NCDENR -DWR. This
document presents GMA's proposed site investigation plan.
The areas on either side of the mining corridor have been determined to be a Non- Riverine
Wet Hardwood Forest ( NRWHF) by NCDENR -DWR and it must be avoided by the mining
operations. The NRWHF locations are designated as wetland hardwood forest (7) on the
Biotic Communities Map for the Modified Alternative L mine permit boundary at Bonnerton
(Figure 3). An expanded view of the NRWHF areas and the mining corridor (study area) are
shown on Figure 4.
2.0 Scope of work
GMA's scope of work includes the following major tasks:
• Review the local geology and stratigraphy of the study area.
• Develop a core drilling plan to address mapping of the local stratigraphy of the study
area.
• Develop a monitoring well construction plan to establish the existing water - levels.
• Develop a plan to obtain grain size analysis of stratigraphic units for the study area.
• Develop a plan to determine the vertical and horizontal hydraulic conductivity
(permeability) of stratigraphic units within the study area.
Page 1

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
3.0 Local Geologic Setting
The local geologic setting near the PotashCorp — Aurora mine site is well documented. The
phosphate operations rely on detailed geologic information for developing mine plans,
determining metallurgical characteristics and estimating phosphate ore reserves. Exploratory
core drilling for gathering geologic information for these purposes started in the early 1960s
and continues to this day.
The PCS Aurora mine lies within the Coastal Plain Physiographic Province of North Carolina.
The Coastal Plain is a broad, relatively flat region comprising the eastern third of the State.
Local topography is very flat, with local relief of only about 20 feet between upland plateau
areas and tributaries. Maximum natural relief at all of the three mining tracts (NCPC,
Bonnerton, and South of Highway 33) is approximately 40 feet (not considering mine
reclamation areas and mine - related spoil piles, such as the gypsum stacks).
The natural land surface largely owes its origin to a number of sea -level advances and
retreats that occurred throughout the Pleistocene Epoch (<1.8 million years ago). These
sea- level fluctuations created broad and generally flat terraces that slope gently to the east.
Streams and rivers have incised these terraces to create the current topographic character of
the area.
The Coastal Plain Province is underlain by marine, estuarine, and terrestrial sediments (up to
10,000 feet thick at Cape Hatteras) that were deposited over the past 200 million years. The
property is underlain by approximately 2,500 feet of Jurassic to Recent -aged sediments and
sedimentary rocks that were deposited on top of pre - Mesozoic aged ( >250 million years)
volcanic basement rocks (Lawrence and Hoffman, 1993).
Overlying the Mesozoic is a sequence of Cenozoic -aged ( <65 million years) sediments of
dominantly marine origin. These include significant beds of sand, shelly clay and fossiliferous
sandy limestone.
These Cenozoic sediments have been hydrostratigraphically subdivided into four aquifers
locally, including (from deep to shallow): the Castle Hayne Aquifer, the Pungo River Aquifer,
the Yorktown Aquifer, and the Surficial Aquifer. These aquifers contain fresh water in inland
areas, and are important sources for local and regional water supplies. Table 1 lists the
principal local aquifers that occur beneath the Aurora Phosphate Mine and describes the
characteristics of these aquifers.
Page 2

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
Table 1:
Local Aquifers near the Aurora Phosphate Mine
Aquifer
Formations and Ages
Character and Use
This aquifer occurs as a veneer (up to 70 feet
Surficial Sediments and
thick) of sandy to clayey sediments, locally
=
James City Formation
fossiliferous with shell hash. The aquifer
0
(Pleistocene to Recent)
covers the entire County, except in areas
where deeply incised streams and rivers cut
�
.......... ...............................
into underlying units. Clays within the unit
tend to serve as confining layers and restrict
•�
recharge to underlying aquifers. The aquifer
tE
Yorktown Formation
is not currently used as a significant
U)
(Pliocene)
groundwater source. It may be used
sporadically for irrigation and private
residential water supply.
This fine - grained unit is composed of
interbedded phosphatic clays, diatomaceous
4
Pungo River Formation
clays, phosphatic limestones, silty claystones,
L
iR
(Miocene)
coquinas, calcareous clays, and phosphatic
o
sands. It is not a mayor water - producing
CM Cr
aquifer, but can supply usable quantities of
IL
water to some local wells. Phosphate from
this formation is obtained by open -pit mining
at the PotashCorp Aurora Phosphate Mine.
The Castle Hayne Formation is a sandy
E
Castle Hayne Formation
limestone and is characteristically highly
,v
c *;
(Eocene)
fossiliferous (molluscan mold to
bryozoan /echinoid skeletal). The aquifer
typically has a hard cap rock of well- indurated
limestone. The upper limestone unit has very
U c
a
high permeability. Middle to lower sections of
the unit may be less indurated and have
higher sand_and_clay-con-tents ------------------------
The Castle Hayne Aquifer is the most extensively used aquifer in the area. The largest user
of the Castle Hayne Aquifer is PCS, due to the need for depressurization of the aquifer to
allow for safe, dry mining conditions.
The local stratigraphy from land surface to the top of the Castle Hayne Aquifer is described
on the General Geologic Section (Figure 5) (Gilmore, 1983).
Page 3

Site Investigation Plan
Bonnerton Stratigraphy Study
Potash Corp Aurora
March 24, 2015
The upper stratigraphy from land surface to the principal confining layer is the area of
primary interest for this stratigraphic investigation. The units that comprise the Surficial
Aquifer at the site consists of mottled orange, tan to light gray, muddy fine sands (Farmers
Clay and Surface Sand units) and blue -gray to dark gray, muddy fine sands occasionally with
small fossil mulinia shells (Post - Croatan Sand unit). The Farmers Clay and Surface Sand units
are Holocene age sediments and the Post - Croatan Sand unit is a Pleistocene age sediment.
Immediately below the Post - Croatan Sand unit is the primary confining unit for the Surficial
aquifer, locally known as the Gumbo Clay unit (Pleistocene). The Gumbo Clay unit is blue -
gray to dark gray and black, organic rich mud. This unit is typically very greasy to plastic in
nature and intermittently may contain sand and silt streaks along with sporadic fossil oyster
shells.
Below the confining Gumbo Clay unit is a layer of clean, fine to coarse, angular quartz sand,
locally known as the Sugar Sand unit (Pleistocene).
Immediately below the Sugar Sand unit is the James City Formation, also known locally as
the Croatan Formation (Pleistocene). This unit is typically a coarse textured, blue -green to
gray, muddy shell hash and contains a variety of fossil shells and coral fragments. This shell
hash is known locally as the Shell Bed. The Shell Bed is the stratigraphic unit where PCS
removes the upper overburden to for establishing a solid, well drained surface upon which to
operate their mining bench.
The James City Formation overlies the Yorktown Formation (Pliocene). The Yorktown
Formation overlies the Pungo River Formation (Miocene) and which comprises the majority of
the overburden removed in the mine. The Pungo River formation contains the phosphate
bearing ore matrix that is mined at PCS. The two basal units of The Pungo River Formation
are not mined and unconformably overlie the Castle Hayne Limestone (Eocene) at the mine.
Formations below the Sugar Sand unit are extensive throughout the area, are well defined
and will not require any additional investigation or be part of the proposed site investigation
plan.
Locally, the Gumbo Clay unit is the primary confining layer marking the base of the Surfical
Aquifer. Therefore it will be important to understand the extent and properties of the Gumbo
Clay in the mining corridor.
Determining the stratigraphy is needed for the upper and lower horizons of the Gumbo Clay
unit. The Gumbo Clay unit can be quite variable in thickness and surface elevation in respect
to mean sea level (MSL). Existing core samples within the Bonnerton tract indicate the
approximate range in thickness for the Gumbo Clay is: 2 feet minimum, 28 feet maximum,
and 10 feet on average. Variation in the upper surface elevation is: -9 feet MSL minimum,
+19 feet MSL maximum, and +1 feet MSL on average.
Page 4

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
The area for the stratigraphic investigation is the mining corridor and the adjacent NRWHF
areas (Figure 2). GMA has reviewed the existing stratigraphic information from previous core
sample borings completed by PotashCorp at the Bonnerton tract to help determine where
additional borings are needed to properly delineate the stratigraphy at the site (Figure 6).
No pre - mining water levels are available for the Surficial Aquifer in the study area, and
assessing pre - mining water - levels will be required. Shallow monitoring wells will need to be
constructed to determine the pre - mining water - levels.
Grain size analysis of the Farmers Clay, Surface Sand, Post - Croatan Sand and confining
Gumbo Clay layer will be needed for determining hydraulic conductivity at the site as no
previous materials testing data of these units exist within the study area.
Vertical and horizontal hydraulic conductivity (permeability) testing of the confining Gumbo
Clay layer will be needed at the site as no previous data for testing this parameter exists
within the study area.
4.0 Site Investigation Plan
GMA has reviewed aerial mapping data and geologic core drilling information provided by
PCS for the Bonnerton tract, and we have determined that the site investigation plan should
include the following steps:
• Complete core sampling at 10 locations within the mining corridor to the base of the
confining Gumbo Clay unit (Figure 7).
• Complete a photographic record of all core samples taken within the mining corridor.
• Retain a representative number of core samples to evaluate grain size and hydraulic
conductivity analyses of the stratigraphic units from the surface to the base of the
Gumbo Clay confining unit.
• Determine the pre- mining water - levels in the Surficial Aquifer within the mining
corridor by constructing 10 piezometer wells (Figure 7).
• Determine the horizontal hydraulic conductivity of the Gumbo Clay unit within the
mining corridor by conducting slug tests at well locations and /or completing
permeameter testing of core samples from the Gumbo Clay unit. The exact number
and location of these tests will be determined after core drilling information becomes
available. It is anticipated that between 4 and 6 tests will be needed.
• Prepare a site investigation report describing the methodology for achieving the
objectives of the permit conditions, including groundwater monitoring plans to ensure
restoration has established reference hydrology for the site.
Page 5

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
Information for the site investigation report will address the local stratigraphy,
hydrostratigraphy, materials testing data, vertical and horizontal permeability of
stratigraphic units and the pre - mining water - levels in the Surficial Aquifer. The site
investigation report will include the following information:
• Geologic core drilling logs of the 12 core samples.
• Photographic log of the 12 core samples.
• Geologic cross - sections, isopach and structure contour mapping of the stratigraphic
units to the base of the Gumbo Clay unit.
• Grain size analyses.
• Hydraulic conductivity testing results of the upper stratigraphic units.
• Vertical and horizontal hydraulic conductivity testing results (slug tests and /or
permeameter tests) of the Gumbo Clay unit.
• Pre - mining water levels obtained from the piezometer wells including a
potentiometric surface map.
• A post- mining groundwater monitoring plan for water - levels in Surficial Aquifer.
GMA anticipates that the site investigation activities will take approximately 2 to 3 months to
complete. GMA also anticipates that preparation and submittal of the site investigation
report will take approximately 1 month to complete after all the data have been acquired.
5.0 Conclusions and Recommendations
This proposed site investigation plan is designed to address issues and is recommended for
approval by NCDENR -DWR in order to ensure a thorough determination has been made for
the presence, extent and permeability of any confining layers within the mining corridor.
A plan for restoration of each of these confining layers is to be included with the re-
vegetation plan submitted by PCS in the future, in order to ensure pre - mining hydrology is
re- established in the mining corridor. Written approval from NCDENR -DWR is required
before this stratigraphic study is initiated or any restoration is completed.
Page 6

Site Investigation Plan
Bonnerton Stratigraphy Study
PotoshCorp Aurora
March 24, 2015
6.0 Plan Certification
This proposed site investigation plan for the Bonnerton Stratigraphy Study was prepared by a
Professional Geologist familiar with the local geology of the PCS mine site and the Bonnerton
tract. Groundwater Management Associates, Inc., is a professional corporation licensed to
practice geology (C -121) and engineering (C -0854) in North Carolina.
,0- AO'- aav
"Tex" Ivan K. Gilmore, P.G., C.P.G.
Project Manager
Senior Mining Geologist
�!.........pi
��GENSFO
Page 7
SEAL
181
IK„�1�Mp��.

Site Investigation Plan
Bonnerton Stratigraphy Study
PotashCorp Aurora
March 24, 2015
7.0 List of References
Lawrence, D. P., and C. W. Hoffmann, 1993, "Geology of basement rocks beneath the North
Carolina Coastal Plain ", North Carolina Geological Survey, Bulletin 95, 60p, one Plate.
Gilmore, I. K., 2014, reference page 6, General Geologic Section from 1983, °Invertebrates
and Plants ", North Carolina Fossil Club, Volume 1, 295p.
Page 8

Figures

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NONRIVERINE WET HARDWOOD FOREST (NRWHF) ACRES
20
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�
16 17
BONNERTON BASE PROJECT AREA 2,806
16 22
18 e
9 0 19 2 6
MODIFIED ALT L - BONNERTON PROPOSED 2,526
18
9 8 16
IMPACT BOUNDARY 5/13/09
6 7
11 B a 11
MODIFIED ALT L - BONNERTON PROPOSED 1,696
to
g
t
a
17 IMPACT BOUNDARY 5/13/09 - EXCAVATION
0 1 7
LIMITS RECOVERABLE CONCENTRATE = 33,478,000 TONS*
19 71
8 11
0
1 5
9
8 1
4
1 9
to
9 9
14 5 1 CREEKS /OPEN WATER
e 8
18 a
1A PUBLIC TRUST AREAS
20
5 1B PERENNIAL STREAM
7
11 9
1C INTERMITTENT STREAM
8
10
18 2 WETLAND BRACKISH MARSH COMPLEX
5 15
5 5 18
3 WETLAND BOTTOMLAND HARDWOOD FOREST
5
15 3
4 WETLAND HERBACEOUS ASSEMBLAGE
t7 7 17 7
1tb 1
ASSEMBLAGE
t
5
6 WETLAND PINE PLANTATION
TO
15 22
7 WETLAND HARDWOOD FOREST
DURHAM 15 3
5
8 WETLAND MIXED PINE - HARDWOOD FOREST
C 3
15 1
9 WETLAND PINE FOREST
9 1 s
5 /�
10 WETLAND POCOSIN - BAY FOREST
s
15 4 1113
11 WETLAND SAND RIDGE FOREST
31C
12 POND
15 14 10
13 WETLAND MAINTAINED AREA
e 5 5 15
15 11
14 UPLAND HERBACEOUS ASSEMBLAGE
15 UPLAND SHRUB — SCRUB ASSEMBLAGE
e
5
16 UPLAND PINE PLANTATION
3
1t
17 UPLAND HARDWOOD FOREST
3 5 O
10 1
18 UPLAND MIXED PINE — HARDWOOD FOREST
1 t
1
19 UPLAND PINE FOREST
e
1e
20 UPLAND SAND RIDGE FOREST
1 5 15 10
14
21 UPLAND AGRICULTURAL LAND
15
0 7
22 UPLAND NON — VEGETATED /MAINTAINED AREA
2D
10 7
3 5 1 1 10
2
1 10 7
10 1 76 7
20 7
2
18 9 7
18
18
19
*PROVIDED BY PCS PHOSPHATE 5/13/09
N BOUNDARY AS SHOWN INCLUDES DCM /CAMA AVOIDANCE
1,800 0
1,800 Feet
O�
Basemap Provided By
PotashCorp— Aurora
>roFtiR I �v
GMA
1530 Hwy. 306 South
Aurora, NC 27806
A�CCS+O j �
Groundwater Management Aesoclatae, Inc.
File: 436- 26.dwg
BIOTIC COMMUNITIES MAP
FOR MODIFIED ALTS cal �L, BONNERTON TRACT
Date: 3/4/15
Project No. 436 -26
PCS PHOSPHATE CO., INC. AURORA, NC
Figure: 3

21
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_
NONRIVERINE WET HARDWOOD FOREST (NRWHF)
ACRES
BONNERTON BASE PROJECT AREA
2,806
-
MODIFIED ALT L - BONNERTON PROPOSED
2,526
IMPACT BOUNDARY 5/13/09
MODIFIED ALT L - BONNERTON PROPOSED
1,698
IMPACT BOUNDARY 5/13/09 - EXCAVATION
LIMITS RECOVERABLE CONCENTRATE = 33,478,000
TONS*
1
CREEKS /OPEN WATER
1A PUBLIC TRUST AREAS
1B PERENNIAL STREAM
1C INTERMITTENT STREAM
2
WETLAND BRACKISH MARSH COMPLEX
3
WETLAND BOTTOMLAND HARDWOOD FOREST
4
WETLAND HERBACEOUS ASSEMBLAGE
5
WETLAND SHRUB - SCRUB ASSEMBLAGE
6
WETLAND PINE PLANTATION
7
WETLAND HARDWOOD FOREST
8
WETLAND MIXED PINE - HARDWOOD FOREST
9
WETLAND PINE FOREST
10
WETLAND POCOSIN - BAY FOREST
11
WETLAND SAND RIDGE FOREST
12
POND
13
WETLAND MAINTAINED AREA
14
UPLAND HERBACEOUS ASSEMBLAGE
15
UPLAND SHRUB - SCRUB ASSEMBLAGE
16
UPLAND PINE PLANTATION
17
UPLAND HARDWOOD FOREST
18
UPLAND MIXED PINE - HARDWOOD FOREST
19
UPLAND PINE FOREST
20
UPLAND SAND RIDGE FOREST
21
UPLAND AGRICULTURAL LAND
22
UPLAND NON - VEGETATED /MAINTAINED AREA
*PROVIDED BY
PCS PHOSPHATE 5/13/09
i
NOTE: BOUNDARY AS SHOWN INCLUDES DCM /CAMA AVOIDANCE
900 0
I
900 Feet
NEEME!
Basemap Provided By.
PotashCorp— Aurora
GMA
1530 Hwy. 306 South
Aurora, NC 27806
Grmndwobr Monogwn.nt Amwclata, Inc.
File: 436- 26.dwg
BIOTIC COMMUNITIES MAP FOR
MODIFIED ALTERNATIVE L, BONNERTON TRACT
Date: 3/4/15
Project No. 436-261
PCS PHOSPHATE CO., INC.
AURORA, NC
Figure:4

.� RiF14111plei •
1. Farmer's clay - 5and, silt and organic debris in a clayey matrix. Tan, gray to
limonitic black
black in color, usually with streaks. Sometimes occurs a5 a organic
rich peaty clay and mud.
— 2. Surface Sands - Fine grained 5and to silt being organic and slightly clayey.
Variegated tan to gray in color. Sometimes occurs as variable clean quartz sand
with clay lenses. Some heavy minerals present, Occurs flat to cro55- bedded with
limonitic incrustations. Toward base of unit color darkens and 5and size iS greater
"Ice ".
sometimes containing pebbles and striated igneous rocks from Rafts
..: 3. Post - Croatan Sands -Blue gray silty to Sandy mud and clay with abundant
(Mulinea) pelecypod and gastropod Shells. This unit contains mica and heavy
minerals. Also, in the matrix are various types of organic matter. Many of the +G�
:r
0 fossils found in this unit are in 'Ills position ". C
i
Es–Q 4. Gumbo Clay - Biue gray to dark brown or black Sandy to pure clay. Top of this unit
ti= 4
contains much 5and and 9itt with layers of peat, sand and organics such as roots and
wood fragmenteo. Center of unit i5 very impervious, greasy pure clay. Base of unit
#,
w sometimes contains abundance of organic debris and 5and streaks. Base may be black
or brown in colorand occasionally becomes a "coon" oyster bioherm.
A
5. Sugar Sands - Poorly sorted, white to gray, fine to very coarse, angular to
LAJ
Ri sub- rounded quartz sand. 5and is sometimes translucent. Rarely contains
4 organics. Heavy minerals and mica do occur. High angle cross - bedding is evident
sedimentary Structure. Base of unit becomes very coarse quartz sand and gravel.
{ Sometimes containing gray clay lenses throughout unit. Occasionally this unit
' may overlie or be completely replaced by Croatan clay, which is a shely dense clay.
6. Shell Sed - Blue green clayey silty Shell hash to Shelly Band. Abundant glauconite sand and
At throughout. Very fo5eilifemu5 unit containing wide variety of pelecypods, gastropods, and
coelenterat;ee. Sharp unconformable, undulatory contacth are found both above and below this
�.. unit. Channels in the upper Surface are filled by 5and from the overlying unit. Also, this unit
may grade into a finer Shell hash with coarse Sand and pebbles as it may "Scour" out underlying
Yorktown clay Sometimes uuite despiy in old drainage patterns. Base of unit Sometimes
f
T includes ham limonitic concretions of glauconitic. sand cemented by CaCo3, known a5 "Boulder
— �t Sed'. Drainage from base of unit "weeps" at contact with underlying clay forming diStictive iron
oxide stained Streaks on exposure of clean face.
.,a 7. Yorktown Clay - Light gray Silty to Sandy, 5emi-indurated cast and moldic
0 F _ Tun - telly clay. May be a marly sand at times.
8. Light green -gray Bitty stiff mart' clay with minor Shely 5treak5 and occasional
cast and moldic Turrrtella erreak5.
3 9. Green -gray semi - indurated marly clay with occasional lone fragments, lignite
and mushy shell fragments.
10. Green -gray Stiff sitty manly clay with occasional quartz Sand Streaks. Also contains
abundant echinoid Spines. Base of unit Sometimes corrtainS large black phosphatic pebbles.
11. Light gray Sandy Stiff marly clay with abundant pecten Shells, reworked
phosphate pebbles, phosphatic bones, and teeth.
12. Dark green phosphatic sandy clay. Composed mostly of reworked materials
including pebbles and fos5il5 that have been pho5phatized. Sometimes containing
chalky, mushy, Shell fragments and abundant quartz pebbles and sand streaks. At
base of unit an abundance of large phosphatic pebbles.
13. Chartreuse Bed - Yellowioh green Sandy bryozoan hash. Contains only 5pame
fine grained phosphatic black sand.
14. Coquina Beds - lrterbedded Soft to indurated marly gray clay and white coquinold
limestone with rich biack clayey phosphatic Sand. This unit contains abundant variety of
fo95i19 and black vuggy - pho5phatic pebbles known as microophorite.
15. Phosphate Ore Manx - Black to olive green clayey fine grained phosphatic sand
with minor fossil remains.
• •" 16. Light green semi - indurated phosphatic clay. Slightly calcareous with Some
dolo silt and quartz sand streaks. Also with minor pebbles and fossil remains.
17. Olive green to black clayey fine grained phosphatic 5and with minor fossil remains.
� 18. Polostone Unit - Indurated gray to light green dolostone. Forms as lenticular
OC deposits in ore body. Phosphate pebbles and clam borings are present. Unit may
o contain very hard light green Siliceous streaks.
co
19. Olive green very clayey phosphatic 5and. Clay content increa5e9 with depth.
aAbundant coarse phosphatic pebbfe5 and fo55i15 found at ba9e. Base of ore matrix.
20. Caprock - Hard light green fine grained dolomitic sandstone. Contains
abundant quartz and phosphatic pebbles and cast and molds of pelecypodo. Some
calcite also present.
21. Lean Ore - Olive green fossil'rferouo Slighty phosphatic clay. Very abundant
phosphate pebbles and fossil remains. Also in matrix are large quartz pebbled.
Sparse dolomitic and phosphatic 5and present. At base of unit exiot5 an
errooionai Surface which iS dense black phosphate replacing vuggy limestone.
22. White to tan cast and moldic coquinoid limestone. Artesian aquifer. Top of
unit contains loose quartz 5and in lattice grading to vuggy limestone, loosely
cemented to hard, with beds of various coarse to fine textured coquina. Bottom of
Section becomes a glauconitic Silty, Shelly clay. Average thickneoe iS ± 2501.
APR �D
t72015Groundwater
Management Associates, Inc.
File: 436- 26.dwg
!!"R - WgrER
GENERAL GEOLOGIC SECTI 401 & BUFFEf RESOURCE
Date: 3/4/15
Project No. 436 -26
PCS PHOSPHATE CO., INC. AUR
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