Formation And Occurrences Of Laumontite And Related Minerals In The Carolinas And Virginia, Middle Mesozoic Zeolite Facies Metamorphism Southern Appalachian Piedmont

Formation And Occurrences Of Laumontite And Related Minerals In The Carolinas And Virginia, Middle Mesozoic Zeolite Facies Metamorphism Southern Appalachian Piedmont

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  Formation And OccurrencesOf Laumontite And Related Minerals In The Carolinas And Virginia, Middle Mesozoic Zeolite Facies Metamorphism Southern Appalachian Piedmont Donald R. Privett, P.G. S.T.A. R. Environmental 1 Circle Street Great Falls, SC 29055 ABSTRACT A 175 -150 Ma hydrothermal zeolite grade metamorphic event altered most pre-Jurassic rocks in the southern Appalachian Piedmont from south central Georgia to southern Virginia. Laumontite fills fractures and replaces plagioclase in exposed and in drilled and cored subsurface rocks. A swarm of 200 Ma northwest/north striking diabase dikes were injected and basalt flowed into into rift valleys during initial Atlantic rifting, followed by filling of half grabens with immature clastic sediments. Fractures (joints and faults) served as conduits for calcium-saturated warmed water that crystallized laumontite, prehnite, calcite and other zeolites. This period of zeolite grade thermal alteration metamorphism is widespread. GENERAL GEOLOGY Piedmont Neoproterozoic and Paleozoic igneous, metamorphic, and Triassic igneous and sedimentary rocks of the Southern Appalachians were subjected to a period of zeolite grade thermal metamorphism about 175150 Ma evidenced by the widespread zeolite occurrences in older and younger intrusive and in older metamorphosed host rocks mostly diorites and granites. Figure 1 is a tectonic map (Hatcher, et. al., 2007) showing the area geologic structures. ZEOLITE PARAGENESIS Zeolite grade thermal metamorphism refers to the crystallization of fracture-filling and replacement zeolites and prehnite in host rocks. The zeolite facies is considered to represent low grade (low temperatures and low pressure) hydrothermal metamorphism to encompass all mineral, textural, and chemical changes resulting from hot waters, steam or/and gas at lower T/P than greenschist facies metamorphism. Laumontite and other zeolites have been the subject of theoretical considerations and experimental limit determinations (Coombs, 1952) ( Thompson, 1971, Frost, 1980, Loui, 1971) plus detailed paragenesis studies (Boles and Coombs, 1977 and Suranam, 1973). Still there is considerable disparity between theoretical and experimental temperature and pressure limits, and the independently determined substantially lower temperatures of natural formation. Complex ever-changing variables lower and inhibit formation. Boles and Coombs (1977) summarized the parameters thought to control the temperature and pressures of formation of zeolites. Experimentally determined temperatures are both higher and lower than values obtained under natural conditions. Fluid pressure gradients, CO2 and H2O, activities of CO2, H20, ratio of water and CO2, the permeability, nucleation and reaction kinetics, oxygen fugacity and presence of additional ions can alter the temperatures of formation. Stability limits determined vary widely; Loui (1971) obtained upper limits of 230º – 325º C at 0.5 kb, while Thompson (1971) obtained values of 250ºC at 2.75 kb. The lower limit is in even greater conflict with natural occurrences. Loui (1971) obtained values of 150º - 200º C at 1 kb where p f = p t the lowest recorded temperature of formation is 43º C (McCulloh, 1981) for laumontite that crystallized on rocks exposed at the Suspe Hot Springs, California. Temperatures of 50º C for laumontite, 90º C for prehnite (Boles and Coombs, 1977) and 104º C (Castino and Sparks, 1974) have been estimated for laumontite in buried sedimentary rocks. Siki, (1969) reported 75º + 5° C for laumontite formed in hot springs. Using calcite fluid inclusions Meghan, Robinson and Delaney (1982) determined that laumontite filled amygdules in lava flows in Iceland formed at 140º - 200º C.
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  Zeolites occur inthe geothermal areas of Iceland, (Kristmannedottir and Tomanson,1978), (Mehegan, Robinson and Delaney, 1982) and New Zealand thermal areas (Barnes, 1977) and in metamorphic rocks of California, (Madsen, and Murata, 1970). LAUMONTITE DISTRIBUTION Laumontite is present in the majority of rock exposed in the Piedmont region. Laumontite has been identified from over 100 separate locations in North Carolina, South Carolina, Georgia and southern Virgina in relatively unweathered outcrops and in rock exposed in foundations, trenches, quarries, mined caverns, and in cores from borings for power plants and cuttings from water wells and exploratory test wells. Table 1 and Figure 2 shows the general geographic area of interest and earlier referenced laumontite occurrences. The geographic distribution of additional laumontite in the Carolinas, Georgia and Virginia is shown in Table 2 and Figure 3. Table 1 shows the previously reported occurrences. It occurs in gneisses of the Inner Piedmont; metamorphosed and unmetamorphosed igneous rock and metasedimentary rocks of the Charlotte Belt (Privett, 1974a) and the Kings Mountain Belt; metavolcanic and metasedimentary rock of the Carolina Slate Belt and Triassic - Jurassic sedimentary and igneous rocks. The discovery of laumontite in the buried Triassic rocks and in cored basement below the Triassic of South Carolina and south central Georgia suggest that laumonatization is even more extensive,because, laumontite fills amygdules and replaces plagioclase in a 184 +/- 3 myo basalt from Dorchester county, S.C. (Gotten et.al.,1983) and is present in Triassic sedimentary and older igneous rocks from South Central Georgia (Chowns and Williams,1983). OCCURRENCE Laumontite occurs as: (1) single pink and white euhedral crystals in druses and incompletely filled veins where it crystallized on host rock, (prehnite, epidote and quartz ) (Figure 4), (2) veinlets of matted interpenetrating crystal aggregates filling single and multiple narrow fractures and joints (Figure 5), and (3) common replacement of plagioclase forming partial to complete "mosaic pseudomorphs" of laumontite after plagioclase which are composed of minute laumontite crystals and albite (Figures 6 ). Laumontite is identified by microscopic study, in diffuse plane light, laumontized plagioclase (Figure 7A and B) displays a mottled texture (Figure 8 A and B), and polysynthetic twinning of plagioclase is destroyed; partly replaced plagioclase retains its twinning, however, plagioclase develops a mottled texture. Laumontite imparts a pinkish color to the altered and replaced plagioclase. This color change is a good indication of, and appears to be directly proportional to, the intensity of laumontization. The sequence is shown by partly replaced laumontite; calcite crytallized at the interior of the vein. Coarse grained microscopic crystals of laumontite under crossed polars (Figure 9) display a somewhat wavy extinction. Rock cores (Figures 10 and 11) contain replacement and fracture filling laumontite. Intenesly altered rocks are sometimes veined with laumonitite-calcite (Figures 12 and 13) where calcite crystallized at lower T/P fills the interior of veins. Figures 14 and 15 show fine grained replacement and fracture filling laumontite in outcrop and on an exposed weathered surface of saprolite. Coarsly crystallized white laumontite (Figure 16) is occasionaly present on broken rock surfaces. The x-ray reflections (Table 3) vary with the relative humidity; therefore, the material is best described as laumontite-leonhardite. Laumontite readily dehydrates to leonhardite unless the sample is kept under conditions of 100% relative humidity. Partial re-hydration of leonardite to laumontite can be observed under the polarizing microscope when placed in water. ORIGIN Tectonic activity about 175 -150 my, in the Triassic and Jurassic consisted of the rifting and separation following the breakup of Pangea and susequent seperation of Laurasia. This tectonism fractured old weaker shears, forming new joints and faults. Siliceous cataclasite and quartz mylonites formed in the stressed rocks. Immature clastics were deposited in subsiding half grabens with later basaltic flows, injection of diabase dikes and basaltic to diabase sills. Basalt flows present in Triassic sedimentary rock heated circulating groundwaters which probably mixed with hydrothermal fluids to react with plagioclase forming prehnite and laumontite. The excessive calcium reacted with silica to produce the fracture filling laumontite and calcite with even lower temperatures other zeolites crystalllized. Two generations of diabase dikes are evident; suggesting that igneous activity persisted as
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  stress changed. (Ragland,Hatcher and Whittington, D., 1983 ) As temperatures subsided, other zeolites crystallized( heulandite and stilbite). This period of zeolite grade thermal alteration metamorphism is widespread in rocks of the southern Appalachians especially Charlotte Terrane. ACKNOWLEDGEMENTS I thank Dr. Robert D. Hatcher, Jr.,UT Distinguished Scientist and Professor of Geology, Department of Geological Sciences, University of Tennessee Knoxville, Tennessee for his insightful and complete review of my manuscript and preparation of Figures 1, 2 and 3. Phoebe Hoffman kindly directed me to correct context errors, thank you.
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  Table I SUMMARYOF PREVIOUSLY REPORTED LAUMONTITE OCCURRENCES Location Host Rocks Near Durham, NC types of Other zeolites laumontite* FF R D Metamorphosed greenstone and crystal tuffs Foote mine Cleveland Spodumene pegmatites and County, NC amphibolites Nello Teer Quarry, Diabase sill Durham, NC (Triassic)sedimentary rocks Near Great Falls, meta-adamellite southeastern Chester, Co., SC Western Rowan Co.,NC Diorite intruded by 300 ma. (Woodleaf Quarry) adamellite x Southern Fairfield Co., SC V.C. Summers plant Near Apex, Wake Co., NC Eastern Cherokee Co., SC Eastern Fairfield Co., SC Near Tirzah North Central York Co.,SC almandine amphibolite ? (no Probe) and granodiorite x Diabase dikes and Triassic sedimentary rocks Rhyolites and felsic gneiss x Other Secondary Minerals References Furbish, 1965 x x x x x x x x prehnite and about 80 secondary minerals Furbish, 1972 epidote x harmontone heulandite x x Granite and hornblende x gneiss and 300 m.y. adamellite Metadiorite, diorite, mafic dikes x and Triassic diabase dikes Meta-adamellite and North Central York Co., metamorphosed mafic dikes x SC (Catawba) (532 m.y.) x x x Riverside Shopping Center off US 58 Danville, VA Hylas zone - central Virginia Monticello Reservoir 6 km. south of V.C. Summer N. P. Dorchester Co, SC CC# 1 South central Georgia x stilbite Granite, gneiss, hornblende gneiss x x stilbite, chabazite heulandite x stilbite Sheared gneiss, schist and granite quartz monzonite x x x heulandite early Jurassic basalt x diabase, sandstone and felsic x volcanics metagabbro x x x barite and saponite Ragland, 1977 calcite, Privett, 1974b epidote, chlorite epidote, calcite chlorite Law Engineering, 1975 prehnite, epidote Butler, 1976 calcite, epidote, chlorite, prehnite Privett, 1977(a) x Keystone Blue quarry, Elberton fine-grained biotite northeastern Georgia granite cut by dikes of pegmatitic granite and diabase. Privett, 1973a x stilbite, prehnite, calcite epidote, Privett, I973b chabazite heulandite flourite scolecite chlorite South Carolina Gas and Electric, 1977 x quartz, flourite, Privett, 1977(b) quartz Bobyarchick and Glover, 1979 Secor, 1982 x Old Pineville Quarry, York Co. SC Iredell Co., NC between schist x I- 40 and US 64/70. Brevard Zone near amphibolite grade gneiss and x Atlanta Chattahochee schist crosscuts regional Tunnel, Cobb County, foliation. Ga White, 1969 Gotfried, 1983 heulandite stilbite x chabazite and the radiating zeolite ? stilbite,fine grained individual crystals 0.1 to 1.0 mm, well crystallized. prehnite, epidote pumpellite calcite prehnite epidote quartz prehnite (1).quartz-calcite-chlorite assemblage later laumontite, prehnite, calcite and (2).orange staining of albite and replacement of biotite by chlorite. Fluorite-chloritepyrite-quartz, and calcite Chones and Williams, 1983 Butler, 1983 Milton, 1981 Burnley, P.C. , et.al., 2008 Bulger, Dan, et.al., 2008
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  *FF = Fracturefilling R=Replacement D= Druse Table 2. Summary of Additional Laumontite Occurrences Type of laumontite Location Other Zeolites and Secondary Minerals Host Rock R Metadiorite x x epidote Gabbro metagabbro McGuire Nuclear Sta. and Cowans Ford Dam Foundation borings northwestern Mecklenburg and Lincoln Co., NC, Duke Power core repository. FF D x x prehnite, calcite Medium-grained blue-gray biotite adamellite x x prehnite Metagabbro x x epidote calcite hornblende schist cut by small pegmatites Hornblende gneiss Augen granite gneiss and pegmatites biotite gneiss and porphyry dikes Metagranite and mafic dikes x x Pineville Quarry southern Mecklenburg Co., NC off Hwy. 51 rock core. Duke Power core repository. Boring, N.E. Gaston Co. NC .2 mi. east of US 16 on the Catawba River (Riverbend) Duke Power core repository Arrowood Quarry 0.4 mi; east I-77 Mecklenburg Co. NC, Duke Power core repository Hyco Reservoir, Person Co. NC (road below dam) Whitnel Quarry near Lenior, Caldwell Co., NC Hickory Quarry 0.5 mi. north US 321, 0.8 mi. East County Road 1536, Catawba Co. NC Quarry off SC 901, northeastern Fairfield Co. Borrow Pit off SC 72, S.W. Chester Co. SC also in roadcuts for new bridge 2007. Borings North Cabarrus, Northeastern Rowan, Davidson, Davie, Guilford, Stokes and Alamance counties,NC 52 occurrences, Duke Power core repository, South Boston, VA. Boring Rock Hill Printing, White St. Rock Hill, SC, Duke Power core repository. Apt. Complex off SC 161,Rock Hill, SC. Great Falls, SC, Chester County Rd. borrow pit. North Quarry, west of Winston-Salem, Forsythe Co. NC. Stokesdale Quarry 1 mile west NC 158 Guilford Co. NC. Jamestown Quarry, off County road 1147, 1.5 miles east of I-85. Guilford Co. NC. Lexington Quarry off county Road 1646, 0.7 mi. east US 52 Davidson Co. NC. x x Epidote calcite epidote calcite x x epidote x x prehnite epidote x Granite, diorite sheared igneous rocks; metasedimentary and metavolcanic rocks. hornblende gneiss cut by pegmatites Metadiorite x x x x x x Metadiorite metagranite Foliated granite to hornblende gneiss Biotite-hornblende gneiss cut by mafic dikes Hornblende gneiss and metagranite Adamellite cutting metadiorites and amphibolites Albite granite - (300 m.y.) 27 separate borings[ x x x x x x prehnite, calcite, epidote stilbite, epidote, calcite epidote epidote calcite, epidote x chabazite, stilbite, calcite stilbite, heulandite, quartz calcite prehnite, epidote, calcite X x x x x x Churchland pluton-Davie and x Davidson Counties, NC Duke Power core repository, Boring Marshall Steam Station off Hwy. 150 Metadiorite x eastern Catawba Co. NC, Duke Power core repository. Smith Grove Quarry, Davie Co. NC Gabbro-diorite x Central Rock Products Quarry, east 421. central Metagranite x Guilford Co. NC Granodiorite Pomona Quarry south 1-40 at end of Co. Road Chlorite schist and granite x I539. gneiss Inactive quarry, Kings Creek, western York, Co., metadiorite x SC 4 borings near Kings Creek eastern Cherokee metadiorite x Co. , SC (across creek from above), Duke Power core repository *FF = Fracture filling R=Replacement D= Druse x prehnite, epidote x prehnite, epidote x prehnite, epidote stilbite, calcite epidote x prehnite, calcite
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  3.04 2.97 2.88 2.80 2.63 2.58 Table 3 X-Ray DiffractionPowder Data laumontite-leonhardite II III IV w I dA I dA I dA I 84 9.50 100 9.46 100 9.44 100 80 6.84 90 6.84 80 6.83 75 w 6.19 10 6.20 W 6.18 10 18 5.04 10 5.04 10 5.04 20 30 4.73 30 4.72 30 4.72 14 25 4.49 27 4.49 15 4.49 22 100 4.16 95 4.16 100 4.15 100 w 3.78 w 3.77 w 3.77 18 28 3.66 40 3.56 30 3.65 56 56 3.51 55 3.51 40 3.50 60 16 3.41 10 3.41 10 3.41 16 w 3.35 w W 3.36 40 50 3.28 50 3:27 50 3.27 60 18 3.21 38 3.20 25 3.19 60 32 3.17 20 3.15 25 3.15 32 3.07 15 46 3.03 40 3.03 40 3.03 40 W 2.96 W 2.95 W 24 2.89 30 2.88 25 2.87 25 12 2.79 12 2.80 W 2.79 22 w 2.60 25 2.63 w 2.64 W 28 2.57 w 2.57 20 2.57 30 2.52 2.44 14 26 2.36 2.27 2.22 2.18 2.16 24 12 w 14 30 I hkl(s) 110 200 201 111 220 221 130 131 401 002 131 312 040 311 330 402 420 240 511 422 331.512 241 132 222,203 601,441 403 151 250 622 060 333,620 I. II III. IW W (s) dA 9.52 6.98 6.23 5.05 4.74 4.52 4.17 3.77 3.67 3.52 3.41 3.37 3.27 3.20 3.16 2.45 2.39 2.36 2.29 2.21 2.19 2.15 30 16 w w w 25 15 2.52 2.44 w 25 2.36 2.27 2.22 15 10 w 2.15 20 dA 9.43 6.83 6.18 5.04 4.72 4.49 4.15 3.76 3.66 3.51 3.40 3.36 3.27 3,20 I 78 s6 w 18 16 32 100 w 42 94 26 34 63 45 3.09 3.03 2.95 2.88 2.80 2.64 2.57 2.54 2.52 2.44 2.39 2.36 2.27 2.22 2.18 2.15 w 45 w 38 w w 34 w w 43 w 23 w w w 28 Euhedral white crystal on diorite. Woodleaf (luarry. Rowan County Pink asicular crystals, Lexin 9ton Quarry, Davidson County, North Carolina Laumontite, pink asicular crystals from -790 feet in well drilled in East Spencer, Rowan County, NC, Isenhour Brick and Tile Company. Leonhardite. Madsen and Murata, 1970, p. 193 Laumontite, LIou, 1971, p. 386. after Liou, 1971, p. 386.
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  Reference Cited Barnes, Ivan,1977, Warm Springs, South Island, New Zealand, and their potentials to yield laumonite: abs. : G.S.A. Abstracts with Programs, vol. 9, no. 2, p. 116. Bobyarchick, A R. and Glover, I., III, 1979, Deformation and metamorphism in the Hylas Zone and adjacent parts of the eastern Piedmont in Virginia: G.S.A. Bull., vol. 90, p 739-752. Boles JR and Coombs DS, 1977, Zeolite facies alteration of sandstones in the Southland Syncline, New Zealand: Am J Sci v. 277, pp. 982–1012. Bulger, D. Wehby, Jennifer, Freeman, et. al., 2008, Mineralogy of zeolites from the Keystone Blue Quarry, Elberton Batholith, northeast Georgia, Southeastern section GSA, p Burnley, P.C. Raymer, J, and Terrell, J. R.., 2008, Characterization of veins and associated alteration observed in the Chattahochee Tunnel, Cobb County, Ga , GSA, Abstracts, p. . Butler, J. R., 1976, Geology of the propane storage near Tirzah central York County, South Carolina SC. Devel. Board, Division of Geology, Geologic Votes, v. 20, n. 1. p. 26-32. Butler,J.R.,1983, Geologic History of the Charlotte Belt at the Old Pineville Quarry Northeastern York County SC: SC Geologic Notes, vol. 27, p. 13-24. Castano, J. P. and Sparks, D. M., 1977, Interpretation of vitrinite reflectance measurements in sedimentary rocks and determination of burial history using vitrinite reflectance and authigenic minerals: G.S.A., Spec. Pap. 153, p. 3152. Chowns, T. M. and Williams, C. T., 1983, Pre-Creteceous rocks beneath the Georgia Coastal Plain-Regional implications, in Gohn, G.S., ed., Studies related to the Charleston. South Carolina, earthquake of 1886- Tectonics and Seismicity: U.S. Geological Survey Professional Paper, 1313, p. L1-L42. Coombs, D., 1952, Cell size, optical properties, and chemical composition of laumontite and leonhardite: Amer. Mineral., 37, p. 822-830 Daniels, D. L., Ziet, Isadore, and Popenoc, Peter, 1983, Distribution of subsurface lower Mesozoic rocks in the Southeastern United States as interpreted from regional areomagmatic and gravity maps, in Gohn, G.S., ed., studies related to the Charleston, South Carolina earthquake of 1886- Tectonics and seismicity. Geological Survey Professional Paper 1313, p. Kl-K24. DeBoer J., 2, 1983, Magnetic and paleomagnetic evidence bearing on hot spot models for Mesozoic magnetism: GSA, Abstracts with Programs, v. 15, p. 91 DeBoer, J, and Snider, F. G., 1979, Magnetic and chemical variations of Mesozoic diabase dikes from eastern North America: Evidence for a hot spot in the Carolina's: G.S.A. Bull., v. 90, p. 185-198. Frost, B. R. ,1980, Observations on the boundary between zeolite facies and prehnite-pumpellyite facies, Contributions. Mineral. Petrology, v. 73, p-365-373. Furbish, W. J.,1965, Laumontite-leonhardite from Durham County. N.C., Southeastern Geology, v. 6, p. 189-200. Gottfried, D., Annell, C. S., and Byerly, G. R., 1983, Geochemistry and tectonic significance of subsurface basalts near Charleston, South Carolina – Clubhouse Crossroads test holes #2 and #3, Chapter D of Gohn, G. S., ed., Studies related to the Charleston, South Carolina,earthquake of 1886 – Tectonics and seismicity: U.S. Geological Survey Professional Paper 1313-D, 17 p.
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  Hatcher, R. D.,Bream,, B. R. and Merschat.,A. J. 2007, Tectonic map of the southern and central Appalachians: a tale of three orogens and a complete Wilson Cycle: Memoirs-Geological Society of America 200: p. 595. Kristmannedottir, H. and Tomanson, J.,1978, Zeolite zones in geothermal areas in Iceland, natural zeolites occurrences, properties, use: edited by L. B. Sand and F. M. Mumpton, Pergamon, New York, 546 pp. Law Engineering. 1975, Geology of the Wateree Nuclear Site, interim report to Duke Power. Liou, J. G. 1971a, P-T stabilities of laumonite-wairakite, lawsonite and related minerals in the system of CaAl2 SiO2H2O: J. Petrology, v. 12, p. 379-411. Loui, J, G., 1971b, Synthesis and stability relations of prehnite, Ca2Al2Si3010(OH)2: Am. Mineral. V. 56, p. 507-531. Madsen, P. M. and Murata, K.J.., 1970, Occurrence of laumontite is Tertiary sandstones of the Central Coast Ranges, California.. US Geol. Surv. Prof. Pap. 7OO-D, D188--D195. McCulloh. T. H., Frizzell, V. A., Jr., Stewart, R. J., and Barnes, I.,1981, Precipitation of laumontite with quartz, thenardite, and gypsum at Sespe Hot Springs, western Transverse Ranges, California.. Clays and Clay Minerals, v. 29, p. 353-364. Mehegan, J. M., Robinson, P. T. and Delaney, J.R.., 1982, Secondary mineralization and hydrothermal alteration in the Reydarfjordur drill core, eastern Iceland, J. Geophys. Res., v. 87, p. 6511-6524. o o Goldsmith, Richard, Milton, Daniel J., and Horton, Jr., 1988, Geologic Map of the Charlotte 1 x 2 Quadrangle, North Carolina and South Carolina: U.S. Geological Survey Miscellaneous Investigations Series, Map I-1251-E, scale 1:250,000. Miyashiro, A and Shido, F., 1970, Progressive metamorphism in zeolite assemblages: Lithos v. 31, p.251-260. Privett, D. R., 1973a, Laumontization near the northern margin of the Liberty Hill batholith, southern Chester County, South Carolina: South Carolina Geological Survey. Geologic Notes, v. 17, no. 3, p 49-54.. Privett, D.R., 1973b, Paragenesis of an unusual hydrothermal zeolite assemblage in a diorite-granite contact zone, Woodleaf, Rowan County, North Carolina: Southeastern Geology, v. 15, no. 2, p. 105-118. Privett, D. R., 1974a, widespread laumontization in the central Piedmont of North Carolina and southern Virginia (abs. J, Geological Survey of America Abstracts with Programs, v. 6, no. 4,p. 389-390. Privett, D. R., 1974b, Laumontization in the Kings Mountain belt rocks, Cherokee county, S. C.: Geologic Notes,S. C. Dev. Bd., Div of Geology, v. 18, p. 31 - 35. Privett, D. R., 1977a, Widespread zeolitization in the central Charlotte Belt, north-central York county, South Carolina (abs.): Geological Society of America Abstracts with Programs, v. 9, no 2, p. 176. Privett, D R., 1977b, An unusual octahedral flourite, stilbite, laumontite, calcite and quartz assemblage in Danville. Virginia. Va. Minerals, v. 23, p. 7-9. Ragand, P.C,, 1977, The use of zeolites to determine the age of last motion on a fault: a case history (abs.): Geol. Soc. Amer. Abstracts with Program. V. 9, P- 176-177. Ragland, P.C., Hatcher, R.D., Jr., and Whittington, D., 1983, Juxtaposed Mesozoic diabase dike sets from the Carolinas: A preliminary assessment: Geology, v. 11, p. 394–399. Seki, Y., 1969, Facies series in low-grade metamorphism: Geol. Soc. Japan. v. 75; p. 255-66.
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  Secor, D. T.,Jr.,Peck, L. S., Pitcher, D. M., Prowell, D. C., Simpson, D. H., Smith, W A. and Snoke. A. W., 1982, Geology of the area of induced seismic activity at Monticello reservoir, South Carolina: Jour. Geophysics. Res., v. 87, p. 6945-6957. S.C.E. and G. Company,1977, Virgil C. Summer Nuclear station, Final Safety Analysis Report, 1977, v. 2, Columbia, S.C. Surdam, R. C., 1973, Low- grade metamorphism of tuffaceous rocks in the Karmutsen Group, Vancouver Island, British Columbia, Geol. Soc. Am. Bull.v. 84, p. 1911-1922. Thompson, A, B., 1970, Laumontite equilibria and the zeolite facies, Am. Jr. Sci.,v.269, p. 267-275. Thompson, A. B., 1971, P C02 in low-grade metamorphism; zeolite. carbonate, clay mineral, prehnite relations in the system CaO-Al203-Si02-C02-H20: Contrib. Mineral. Petrology. 33: p.145-161. White, J. S., Jr,, 1969, A lithiophosphate occurrence in North Carolina: Am. Mineral, v- 54, p. 1467-1469. Zen, E. and Thompson, A. B., 1974, Low-grade regional metamorphism: mineral equilibrium relations; Annual Rev. of Earth and planetary Sci., v. 2, p. 179-212. Figure 1. Geologic Provinces SC, NC, Va., and Ga. Hatcher, Tectonic index map, 2007.
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  Figure 4. Carse-grainedwhite laumontite on fracture in diorite, Woodleaf Quarry, Rowan County, NC. Figure 5. Brecciated diorite with vein filled by white calcite and pink laumontite. Lexington Quarry, Davidson County, NC
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  6A 6B Figure 6A andB “Pseudomorph” of laumontite after plagioclase, displaying the typical mottled mosaic texture seen in plane light.
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  Figure 7 Textureof partly laumonitized plagioclase in quartz monzonite, mottled texture, center unaltered. Plane light. Lexington Quarry, Davidson County, NC Figure 8 A and B. Texture of partly laumontized plagioclase in quartz monzonite, Lexington Quarry Davidson County, NC. The plagioclase crystal in the center bottom still retains twinning while twinning is nearly destroyed in the more completely altered crystal at the right. A. plane light. B. crossed polars
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  Figure 9. Coarsegrained laumontite crystals crossed polars. Lexington Quarry, Davidson County, NC Figure 10.. Coarse Laumontite - calcite. Small calcite crystals at margins. Crossed polars.
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  Figure 11. Pinkfracture filling – replacement laumontite in core. Churchland Granite. Davie Co, NC. Duke Energy core. Figure 12. Rock core containing fracture filling veinlets of acicular laumontite. Duke Energy core. Cherokee County, SC.
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  Figure 13. Intenselyaltered rock, with fracture filling laumontite-calcite, crossed polars. Figure 14. Fracture filling laumontite veinlets,crossed polars scale 1 cm 0.5 mm. Lexington Quarry, Davidson County, NC.
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  Figure 15. Intenselyaltered metadiorite? With replacement and fracture filling laumontite - leonhardite. Compass left bottom scale. Figure 16. Coarse grained white laumontite, Cherokee County, SC Cherokee Nuclear Site. . Duke Energy 1 cm equals 1 cm.