Chapter 16: “Appalachian Sedimentary Cycles During the Pennsylvanian: Changing Influences of Sea Level, Climate, and Tectonics

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Chapter 16: “Appalachian sedimentary cycles during the Pennsylvanian: Changing influences of sea level, climate, and tectonics” (Greb et al.), in Fielding, C.R., Frank, T.D., and Isbell, J.L., eds., Resolving the Late Paleozoic Ice Age in Time and Space: Geological Society of America Special Paper 441.

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The Geological Society of America Special Paper 441 2008

Appalachian sedimentary cycles during the Pennsylvanian: Changing inﬂ uences of sea level, climate, and tectonics

Stephen F. Greb Kentucky Geological Survey, University of Kentucky, Lexington, Kentucky 40506, USA

Jack C. Pashin Geologic Survey of Alabama, Alabama State Oil and Gas Board, Tuscaloosa, Alabama 35486, USA

Ronald L. Martino Department of Geology, Marshall University, Huntington, West Virginia 25755, USA

Cortland F. Eble Kentucky Geological Survey, 228 MMRB, University of Kentucky, Lexington, Kentucky 40506, USA

ABSTRACT

Various orders of marine fl ooding surface–bounded depositional sequences are recognized in coal-bearing, Pennsylvanian-age strata of the greater Appa- lachian Basin. The best preserved of these from the Lower Pennsylvanian are in the southern and central Appalachians; Middle Pennsylvanian cyclothemic sequences are best preserved in the central Appalachians; and Upper Pennsylvanian cyclothemic sequences are best preserved in the northern Appalachians. Palynological and lithostrati graphic correlations to global time scales have been used to infer eustatic controls on accumulation of cyclothem-scale sequences in each of these areas, albeit with signifi cant tectonic and climatic overprints. New U-Pb absolute age dates from upper Lower Pennsylvanian and Middle Pennsylvanian tonsteins in the central basin can be used to infer an average maximum duration of 0.1 m.y. for minor transgressive-regressive depositional cycles, which supports the possibility of short eccentricity-driven eustatic infl uences on sedimentation. Although glacial eustasy infl uenced Pennsylvanian sedimentation throughout the basin, the thickness, lateral continuity, and constituent facies of high-frequency depositional cycles were strongly infl uenced by changing rates of tectonic accommodation in at least three depocenters, sediment fl ux, and changing paleoclimate.

Keywords: Carboniferous, cyclothem, sequence, coal, eustasy.

Greb, S.F., Pashin, J.C., Martino, R.L., and Eble, C.F., 2008, Appalachian sedimentary cycles during the Pennsylvanian: Changing inﬂ uences of sea level, climate, and tectonics, in Fielding, C.R., Frank, T.D., and Isbell, J.L., eds., Resolving the Late Paleozoic Ice Age in Time and Space: Geological Society of America Special Paper 441, p. 235–248, doi: 10.1130/2008.2441(16). For permission to copy, contact [email protected]. ©2008 The Geological Society of America. All rights reserved.

235 236 Greb et al.

INTRODUCTION

The Appalachian Basin is one of the largest coal-producing regions in the world, with annual production of more than 390 million short tons. The vast coal resources and long history of mining have made this region a major focus of Carboniferous studies. One area of research that has received considerable attention through the years is the cyclothem concept and the idea that repetitive sedimentation patterns in the Appalachian Basin resulted from Gondwanan glaciation (e.g., Wanless and Shepard, 1936). Several orders of cycles have been reported in different parts of the basin (Busch and Rollins, 1984; Donaldson and Eble, 1991; Chesnut, 1992, 1994), and these have variously been interpreted as resulting from glacial eustasy (e.g., Busch and Rollins, 1984), delta-lobe switching (e.g., Ferm, 1974), climatic changes (e.g., Cecil et al., 1985), and tectonic controls (e.g., Klein and Willard, 1989). In more recent years, sequence and genetic stratigraphic techniques have been used to defi ne and subdivide depositional successions into lowstand, highstand, and transgressive sequences similar in scale to the allocycles of earlier workers (Aitken and Flint, 1994, 1995; Chesnut, 1994; Gastaldo et al., 1993; Martino, 1996; Pashin, 1998; Greb et al., 2004; Martino, 2004). The mechanism responsible for formation of these minor, cyclothem-scale depositional sequences, either in response to high-magnitude sea-level changes in the Milankovitch orbital eccentricity band (e.g., Heckel, 1994) or in response to the inter- action of eustasy and rapid tectonic accommodation (e.g., Pashin, 2004), may have depended on the age and position of the strata relative to basin depocenters. Widespread, fl ooding surface–bounded depositional units were best developed at different times across the Appalachian trend. Examples of Pennsylvanian strata from the Appalachians are described and compared in order to examine the relative infl u- ence of glacial eustasy, climate, and tectonics on sedimentation in different parts of the basin at different times in the Pennsyl- vanian. Estimates of cyclothem-scale duration based on new age dates in the central Appalachian Basin fall within the fi fth-order short eccentricity range, supporting glacial-eustatic infl uences analogous to those that have been active for the past two million years for some of these sequences.

Tectonics and Depocenters

The Appalachian foreland basin developed in response to thrust and sediment loading on the convergent margin of the Laurentian craton during the Acadian, Taconic, and Alleghanian-Variscan orogenies (Thomas, 1976, 1995; Tankard , 1986; Chesnut, 1991). Discrete depocenters developed along Figure 1. Isopach map (A) of Pennsylvanian strata in the greater Appa- lachian Basin (modifi ed from Wanless, 1975) and (B) generalized the Appalachian trend (Fig. 1A) cratonward of promontories cross sections across the basin (A–A′ modifi ed from Wanless, 1975; on the continental margin in the middle to late Mississippian B–B′ and C–C′ modifi ed from Chesnut, 1992; D–D′ and E–E′ from (Thomas, 1976, 1995; Quinlan and Beaumont, 1984). The Edmunds et al., 1999, and Wanless, 1975). greatest preserved thickness of Pennsylvanian strata, more than 2438 m (8000 ft), accumulated in the Cahaba coalfi eld of the greater Black Warrior Basin (Figs. 1A and 1B) in response to Appalachian sedimentary cycles during the Pennsylvanian 237

converging thrust and sediment loads in the Alabama recess Torispora secures–Vestispora fenestrate (SF) microfl oral zone of (Pashin et al., 1995; Pashin, 1997). Discrete coalfi elds in the Peppers (1996), and a 310–311 Ma age corresponds relatively greater Black Warrior Basin are in large synclinoria separated by well with the stratigraphic position of the coal based on palyno- thin-skinned folds and thrust faults. Although the Black Warrior morphs in recent time scales (Fig. 2). Recent U-Pb analyses Basin is largely a Ouachita foreland basin (e.g., Thomas, 1976, of zircons from the tonstein have yielded a slightly older date, 1995), a signifi cant fl exural depocenter formed adjacent to 314.6 ± 0.9 Ma (Lyons et al., 2006). The older age for the the Appalachian orogen during the early Pennsylvanian (e.g., same bed may indicate a discrepancy between dating methods Pashin, 1994a, 2004), and the coalfi elds of the greater Black that needs to be investigated. A 314 Ma age would make the Warrior Basin are typically considered to be Appalachian by the coal Langsettian, which is older than would be inferred from mining industry and in coal resource studies. palynomorphs (Fig. 2). The other bed that has been dated is the In the central Appalachian basin, more than 1000 m (4000 ft) Upper Banner coal, Norton Formation, of Virginia (Fig. 2). of Pennsylvanian strata are preserved in southeastern Kentucky The Upper Banner is in the Schulzospora rara –Laevigatosporites and southwestern Virginia (Figs. 1A and 1B). The central area desmoinensis (SR) microfl oral zone of Peppers (1996). U-Pb extends northward to the northern margin of the Rome Trough, analyses indicates a 316.1 ± 0.8 Ma date (Lyons et al., 1997; which is a late Proterozoic–Early Cambrian graben that formed Outerbridge and Lyons, 2006), which is toward the base of the during Iapetan rifting. The northern margin of the Rome Trough Langsettian and close to or older than ages that would be based acted as a hinge line throughout much of the Pennsylvanian, and on palynofl ora depending on the time scale used (Fig. 2). Pennsylvanian strata thicken southward into the central Appa- lachian depocenter (Donaldson et al., 1985; Donaldson and Eble, APPALACHIAN BASIN SEDIMENTARY SEQUENCES 1991; Greb and Chesnut, 1996; Greb et al., 2002a, 2004). In the northern Appalachian Basin, 1300–1500 m (4400– Lower Pennsylvanian Sedimentary Cycles 4800 ft) of Pennsylvanian strata are preserved in the southern anthracite fi eld of eastern Pennsylvania (Figs. 1A and 1B). What Lower Pennsylvanian coals are thickest and most wide- remains of this depocenter is intensely deformed, and it is sepa- spread in the Black Warrior Basin (southern Appalachian Basin) rated by a broad anticlinorium from the main bituminous coalfi elds and the southwest Virginia coalfi eld of the central Appalachian of western Pennsylvania (Edmunds, 1999; Edmunds et al., 1999). Basin. The best-developed cyclothem-scale packages are in the Pennsylvanian strata are thinner in the bituminous coalfi elds to the Black Warrior Basin, where marine fl ooding surfaces and con- west, but they contain several extensive thick coals, including the densed sections above major coal zones facilitate regional corre- Pittsburgh Coal, which contains the basin’s largest resource and is lation. Similar-scale units exist in the Lower Pennsylvanian of the the second most productive seam in the United States. central Appalachian Basin, but, thick, conglomeratic, quartzose fl uvial sandstones and paleovalley fi lls truncate the coal-bearing Stratigraphy and Age Determinations section in updip areas (Fig. 1B; Miller, 1974; Nolde, 1994; Greb and Chesnut, 1996). Northward into Ohio and Pennsyl- There are at least 24 coalfi elds along the Appalachian trend; vania, large parts of the Lower Pennsylvanian section are absent some represent depocenters or structural basins, whereas others (Figs. 1B and 2); some areas are dominated by conglomeratic are defi ned on the basis of formation boundaries, coal rank, or sandstones (Fig. 1B), there are fewer coal beds, and widespread political (state) boundaries. Each of the coalfi elds has its own marine facies are lacking (Rice et al., 1994b; Slucher and Rice, stratigraphic nomenclature, and some examples are shown 1994; Eble, 1994; Edmunds et al., 1999). in Figure 2. In general, the shared nomenclature and similar The unusually thick Langsettian section in the Black War- formation boundaries of the Upper Pennsylvanian and parts rior Basin affords a high degree of stratigraphic resolution that of the Middle Pennsylvanian in Figure 2 represent areas of is helpful for deciphering the nature and controls on deposi- broadly correlative strata, whereas the variation in Lower tional cyclicity during the early Pennsylvanian (Figs. 3 and 4; Pennsyl vanian nomenclature and formation boundaries rep- Pashin et al., 1991; Liu and Gastaldo, 1992; Gastaldo et al., resents thickness and lithostratigraphic variability in different 1993; Pashin, 1994a, 1994b, 1998, 2004). Detailed correlation parts of the basin (Fig. 1B). Correlations between coalfi elds are of well logs in the southeastern part of the Black Warrior Basin based on lithostratigraphy but constrained by palynology and indicates that each major depositional cycle from the Mary Lee megafl ora (Fig. 2; Read and Mamay, 1964; Phillips et al., 1974, coal zone through the Gwin coal zone contains four subordi- 1985; Blake et al., 2002; Eble, 2003). nate intervals bounded by fl ooding surfaces or the tops of major There are two beds with absolute age dates from the coal beds (Fig. 5, 6; Pashin and Raymond, 2004). Pashin (2004) basin. Sanidines from a tonstein in the Fire Clay coal of east- considered fl ooding surface–bounded depositional units to be ern Kentucky (middle Hyden Formation in Fig. 2) and West parasequences (sensu Van Wagoner et al., 1988) and genetic Virginia have been dated at 310 ± 0.8 Ma (Rice et al., 1994a), stratigraphic sequences sensu Galloway (1989) (Figs. 3–6). 311 ± 1 Ma (Hess and Lippolt, 1986), and 312 ± 1 Ma (Lyons Fourth-order Pottsville cycles (Fig. 3) are typically less than et al., 1992) using 40Ar/39Ar techniques. The coal is in the 200 m (6500 ft) thick, and subordinate, fi fth-order cycles are 238 Greb et al.

Figure 2. Correlations of Pennsylvanian series and epochs based on recent time scales compared to selected stratigraphy from the greater Appa- lachian Basin (state nomenclature modifi ed from Patchen et al., 1984a, 1984b; Kentucky—Chesnut, 1992; Virginia—Nolde, 1994; Pennsylvania— Edmunds et al., 1999). Note that Harland et al. (1990) had the Moscovian boundary much lower than the Duckmantian, so that on this correlation chart, the ages appear out of succession. North American megafl oral zones are from Read and Mamay (1964), Eastern North American microfl oral zones are from Peppers (1996), Western European microfl oral zones are from Clayton et al. (1977), and correlations between zones are based on Eble (2003). The Torispora secures–Vestispora fenestrate (SF) Microfl oral zone is shown in its position for the Illinois Basin, but it may be younger in the Appalachian Basin. The Dunkard Group may be partly Lower Permian. Correlations to recent international time scales are shown to illustrate changes in ages correlated to Pennsylvanian series and stages, which infl uence estimates of depositional cycle duration. In the stratigraphic columns, units are formation names unless otherwise stated. Al.—Allegheny, Ck.—Creek, Gp.—Group, Mt.—Mountain, Ss—Sandstone.

10–100 m thick. Fourth-order cycles generally include a marine ville, the quartzose sandstone units are typically developed shale unit that coarsens upward into sandstone, which is capped basin ward of a thick deltaic succession (Fig. 4). The base of the by a lithologically heterogeneous coal zone (Pashin et al., 1991). quartzose sandstone has been interpreted as a lowstand surface At the base of the thick marine shale, Liu and Gastaldo (1992) of erosion, and the main body of the sandstone has been inter- recognized a transgressive ravinement surface that serves as a preted as an early transgressive deposit (Pashin, 1994b, 1998). cycle boundary (Fig. 4). Above the ravinement is a thin (<1 m) The upper part of each cycle contains a heterogeneous coal condensed section containing a marine fossil assemblage that zone containing a spectrum of fl uvial and deltaic environments. is overlain by a thick, progradational shale-sandstone interval, Fluvial and interfl uvial deposits, including texturally and compo- which has been interpreted to represent deltaic progradation at sitionally immature litharenite, predominate in the southeastern highstand (Gastaldo et al., 1993; Pashin, 1994b, 1998). Above part of the basin, whereas marginal-marine deposits suggestive the progradational package in many depositional cycles, there is of destructive, tide-dominated deltaic systems are common in the a quartzose sandstone unit that locally forms hydrocarbon res- northwestern part. Tidal facies are most common in the upper ervoirs and has been interpreted as an aggradational package parts of the coal zones, suggesting that most coal zones are part deposited in a range of depositional environments, including of a transgressive systems tract (Pashin, 1998, 2004). At the top tidal sandbanks and beaches (e.g., Hobday, 1974; Pashin, 1994b, of the coal zone, another ravinement surface and condensed sec- 1998; Demko and Gastaldo, 1996). In the upper part of the Potts- tion mark the start of another depositional cycle (Figs. 4–6). Figure 3. Measured section and geophysical well log showing fl ooding surface (FS)–bounded depositional units in the upper Pottsville Formation, Black Warrior Basin, Alabama (after Pashin and Raymond, 2004). Gr—Gamma ray. Figure 4. Idealized depositional model of a major (fourth-order) sequence in the Pottsville Formation of the Black Warrior Basin (southern Appalachians) showing generalized facies and sequence-stratigraphic interpretations (after Pashin, 1994b).

Figure 5. Generalized stratigraphic cross section of the Pottsville Formation in the Black Warrior Basin of Alabama showing major depositional cycles and facies patterns (after Pashin, 1994b). Appalachian sedimentary cycles during the Pennsylvanian 241

Figure 6. Idealized stratigraphic model of a major (fourth-order) sequence containing four subordinate (ﬁ fth-order) sequences in the upper Pottsville Formation of the eastern Black Warrior Basin (after Pashin and Raymond, 2004).

Middle Pennsylvanian Sedimentary Cycles Warrior Basin, but Middle Pennsylvanian fl uvial sandstones are usually micaceous rather than quartzose. These lowstand sur- Middle Pennsylvanian coal beds are best preserved in the faces would defi ne sequence boundaries if Vail-type sequences central Appalachian Basin in the eastern Kentucky, southern were used for analyses (sensu Van Wagoner et al., 1988). West Virginia, and part of the southwest Virginia coalfi elds Each genetic sequence contains fi ve to six minor (fi fth- (Figs. 1B and 2). Here, the base of the Middle Pennsylvanian order) transgressive-regressive intervals (coal-clastic cycles of (Duckmantian, Atokan) is the base of the Betsie Shale (Fig. 2; Chesnut, 1992). These cyclothem-scale sequences are less than Pikeville and Kanawha Formations), which is a thick (10–50 m) 30 m (100 ft) thick, generally 9 to 15 m (30 to 50 ft) thick. Most coarsening-upward marine unit (Rice et al., 1987; Chesnut, 1991, cycles consist of a brackish to marine shale (Chesnut, 1991) that 1992; Blake et al., 1994). A succession of similar-scale marine coarsens upward into either a sandstone capped by an under- units allows the Middle Pennsylvanian of the central Appalachian clay (poorly developed paleosol) and a relatively widespread Basin to be divided into three major fl ooding surface–bounded coal bed, or a fl uvial sandstone overlain by an underclay depositional units (Greb et al., 2004), which can be defi ned as and coal bed (Chesnut, 1992, 1994). Facies descriptions typi- genetic stratigraphic sequences (sensu Galloway, 1989) as shown cal of these cycles are discussed in Ferm and Horne (1979), in Figure 7. Major cycles are less than 335 m (1110 ft) thick; they Donaldson et al. (1985), Chesnut (1992, 1994), Aitken and Flint are generally 45–60 m (150–200 ft) thick across much of the cen- (1994, 1995), and Martino (1996). Overall, facies are similar to tral basin and thin toward the basin margin (Fig. 8). those described for the Lower Pennsylvanian in the Black War- The marine shale members used to divide the Middle rior Basin (Fig. 6), but they have a lower percentage of marine Pennsylvanian into genetic sequences are similar to the facies. Updip thinning and truncation by overlying fl uvial facies Lower Pennsylvanian marine shales of the southern Appa- are common, especially toward the basin margin (Fig. 8). Local lachians, but signifi cantly thinner. The base of each is a major variations in cycle thickness have been attributed to lateral facies marine fl ooding surface (Chesnut, 1992; Blake et al., 1994; changes (e.g., syndepositional channeling), differential compac- Martino, 1994, 1996; Aitken and Flint, 1994, 1995). The shales tion, and syndepositional faulting (Ferm and Horne, 1979; Greb coarsen upward into progradational facies. Scours at the bases of et al., 2002a, 2004). Some coals are interpreted to have accu- fl uvial sandstones or gleyed underclays at the top of coarsening- mulated as ombrogenous or domed peats, analogous to modern upward facies have been interpreted as lowstand surfaces (Aitken Sumatran peats, in tropical everwet climates (Cecil et al., 1985; and Flint, 1994, 1995; Martino, 1994, 1996), similar to the Black Eble and Grady, 1990, 1993; Greb et al., 2002b). 242 Greb et al.

Upper Pennsylvanian Sedimentary Cycles

Upper Pennsylvanian strata are mostly restricted to the northern Appalachian Basin (Figs. 1B and 2). The base of the Upper Pennsylvanian is placed between the Mahoning and Brush Creek Coals of the Glenshaw Formation based on palynomorphs. This position is marked by the extinction of nearly all arborescent lyco- pods between megafl oral zones 10 and 11 of Read and Mamay (1964), and between the Lycospora granulata–Granasporites medius (GM) and Punctatisporites minutus–Punctatisporites obliquus (MO) microfl oral zones of Peppers (1996) (Fig. 2; Phillips et al., 1974, 1985; Peppers, 1996). In general, it is easier to correlate Upper Pennsylvanian strata than older Pennsylvanian strata (Fig. 2). Repetitive, cyclothem-scale sequences are well developed in the Glenshaw Formation. Eleven cyclothems (allocyclic, transgressive-regressive units) were described by Busch and Rollins (1984); nine were identifi ed by Martino (2004) (Fig. 9). Typical depositional cycles are 5–30 m thick. Typical facies have been described in Ferm and Horne (1979), Busch and Rollins (1984), Donaldson et al. (1985), and Martino (2004). Busch and Rollins (1984) used transgressive surfaces as allocycle boundaries and included the basal contact of marine units as well as correlative horizons within terrestrial sequences termed “climate change surfaces.” These were defi ned as con- tacts between continental strata formed under arid subaerial conditions (e.g., aridosols, vertisols), and overlying coal and lacustrine limestone formed under more humid conditions. Red and green, pedogenically modifi ed mud rocks are common at the base of Glenshaw sequences (Fig. 9). Aridosols are more frequent than vertisols, and pedogenic and lacustrine micritic limestones are common. The top of extensive paleosols and the base of incised valley fi lls (IVF1 and IVF 2 in Fig. 10) represent lowstand surfaces and Vail-type sequence boundaries (sensu Van Wagoner et al., 1988). In Glenshaw cycles, some paleosols are overlain by coals and lacustrine limestones interpreted to have accumulated as part of transgressive systems tracts (TST in Fig. 10; Martino, 2004). These coals have different quality, thickness, and palynological characteristics than older coals in the basin (Cecil et al., 1985; Cecil, 1990) and are interpreted to have been deposited in planar, topogenous, rather than domed, ombrogenous mires (Eble, 2003). Glenshaw coals tend to be thin, but the Upper Pennsylvanian Pittsburgh coal bed (base of the Monongahela Formation or Group, Fig. 2) is regionally thick, and it is one of the most laterally extensive coal beds in the United States (Greb et al., 2003). Marine gray shale facies in the Glenshaw are similar to their Middle and Lower Pennsylvanian counterparts, but the Glenshaw Figure 7. Composite measured section showing major fl ooding surface also contains several widespread marine carbonates with open- (FS)–bounded depositional units in part of the Middle Pennsylvanian marine fauna (Fig. 9). Several of these carbonates have been Breathitt Group, central Appalachian Basin, eastern Kentucky (after correlated westward into the Illinois Basin and Midcontinent on Greb et al., 2002a). Individual sections are reference sections for the Pikeville, Hyden, Four Corners, and Princess Formations (see Fig. 2). the basis of stratigraphic position constrained by biostratigraphy Minor fl ooding surfaces overlie many of the coal beds and can be used (Busch and Rollins, 1984; Heckel, 1994, 1995). The common to defi ne minor depositional sequences as shown in Figure 11. occurrence of Spirorbis within “nonmarine” limestones that cap Appalachian sedimentary cycles during the Pennsylvanian 243

Figure 8. Generalized stratigraphic cross section of part of the Middle Pennsylvanian Breathitt Group in eastern Ken- tucky, showing fourth-order ﬂ ooding surface–bounded depositional sequences, major marine members, and marginward thinning and amalgamation of major and subordinate (ﬁ fth-order) depositional cycles (after Greb et al., 2002a).

paleosols suggests at least intermittent connection of lakes with the sea during sea-level highstands (Cassle et al., 2006; Martino et al., 2006). Glenshaw limestones are capped by shales, silt- stones, and sandstones deposited in a wide array of prograding deltaic and alluvial facies in highstand systems tracts (HST in Fig. 10; Martino, 2004). Evidence of tidal facies is signiﬁ cantly less than in the Middle and Lower Pennsylvanian to the south. Likewise, a wide variety of marine ichnogenera (e.g., Olivellites, Conostichus, Asterosoma) that are common in marine and tidal sands and shales in the Lower and Middle Pennsylvanian are absent in the Glenshaw (Martino, 2004).

DISCUSSION

A comparison of the cyclothem-scale depositional sequences in the greater Appalachian Basin shows that the effects of differing mechanisms on sedimentation varied in time. A hierarchy of depositional units in several parts of the basin has been used to infer cycles of different origin, such as tectonic and eustatic, or different Milankovitch order (Donaldson and Eble, 1991; Chesnut, 1992, 1994; Maynard and Leeder, 1992; Pashin, 1994a, 2004). Likewise, several reports have correlated parts of the Pennsylvanian section to international time scales to infer cycle durations of ~0.4 m.y., similar to the long eccentricity cycle (Busch and Rollins, 1984; Chesnut, 1994; Pashin, 2004). Pashin and Raymond (2004) suggested that a hierarchi- cal stacking of long and short eccentricity cycles was at times effective (Fig. 6). The variability in recent Pennsylvanian time scales (see Fig. 2) has a signifi cant impact on estimates of past cycle duration, although most estimates of minor transgressive- regressive allocycles fall within the range of Milankovitch eccentricity parameters. Figure 9. Composite section of the upper Middle and Upper Pennsyl- The new U-Pb dates for the Fire Clay (314.6 ± 0.09 Ma) vanian Glenshaw Formation, from outcrops along the Kentucky–West and the Upper Banner (316.1 ± 0.8 Ma) coals of the central Virginia border in the northern Appalachian Basin, showing fourth- basin (e.g., Outerbridge and Lyons, 2006) allow for estimates order sequences (numbered) delineated by Martino (2004). The tops of widespread, mature paleosols are interpreted as fl ooding surfaces, to be made independent of correlations to changing time scales which coincide with interfl uvial sequence boundaries. For associated and biozones. There are 15 fl ooding surface–bound deposi- incised valley-fi lls, see Figure 12 in Martino (2004). tional cycles between the two coal beds in Kentucky (based on 244 Greb et al.

Figure 10. Idealized depositional model of a fourth-order sequence in the Glenshaw Formation of the northern Appalachian Basin showing generalized facies and sequence-stratigraphic interpretations (HST—highstand system tract; IV—incised valley; LST—lowstand system tract, mfs—maximum ﬂ ooding surface; SB—sequence boundary; TST—transgressive system tract). Incised valleys and sequence boundaries are numbered 1 and 2 to show sequence succession.

Chesnut’s 1991 identifi cation of marine zones), representing 1.5 m.y. (Fig. 11). Therefore, mean cycle duration is at least 0.1 m.y., which is equivalent to the short eccentricity cycle. It is the fi fth-order, short eccentricity cycle that was the dominant climatic signal during the Pleistocene glaciation (Imbrie, 1985). This average estimate should be treated cautiously, however, because the durations of individual depositional cycles likely varied similar to the durations of depositional cycles in the last two million years (0.8–1.3 m.y.). Also, changing rates of foreland basin subsidence may have infl uenced cycle duration. In the Lower Pennsylvanian of the Black Warrior Basin (southern Appalachians), for example, Pashin (2004) deter- mined that estimated average depositional cycle durations (based on correlations to the time scale of Harland et al., 1990) from the base of the Pottsville through the Black Creek coal zone decrease from 1.2 to 0.8 m.y. when adjusted for subsidence. Those results indicate that similar-scale depositional cycles, containing similar facies, might refl ect different forcing mechanisms at different times. Aside from estimates of high-frequency cyclicity approxi- mating Milankovitch periodicities, numerous authors have suggested that the basinwide extent of the depositional cycles and their interbasinal correlation are crucial for differentiating global glacial-eustatic from regional tectonic controls (e.g., Dickinson et al., 1994). In the Appalachian Basin, the most Figure 11. Depositional cycles between the Upper Banner and Fire widely correlated units are those of the upper Middle and Upper Clay coal beds in the central Appalachian Basin, showing recent radiometric dates from Outerbridge and Lyons (2006) and Lyons Pennsyl vanian. Glenshaw allocycles are most complete along et al. (1997, 2006). Not all cycles are preserved in all areas. paleo-interfl uves (Martino, 2004). Many have been correlated to coalfi elds in the northern basin, and westward into the Illinois Basin and Midcontinent (Heckel, 1994, 1995). Extrabasinal on the continental shelf and relief along the surface of onlap correlations are based on lithostratigraphy broadly constrained that exceeded the amount of sea-level change (Heckel et al., by palynology of coal beds (Peppers, 1996; Eble, 2003) and 1998). Nadon and Kelly (2004), however, noted that along the conodonts in marine carbonates (e.g., Heckel, 1995). Differ- margin of the northern Appalachian Basin, fl uvial dissection ences in facies and preservation of shorter-term cycles between of sequences during multiple lowstands created intersecting the Midcontinent and Appalachian Basin are interpreted to sequence boundaries across a wide range of scales, but well have been caused by the position of the Appalachian Basin high within the available biostratigraphic resolution. Appalachian sedimentary cycles during the Pennsylvanian 245

Correlations of older Pennsylvanian sequences between (10–100 m) scale of sedimentation varies considerably across the depocenters (Fig. 2) and other basins are more diffi cult. A com- basin, and lateral and vertical facies variability is also common. parison of regional cross sections (Fig. 1B) shows that tectonic Tectonic subsidence in three depocenters strongly infl uenced accommodation was greatest in the Lower Pennsylvanian in each the preservation and sedimentologic expression of Lower and of the depocenters and much greater in the southern depocenter Middle Pennsylvanian depositional cycles, resulting in thinning, than the central and northern depocenter. The greater thickness amalgamation, and truncation of sedimentary cycles on basin and abundance of Lower Pennsylvanian depositional cycles in margins and between depocenters. New estimates of fi fth-order, Alabama than in the central and northern parts of the Appa- fl ooding surface–bounded depositional cycles constrained by lachian Basin are likely due to greater tectonic accommodation two absolute age dates in the central Appalachian Basin suggest of the southern depocenter in the Lower Pennsylvanian, as well deposition in the short-order (0.1 m.y.) eccentricity range and as the downdip position of the southern depocenter relative to the glacio-eustatic mechanisms for some cycles, although changing rest of the basin. A downdip position accounts for the southern subsidence rates strongly infl uenced preservation of different depocenter’s higher percentage of marine facies relative to the thickness and likely durations of sequences. Changing paleo- central and northern basin. climate particularly infl uenced depositional patterns during the Differential accommodation resulted in updip pinch-outs upper middle and late Pennsylvanian, resulting in cyclothems and merging sequence boundaries along depocenter margins with pedogenically altered red beds, thick paleosols, and lacus- (Figs. 1B, 5, and 8). Also, the overall progradational stacking pat- trine carbonates, rather than the typical coal-clastic cyclothems tern of the Lower Pennsylvanian Pottsville section in Alabama of the early and middle Pennsylvanian to the south. (Pashin et al., 1995), and Middle Pennsylvanian Breathitt section of the central Appalachian Basin (Chesnut, 1994), may have ACKNOWLEDGMENTS been caused by advancing thrust and sediment loads in the Appa- lachian orogen (e.g., Tankard, 1986). The authors thank Bill Outerbridge for discussions on the The Upper Pennsylvanian allocycles that have been cor- new age dates of the Fireclay and Banner coal beds. We also related outside of the basin, and interpreted as representing thank Chris Fielding and Greg Nadon for their helpful reviews. glacio-eustatic infl uences, are restricted to the northern Appa- lachians. These depositional cycles are more widespread and REFERENCES CITED more uniform in thickness and facies in this region than their older counterparts in the northern basin, or in the central and Aitken, J.F., and Flint, S.S., 1994, High-frequency sequences and the nature of incised-valley fi lls in fl uvial systems of the Breathitt Group (Pennsyl- southern parts of the basin. At least one reason for this differ- vanian), Appalachian foreland basin, eastern Kentucky, in Dalrymple, R., ence is that there was much less tectonic subsidence in the later Boyd, R.R., and Zaitlen, B., eds., Incised Valley Systems—Origin and Pennsylvanian of the northern basin than the early Pennsyl- Sedimentary Sequences: Society of Economic Paleontologists and Miner- alogists Special Publication 51, p. 353–368. vanian, and there was less clastic fl ux from the basin margins. Aitken, J.F., and Flint, S.S., 1995, The application of high-resolution sequence Climate change (Cecil et al., 1985; Cecil, 1990), as indicated stratigraphy to fl uvial systems; a case study from the Upper Carbonifer- by changes in fl ora (Peppers, 1996; Phillips et al., 1974, 1985), ous Breathitt Group, eastern Kentucky: Sedimentology, v. 42, p. 3–30, doi: 10.1111/j.1365-3091.1995.tb01268.x. coal characteristics (Eble, 2003), and extensive pedogenesis Blake, B.M., Jr., Keiser, A.F., and Rice, C.L., 1994, Revised stratigraphy and (Donaldson et al., 1985), resulted in widespread paleosols nomenclature for the Middle Pennsylvanian Kanawha Formation in and extensive weathering of the topography. Late Pennsyl- southwestern West Virginia, in Rice, C.L., ed., Elements of Pennsylvanian Stratigraphy, Central Appalachian Basin: Geological Society of America vanian weathering created broad fl at surfaces on which exten- Special Paper 294, p. 41–53. sive marine units could be deposited during transgression, but Blake, B.M., Jr., Cross, A.T., Eble, C.F., Gillespie, W.H., and Pfefferkorn, H.W., also upon which signifi cant erosion and nondeposition of the 2002, Selected plant megafossils from the Carboniferous of the Appala- chian Region, eastern United States—Geographic and stratigraphic distri- sedimentary record took place. Climatic cycles between wetter bution: Alberta, Canada, International Carboniferous Congress, Compte (coals, ultisols) and drier (nonmarine carbonates and vertisols) Rendu, 132 p. climates may also have infl uenced late Pennsylvanian sedimen- Busch, R.M., and Rollins, H.B., 1984, Correlation of Carboniferous strata using a hierarchy of transgressive-regressive units: Geology, v. 12, p. 471–474, tation and contributed to geochemical and pedogenic differ- doi: 10.1130/0091-7613(1984)12<471:COCSUA>2.0.CO;2. ences in constituent facies of depositional cycles as compared Cassle, C.F., Gierlowski-Kordesch, E., and Martino, R.L., 2006, Spirorbis to the early and middle Pennsylvanian (Busch and Rollins, as an indicator of marine infl uence in Pennsylvanian cyclothems [abs.]: Geological Society of America Abstracts with Programs, v. 38, 1984; Cecil et al., 1985, 2004; Cecil, 1990). no. 4, p. 5. Cecil, C.B., 1990, Paleoclimate controls on stratigraphic repetition of chemical CONCLUSIONS and siliciclastic rocks: Geology, v. 18, p. 533–536, doi: 10.1130/0091-76 13(1990)018<0533:PCOSRO>2.3.CO;2. Cecil, C.B., Stanton, R.W., Neuzil, S.G., Dulong, F.T., Ruppert, C.F., and Pierce, The repetitive sedimentation style of the Pennsylvanian B.S., 1985, Paleoclimate controls on late Paleozoic sedimentation and peat has long been attributed to glacial eustasy, although the classic formation in the central Appalachian Basin (U.S.A.): International Journal of Coal Geology, v. 5, p. 195–230, doi: 10.1016/0166-5162(85)90014-X. Appalachian-type cyclothem is only typical of the Upper Penn- Cecil, C.B., Dulong, F.T., Edgar, N.T., and Ahlbrandt, T.S., 2004, Carbonifer- sylvanian in the northern Appalachian Basin. The cyclothem ous paleoclimates, sedimentation, and stratigraphy, in Cecil, C.B., and 246 Greb et al.

Edgar, N.T., eds., Predictive Stratigraphic Analysis—Concept and Appli- example from the Black Warrior Basin, USA: Geologische Rundschau, cation: U.S. Geological Survey Bulletin 2110, p. 27–28. v. 82, p. 212–226, doi: 10.1007/BF00191827. Chesnut, D.R., Jr., 1991, Paleontological Survey of the Pennsylvanian Rocks of Gradstein, F.M., Ogg, J.G., and Smith, A.G., 2004, A Geologic Time Scale, 2004: the Eastern Kentucky Coal Field: Kentucky Geological Survey, Series 11, Cambridge, Cambridge University Press, 509 p., www.stratigraphy.org. Information Circular 36, 71 p. Greb, S.F., and Chesnut, D.R., Jr., 1996, Lower and lower middle Pennsyl- Chesnut, D.R., Jr., 1992, Stratigraphic and Structural Framework of the Car- vanian fl uvial to estuarine deposition, central Appalachian Basin— boniferous Rocks of the Central Appalachian Basin: Kentucky Geological Effects of eustasy, tectonics, and climate: Geological Society of Survey, Series 11, Bulletin 3, 42 p. America Bulletin, v. 108, p. 303–317, doi: 10.1130/0016-7606(1996)108 Chesnut, D.R., Jr., 1994, Eustatic and tectonic control of deposition of the <0303:LALMPF>2.3.CO;2. Lower and Middle Pennsylvanian strata of the central Appalachian Basin, Greb, S.F., Eble, C.F., and Chesnut, D.R., Jr., 2002a, Comparison of the in Dennison, J.M., and Ettensohn, F.R., eds., Tectonic and Eustatic Con- Eastern and Western Kentucky coal fi elds, U.S.A.—Why are coal dis- trols on Sedimentary Cycles: Society for Sedimentary Geology, Concepts tribution patterns and sulfur contents so different in these coal fi elds?: in Sedimentology and Paleontology, no. 4, p. 51–64. International Journal of Coal Geology, v. 50, p. 89–118, doi: 10.1016/ Clayton, G., Coquel, R., Doubinger, J., Guehn, K.J., Loboziak, S., Owens, S0166-5162(02)00115-5. B., and Streel, M., 1977, Carboniferous miospores of western Europe: Greb, S.F., Eble, C.F., Hower, J.C., and Andrews, W.M., 2002b, Multiple-bench Illustration and zonation: Rijks Geologische Dienst, Mededelingen, v. 29, architecture and interpretations of original mire phases in middle Penn- p. 1–71. sylvanian coal seams—Examples from the Eastern Kentucky coal fi eld: Demko, T.M., and Gastaldo, R.A., 1996, Eustatic and allocyclic infl uences International Journal of Coal Geology, v. 49, p. 147–175, doi: 10.1016/ on deposition of the Lower Pennsylvanian Mary Lee coal zone, Warrior S0166-5162(01)00075-1. Basin, Alabama: International Journal of Coal Geology, v. 31, p. 3–19, Greb, S.F., Andrews, W.M., Eble, C.F., DiMichele, W., Cecil, C.B., and Hower, doi: 10.1016/S0166-5162(96)00009-2. J.C., 2003, Desmoinesian coal beds of the Eastern Interior and surround- Dickinson, W.R., Soreghan, G.S., and Giles, K.A., 1994, Glacio-eustatic origin ing basins: The largest tropical peat mires in Earth history, in Chan, of Permo-Carboniferous stratigraphic cycles: Evidence from the southern M.A., and Archer, A.W., eds., Extreme Depositional Environments: Mega Cordilleran foreland region, in Dennison, J.M., and Ettensohn, F.R., eds., End Members in Geologic Time: Geological Society of America Special Tectonic and Eustatic Controls on Sedimentary Cycles: Society for Sedi- Paper 370, p. 127–150. mentary Geology, Concepts in Sedimentology and Paleontology, no. 4, Greb, S.F., Chesnut, D.R., Jr., and Eble, C.F., 2004, Temporal changes in coal- p. 25–34. bearing depositional sequences (Lower and Middle Pennsylvanian) of the Donaldson, A.C., and Eble, C.F., 1991, Pennsylvanian coals of central and east- central Appalachian Basin, U.S.A., in Pashin, J.C., and Gastaldo, R.A., ern United States, in Gluskoter, H.G., Rice, D.D., and Taylor, R.B., eds., eds., Coal-Bearing Strata: Sequence Stratigraphy, Paleoclimate, and Tec- Economic Geology, United States: Boulder, Colorado, Geological Soci- tonics of Coal-Bearing Strata: American Association of Petroleum Geolo- ety of America, Geology of North America, v. P-2, p. 523–546. gists, Studies in Geology, v. 51, p. 89–120. Donaldson, A.C., Renton, J.J., and Presley, M.W., 1985, Pennsylvanian depo- Harland, W.B., Armstrong, R.L., Cox, A.V., Craig, L.E., Smith, A.G., and systems and paleoclimates of the Appalachians: International Journal of Smith, D.A., 1990, A Geologic Time Scale 1989: Cambridge, Cambridge Coal Geology, v. 5, p. 167–193, doi: 10.1016/0166-5162(85)90013-8. University Press, 263 p. Eble, C.F., 1994, Palynostratigraphy of selected Middle Pennsylvania coal beds Heckel, P.H., 1994, Evaluation of evidence for glacio-eustatic control over in the Appalachian basin, in Rice, C.L., ed., Elements of Pennsylvanian marine Pennsylvanian cyclothems in North America and consideration Stratigraphy, Central Appalachian Basin: Geological Society of America of possible tectonic effects, in Dennison, J.M., and Ettensohn, F.R., eds., Special Paper 294, p. 55–68. Tectonic and Eustatic Controls on Sedimentary Cycles: Society of Eco- Eble, C.F., 2003, Palynological perspectives of late middle Pennsylvanian coal nomic Paleontologists and Mineralogists (Society of Sedimentary Geol- beds (USA), in Cecil, C.B., and Edgar, T.N., eds., Climate Controls on ogy), Concepts in Sedimentology and Paleontology, no. 4, p. 65–87. Stratigraphy: Society for Sedimentary Geology Special Publication 77, Heckel, P.H., 1995, Glacial-eustatic base-level-climatic model for late middle p. 123–136. to late Pennsylvanian coal-bed formation in the Appalachian Basin: Jour- Eble, C.F., and Grady, W.C., 1990, Paleoecological interpretation of a nal of Sedimentary Research, v. B65, p. 348–356. middle Pennsylvanian coal bed in the central Appalachian Basin, Heckel, P.H., Gibling, M.R., and King, N.R., 1998, Stratigraphic model for U.S.A.: International Journal of Coal Geology, v. 16, p. 255–286, doi: glacial-eustatic Pennsylvanian cyclothems in highstand nearshore detrital 10.1016/0166-5162(90)90054-3. regimes: The Journal of Geology, v. 106, p. 373–383. Eble, C.F., and Grady, W.C., 1993, Palynologic and petrographic characteristics Hess, J.C., and Lippolt, H.J., 1986, 40Ar/39Ar ages of tonstein and tuff sani- of two middle Pennsylvanian coal beds and a probable modern analogue, dines—New calibration points for the improvement of Upper Car- in Cobb, J.C., and Cecil, C.B., eds., Modern and Ancient Coal-Forming boniferous time scale: Chemical Geology, v. 59, p. 143–154, doi: Environments: Geological Society of America Special Paper 286, 10.1016/0009-2541(86)90047-1. p. 119–138. Hobday, D.K., 1974, Beach- and barrier-island facies in the Upper Carbonifer- Edmunds, W.E., 1999, Pennsylvanian-Permian transition and Permian, in ous of northern Alabama, in Briggs, G., ed., Carboniferous of the south- Shultz, C.H., ed., The Geology of Pennsylvania: Pennsylvania Geological eastern United States: Geological Society of America Special Paper 148, Survey Special Publication 1, p. 171–177. p. 209–223. Edmunds, W.E., Skema, V.W., and Flint, N.K., 1999, Pennsylvanian, in Shultz, Imbrie, J., 1985, A theoretical framework for the Pleistocene ice ages: Geologi- C.H., ed., The Geology of Pennsylvania: Pennsylvania Geological Survey cal Society of London Quarterly Journal, v. 142, p. 417–432. Special Publication 1, p. 149–169. Klein, G.D., and Willard, D.A., 1989, Origin of the Pennsylvanian coal-bearing Ferm, J.C., 1974, Carboniferous environmental models in the eastern United cyclothems of North America: Geology, v. 17, p. 152–155, doi: 10.1130/ States and their signifi cance, in Briggs, G., ed., Carboniferous of the 0091-7613(1989)017<0152:OOTPCB>2.3.CO;2. Southeastern United States: Geological Society of America Special Liu, Y., and Gastaldo, R.A., 1992, Characteristics of a Pennsylvanian Paper 148, p. 79–96. ravinement surface: Sedimentary Geology, v. 77, p. 197–213, doi: Ferm, J.C., and Horne, J.C., eds., 1979, Carboniferous Depositional Environ- 10.1016/0037-0738(92)90126-C. ments in the Appalachian Region: Columbia, South Carolina, Department Lyons, P.C., Outerbridge, W.F., Triplehorn, D.M., Evans, H.T., Jr., Congdon, of Geology, University of South Carolina, 760 p. R.D., Capiro, M., Hess, J.C., and Nash, W.P., 1992, An Appalachian Galloway, W.E., 1989, Genetic stratigraphic sequences in basin analysis. isochron—A kaolinized Carboniferous air-fall volcanic-ash deposit I: Architecture and genesis of fl ooding-surface–bounded depositional (tonstein): Geological Society of America Bulletin, v. 104, p. 1515–1527, units: The American Association of Petroleum Geologists Bulletin, v. 73, doi: 10.1130/0016-7606(1992)104<1515:AAIAKC>2.3.CO;2. p. 125–142. Lyons, P.C., Krogh, T., Kwok, Y., and Zodrow, E.L., 1997, U-Pb age of zircon Gastaldo, R.A., Demko, T.M., and Liu, Y., 1993, Application of sequence and crystals from the upper Banner tonstein (Middle Pennsylvanian), Virginia; genetic stratigraphic concepts to Carboniferous coal-bearing strata: An absolute age of the Lower Pennsylvanian–Middle Pennsylvanian bound- Appalachian sedimentary cycles during the Pennsylvanian 247

ary and depositional rates for the Middle Pennsylvanian, central Appa- Tuscaloosa, Alabama Geological Society, 34th Annual Field Trip Guide- lachian Basin: Prace Panstwowego Instytutu Geologicznego, Proceedings book, p. 19–28. XIII International Congress on Carboniferous and Permian, v. 157, part 1, Pashin, J.C., 1998, Stratigraphy and structure of coalbed methane reservoirs in p. 159–166. the United States: An overview: International Journal of Coal Geology, Lyons, P.C., Krogh, T.E., Kwok, Y.Y., Davis, D.W., Outerbridge, W.F., v. 35, p. 209–238, doi: 10.1016/S0166-5162(97)00013-X. and Evans, H.T., Jr., 2006, Radiometric ages of the Fire Clay tonstein Pashin, J.C., 2004, Cyclothems of the Black Warrior Basin, Alabama, U.S.A.: [Pennsylvanian (Upper Carboniferous), Westphalian, Duckmantian]: A Eustatic snapshots of foreland basin tectonism, in Pashin, J.C., and comparison of U-Pb zircon single crystal ages and 40Ar/39Ar sanidine Gastaldo, R.A., eds., Coal-Bearing Strata: Sequence Stratigraphy, Paleo- single-crystal plateau ages: International Journal of Coal Geology, v. 67, climate, and Tectonics of Coal-Bearing Strata: American Association of p. 259–266. Petroleum Geologists, Studies in Geology, v. 51, p. 199–217. Martino, R.L., 1994, Facies analysis of middle Pennsylvanian marine units, Pashin, J.C., and Raymond, D.E., 2004, Glacial-eustatic control of coalbed southern West Virginia, in Rice, C.L., ed., Elements of Pennsylvanian methane reservoir distribution (Pottsville Formation; Lower Pennsyl- Stratigraphy, Central Appalachian Basin: Geological Society of America vanian) in the Black Warrior Basin of Alabama: Tuscaloosa, Alabama, Special Paper 294, p. 69–86. University of Alabama College of Continuing Studies, 2004 International Martino, R.L., 1996, Stratigraphy and depositional environments of the Coalbed Methane Symposium Proceedings, Paper 0413, 15 p. Kanawha Formation (middle Pennsylvanian), southern West Virginia, Pashin, J.C., Ward, W.E., II, Winston, R.B., Chandler, R.V., Bolin, D.E., Richter , U.S.A.: International Journal of Coal Geology, v. 31, p. 217–248, doi: K.E., Osborne, W.E., and Sarnecki, J.C., 1991, Regional analysis of the 10.1016/S0166-5162(96)00018-3. Black Creek–Cobb coalbed-methane target interval, Black Warrior Basin, Martino, R.L., 2004, Sequence stratigraphy of the Glenshaw Formation Alabama: Alabama Geological Survey Bulletin, v. 145, 127 p. (Middle-Late Pennsylvanian) in the central Appalachian Basin, in Pashin, J.C., Carroll, R.E., Barnett, R.L., and Beg, M.A., 1995, Geology and Pashin, J.C., and Gastaldo, R.A., eds., Coal-Bearing Strata: Sequence coal resources of the Cahaba coal fi eld: Alabama Geological Survey Bul- Stratigraphy, Paleoclimate, and Tectonics of Coal-Bearing Strata: letin, v. 163, p. 1–49. American Association of Petroleum Geologists, Studies in Geology, Patchen, D.G., Avary, K.L., and Erwin, R.B., 1984a, Northern Appalachian v. 51, p. 1–28. Basin Correlation Chart: Tulsa, Oklahoma, American Association of Martino, R.L., Gierlowski-Kordesch, E., Blake, B.M., and Eble, C.F., 2006, Petroleum Geologists, Correlation chart series, Correlation of Strati- Stratigraphy and depositional framework of the Twomile Limestone (late graphic Units in North America, sheet 11, 1 sheet. Pennsylvanian) of West Virginia [abs.]: Geological Society of America Patchen, D.G., Avary, K.L., and Erwin, R.B., 1984b, Southern Appalachian Abstracts with Programs, v. 38, no. 4, p. 5. Basin Correlation Chart: Tulsa, Oklahoma, American Association of Maynard, J.R., and Leeder, M.R., 1992, On the periodicity and magnitude Petroleum Geologists, Correlation chart series, Correlation of Strati- of Late Carboniferous glacio-eustatic sea-level changes: Journal of graphic Units in North America, sheet 12, 1 sheet. the Geological Society of London, v. 149, p. 303–311, doi: 10.1144/ Peppers, R.A., 1996, Palynological Correlation of Major Pennsylvanian gsjgs.149.3.0303. (Middle and Upper Carboniferous) Chronostratigraphic Boundaries in Menning, M., Alekseev, A.S., Chuvashov, B.I., Devuyst, F.X., Forke-Holger, C., the Illinois and Other Coal Basins: Geological Society of America Mem- Grunt, T.A., Hance, L., Heckel, P.H., Izokh, N.G., Yin, Y.G., Jones, P.J., oir 188, 108 p. Kotlyar, G.V., Kozur, H.W., Nemyrovska, T.I., Schneider, J.W., Wang, Phillips, T.L., Peppers, R.A., Avcin, M.J., and Laughnan, P.F., 1974, X.D., Weddige, K., Weyer, D., and Work, D.M., 2006, Global time scale Fossil plants and coal: Patterns of change in Pennsylvanian swamps and regional stratigraphic reference scales of central and west Europe, in the Illinois Basin: Science, v. 184, p. 1367–1369, doi: 10.1126/ east Europe, Tethys, south China, and North America as used in the science.184.4144.1367. Devonian-Carboniferous-Permian Correlation Chart 2003 (DCP 2003): Phillips, T.L., Peppers, R.A., and DiMichele, W.A., 1985, Stratigraphic and Palaeogeography, Palaeoclimatology, Palaeoecology, v. 240, p. 318–372, interregional changes in Pennsylvanian coal-swamp vegetation: Environ- doi: 10.1016/j.palaeo.2006.03.058. mental inferences: International Journal of Coal Geology, v. 5, p. 43–109, Miller, M.S., 1974, Stratigraphy and Coal Beds of Upper Mississippian and doi: 10.1016/0166-5162(85)90010-2. Lower Pennsylvanian Rocks in Southwestern Virginia: Virginia Division Quinlan, G.M., and Beaumont, C., 1984, Appalachian thrusting, lithospheric of Mineral Resources Bulletin 84, 211 p. fl exure, and the Paleozoic stratigraphy of the Eastern Interior of North Nadon, G.C., and Kelly, R.R., 2004, The constraints of glacial eustasy America: Canadian Journal of Earth Sciences, v. 21, p. 973–996. and low accommodation on sequence-stratigraphic interpretations of Read, C.C., and Mamay, S.H., 1964, Upper Paleozoic Floral Zones and Floral Pennsylvanian strata, Conemaugh Group, Appalachian Basin, U.S.A., Provinces of the United States: U.S. Geological Survey Professional in Pashin, J.C., and Gastaldo, R., eds., Coal-Bearing Strata: Sequence Paper 454-K, 35 p. Stratigraphy, Paleoclimate, and Tectonics of Coal-Bearing Strata: Rice, C.L., Currens, J.C., Henderson, J.A., Jr., and Nolde, J.E., 1987, The Betsie American Association of Petroleum Geologists, Studies in Geology, Shale Member—A Datum for Exploration and Stratigraphic Analysis of v. 51, p. 29–44. the Lower Part of the Pennsylvanian in the Central Appalachian Basin: Nolde, J.E., 1994, Devonian to Pennsylvanian stratigraphy and coal beds of U.S. Geological Survey Bulletin 1834, 17 p. the Appalachian Plateaus Province, in Nolde, J.E., Whitlock, W.W., Rice, C.L., Belkin, H.E., Henry, T.W., Zartman, R.E., and Kunk, M.J., 1994a, Lovett, J.A., and Henika, W.S., eds., Geology and Mineral Resources of The Pennsylvanian Fire Clay tonstein of the Appalachian Basin—Its dis- the Southwest Virginia Coalfi eld: Virginia Division of Mineral Resources tribution, biostratigraphy, and mineralogy, in Rice, C.L., ed., Elements of Publication 131, p. 1–85. Pennsylvanian Stratigraphy, Central Appalachian Basin: Geological Soci- Outerbridge, W.F., and Lyons, P.C., 2006, An absolute time table for the Lower ety of America Special Paper 294, p. 87–113. to Middle Pennsylvanian Breathitt Group of Kentucky: Geological Soci- Rice, C.L., Kosanke, R.M., and Henry, T.M., 1994b, Revision of nomen- ety of America Abstracts with Programs, v. 38, no. 7, p. 116. clature and correlations of some Middle Pennsylvanian units in the Pashin, J.C., 1994a, Flexurally infl uenced eustatic cycles in the Pottsville northwestern part of the Appalachian Basin, Kentucky, Ohio, and West Formation (Lower Pennsylvanian), Black Warrior Basin, Alabama, in Virginia, in Rice, C.L., ed., Elements of Pennsylvanian Stratigraphy, Dennison, J.M., and Ettensohn, F.R., eds., Tectonic and Eustatic Controls Central Appa lachian Basin: Geological Society of America Special on Sedimentary Cycles: Society for Sedimentary Geology, Concepts in Paper 294, p. 7–27. Sedimentology and Paleontology, no. 4, p. 89–105. Slucher, E.R., and Rice, C.L., 1994, Key rock units and distribution of marine and Pashin, J.C., 1994b, Cycles and stacking patterns in Carboniferous rocks of brackish water strata in the Pottsville Group, northeastern Ohio, in Rice, the Black Warrior foreland basin: Gulf Coast Association Geological C.L., ed., Elements of Pennsylvanian Stratigraphy, Central Appa lachian Societies Transactions, v. 44, p. 555–563. Basin: Geological Society of America Special Paper 294, p. 27–40. Pashin, J.C., 1997, Stratigraphy and depositional environments of the Pottsville Tankard, A.J., 1986, Depositional response to foreland deformation in the Formation (Lower Pennsylvanian) in the Coosa coalfi eld, in Bearce, D.N., Carboniferous of eastern Kentucky: American Association of Petroleum Pashin, J.C., and Osborne, W.E., eds., Geology of the Coosa Coalfi eld: Geologists Bulletin, v. 70, p. 853–868. 248 Greb et al.

Thomas, W.A., 1976, Evolution of the Appalachian-Ouachita continental mar- Van Wagoner, J.C., eds., Sea-Level Changes: An Integrated Approach: gin: The Journal of Geology, v. 84, p. 323–342. Society of Economic Paleontologists and Mineralogists (Society of Sedi- Thomas, W.A., 1995, Diachronous thrust loading and fault partitioning of mentary Geology) Special Publication 42, p. 39–45. the Black Warrior foreland basin within the Alabama recess of the late Wanless, H.R., 1975, The Appalachian region, in McKee, E.D., and Crosby, Paleozoic Appalachian-Ouachita thrust belt: Society of Economic Paleon- E.J., eds., Paleotectonic Investigations of the Pennsylvanian System in the tologists and Mineralogists (Society of Sedimentary Geology) Special United States: U.S. Geological Survey Professional Paper 853-C, 62 p. Publication 52, p. 111–126. Wanless, H.R., and Shepard, F.P., 1936, Sea level and climatic changes related Van Wagoner, J.C., Posamentier, H.W., Mitchum, R.M., Jr., Vail, P.R., Sarg, to late Paleozoic cycles: Geological Society of America Bulletin, v. 47, J.F., Loutit, T.S., and Hardenbol, J., 1988, An overview of the funda- p. 1177–1206. mentals of sequence stratigraphy and key deﬁ nitions, in Wilgus, C.K., Hastings, B.S., Kendall, K.C.G.St.C., Posamentier, H.W., Ross, C.A., and MANUSCRIPT ACCEPTED BY THE SOCIETY 19 NOVEMBER 2007

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