Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada, and Inyo County, California

Data Series 280

Table 3. Description of samples analyzed for strontium isotopic compositions from boreholes at the Nevada Test Site, Nye County, Nevada.

[Stratigraphic units are from lithology logs included in borehole completion reports to U.S. Department of Energy (see U.S. Geological Survey, 2006, for compilation of data and references, as well as Maldonado and others [1979], and Carr and others [1986]). Stratigraphic unit symbols are defined in table 1. Core and cutting samples were obtained in 2006 except for samples from boreholes UE–25 a #3 and UE–25 p #1, which were obtained in the early 1990s. Borehole depths are measured in feet below land surface. Abbreviations: DOE, Department of Energy; m, meter; mm, millimeter; >, greater than; <, less than; ±, plus or minus]

DOE borehole identification No.	Top depth (m)	Bottom depth (m)	Sample identification No.	Sample type	Stratigraphic unit symbol	Description
Army #1	261.8	261.8	Army 1(859)	Core	Cn-s	Mottled medium-to-dark grey, medium-grained limestone. Minor fractures filled with thin white secondary calcite. No alteration apparent.
262.7	262.7	Army 1(862)	Core	Cn-s	Friable, altered limestone consisting of equant, medium-grained, dark grey calcite crystals with intergranular iron-stained (clayey?) material. Also several fragments of other rock or vein material present as rounded clasts.
299.3	302.4	Army 1(982)A	Core	Cn-h	Uniform, coarse-grained, medium-grey dolomite. Minor color mottling between light and medium grey.
299.3	302.4	Army 1(982)B	Core	Cn-h	Thick (>15 mm) vein of sparry white-to-reddish tan calcite cutting grey dolomite. Sample isolates calcite vein from host rock.
388.9	345.0	Army 1(1112)	Core	Cn-h	Highly broken and altered limestone. Original light grey, medium grained carbonate is highly fractured and altered to friable, brown clay-rich material.
594.7	594.7	Army 1(1951)	Core fragments	Cb	Fragments of equigranular, coarse-grained, light-grey limestone with abundant fractures, some of which contain secondary cement and red-brown staining.
ER–3–1	694.9	698.0	ER3–1(2280)	Coarse cuttings	Cb	Medium-to-coarse grained, medium grey limestone.
786.4	789.4	ER3–1(2580)	Cuttings	Cb	Massive fine-grained, light grey limestone.
ER–5–3#2	1,456.9	1,460.0	ER5–3 2(4780)	Cuttings	Dsv	Medium-to-coarse grained, pinkish grey limestone.
ER–6–1#2	661.4	664.5	ER6–1 2(2170)	Cuttings	Dsv	Coarse grained, white-to-light grey dolomite.
801.6	804.7	ER6–1 2(2630)	Cuttings	Sl	Coarse grained, white-to-light grey dolomite.
862.6	865.6	ER6–1 2(2830)	Cuttings	Sl	Coarse grained, white-to-light grey dolomite.
911.3	914.4	ER6–1 2(2990)	Cuttings	Oes	Medium-to-coarse grained, grey dolomite.
ER–6–2	557.8	560.8	ER6–2(1830)	Cuttings	Cb	Medium-grained, grey limestone.
648.9	648.9	ER6–2(2129)	Core	Cb	Uniform medium-grained, brownish grey dolomite with scattered thin fractures containing fine-grained white filling material.
725.1	725.1	ER6–2(2379)	Core	Cb (mineralized fault)	Mottled medium-to-coarse grained, dark grey dolomite. Mottling is caused by irregular patches of coarser, lighter crystals surrounded by finer, darker crystals. Rock is cut by scattered thin, white-calcite-filled veins.
796.4	796.4	ER6–2(2613)	Core	Dg	Medium-grained, medium grey limestone with numerous thin fractures filled with white secondary calcite. No evidence of staining or alteration.
ER–6–2	829.5	829.5	ER6–2(2721.5)	Core	Dg (mineralized fault)	Mottled, fine-grained limestone consisting of light grey carbonate with extensive recrystallization and solution-breccia replacement textures. More-recent fractures commonly have light amounts of red staining.
ER–7–1	655.3	658.4	ER7–1(2150)	Coarse cuttings	Op	Very coarse-grained, medium grey limestone with patches or veins of finer grained carbonate that are either the same color as rock mass or lighter cream to reddish tan to brownish red.
728.5	731.5	ER7–1(2390)	Coarse cuttings	Op	Cuttings of very coarse-grained, medium grey limestone with very uniform consistency. No veins or accessory phases observed, but many of the calcite crystals and fragment surfaces are mildly stained brownish red.
ER–12–1	524.3	527.3	ER12–1(1720)	Cuttings	Lower Dg or upper Dsi	Fine-to-medium grained carbonate including both medium grey and dark grey components. Both graphite and dispersed fine-grained pyrite are common, as are fragment surfaces coated with reddish-brown staining.
1,018.0	1,021.1	ER12–1(3340)	Cuttings	Upper Dsv	Homogeneous sample of coarse-grained, white-to- light grey carbonate. Fragments are clean with no staining or other discoloration on surfaces.
ER–12–3	1,103.4	1,106.4	ER12–3(3620)	Cuttings	Mid to Late Ordovician	Uniform medium-grained, dark-grey dolomite with minor thin, white carbonate veins. Some veins are stained red.
1,368.6	1,371.6	ER12–3(4490)	Cuttings	Mid Ordovician to Late Cambrian	Fine-to-coarse grained, light-to-dark grey limestone with minor color laminae in some fragments. Occassional thin, coarsely crystalline white carbonate veins. Minor iron staining.
1,475.2	1,478.3	ER12–3(4840)	Cuttings	Mid Ordovician to Late Cambrian	Fine-to-coarse grained, medium-grey limestone with laminae in some fragments. Occasional thin white carbonate veins. Pyrite present on one fragment, but no noticable iron staining.
ER–12–4	786.4	789.4	ER12–4(2580)	Coarse cuttings	DSu	Cuttings dominated by medium- to coarse-grained, white-to-light grey dolomite. Small grains of an equant black mineral (oxidized pyrite?) are scattered throughout. Some surfaces have red staining.
1,051.6	1,054.6	ER12–4(3450)	Coarse cuttings	Mid Ordovician to Late Cambrian	Cutting sample includes a range of dolomite fragments. Coarse-grained, white-greenish-grey fragments are dominant, but medium-grained, medium-to-dark grey fragments also are common.
1,094.2	1,097.3	ER12–4(3590)	Cuttings	Mid Ordovician to Late Cambrian	Medium-to-coarse grained, medium-grey dolomite with abundant fine crystals of oxidized pyrite and coarse, white acicular mineral (tremolite?).
ER–16–1	1,079.0	1,082.0	ER16–1(3540)	Cuttings	Dg	Cuttings are dominated by fine-grained, black carbonate with graphite-like sheen on surfaces. Other lithologies are present, but were excluded from sample.
1,158.2	1,161.3	ER16–1(3800)	Cuttings	Dg	Medium-sized cuttings contain a heterogeneous suite of rock types, though most are carbonate. Lithologies range from coarse-grained, marble-like material to fine-grained, dark grey material similar to ER16–1(3540). Bulk material used for powder sample with no further picking.
HTH–3	563.9	566.9	HTH–3(1850)	Core fragments	Op	Fragments of equigranular, coarse-grained, medium-grey dolomite with abundant fractures, some of which contain micro-breccia and fine, white secondary cement ± brown staining.
TW–C	444.4	444.4	TW–C(1458)	Core	Dg	Medium-grained, grey limestone cut by numerous fractures filled with <1- to 5-mm-thick white secondary calcite veins. Minor red staining in some veins.
446.6	446.6	TW–C(1463.5)	Core	Dg	Coarse-grained, mottled grey limestone with extensive secondary veining and recrystallization that yields solution-breccia textures in areas. Secondary calcite is white to brownish red.
TW–D	540.4	541.6	TW–D(1773)	Cuttings	Cn-d	Massive, fine-to-medium-grained, grey limestone. Coarse cuttings have spotty, clay-like coating on fragment surfaces.
UE–1c	545.6	548.6	UE1c(1790)	Coarse cuttings	Op	Coarse-grained, grey limestone. Several chips have fine-grained, brownish material that coat fracture surfaces or form thin veins.
566.9	570.0	UE1c(1860)	Coarse cuttings	Op	Massive, fine-to-medium-grained, light pinkish to greenish brown limestone.
UE–1h	902.2	905.3	UE1h(2960)	Cuttings	Cn or Cb	Coarse grained, white-to-light grey dolomite.
UE–2ce	438.9	442.0	UE2ce(1440)	Cuttings	Cn or Cb	Coarse grained, white-to-light grey dolomite.
UE–7nS	625.5	625.5	UE7nS(2052.2)	Core	Op-av	Mottled limestone consisting of medium-to-coarse grained, light-brown limestone with irregular patches of fine-grained, brownish-red alteration product.
667.5	667.5	UE7nS(2190)	Core	Op-av	Mottled coarse-grained limestone. Patches of coarse, light grey limestone are separated by lenses and veins of finer-grained, iron-stained material.
UE–10j	393.2	394.7	UE10j(1290)	Coarse cuttings	Cn-s	Massive, fine-to-medium-grained grey dolomite. Rock is highly fractured with very thin white, clay-like material commonly present in fractures.
UE–10j	567.8	567.8	UE10j(1863)	Core	Cn-h	Fine-grained, dark-grey dolomite with distinct 1-to-5-mm-thick bedding-plane laminations defined by thin, light brown stylolitic planes and thicker planes of white secondary calcite. Thin veins with white calcite also cut across bedding.
625.1	625.1	UE10j(2051)	Core	Cn-d	Uniform, brownish-red, marly shale with conchoidal fracturing along shaley partings. Fine crystals are apparent under magnification. Some fracture surfaces have additional red staining.
656.5	656.5	UE10j(2154)	Core	Cb-b	Massive coarse-grained, white-to-light grey dolomite. Minor fractures contain light brown staining.
UE–15d	1,816.6	1,817.8	UE15d(5960)	Core	Zj or Zn	Mostly medium-grained, grey dolomite with planar foliation defined by color streaks and grain elongation, but also patches of greenish white, coarse-grained dolomite breccia. Accessory pyrite present in both phases.
1,827.0	1,827.0	UE15d(5994)	Core	Zj or Zn	Fine-grained, medium-grey dolomite with light-colored spots of coarser carbonate. Scattered fractures are filled with white secondary carbonate.
UE–16d	311.0	313.9	UE16d(1020)	Cuttings	PPt	Massive, fine-to-medium-grained, grey limestone.
472.4	475.5	UE16d(1550)	Cuttings	MDe	Very coarse, white-to-light grey limestone concentrated from heterogeneous lithologies (including volcanic and fine-grained carbonates) in cuttings sample by extensive hand picking.
UE–25 a #3	43.3	43.4	UE25a3–142	Core	Mc or MDg	Dark grey, very-fine-grained shale/argillite.
98.9	99.0	UE25a3–324	Core	Mc or MDg	Dark grey, very-fine-grained shale/argillite.
150.4	150.5	UE25a3–493	Core	Mc or MDg	Dark grey, very-fine-grained shale/argillite.
208.4	208.5	UE25a3–684	Core	Mc or MDg	Dark grey, very-fine-grained shale/argillite.
263.0	263.1	UE25a3–863	Core	Mc or MDg	Dark grey, very-fine-grained shale/argillite.
325.7	325.9	UE25a3–1069	Core	Mc or MDg	Dark grey, very-fine-grained shale/argillite.
435.9	436.0	UE25a3–1430	Core	Mc or MDg	Light tannish-grey, thermally altered shale/argillite.
525.0	525.1	UE25a3–1722	Core	Mc or MDg	Light grey, thermally altered shale/argillite.
562.5	562.6	UE25a3–1846	Core	Mc or MDg	Light grey, thermally altered shale/argillite.
637.8	637.9	UE25a3–2093	Core	Mc or MDg	Light grey, coarse-grained metasandstone.
697.2	697.3	UE25a3–2287	Core	Mc or MDg	Light greenish-grey, calcareous argillite.
741.1	741.2	UE25a3–2432	Core	Du	Dark orange-yellow, ferruginous clay seam.
759.6	759.7	UE25a3–2492	Core	Du	White calcitic marble.
766.4	766.5	UE25a3–2514	Core	Du	Light grey, laminated marble.
UE–25 p #1	1,277.9	1,278.0	HD–622	Core	DSlm	Light grey, massive, pelloidal dolomite.
1,284.1	1,284.2	HD–621	Core	DSlm	Light grey, fine-grained, massive dolomite.
1,798.3	1,798.4	UE25p 1–5900	Core	Sr	Dark grey, fine-grained dolomite with thin lamellae.

DOE borehole identification No.

Top depth (m)

Bottom depth (m)

Sample identification No.

Sample type

Stratigraphic unit symbol

Description

Army #1

261.8

Army 1(859)

Core

Cn-s

Mottled medium-to-dark grey, medium-grained limestone. Minor fractures filled with thin white secondary calcite. No alteration apparent.

262.7

Army 1(862)

Core

Cn-s

Friable, altered limestone consisting of equant, medium-grained, dark grey calcite crystals with intergranular iron-stained (clayey?) material. Also several fragments of other rock or vein material present as rounded clasts.

299.3

302.4

Army 1(982)A

Core

Cn-h

Uniform, coarse-grained, medium-grey dolomite. Minor color mottling between light and medium grey.

299.3

302.4

Army 1(982)B

Core

Cn-h

Thick (>15 mm) vein of sparry white-to-reddish tan calcite cutting grey dolomite. Sample isolates calcite vein from host rock.

388.9

345.0

Army 1(1112)

Core

Cn-h

Highly broken and altered limestone. Original light grey, medium grained carbonate is highly fractured and altered to friable, brown clay-rich material.

594.7

Army 1(1951)

Core fragments

Fragments of equigranular, coarse-grained, light-grey limestone with abundant fractures, some of which contain secondary cement and red-brown staining.

ER–3–1

694.9

698.0

ER3–1(2280)

Coarse cuttings

Medium-to-coarse grained, medium grey limestone.

786.4

789.4

ER3–1(2580)

Cuttings

Massive fine-grained, light grey limestone.

ER–5–3#2

1,456.9

1,460.0

ER5–3 2(4780)

Cuttings

Dsv

Medium-to-coarse grained, pinkish grey limestone.

ER–6–1#2

661.4

664.5

ER6–1 2(2170)

Cuttings

Dsv

Coarse grained, white-to-light grey dolomite.

801.6

804.7

ER6–1 2(2630)

Cuttings

Coarse grained, white-to-light grey dolomite.

862.6

865.6

ER6–1 2(2830)

Cuttings

Coarse grained, white-to-light grey dolomite.

911.3

914.4

ER6–1 2(2990)

Cuttings

Oes

Medium-to-coarse grained, grey dolomite.

ER–6–2

557.8

560.8

ER6–2(1830)

Cuttings

Medium-grained, grey limestone.

648.9

ER6–2(2129)

Core

Uniform medium-grained, brownish grey dolomite with scattered thin fractures containing fine-grained white filling material.

725.1

ER6–2(2379)

Core

Cb (mineralized fault)

Mottled medium-to-coarse grained, dark grey dolomite. Mottling is caused by irregular patches of coarser, lighter crystals surrounded by finer, darker crystals. Rock is cut by scattered thin, white-calcite-filled veins.

796.4

ER6–2(2613)

Core

Medium-grained, medium grey limestone with numerous thin fractures filled with white secondary calcite. No evidence of staining or alteration.

ER–6–2

829.5

ER6–2(2721.5)

Core

Dg (mineralized fault)

Mottled, fine-grained limestone consisting of light grey carbonate with extensive recrystallization and solution-breccia replacement textures. More-recent fractures commonly have light amounts of red staining.

ER–7–1

655.3

658.4

ER7–1(2150)

Coarse cuttings

Very coarse-grained, medium grey limestone with patches or veins of finer grained carbonate that are either the same color as rock mass or lighter cream to reddish tan to brownish red.

728.5

731.5

ER7–1(2390)

Coarse cuttings

Cuttings of very coarse-grained, medium grey limestone with very uniform consistency. No veins or accessory phases observed, but many of the calcite crystals and fragment surfaces are mildly stained brownish red.

ER–12–1

524.3

527.3

ER12–1(1720)

Cuttings

Lower Dg or upper Dsi

Fine-to-medium grained carbonate including both medium grey and dark grey components. Both graphite and dispersed fine-grained pyrite are common, as are fragment surfaces coated with reddish-brown staining.

1,018.0

1,021.1

ER12–1(3340)

Cuttings

Upper Dsv

Homogeneous sample of coarse-grained, white-to- light grey carbonate. Fragments are clean with no staining or other discoloration on surfaces.

ER–12–3

1,103.4

1,106.4

ER12–3(3620)

Cuttings

Mid to Late Ordovician

Uniform medium-grained, dark-grey dolomite with minor thin, white carbonate veins. Some veins are stained red.

1,368.6

1,371.6

ER12–3(4490)

Cuttings

Mid Ordovician to Late Cambrian

Fine-to-coarse grained, light-to-dark grey limestone with minor color laminae in some fragments. Occassional thin, coarsely crystalline white carbonate veins. Minor iron staining.

1,475.2

1,478.3

ER12–3(4840)

Cuttings

Mid Ordovician to Late Cambrian

Fine-to-coarse grained, medium-grey limestone with laminae in some fragments. Occasional thin white carbonate veins. Pyrite present on one fragment, but no noticable iron staining.

ER–12–4

786.4

789.4

ER12–4(2580)

Coarse cuttings

DSu

Cuttings dominated by medium- to coarse-grained, white-to-light grey dolomite. Small grains of an equant black mineral (oxidized pyrite?) are scattered throughout. Some surfaces have red staining.

1,051.6

1,054.6

ER12–4(3450)

Coarse cuttings

Mid Ordovician to Late Cambrian

Cutting sample includes a range of dolomite fragments. Coarse-grained, white-greenish-grey fragments are dominant, but medium-grained, medium-to-dark grey fragments also are common.

1,094.2

1,097.3

ER12–4(3590)

Cuttings

Mid Ordovician to Late Cambrian

Medium-to-coarse grained, medium-grey dolomite with abundant fine crystals of oxidized pyrite and coarse, white acicular mineral (tremolite?).

ER–16–1

1,079.0

1,082.0

ER16–1(3540)

Cuttings

Cuttings are dominated by fine-grained, black carbonate with graphite-like sheen on surfaces. Other lithologies are present, but were excluded from sample.

1,158.2

1,161.3

ER16–1(3800)

Cuttings

Medium-sized cuttings contain a heterogeneous suite of rock types, though most are carbonate. Lithologies range from coarse-grained, marble-like material to fine-grained, dark grey material similar to ER16–1(3540). Bulk material used for powder sample with no further picking.

HTH–3

563.9

566.9

HTH–3(1850)

Core fragments

Fragments of equigranular, coarse-grained, medium-grey dolomite with abundant fractures, some of which contain micro-breccia and fine, white secondary cement ± brown staining.

TW–C

444.4

TW–C(1458)

Core

Medium-grained, grey limestone cut by numerous fractures filled with <1- to 5-mm-thick white secondary calcite veins. Minor red staining in some veins.

446.6

TW–C(1463.5)

Core

Coarse-grained, mottled grey limestone with extensive secondary veining and recrystallization that yields solution-breccia textures in areas. Secondary calcite is white to brownish red.

TW–D

540.4

541.6

TW–D(1773)

Cuttings

Cn-d

Massive, fine-to-medium-grained, grey limestone. Coarse cuttings have spotty, clay-like coating on fragment surfaces.

UE–1c

545.6

548.6

UE1c(1790)

Coarse cuttings

Coarse-grained, grey limestone. Several chips have fine-grained, brownish material that coat fracture surfaces or form thin veins.

566.9

570.0

UE1c(1860)

Coarse cuttings

Massive, fine-to-medium-grained, light pinkish to greenish brown limestone.

UE–1h

902.2

905.3

UE1h(2960)

Cuttings

Cn or Cb

Coarse grained, white-to-light grey dolomite.

UE–2ce

438.9

442.0

UE2ce(1440)

Cuttings

Cn or Cb

Coarse grained, white-to-light grey dolomite.

UE–7nS

625.5

UE7nS(2052.2)

Core

Op-av

Mottled limestone consisting of medium-to-coarse grained, light-brown limestone with irregular patches of fine-grained, brownish-red alteration product.

667.5

UE7nS(2190)

Core

Op-av

Mottled coarse-grained limestone. Patches of coarse, light grey limestone are separated by lenses and veins of finer-grained, iron-stained material.

UE–10j

393.2

394.7

UE10j(1290)

Coarse cuttings

Cn-s

Massive, fine-to-medium-grained grey dolomite. Rock is highly fractured with very thin white, clay-like material commonly present in fractures.

UE–10j

567.8

UE10j(1863)

Core

Cn-h

Fine-grained, dark-grey dolomite with distinct 1-to-5-mm-thick bedding-plane laminations defined by thin, light brown stylolitic planes and thicker planes of white secondary calcite. Thin veins with white calcite also cut across bedding.

625.1

UE10j(2051)

Core

Cn-d

Uniform, brownish-red, marly shale with conchoidal fracturing along shaley partings. Fine crystals are apparent under magnification. Some fracture surfaces have additional red staining.

656.5

UE10j(2154)

Core

Cb-b

Massive coarse-grained, white-to-light grey dolomite. Minor fractures contain light brown staining.

UE–15d

1,816.6

1,817.8

UE15d(5960)

Core

Zj or Zn

Mostly medium-grained, grey dolomite with planar foliation defined by color streaks and grain elongation, but also patches of greenish white, coarse-grained dolomite breccia. Accessory pyrite present in both phases.

1,827.0

UE15d(5994)

Core

Zj or Zn

Fine-grained, medium-grey dolomite with light-colored spots of coarser carbonate. Scattered fractures are filled with white secondary carbonate.

UE–16d

311.0

313.9

UE16d(1020)

Cuttings

PPt

Massive, fine-to-medium-grained, grey limestone.

472.4

475.5

UE16d(1550)

Cuttings

MDe

Very coarse, white-to-light grey limestone concentrated from heterogeneous lithologies (including volcanic and fine-grained carbonates) in cuttings sample by extensive hand picking.

UE–25 a #3

43.3

43.4

UE25a3–142

Core

Mc or MDg