MRCSP Phase I Geologic Characterization Report - Midwest ...

APPENDIX A: UPPER CAMBRIAN ROSE RUN SANDSTONE
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ORIGIN OF NAMES, TYPE SECTION, SIGNIFICANT
EARLIER STUDIES ON THIS INTERVAL
The Rose Run sandstone was first described and named by Freeman
(1949) from the Judy and Young #1 Rose Run Iron Co. well
in Bath County, Kentucky where about 70 feet of poorly sorted
sandstone was encountered approximately 300 feet below the Knox
unconformity. Butts (1918) initially named the Upper Sandy member
of the Gatesburg Formation (Rose Run equivalent) from outcrop
studies in central Pennsylvania. Wagner (1961, 1966a,b,c, 1976)
conducted subsurface studies of Cambrian-Ordovician stratigraphy
of western Pennsylvania and bordering states and attempted to establish
a workable nomenclature for this interval. He adopted the
central Pennsylvania nomenclature of Kay (1944), Wilson (1952),
and others for the majority of rocks in western Pennsylvania. In this
classification scheme, the Gatesburg Formation in western Pennsylvania
is subdivided, in ascending stratigraphic order, into the Lower
Sandy member, the Ore Hill member, and the Upper Sandy member
(see Figure 5).
Janssens (1973), in a detailed stratigraphic study of the Cambrian-Ordovician
rocks in Ohio, extended the use of the term Rose
Run from the subsurface of Kentucky into Ohio, but did not attempt
to name it as a formal unit. He recognized the Copper Ridge, Rose
Run, and Beekmantown as informal units of the Knox Dolomite.
More recently, Riley and others (1993) performed a detailed investigation
of the Rose Run in Ohio and Pennsylvania. They recognized
the Copper Ridge, Rose Run, and Beekmantown as mappable,
correlable units in the subsurface based on cores, cuttings, and
geophysical logs, and suggested that these units be recognized as
formal units in Ohio.
Regional subsurface correlations of the Cambrian-Ordovician
interval across the Appalachian basin have been published that
illustrate the lateral extent of the Rose Run and equivalent units
(Ryder, 1991; 1992a,b; Ryder and others, 1992, 1996). A more detailed
review of nomenclature, and previous work on the Rose Run
and equivalent units, can be found in Riley and others (1993) and
Baranoski and others (1996).
NATURE OF LOWER AND UPPER CONTACTS
The Rose Run sandstone directly overlies the Copper Ridge Dolomite
or equivalent throughout the mapped area (Figure 5). The
base of the unit is typically a gradational contact with the underlying
Copper Ridge Dolomite and is difficult to correlate consistently
across the basin using geophysical logs. In Ohio, the Rose Run interval,
as recognized in core and geophysical logs, consists of a stacked
sequence of as many as five sandstone units interbedded with thin,
low-permeability dolostone and carbonaceous shale (Baranoski and
others, 1996; Riley and others, 2002). The basal sandstone unit of
the Rose Run interval is typically separated from the main sandstone
body by a dolostone lens approximately 30 feet thick (Figure A4-
2). The contact with the underlying Copper Ridge is placed at the
base of this lowermost sandstone unit. This lowermost sandstone
is less developed in southern Ohio and Kentucky. In Kentucky, the
lowermost sandstone unit of the Rose Run in Ohio is either poorly
developed or absent. Thus, the Rose Run-Copper Ridge contact is
identified at the base of the main (i.e., well-developed) sandstone
interval there, which is stratigraphically higher in the section than in
central Ohio. Therefore, the thickness of the Rose Run, as mapped
in Kentucky, is less than that mapped in Ohio (Figure A4-3). The
base of the Rose Run or equivalent in West Virginia and Pennsylvania
is also difficult to identify consistently on geophysical logs
because of the heterogeneity of the interval, but is typically placed
at the base of the lowermost sandstone unit as in Ohio.
The Rose Run sandstone conformably underlies a dolostone interval
called the Beekmantown Formation in Ohio and eastern Kentucky
(equivalent to the Mines Member of the Gatesburg Formation
in central Pennsylvania), except within the Rose Run subcrop trend,
where the Beekmantown is absent because of erosion on the Knox
unconformity. Where the Beekmantown is eroded, either the Wells
Creek Formation or Black River Group directly overlies the Rose
Run. In areas with Beekmantown dolostone, the contact is gradational
and the top of the Rose Run is placed at the top of the first
well-developed, porous, sandstone unit underlying a low-permeability,
nonporous dolostone (Riley and others, 1993; Baranoski and
others, 1996; Riley and others, 2002). Within the Rose Run subcrop
trend, the top of the Rose Run sandstone is a sharp, unconformable
contact, and is placed at the top of porous, permeable sandstone
that is overlain by impermeable interbedded shale and dolostone of
the Wells Creek, or by impermeable, nonporous, dolostone of the
Black River.
LITHOLOGY
The Rose Run interval, as described in subsurface core in Ohio,
consists of white to light gray, fine-to medium-grained, sub- to
well-rounded, moderately sorted, quartz arenites to subarkoses
interbedded with thin lenses of nonporous dolostone (Riley and
others, 1993; Baranoski and others, 1996). Glauconite and green
shale laminae occur locally. Low-angle cross bedding is the most
common sedimentary structure observed in both core and formation
micro-imager (FMI) logs. Ripple marks have also been noted
in both core and FMI logs. Polygonal mud cracks are present in
several of the cores, indicating subaerial exposure of the sandstones
during low stands in sea level.
In core and outcrop in Pennsylvania, the Rose Run equivalent, the
Upper Sandy member of the Gatesburg Formation, contains three
principal facies: 1) sandstone; 2) mixed sandstone and dolostone;
and 3) dolostone (Riley and others, 1993). The sandstone facies consist
of light-gray, fine-grained, well-sorted quartz arenites. The principal
cement is silica. Cross bedding is present, including herringbone
cross-stratification. The mixed sandstone and dolostone facies
is dominated by sandstone that consists of fine- to medium-grained,
moderately well sorted quartz arenites. The principal cement is dolomite.
The dolostone facies are light-gray to olive-gray and display
nodular bedding and bioturbation. Outcrops in central Pennsylvania
contain “ribbon rocks” (thin-bedded, wave-rippled and burrowed
dolostone), wavy dololaminite, flat pebble conglomerates, and
thrombolitic algal mounds in the dolostone facies (Riley and others,
1993). Ooid grainstones are common within the dolostone facies.
From a regional study of cores and outcrops in Ohio and Pennsylvania
(Riley and others, 1993), monocrystalline quartz and potassium
feldspar are the dominant framework constituents in the Rose
Run. Polycrystalline quartz and chert generally comprise less than
one percent of the sandstone and appear in the more feldspathic
samples. Minor amounts (less than one percent) of muscovite and
accessory minerals—zircon, tourmaline, garnet, and pyrite—occur
locally. Allochems are locally abundant in the Rose Run and include
dolostone clasts, glauconite, peloid and dolomitized ooids. Four
major cementing agents occurring in the Rose Run include: 1) dolomite;
2) clays; 3) quartz overgrowths; and 4) feldspar overgrowths
(Riley and others, 1993). Dolomite is the dominant cementing agent
as observed in cores throughout Ohio and Pennsylvania. Five pore
textures were observed in the Rose Run, including: 1) intergranular