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1 GSA Data Repository Item Verdel, C., Wernicke, B. P. and Bowring, S. A., The Shuram and subsequent Ediacaran carbon isotope excursions from southwest Laurentia: Geological Society of America Bulletin (submitted). MEASURED SECTIONS APPENDIX 1: MEASURED SECTIONS Munsell colors of fresh (F) and weathered (W) surfaces used in some descriptions Johnson Canyon section 235 m: base of Stirling Quartzite. Light-grey to white quartzite m: purple siltstone and quartzite. Very little carbonate m: red-brown dolomitic siltstone (N3 and 5YR 4/4) and occasional limestone and dolostone beds m: thin-bedded, tan dolostone (W:10YR 6/6, F:5YR 5/4) and pink limestone (F&W:5YR 5/4) m: reddish-grey siltstone and minor dolostone. 5YR 3/ m: Johnnie oolite. 5Y 8/4 to 5Y 7/6. Breccia at top not present here. Breccias at base and within oolite m: dark grey siltstone. N m: green siltstone with thin, orange dolostone beds. W:10YR 6/6 F:10G 6/ m: green siltstone. 10 GY 7/ m: thin-bedded, red-brown dolostone. W:5YR 5/5 F:5B m: greyish purple quartzite, more shale than below m: greyish purple quartzite m: orange dolostone m: brown siltstone 49 m: thin-bedded stromatolites m: orange to brown dolostone m: mainly purple shale, ~5% green-grey siltstone m: orange to brown dolostone, medium grey on fresh surfaces m: light purple to grey quartzite 12 m: thin breccia 0-14 m: orange to light tan laminated dolostone South Fork Hanaupah Canyon section (corrected for thickness of sill at ~237 m) 563 m: white quartzite. Stirling A Member, if not lower m: siltstone with increasing quartzite. Occasional carbonate m: green siltstone 1

2 m: thin ridge former of quartzite and thin dolostone m: grey siltstone m: lt. green siltstone with thin brown dolostone beds m: grey siltstone m: grey-green siltstone m: brown weathering siltstone m: lt. green siltstone m: penecontemporaneous conglomerate m: grey siltstone m: green siltstone with tan carbonate m: grey-green siltstone m: grey-green siltstone with brown carbonate m: grey-green siltstone m: grey siltstone with thin carbonate beds m: grey siltstone m: grey siltstones with limestone beds m: grey to red-brown siltstones m: quartzite, hornfelsed m: thin bedded quartzite m: interbedded green-grey limestone and thin quartzite beds m: grey siltstones m: grey siltstones with increasing tan carbonate beds m: grey, ridge-forming siltstone. Minimal carbonate m: grey siltstones with increasing amount of carbonate m: grey siltstones m: lt. grey/green siltstones with more thin carbonate beds than below m: grey siltstone/phyllites with thin carbonate beds 0-18 m: lt. grey siltstones/phyllites North Fork Hanaupah Canyon section 126 m: quartzite, base of Stirling Quartzite m: brown, sandy dolostone. Massive, no laminations. Numerous carbonate clasts. A few stromatolitic laminations m: buff, massive dolostone m: buff dolostone, less sandy m: buff, massive dolostone m: stromatolitic dolostone m: sandy, massive dolostone m: sandy, buff dolostone. Small, branching, concave-down stromatolites m: sandy, massive, buff dolostone. Rare carbonate clasts. Sandier up-section m: Laminated, buff dolostone. Domed stromatolites m: sandy, brecciated, massive dolostone m: green, laminated siltstone m: massive, buff dolostone. Brecciated at base and throughout. Laminated in upper 25 cm m: laminated dolostone, gradational contact with siltstone below 2

3 m: laminated, yellow-brown dolostone with siltstone m: red-brown dolostone. Sandy, with clasts at the base. Fining upward and laminated at the top m: thinly laminated, red-brown dolostone. Possible soft sediment deformation m: massive, light-purple quartzite with pebble- to boulder-size carbonate clasts m: carbonate breccia. Brown dolostone clasts and rare quartzite clasts in sandy dolostone matrix m: tubes(?) in fine-grained dolostone m: breccia bed. Carbonate clasts 1-10 cm in width. A few quartzite clasts also m: brown, sandy, cross-bedded dolostone. Gradational contact with quartzite below m: pink, cross-bedded quartzite m: white to light-grey orthoquartzite. "White marker bed" m: quartzite, more massive than below m: fine grained, thin-bedded quartzite m: quartzite, slight increase in grain size 0-6 m: thin-bedded (1-2 cm) very fine grained purple quartzite. Rare thin dolostone beds. Black laminations jud: Johnnie upper dolostone, measured section near Wildrose Pk m: Light grey, sandy dolostone. Mainly massive, but laminated in places. Numerous breccias. Lower contact not well exposed. Overlain by dark grey siltstones. In other locations, upper 2 m consists of white to tan, thinly laminated dolostones with domal stromatolites and green siltstones, underlain by 2 m of brecciated, sandy dolostone. TC1 section m: light grey, sandy limestone. Grades downward into dolomitic sandstone. Overlain by dark grey siltstone m: dolomitic sandstone. Occasional breccia clasts. Decreasing dolomite upward in the section m: carbonate breccia. At 46.5 m becomes very sandy. At 64 m not as brecciated, mainly just dolomitic, coarse grained sandstone m: light grey siltstone m: brown, thin-bedded to laminated dolostone m: green to grey siltstone m: laminated brown dolostone, carbonate turbidites(?) m: light green and pink siltstone m: medium brown to light brown dolostone, cross-bedded (flow direction to the N) m: green to brown siltstone m: light grey to green siltstone 0-10 m: red to brown, thin-bedded dolostone TC2 section 46 m: blue-grey limestone near top of block. Block overlain by grey siltstone. 44 m: white limestone within block 3

4 40 m: blue-grey limestone in block 38 m: white limestone within block 36 m: blue-grey limestone within block 33 m: white limestone within block 31 m: base of larger block. Blue-grey limestone. 25 m: block of white limestone overlain by grey siltstone m: brown dolostone turbidites 2-22 m: grey siltstone 0-2 m: light grey dolostone within Zjm TC3 section m: limestone, F:5PB 3/2 W:10YR 6/2 to N2. Well-bedded. Often contains granular to pebble-size chips of brown carbonate. Overlain by light grey to pink siltstone (Zju) m: carbonate breccia. Matrix (5RP 8/2 to 10YR 6/6) is silty and dolomitic. Clasts (5PB 5/2 to 5PB 3/2) are pebble to boulder size and frequently clast supported m: blue-grey sandy limestone. Brecciated in lower meter, intact above. Quartz and calcite veins throughout. Matrix of breccia is light brown (5YR 5/6). Limestone, F&W: 5PB 5/2 to 5PB 3/ m: siltstone. F:10G 8/2 W:5YR 4/1. Phyllitic. mm-scale pyrite cubes. 0-5 m: brown siltstone (5YR 4/4). Contains pebble to boulder-size clasts of grayish-pink (5R 8/2) limestone, often sandy, and rare clasts of dusky blue (5PB 3/2) limestone. Matrix supported clasts. TC4 section m: black siltstone with rounded carbonate boulders up to ~1.5 m in diameter. Overlain by light grey siltstone (Zjl) m: C4. Light grey siltstone m: C4. Grey dolostone, weathers orange m: Cycle 4 (C4). Light grey laminated dolostone m: C3. Light grey siltstone m: C3. Grey dolostone, weathers orange m: Cycle 3 (C3). Light grey laminated dolostone, siliciclastics decrease upward m: C2. Light grey siltstone m: C2. Tan dolostone, weathers orange m: Cycle 2 (C2). Light grey laminated dolostone with thin silty beds, as 61 to 63.5 m interval m: C1. Light grey siltstone with orange dolostone in lower meter m: Cycle 1 (C1). Light grey laminated to thin bedded dolostone. Alternate layers are brown dolomitic siltstone. Resembles "Radcliffe" interval from 9 to 10 m m: reddish brown siltstone as below, but with increasing amount of thin dolostone beds. Orange weathering dolostone beds in upper part m: reddish brown siltstone with occasional thin, brown dolostone beds m: breccia bed. Matrix is siltstone and thin bedded to laminated dolostone. Clasts are carbonate and are matrix supported. 4

5 12-23 m: light grey siltstone. Occasional thin beds of brown laminated dolostone m: light grey, massive dolostone, weathers orange m: light grey siltstone. Gradational contact with underlying carbonate m: light brown laminated dolostone. Contains thin, darker brown beds of siltstone. Resembles Radcliffe Member of Noonday Dolomite. 7-9 m: light grey, laminated dolostone m: grey, massive dolostone m: light grey, laminated dolostone 3-5 m: grey, massive dolostone m: grey, laminated dolostone. Lighter grey than below m: grey, laminated dolostone, weathers brown TC5 section m: dark green siltstone overlain by quartzite of the Stirling A Member m: grey and purple, granular quartzite m: dark grey siltstone (Zju) m: breccia. Pink, thin bedded to laminated dolostone m: light grey, resistant siltstone m: light grey siltstone, poorly outcropping m: brown, limey siltstone m: light grey to light green siltstone m: tan, dolomitic siltstone m: green siltstone m: tan, laminated dolomitic siltstone m: tan siltstone m: grey to green siltstone m: pink, silty dolostone. Laminated to thin-bedded m: light green and tan siltstone. Possibily dolomitic. Poorly outcropping m: purple-grey laminated dolostone and limestone m: grey-green siltstone m: tan, laminated dolostone m: grey-green dolomitic siltstone m: pink, thin bedded, dolostone and limestone m: grey, laminated dolomitic siltstone m: pink, thin bedded to laminated limestone m: purple, silty, thin bedded dolostone and limestone m: light grey to green, "mint green" siltstones m: light brown oolitic dolostone m: tan, silty dolostone overlying light grey siltstone TC6 section m: dark grey dolostone m: grey siltstone and sandstone m: dark grey massive dolostone m: light grey siltstone m: grey, massive dolostone 5

6 3-8 m: grey siltstone and sandstone m: light grey laminated dolostone m: dark grey siltstone and quartzite m: dark grey laminated dolostone. Overlies ledge of grey to purple sandstone (Zsc). Indian Pass section m: grey dolostone (sample IP3 from top). Overlain by grey and purple sandstone m: poorly outcropping m: grey and orange laminated limestone, weathers orange (sample IP2 from base) m: laminated brown dolostone. Poorly outcropping m: laminated purple dolostone (sample IP1 from base). Chocolate brown on weathered surface. Overlies thin green sandstone and, below that, silver siltstone and coarse- grained sandstone. 2 m to approximately 446 m: sandstones of the Stirling A Member m: brown to orange, sandy dolostone (includes samples FM3 and FM4). Becomes less sandy up section. Overlain by Stirling Quartzite m: brown, very coarse-grained, thin bedded, dolomitic sandstone m: orange-brown sandy dolostone (includes samples FM1 and FM2). Overlies brown to green, coarse-grained to granular sandstone, becoming more dolomitic up section. Lees Camp section m: mainly grey sandstone, much less carbonate than below m: alternating grey sandstones and brown dolostone m: laminated grey dolostone, massive in places m: grey, ridge-forming dolostone m: poorly outcropping tan and grey dolostone m: tan and grey, thin-bedded dolostone m: ridge-forming grey dolostone m: grey siltstone with thin, brown dolostone beds. 364 to 527 m: grey siltstones, little or no carbonate. Poorly outcropping m: siltstones and thin bedded sandstone, less carbonate than below m: alternating brown dolostone and siltstone m: thin brown dolostone 13 to approximately 310 m: grey sandstone and siltstones 2-13 m: massive, sandy dolostone 0-2 m: laminated, purple to pink dolostone. Overlies siltstone and sandstone. 6

7 Table DR1. C and O isotope data Johnson Canyon Base of section at approximately N, W (NAD27 continental US datum) Sample Stratigraphic δ 13 C VPDB δ 18 O VPDB Notes position (m) ( ) ( ) JC JC JC JC JC JC JC JC JC JC JC JC Break in section at prominent reddish brown dolostone below oolite JC JC JC Base of Johnnie oolite JC JC JC Top of Johnnie oolite JC Base of pink limestones JC JC JC JC JC JC Top of pink limestones JC JC JC JC JC JC JC JC JC Stirling contact at 235m 7

8 South fork, Hanaupah Canyon Base of section at approximately N, W Sample Stratigraphic δ 13 C VPDB δ 18 O VPDB Notes position (m) ( ) ( ) LA LA LA LA LA LA LA HC HC HC LA HC HC LA HC Base of edgewise conglomerate HC Top of edgewise conglomerate HC HC LA LA LA LA LA LA Stirling contact at ~563m North fork, Hanaupah Canyon Base of section at approximately N, W Sample Stratigraphic δ 13 C VPDB δ 18 O VPDB Notes position (m) ( ) ( ) CVNHC White marker bed at 22 to 27.5m CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC Stirling contact at 126m 8

9 Johnnie upper dolostone, near Wildrose Peak Section measured at approximately N, W. Samples collected from various locations within the unit. Sample Stratigraphic δ 13 C VPDB δ 18 O VPDB Notes position (m) ( ) ( ) PM PM PM PM PM PM PM PM PM PM PM58 ~ Giant ooids, values not plotted TC1 Section location shown on Fig. 9 Stratigraphic position Sample (m) d 13 C PDB d 18 O PDB Notes PM PM PM PM Zjm/breccia contact at ~39m PM PM PM Breccia/Zju contact at ~122.5m TC2 Section location shown on Figs. 9 and 10 Stratigraphic position Sample (m) d 13 C PDB d 18 O PDB Notes PM Dolostone in Zjm PM Dolostone in Zjm PM Lower block PM Base of upper block PM PM PM PM PM PM Top of upper block 9

10 TC3 Section location shown on Fig. 9 Stratigraphic position Sample (m) d 13 C PDB d 18 O PDB Notes TC Base of blue-grey limestone TC TC TC TC TC TC m below top of blue-grey limestone TC Base of black limestone TC TC TC TC TC TC TC TC TC TC TC TC Top of black limestone TC4 Section location shown on Fig. 9 Stratigraphic position Sample (m) d 13 C PDB d 18 O PDB Notes JL JL Jl JL JL JL JL JL Near base of deepening-upward cycles JL JL

11 TC5 Section location shown on Fig. 9 Stratigraphic position Sample (m) d 13 C PDB d 18 O PDB Notes AP Base of Zjm AP AP Oolitic dolostone AP Oolitic dolostone AP AP AP AP Pink, thin-bedded limestone AP Pink, thin-bedded limestone AP Pink, thin-bedded limestone AP AP AP AP AP AP AP AP AP AP AP Pink thin-bedded dolostone at base of breccia interval AP AP Dolostone at top of breccia AP AP AP Stirling contact at ~490m TC6 Section location shown on Fig. 9 Stratigraphic position Sample (m) d 13 C PDB d 18 O PDB Notes SD At base of Stirling D member SD SD SD SD

12 Indian Pass FM samples from approximately N, W IP samples from approximately N, W Sample Stratigraphic position (m) δ 13 C VPDB ( ) δ 18 O VPDB ( ) Notes FM Upper Johnnie Fm. FM Upper Johnnie Fm. FM Upper Johnnie Fm. FM Upper Johnnie Fm. IP Stirling A Member marker bed IP Stirling A Member marker bed IP Stirling A Member marker bed Lees Camp Base of section at approximately N, W Sample Stratigraphic position (m) δ 13 C VPDB ( ) δ 18 O VPDB ( ) Notes LC Stirling A Member marker bed LC Stirling A Member marker bed LC Stirling A Member marker bed LC Base of Stirling C Member LC LC LC Base of Stirling D Member LC LC LC LC LC LC LC LC

13 Composite C isotope profile (data plotted on Fig. 15) Sample Cumulative stratigraphic position (m) 13 C VPDB ( ) 18 O VPDB ( ) Notes JC Base of Johnson Canyon section JC JC JC JC JC JC JC JC JC JC JC JC JC JC Base of Johnnie oolite JC JC JC Top of Johnnie oolite JC Base of pink limestones JC

14 JC JC JC JC JC Top of pink limestones JC JC JC JC JC JC JC JC JC Top of Johnson Canyon section LA Base of S. Fork Hanaupah Canyon section LA LA LA Composite C isotope profile (continued) Sample Cumulative stratigraphic position (m) 13 C VPDB ( ) 18 O VPDB ( ) Notes LA LA LA

15 HC HC HC LA HC HC LA HC HC HC HC LA LA LA LA LA LA Top of S. Fork Hanaupah Canyon section CVNHC Base of N. Fork Hanaupah Canyon section CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC

16 CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC Top of N. Fork Hanaupah Canyon section AP Zju, Trail Canyon AP Zju, Trail Canyon AP Zju, Trail Canyon FM Base of Indian Pass section FM Composite C isotope profile (continued) Sample Cumulative stratigraphic position (m) 13 C VPDB ( ) 18 O VPDB ( ) Notes FM FM IP Stirling A Member marker bed, Indian Pass IP Stirling A Member marker bed, Indian Pass IP Stirling A Member marker bed, Indian Pass LC Base of Lees Camp section LC Stirling A Member marker bed LC Stirling A Member marker bed 16

17 LC Base of Stirling C Member LC LC LC Base of Stirling D Member LC LC LC LC LC LC LC LC

18 TABLE S1 18

19 Johnson Canyon Base of section at approximately N, W (NAD27 CONUS datum) Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) JC JC JC JC JC JC JC JC JC JC JC JC Break in section at prominent reddish brown dolostone below oolite JC JC JC Base of Johnnie oolite JC JC JC Top of Johnnie oolite JC Base of pink limestones JC JC JC JC JC JC Top of pink limestones JC JC JC JC JC JC JC JC JC Stirling contact at 235 m

20 South fork, Hanaupah Canyon Base of section at approximately N, W Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) LA LA LA LA LA LA LA HC HC HC LA HC HC LA HC Base of edgewise conglomerate HC Top of edgewise conglomerate HC HC LA LA LA LA LA LA Stirling contact at ~563 m

21 North fork, Hanaupah Canyon Base of section at approximately N, W Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) CVNHC White marker bed at 22 to 27.5 m CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC Stirling contact at 126 m

22 Johnnie upper dolostone, near Wildrose Peak Section measured at approximately N, W. Samples collected from various locations within the unit. Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) PM PM PM PM PM PM PM PM PM PM PM58 ~ Giant ooids, values not plotted

23 TC1 Section location shown on Fig. 9 Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) PM PM PM PM Zjm/breccia contact at ~39 m PM PM PM Breccia/Zju contact at m

24 TC2 Section location shown on Figs. 9 and 10 Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) PM Dolostone in Zjm PM Dolostone in Zjm PM Lower block PM Base of upper block PM PM PM PM PM PM Top of upper block

25 TC3 Section location shown on Fig. 9 Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) TC Base of blue-grey limestone TC TC TC TC TC TC m below top of blue-grey limestone TC Base of black limestone TC TC TC TC TC TC TC TC TC TC TC TC Top of black limestone

26 TC4 Section location shown on Fig. 9 Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) JL JL JL JL JL JL JL JL Near base of deepening-upward cycles JL JL

27 TC5 Section location shown on Fig. 9 Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) AP Base of Zjm AP AP Oolitic dolostone AP Oolitic dolostone AP AP AP AP Pink, thin-bedded limestone AP Pink, thin-bedded limestone AP Pink, thin-bedded limestone AP AP AP AP AP AP AP AP AP AP AP Pink thin-bedded dolostone at base of breccia interval AP AP AP AP AP Stirling contact at ~490 m

28 TC6 Section location shown on Fig. 9 Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) SD Base of Stirling D Member SD SD SD SD

29 Indian Pass FM samples from approximately N, W IP samples from approximately N, W Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) FM Upper Johnnie Fm. FM Upper Johnnie Fm. FM Upper Johnnie Fm. FM Upper Johnnie Fm. IP Stirling A Member marker bed IP Stirling A Member marker bed IP Stirling A Member marker bed

30 Lees Camp Base of section at approximately N, W Sample Stratigraphic 13 C VPDB 18 O VPDB Notes position (m) ( ) ( ) LC Stirling A Member marker bed LC Stirling A Member marker bed LC Stirling A Member marker bed LC Base of Stirling C Member LC LC LC Base of Stirling D Member LC LC LC LC LC LC LC LC

31 Composite C isotope profile (data plotted on Fig. 15) Sample Cumulative 13 C VPDB 18 O VPDB Notes stratigraphic position (m) ( ) ( ) JC Base of Johnson Canyon section JC JC JC JC JC JC JC JC JC JC JC JC JC JC Base of Johnnie oolite JC JC JC Top of Johnnie oolite JC Base of pink limestones JC JC JC JC JC JC Top of pink limestones JC JC JC JC JC JC JC JC JC Top of Johnson Canyon section LA Base of S. Fork Hanaupah Canyon section LA LA LA

32 Composite C isotope profile (continued) Sample Cumulative stratigraphic position (m) 13 C VPDB ( ) 18 O VPDB ( ) Notes LA LA LA HC HC HC LA HC HC LA HC HC HC HC LA LA LA LA LA LA Top of S. Fork Hanaupah Canyon section CVNHC Base of N. Fork Hanaupah Canyon section CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC CVNHC Top of N. Fork Hanaupah Canyon section AP Zju, Trail Canyon AP Zju, Trail Canyon AP Zju, Trail Canyon FM Base of Indian Pass section FM

33 Composite C isotope profile (continued) Sample Cumulative stratigraphic position (m) 13 C VPDB ( ) 18 O VPDB ( ) Notes FM FM IP Stirling A Member marker bed, Indian Pass IP Stirling A Member marker bed, Indian Pass IP Stirling A Member marker bed, Indian Pass LC Base of Lees Camp section LC Stirling A Member marker bed LC Stirling A Member marker bed LC Base of Stirling C Member LC LC LC Base of Stirling D Member LC LC LC LC LC LC LC LC

34 0 δ 13 C PDB Johnson Canyon -5 S. Fork, Hanaupah Canyon N. Fork, Hanaupah Canyon -10 jud, Wildrose Pk. TC1 δ 18 O PDB -15 TC2 TC3-20 TC4 TC5 TC6-25 Indian Pass Lees Camp -30

35 Ratios Age (Ma) Sample Pb(c) Pb* Th 206 Pb 208 Pb 206 Pb 207 Pb 207 Pb 206 Pb 207 Pb 207 Pb corr. Fractions (pg) Pb(c) U 204 Pb 206 Pb 238 U err 235 U err 206 Pb err 238 U 235 U 206 Pb coef. (a) (b) (c) (d) (e) (2 %) (e) (2 %) (e) (2 %) BW z (.09) (.15) (.11) z (.07) (.12) (.09) z (.13) (.15) (.08) z1a (.08) (.13) (.10) z2a (.09) (.13) (.09) z3a (.05) (.09) (.08) BW z (.09) (.27) (.24) z (.12) (.27) (.23) z (.10) (.21) (.17) z1a (.06) (.16) (.14) z2a (.06) (.10) (.08) z3a (.09) (.37) (.34) z (.17) (.75) (.68) (a) Air-abraded single zircon analyses. (b) Total common-pb in analyses. (c) Measured ratio corrected for spike and fractionation only. (d) Radiogenic Pb. (e) Corrected for fractionation spike, blank, and initial common Pb Mass fractionation correction of 0.25%/amu ± 0.04%/amu (atomic mass unit) was applied to single-collector Daly analyses Total procedural blank less than 0.8 pg for Pb and less than 0.1 pg for U Blank isotopic composition: 206Pb/204Pb = ± 0.53, 207Pb/204Pb = ± 0.35, 208Pb/204Pb = ± 1.1 Corr. coef. = correlation coefficient Age calculations are based on the decay constants of Steiger and Jäger (1977). Common-Pb corrections were calculated by using the model of Stacey and Kramers (1975) and the interpreted age of the sample.

36 REFERENCES CITED Stacey, J.S., and Kramers, J.D., 1975, Approximation of terrestrial lead isotope evolution by a 2- stage model: Earth and Planetary Science Letters, v. 26, p , doi: / x(75) Steiger, R.H., and Jäger, E., 1977, Subcommission on Geochronology: Convention on the use of decay constants in geo- and cosmochronology: Earth and Planetary Science Letters, v. 36, p , doi: / x(77)

REMARKS. NANNOFOSSIL CLAYSTONE, CLAYSTONE, and CALCAREOUS SANDY SILTSTONE

REMARKS. NANNOFOSSIL CLAYSTONE, CLAYSTONE, and CALCAREOUS SANDY SILTSTONE SITE 069 HOLE A CORE R CORED 78.8-78. mbsf 069A-R ACCEORIES NANNOFOIL CLAYSTONE, CLAYSTONE, and CALEOUS SANDY SILTSTONE CC AGE: middle Eocene Major Lithologies: Greenish gray (G 6/) to moderate yellowish