From: Nizich, Sharon [ mailto:Nizich.Sharon@epa.gov ]
Sent: Thursday, September 3, 2015 12:16 PM
To: Szabo, Aaron < Aaron_L_Szabo@omb.eop.gov > Cc: Fairchild, Susan < Fairchild.Susan@epa.gov > Subject: FW: CORRECTED file

Hello Aaron

- Susan our geologist, realized the previous version of this document had a problem with one of the maps. This draft should be clearer for you.

Thanks!

Sharon Nizich Environmental Engineer U.S. EPA/OAR/OAQPS Sector Policies and Programs Division (SPPD) 109 TW Alexander Dr. (D243

- 04) RTP, NC 27711 (919) 541

- 2825

<<OKLAHOMA and OHIO v3.pdf>>

From: Fairchild, Susan
Sent: Thursday, September 03, 2015 11:32 AM
To: Nizich, Sharon; Morales, Mariel; Barnett, Keith Subject: CORRECTED file

The maps, their captions, and the points got messed up in the transition from Word to adobe. So I’ve edited it and I think this one is captured correctly. I didn’t change the text.

Susan Fairchild Senior Environmental Scientist (919) 541

- 5167

USPS Address: OAQPS/SPPD/MMG Mail Code D 243

- 04 Research Triangle Park, NC 27711

## Mercury Content of Oklahoma a nd Ohio Shale Deposits

Supplying the Brick Industry

Report to the Brick MACT Project File

Prepared by: Susan Fairchild

July 29 , 2015- 1

-

EXECUTIVE SUMMARY

Th is report supports development of the emission limits for mercury under the maximum achievable control technology (MACT) standard for the Brick Manufacturing source category

.

Ten shale and c lay deposits in Ohio and Oklahoma are currently used by U.S. brick manufacturing companies as a source of raw material. Available information was reviewed to understand the source(s) of mercury in the clays. The Oklahoma Geological Survey provided detailed historical a nd stratigraphic maps of rock sequences across the state. The Ohio Geological Survey materials were less detailed, but provided similar information.

All clays used in these states are formed by the weathering of shale, a sedimentary rock. Clay deposits

are formed by the weathering of host rock, and are deposited through erosional processes to a local area, usually a geologic basin. While clays can be formed from the weathering of all types of rock, the clays used by the brick industry in Ohio and Oklahoma o riginate from shale sequences formed during the Devonian, Pennsylvanian

, and Permian periods. Note that all Ohio and Oklahoma clay deposits are extracted at or near the surface in ‘pits’.

Variability of mercury content is expected due to the geological events which occurred over the course
of shale sequence formation and the concentration of mercury by the weather ing process. The severity of that variability is dependent on several factors, including volcanic activity during shale formation

, availability of associated minerals with which to form stable bonds, the shales’ carbon content, and irregular rates of organic d eposition

. Given the above factors, we conclude a correlation is apparent between the clay’s organic content, general color of the clay, a nd the relative m ercury content.

METHOD

Existing information was obtained to locat e, identif y , and characterize the geological history of the clay deposit s in this report

. A nalys e s of the mercury content of each clay deposit used by brick
manufactur ers in Oklahoma and Ohio were suppli ed from existing company data collected in rock and soil assays

. No new testing was required. Companies identified each sample of the deposits by location (latitude, longitude), age, rock type

, and sample description.

G eol ogic maps from the State Geologic survey offices and reviews of the geological history were next located online for both Ohio and Oklahoma. The geologic time scale was also reproduced for reference from the Geological Society of America (see Appendix 1).

G oogle Earth © was used to locate deposits by latitude and longitude. Once the deposit was located and a pit was identified , the clay deposit coordinates were transferred to the respective geologic map. The historical geology of e ach area was reviewed and n oted. State G eological S urvey maps, geologic history
reports, cross

- sectional maps and related materials were used to determine the age of surface deposits
and near

- surface deposits, and to ascertain potential origins and explanations of the variation of

m ercury content for the clay deposits, if possible. Other sources of information were also retrieved and reviewed for relevancy to this study.- 2

-

OHIO

Brick companies extract clays from five locations in Ohio, as shown on page 6 in the geologic map ( Figure 1. ) These are the Belden

- Sugarcreek fire clay/shale, site 1; Whitacre Greer

- Lower Kittaning clay

, site 2; Whitacre Greer

- Brookville clay , site 3; Whitacre Greer

- Red clay Pit, site 4; and Glen

- Gery,
Caledonia and Iberia

- Green shale and clay , site 5. While w e did not obtain complete assays of all clays sampled, we note

, in general

, the red color of clays indicates an oxidizing environment with a high

- iron content, and the green and gray color s of clays indicates a reducing environment. These distinctions play a significant role in the geochemi stry of the rock from which clays are derived.

Geological Overview:

Overall, the bedrock geology of Ohio consists of late

- Precambrian age igneous and metamorphic rock at depth overlaid by flat lying to gently dipping sedi mentary rocks including carbonat es , evaporite minerals , a nd shales that are alternatingly high in silica and organic content. The shales were formed from sediment s deposit ed beginning 450 million years ago and continuing for another 150 million years there after (i.e., from Upper Ordovician to Lower Permian )

. S urface

- layer Quater nary sediments irregularly overlie shale deposits north and west of the glacial margin. Clay s are found in two geologic basins: Appalachian (younger) basin and the Michigan (older) basin , and the clays used by brick companies are located in Pennsylvanian and Devonian age shale deposits in these basins . The Devonian period in Ohio was preceded by a period of widespread erosion, followed by accumulation of sediment s of marine and sub

- m arine origin in the Michigan basin. Lithification of these sediments formed sandstone, shale, and limestone. Another period of widespread erosion preceded the early and mi d

Pennsylvanian period, characterized by a 16 million year accumulation of deltaic an d marine sandstone, siltstone, and shales in the Appalachian basin

. High carbon content is a characteristic of all clays formed during the Pennsylvanian system, as implied by the name of the period “Carboniferous Period”, particularly the shales, which are deltaic in origin. Site 5 clays are of Devonian age 1 , which predates the Carboniferous Period, and as such would not have a high carbon content. T he Cincinnati and Findlay arches rise between the two basins and several high

- angle normal faults

, located n orth and central in the state, dislocate strata.

The cross section al map at the base of Figure 1 depicts the underlying rock layers along the bent line from A to A’. All five Ohio clay deposits are located in the Greenville Province , shown from the angle apex in the cross section to A’

. Due to regional uplift, rock units exposed at the surface increase in age from the e ast border of Ohio going west to the center of the s tate
, and then decrease in age mid

- state going west

.

One brick company reported a cla y deposit (site 2 in Figure 1 ) of Precambrian age. However, this is an apparent error . According to t he information available from the Ohio Geological Survey

, rocks of this age are not exposed at or near the surface. Site 2 was located using its latitude a nd longitude coordinates with Google Maps © aerial photograph y . The site 2 location then was transferred to the Ohio geologic map, and found to be in the Northeastern quadrant of Ohio. This site is not near known faulting that could explain Precambrian roc ks at the surface. T he oldest exposed rocks in the state,
consist ing mainly of alt ernating shale and limestone se quences , occur in strata of the Ordovician s ystem

1 Late Devonian age clastic rocks and clays from these deposits are found in both the Appalachian and the Michigan (older) basin s . However the Michigan basin is located in the Northwest quadrant of Ohio, and although clay deposits are available in this area, brick companies are not currently using clay deposits from the Michigan basin

.- 3

-

located in the southwest corner of Ohio. 2 We therefore conclude that the site 2 clay deposit is most likely of Pennsylvanian age (potentially the clay from which this shale was initially formed was Precambrian.) The remaining companies reported clay deposits of Devonian and Pennsylvanian ages.

Mercury Content of Ohio Clays Ohio clay mercury content showed the concentration of mercury in clays varied widely between sites and even within the same clay deposit. Sites 1, 3, and 5 were sampled multiple times, and one sample each was obtained from sites 2 and 4. Three samples were obtained from site 1, ranging from 15.6 to
56.9 parts per billion (ppb) mercury ( Hg ) . Five samples were obtained from site 3, ranging from 32.8 to 132 ppb Hg. Site 3 has the overall h ighest average mercury content, highest single measurement, and the wid est range of mercury sample results. Four samples were obtained from site 5, ranging from 12.9 to 18.2 ppb Hg. Only one mercury measurement for Site 4 was provided , and is the lowest single measurement of mercury of any site of Ohio brick clay deposits. Si te 2 mercury content is comparable to that for site 1, a result that is not apparent from a review of the geological map alone.

We note that pre

- anthropogenic mercury is deposited geologically through volcanic, igneous intrusive, hydrogeologic, and other geothermal processes. While faulting in Ohio is noted, the fault zones are not located proximate to, or within the Ohio clay deposits. Orogenous processes w est (Rocky Mountain range) and e ast (Appalachian Mountain range) of the O hio sediment deposition b asins are the likeliest sources of mercury during the Pennsylvanian period.

Mercury is readily absorbed by organic matter, and is also known to bond readily with minerals containing manganese

, sulfur , and iron . Chemical assays of the samp le were not obta ined, but as not ed earlier, the Ohio geological survey reports interspersing of high

- organic content shale with other sedimentary deposits.

Neither igneous intrusives nor active geothermal vents are noted locally, but volcanic activity, which is known to be a source of mercury

, may be responsible for deposition during this period. Remote volcanic activity during the Pennsylvanian period could be a potentially significant so urce of mercury deposition to the deltaic muds, especially those high in organic ma tter, a char acteristic of the thick deltaic shale sequences of the Pennsylvanian system. Proximity to the area of volcanic activity is not necessary for this mechanism to occur. Mercury, emitted to the atmosphere from volcanic activity outside the area,

m ay remain airborne, carried by air currents, and be deposited locally. Erosional processes would also be expected to contribute to migration and accumulation of mercury in t he Appalachian basin sediments, and mercury would be expected to become concentrat ed manganese, sulfur, and iron

bearing minerals, and in areas with accumulated organic matter. Figure 2 is an aerial photograph of site 3, with dark piles indicating high carbon content at the same site with clays of lighter color indicating lower carbon c ontent. The formation of high carbon content sediments during a time of active volcanism indicates the conditions are right for concentration of mercury in the sediment.

2 The youngest Precambrian rocks are located at depth, and the Ohio G eological S urvey reports that rocks of these ages are igneous and metamorphic rocks over 900 million year old, and include granite, gneiss, schist, amphibolite

, and marble. From the Ohio G eological S urvey stratigraphic map, we found that rocks of Precambrian age could only be reached by drilling through 11 layers of rock accumulated in the Appalachian b asin formation in e astern Ohio, which we believe would be cost

- prohibitive.- 4

-

Figure 1

. Geologic Map of Ohio showing the locations of active clay pit s used by the US Brick Industry (Ohio GS , 2015. ) 5

1 3 4 2- 5

-

The diagenesis 3 of the rocks could account for a wide range of mercury content of samples within the same deposit and age. St udies 4 of regional geo chemistry, particularly of mercury deposition to sedimentary rocks, expla i n this process . “The main factors controlling the concentrations of mercury in sedimentary and metasedimentary rocks are: the presence or absence of volcanism in the source areas
and areas of deposition; the amount of manganese oxides in oxidizing environments or the amount of organic material and sulfur in reducing environments; the thermal history of the rock; the intensity of regional hydrothermal activity; and the effect of diagen esis.”

Mc Neal also suggest s a mechanism of mercury enrichment of soils during the weathering process. Mercury compounds which are stable in the environment may be concentrated by the weathering of a large thickness of shale into a smaller volume of clays.

A significant variability of mercury in the clays would be expected as a result of the diagenesis of the shale sequences and the concentration of mercury by weathering as each layer of shale is exposed and weathered, forming the clay deposit.
Moreover , because the shale that is a source of the clay was also previously formed from clay deposits, the accumulation of mercury from volcanic origin likely includes earlier geologic periods potentially in the Cambrian and Precambrian series. Mercury
content in the clay is not evenly distributed or invariable across a single clay layer because deposition of organic matter, to which mercury forms a stable bond, is not evenly distributed. Minerals associated with

mercury in the oxidizing environment such as mangan ese are typically heterogenous in the host rock, and as a result the mercury accumulation in the clay from this source is likely to be variable across the clay deposit

.

3 Diagenesis in this context refers to processes including alteration by deposition of mercury of volcanic origins, erosional processes and transmittal of mercury through water borne movement, and geochemical processes in both reducing and oxidizing environments.

4 “The Geochemistry of Mercury in Sedimen tary Rocks and Soils in Pennsylvania”. McNeal, James M. and Rose,
Arthur W. Geochimica et. Coamochimica. Acta. Issue 12, Vol.38, pp.1759 To 1784. December 1974. Pergamon

Press

. Figure 2

. Light and dark

- colo red piles are indicative of a range of organic content, and of associated mercury content of the clays. Courtesy Google Earth©, 2015.- 6

-



### Table 1 . Ohio Clay Deposit Mercury Analysis

Hg
Content [ppb] Name Site # 

### Average Hg content for deposit Geologic Description Age

31.7 Belden

- Plants 2, 3,

4, 6

, 8 & 9 Sugarcreek 1 34.7 Lower Kittanning (#5 Fireclay)

Pennsylvanian

System (300

- 325 million years old) 56.9 50% Clarion (#4 Shale) & 50% Brookville (#4 Fireclay)
15.6 Clarion (#4 Shale)
39

Whitacre Greer 2 74.3 Lower Kittanning #5
114

Brookville 32.8
67.7
132
60.2
5.43 Whitacre Greer 3 5.4 Buffalo Shale #7
18.2 Glen

- Gery

Corporation

Caledonia 4 15.55 Shale Devonian (350

- 420 million years old) 12.9
17 Glen

- Gery Corporation

- Iberia 5 15.05 13.1- 7

-

OKLAHOMA

Brick companies extract clays from five locations in Oklahoma, as shown in the geologic map below (Figure 3.) Three clay deposits accessed by the brick industry ( Boral

- Muskogee, site 1; Acme

- Fort Smith, site 2; and Acme

- Tulsa , site 3 ) are from Pennsylvanian

- age shales . T wo deposits (Acme

- Oklahoma , site 4;
and Boral

– Union City , site 5 ) are from younger Permian

- age shales. As with the clays in Ohio, complete metals assays of the Oklahoma clay deposits were not obtained.

Figure 3

. Geologic Map of Oklahoma. (Oklahoma GS , 2015

. )

Geological Overview:

The Pennsylvanian Period (300

- 324 million years ago) in Oklahoma was characterized by crustal activity marked by both mountain building and subsidence across the area. Uplifts to areas w e st and n orthwest established the Ancestral Rockies mountain chain. Previously deposited sediments in the Wichita, Arbuckle, and Ouachita Uplifts became lithified 5 , deformed and raised, forming significant mountains, while rapid nearby subsidence created the Arkoma basin

, which received sediments as they eroded from the highlands. 6

The cross

- sectional diagrams (Figure 4 ) along B to B’, and (Figure 5 ) along E to E’, show the age and configuration of the strata.

5 The term lithified refers to the process by which sediments

-- in this case clay, calcareous deposits, sand, and organic matter

-- become rock, i.e., shale, limestone, sandstone, and coal, respectively.

6 Kenneth S. Johnson, Oklahom a Geological Survey, Educational Publication 9, 2008. 5 4

3 1

2- 8

-

T he Arkoma basin

, in which sites 1

- 3 (Figur e 4) are located

, is on the outer rim of the Ozark Uplift. These clay deposits originat e from marine shale of mid

- Pennsylvanian age, and the deposits are up to 18,000 feet thick. The shale occurs with interbedded sandstone, limestone, conglomerate

, and coa l. Sites 1 and 2 are bordering quaternary sand, silt, clay and gravel flood plain. Site 3 does not border this gravel deposit. Sites 1 and 3 are both located in a structure known as the Claremore Cuesta Plains, and Site 2 is capped by Pennsylvanian age san dstone. While we generally group sites 1

- 3 together geologically, we note that variations within the sediment sources (mountains) would be expected to yield similar
variations in the accumulated sediment. We also note site 2 is not in Oklahoma. While the b rick

company may operate out of Oklahoma, the latitude and longitude coordinates of the clay pit is about

two mile s across the border into Arkansas. 7

A shallow inland sea covered most of Western Oklahoma during the Permian period. Layers of shallow

marine limestones and gray shales in this area intersperse and gradually give way to high iron content deposits of red shales and limestones. Evaporite minerals such as salts and gypsum are also common in the area marked by the last vestiges of the ancient sea. Sites 4 and 5 are located in this area, known as
the Anadarko Basin.

Figure 4

. This cross

- section of the Anadarko basin is the location of sites 4 and 5. (Oklahoma GS.)

Mercury content of Oklahoma Shale and Clay Deposit s

Thus the clays and shale deposits found in the Arkoma Basin (sites 1

- 3) and those found in the Anadarko Basin (sites 4 and 5) are of different ages, formed under different conditions, and of different origins. It is therefore not surprising to find that t he associated mineral assemblages vary widely between these deposits, and may also be expected to vary within each deposit due to the sediment source and alluvial
contribution.

7 This political boundary does not affect the geology. Sites 4 and 5- 9

-

Figure 5

. The Arkoma Basin6 is the location of sites 1, 2, and 3, as shown in this cross section E to E’. (Oklahoma GS)

Mercury samples were fairly consistent within each site, but varied across the Arkoma Basin deposits.
Sites 2 and 3 were each sampled and analyzed for mercury twice and site 1 was sampled and analyzed once. Mercury content of the deposits in the Pennsylvanian shales runs from 14.7 to 34.4 parts per billion, and are generally in the same range. Sites 1 and 4 are each characterize d by one mercury analysis result. Site 5, Permian age shale used by the Union City Boral pit measured the lowest mercury content and the Fort Smith Acme pit averaged the highest.

As with the Ohio clay deposits, contribution to the concentration of mercur y in the clays is largely attributed to distant volcanic activity (in this case, areas to the east and northwest ) and to accumulation of stable mercury compounds in organic material and minerals in the clays as a result of weathering

processes. Figure 5 il lustrates visual differences in clays as an indicator of mercury content.

Table 2. Oklahoma Clay Deposit Mercury Analysis

Hg
Content [ppb] Name Site # Average Hg
content for deposit Geologic

Description Age

21.7 Boral

- Muskogee Plant 1 21.7 Shale Mix

Pennsylvanian 34.4 Acme

- Fort Smith Plant 2 33.9
Shale 33.4
14.7 Acme

- Tulsa Plant 3 16.7 18.7

Acme

- Oklahoma City Plant 4 Clay Permian

1 Boral

- Union City Plant 5 1 Shale Mix Sites 1, 2, and 3- 10

-

Figure 6 below shows aerial photographs of two different clay deposits in Oklahoma

. The Boral plant in Union City uses a clay/ shale mix that is weathered from Permian age shales high in iron, but lower in organic content, as evidenced by the red color. The Union City clay averaged 1 parts per billion (ppb) mercury. The clay pit used by Acme in Fort Smith, Oklahoma is probably higher in organic content (indicate d by the dark gray color), and has a higher mercury content. The Fort Smith deposit averaged about 34 ppb mercury.

Figure 6

. T

wo clay deposits used by the Brick industry in Oklahoma illustrate how color can be an indicator of geochemistry, organic content, and mercury content. (Google Earth , 2015. )

References:

1. Oklahoma Geological Survey. “Geologic Map of Oklahoma”. Kenneth S. Johnson, Educational
Publication 9:2008.

2. Oklahoma Geological Survey. “Geomorphic Provinces of Oklahoma” Kenneth S. Johnson, Neville M. Curtis, Jr., William E. Ham. Educational Publication 9:2008.
3. Ohio Geological Survey. “Geologic Map of Ohio”. Slucher and others. Ohio Department of Natural Resources, Geo logic Records Center, Division of Geological Survey.

4. Google Earth, 2015.

5. “ The Geochemistry of Mercury in Sedimentary Rocks and Soils in Pennsylvania ”. McNeal, James

M. and Rose, Arthur W. Geochimica et. Coamochimica. Acta. Issue 12

, Vol. 38

, pp.1759 T o 1784

. December 1974. Perg am on Press

.- 11

-

Appendix 1. Geologic Time Chart