USGS Logo Geological Survey Professional Paper 215
Geology of the Southern Guadalupe Mountains, Texas
SELECTED STRATIGRAPHIC SECTIONS

In the course of the field work, numerous stratigraphic sections were measured, and these sections were of great aid in working out the stratigraphy of the region. However, it appeared that giving any or all of the sections in the text of this report would confuse, rather than aid, the description of the stratigraphy. They were therefore omitted and the reader is referred to plates 6, 8, 13, and 15, on which most of the sections are shown graphically.

The sections are, however, of great value to geologists who might wish to study the stratigraphy in the field, or the fossil collections obtained from the region. It therefore seems desirable to include in this report some of the sections that are particularly well exposed or contain abundantly fossiliferous zones, or extend across the type localities of formations, and members. Thirteen of these sections are given. As here presented, they are considerably revised and condensed from the original field notes.




SECTION 1

Measured on west slope of Cutoff Mountain, beds 1 to 5 on south side of canyon just north of Texas-New Mexico line, the higher beds in the embayment that slopes westward from the summit. Correction has been made for a fault that crosses the embayment. (See pl. 6.)


Feet

Carlsbad limestone:


16. Light-gray, fine-grained limestone, weathering white, in 6-inch to 1-foot beds. Forms receding ledges at top of mountain45

15. Thin-bedded limestone and pinkish sandstone20

14. Similar to bed 16, forming a cliff45

13. Basal sandstone member: Buff, fine-grained sandstone in thick, rounded ledges, covered on surface with brown crust. Passes above into platy or pinkish limestone55


Goat Seep limestone:


12. Light-gray, fine-grained, dolomitic limestone, weathering white, in beds a few inches to more than a foot thick, with some thick ledges and cliffs, interbedded with fine-grained, pinkish sandstone165

11. Light-gray, dolomitic limestone in 1-foot beds, in members 10 feet or more thick, interbedded with buff, medium-grained, calcareous sandstone like that below147

10. Calcareous, medium-grained, buff sandstone, weathering brown, in 2- to 5-foot beds, in part cross-bedded, and with some layers containing molds of fusulinids. Some layers are more calcareous250


Sandstone tongue of Cherry Canyon formation:


9. Buff or pink, soft, fine-grained sandstone, in thin beds or blocky layers up to 2 feet thick. Some calcareous beds in upper part. Toward top contains irregular siliceous masses and silicified brachiopods206


Bone Spring limestone:
   Cutoff shaly member: (type section):


8. Prominent ledges of drab-gray, fine-grained or dense limestone in 1-foot beds. Some granular beds in lower part contain fragments of crinoid stems and brachiopods. Upper part contains pelecypod imprints. Near middle, soft, platy sandstone and siliceous shale is interbedded113

7. Platy, black siliceous shale and black shaly limestone, interbedded with black, dense limestone. Shales contain small, spherical limestone concretions109

6. Black, dense limestone in beds a few inches thick, weathering dove-gray, with some chert bands. Contains Chonetes and other brachiopods11

   Victorio Peak gray member:


5. Upper division: Thin-bedded limestone, forming receding ledges packed with poorly preserved fusulinids and productids. Top forms an even bed25

4. Gray, fine-grained limestone, in massive beds up to 7 feet thick, forming cliffs above and below, but with a slope near middle. Upper cliff contains chert nodules217

3. Middle division: Pale buff, fine-grained sandstone in rounded 1-foot ledges, overlain by flaggy, porcelainlike, white limestone20

2. White, evenly bedded, laminated limestone in 1-foot beds, some of which contain crinoid fragments and small pisolites, forming 10-foot members. Thinner members of buff, fine-grained, calcareous sandstone are interbedded97

1. Lower division: Gray, fine-grained, somewhat dolomitic limestone in 1- to 6-foot beds. Contains rare, small chert concretions. Thinner beds weather hackly184
Base concealed.


SECTION 7

Measured on west slope of Bartlett Peak, 3/4 mile north of Shirttail Canyon. Section begins at base of projecting promontory of escarpment. On this escarpment, the lower division of the Victorio Peak gray member could not be measured, as it stands in an inaccessible cliff. The description and thickness of the lower division are therefore taken from section 8, one-quarter of a mile to south. (See pls. 6, 8.)


Feet

Goat Seep limestone:


14. Massive, gray dolomite, standing in single cliff, not measured. Top was examined on north slope of Bartlett Peak, where it is a massive, sandy dolomite, containing casts of fossils (locality 7404). Thickness estimated900

13. Gray, dolomitic limestone in 5-foot beds, inter-bedded with thick-bedded, sandy dolomite and thin-bedded sandstone. Beds in this part of formation considerably more sandy here than on adjacent ridges254


Sandstone tongue of Cherry Canyon formation:


12. Buff, brown, or reddish, fine-grained, thin-bedded sandstone, with some thicker-bedded sandstone and a few calcareous layers321


Bone Spring limestone:
   Cutoff shaly member:


11. Dark gray, fine-grained limestone in 6-inch to 1-foot beds, in part cherty, weathering into hackly fragments. Forms poor ledges and rounded slopes133

10. Black, sandy shale and platy limestone38

   Victorio Peak gray member:


9. Upper division: Gray limestone in thick, massive beds, standing in cliffs. Near middle is a bed of calcareous sandstone. Top limestone beds contain abundant fusulinids and some brachiopods186

8. Middle division: Light gray to white calcitic limestone in beds several feet thick, forming slope77

7. Lower division: Stands in inaccessible cliff along line of section 7, in steep ledges along line of section 8, where these observations were made. Gray to dark gray, fine-grained, dolomitic limestone in beds several feet thick, containing fossil fragments and widely spaced, large, gray, and buff chert masses. Weathers gray-brown and pitted. Bed of calcareous sandstone 40 feet above base372

   Black limestone beds:


6. Black, dense, laminated limestone, weathering gray-brown, in beds a few inches thick, with chert masses. Upper part changes to gray color139

5. Light gray to dark gray, granular limestone in beds several feet thick, containing fragments of productids, corals, and crinoids, and occasional chert masses, forming ledges and narrow cliffs. Some interbedded, lenticular, massive, reef like limestone beds, and occasional beds of black limestone (fossil locality 7689)127

4. Dense black limestone in 1-foot beds, with some platy sandy limestone and granular limestone147

3. Light gray, granular limestone, containing fragments of crinoids and other fossils, in 1-foot beds, standing in cliff37

2. Buff, calcareous, fine-grained sandstone in rounded ledges10

1. Black, fine-grained to dense limestone in 6-inch to 2-foot beds that form even, parallel layers. Weathers gray or gray-brown. Chert concretions in some beds435
Base concealed.


SECTION 10

Section on north wall of Shumard Canyon. Bed 1 measured on projecting spur on north side of canyon at entrance; beds 2 and 3 along goat trail a few hundred yards to east; bed 4 on west side of hill whose elevation is 6,402 feet; beds 5 and 6 east of hill. Section ends a short distance below top of Brushy Canyon formation. (See pl. 6).


Feet

Delaware Mountain group:
   Brushy Canyon formation:


6. Buff, medium-grained sandstone in 2-foot to 5-foot beds, in part cross-bedded, in part calcareous. Some layers rest on channeled surfaces. Thin-bedded sandstone in middle112

5. Thin-bedded, buff, friable, fine-grained sandstone with 5-foot bed of medium-grained sandstone near middle. Lies unconformably on limestones below, which rise in a hill to west. Lower sandstones dip 30° off the hill, but dips flatten in higher beds to east105


Bone Spring limestone:
   Victorio Peak gray member:


4. Upper division: White to light gray, fine-grained, calcitic limestone, in beds several feet thick with no chert. Weathers to blue-gray, slightly pitted surfaces. Some beds contain abundant brachiopods (locality 7690). Rests with sharp contact on beds beneath. Thickness on south side of ridge appears to be greater than that given, on account of low south dip165

3. Lower division: Gray-brown; fine-grained, dolomitic limestone, weathering to drab, pitted surfaces. Contains large spherical concretions and knotted masses of chert, which are less abundant above. Beds range in thickness from a few inches to 5 feet, the thicker beds forming ledges, cliffs, and serrated walls. Occasional fossils427

   Black limestone beds:


2. Black, fine-grained to dense limestone in 3-inch to 1-foot beds, with irregular black and brown chert nodules and some interbedded platy layers. Somewhat thicker-bedded above. Beds are truncated at several horizons. Fossil locality 7712 is 300 feet above base385

1. Black, fine-grained to dense limestone, weathering gray or gray-brown, in 3-inch to 1-foot beds, with some knotted chert bands. Two members in lower half up to 30 feet thick of platy, shaly black limestone and sandy limestone. Rock is divided into slices 30 feet or more thick, each of which truncates underlying slice, and each with different dip, which in some slices reaches a maximum of 20°332
Base concealed.


SECTION 11

Measured up spur that projects southwestward from Shumard Peak, east of upper end of section 10. Only upper part (above Brushy Canyon formation) is given here; it begins on south side of spur, 1/2 mile south-southwest of summit of Shumard Peak. (See pl. 6.)


Feet

Capitan limestone: forming cliffs at top of section.

Delaware Mountain group:
   Bell Canyon formation:
      Hegler limestone member:


18. Thin- to thick-bedded or massive, light gray or white limestone, with some chert, interbedded with calcareous sandstone121

17. Thin-bedded to massive, buff, calcareous sandstone, with some limestone lenses36

16. Thin- to thick-bedded, gray or white limestone, with chert seams and some interbedded sandstone. Contains Spirifer, Domopora, and small productids. Forms cliff45

   Cherry Canyon formation:


15. Massive, buff sandstone15

14. Manzanita limestone member: Gray-buff, fine-grained limestone in beds a few inches thick, weathering yellow-brown. Contains irregular chert masses and geodic cavities. Pinches out a short distance to north14

13. Soft, greenish-gray sandstone, weathering buff, in rounded ledges42

   Goat Seep limestone (marginal facies, transitional into Cherry Canyon formation):


12. Buff, fine-grained limestone forming cap of projecting spur15

11. Soft sandstone0

10. Blue-gray to buff limestone, in 6-inch to 1-foot beds, containing a few small chert masses and a Gastrioceras24

9. Buff, fine- to medium-grained, laminated sandstone in beds several inches thick, weathering brown. Interbedded in lower part with gray dolomitic limestone in 2-foot beds120

8. Gray, fine-grained, dolomitic limestone, weathering to smooth, white surfaces, containing fusulinids, crinoid stems, and flat pebbles. Forms thick, lenticular beds, interbedded with sandstone. Several beds rest on channeled surfaces. Passes upward into inter-bedded, thin-bedded limestone and sandstone115

7. Buff, brown-weathering, medium-grained sandstone in beds a few inches thick, with some interbedded limestone59

6. Gray, fine-grained, dolomitic limestone, in lenticular massive beds, containing sandy streaks, breccia, and fusulinids29

5. Medium- to fine-grained, laminated sandstone, weathering brown13

4. Platy, dense, gray limestone, weathering white8

3. Buff, thin-bedded, fine-grained sandstone, with some shaly sandstone below142

2. Fine-grained, dolomitic limestone, weathering drab, in beds several feet thick, containing poorly preserved fusulinids and crinoid stems. Some thinner beds at top. Member thins out to north and south, but interfingers with main mass of Goat Seep limestone north of Shirttail Canyon22

   Cherry Canyon formation:


1. Buff, thin-bedded, fine-grained sandstone, with 15-foot bed of hard, platy sandstone in lower part203

   Brushy Canyon formation: Thick ledges of medium grained sandstone at base.


SECTION 14

Measured along north side of Bone Canyon. Beds 1 and 2, constituting section 14—a, measured up north wall of canyon at its entrance; beds 3 to 11 measured up north wall of canyon one-quarter mile to east; higher beds measured on spur on north side of waste-covered embayment at head of canyon, starting at Bone Spring and ending on bench at foot of Capitan limestone cliff one-quarter mile west of Guadalupe Peek. (See pls. 6, 13.)


Feet

Capitan limestone: Massive white limestone, extending in cliffs up to summit of Guadalupe Peak.

Delaware Mountain group:
   Bell Canyon formation:
      Hegler limestone member:


37. Thin-bedded, white limestone40

36. Yellow-brown, massive sandstone15

35. Blue-gray, dense limestone in 1-foot beds, with some chert nodules and bands, interbedded with thin layers of buff sandstone and calcareous sandstone137

34. Thick-bedded, blue-gray, cherty limestone in prominent ledges and cliffs56

   Cherry Canyon formation:


33. Massive, greenish-buff, fine-grained sandstone with faint laminations, weathering brown or reddish52

32. Manzanita limestone member: Dense, calcarous sandstone in beds a few inches thick, weathering yellow, and standing in ledges and cliffs. Interbedded with thin-bedded, friable, greenish sandstone. Near middle, a 1-foot bed of green chert99

31. Massive, greenish-gray, fine-grained sandstone44

      South Wells limestone member:


30. Buff, sandy, cherty limestone in beds up to 1 foot thick, interbedded with buff sandstone23

29. Buff, thin-bedded, fine-grained sandstone28

28. Hard, dense, calcareous sandstone in beds a few inches thick, weathering buff. Contains geodic cavities, and molds of ammonoids4

27. Buff, thin-bedded, fine-grained sandstone66

26. Laminated, gray or buff, sandy limestone in 3-inch to 6-inch beds, interbedded with grey, platy, shaly sandstone. Forms ragged ledges44

25. Buff, thin-bedded, fine-grained, laminated sandstone148

      Getaway limestone member:


24. Drab, dense, flaggy limestone, interbedded with shaly sandstone19

23. Buff to drab, sandy, dolomitic limestone in a single massive, lenticular bed. Contains pebbles in lower part, and poorly preserved fusulinids11

22. Thin-bedded, buff, fine-grained sandstone24

21. Gray, dense or fine-grained limestone, weathering drab, in beds a few inches to several feet thick46

20. Buff, thin-bedded, laminated, fine-grained sandstone interbedded in upper part with dark shaly sandstone and flaggy, calcareous sandstone. Some channeling170

   Brushy Canyon formation:


19. Buff, medium-grained, quartzitic sandstone, weathering brown and forming a prominent ledge. Rests on channeled surface10

18. Thin-bedded, buff sandstone, with a layer of dark shaly sandstone near middle314

17. Dark, shaly, platy sandstone, with some interbedded buff sandstone, forming prominent ledges72

16. Buff, thin-bedded, fine-grained sandstone72

15. Three ledge-making layers up to 10 feet thick, of dark, shaly, platy sandstone, separated by buff, thin-bedded, fine-grained laminated sandstone115

14. Buff, thin-bedded, fine-grained, laminated sandstone, becoming a little thicker-bedded above145

13. Dark, shaly, platy sandstone, interbedded with some buff sandstone, forming prominent bench28

12. Buff, thin-bedded, fine-grained sandstones50

11. Massive, buff, medium-grained sandstone, in part calcareous. Changes into platy sandstone to east, where it crops out near Bone Spring6

10. Thin-bedded sandstone5

9. Massive, buff, medium-grained sandstone, in part calcareous, containing fusulinid casts and ripple marks22

8. Conglomerate of limestone pebbles in a calcareous sandstone matrix6

7. Sandy, gray or gray-brown limestone in beds several feet thick, with some quite sandy layers and a conglomerate lens near middle33

6. Buff, medium-grained, laminated sandstone in 3-inch to 2-foot beds21

5. Conglomerate of limestone pebbles in a calcareous sandstone matrix4

4. Buff, medium-grained sandstone in 6-inch to 1-foot beds; some cross bedding12

3. Conglomerate of limestone pebbles and cobbles in a sandy limestone matrix. Some interbedded dolomitic sandy limestone that disappears into the conglomerate to northwest. Rests unconformably on Bone Spring limestone, whose top bed is here a lens of massive gray limestone, resting on black limestone16

Bone Spring limestone (type section):
   Black limestone beds:


2. Ledges more prominent than below, of black limestone in 6-inch to 1-foot beds, with some chert. Near middle are lenticular beds of black, fine-grained limestone, containing crinoid stems and other fossil fragments264

1. Black, dense limestone, weathering buff or gray, in well-laminated beds, in part platy, in part several inches thick. Some chert bends and some interbedded shaly or sandy limestone. Some irregular dips and truncation of beds. Forms irregular ledges and bluffs 257
Base concealed.


SECTION 18

Measured up South slope of El Capitan. Bed 1 measured near outer edge of escarpment on south bank of next canyon north of Indian Cave, or 2 miles south-southwest of El Capitan; beds 2 to 10 up west slope of butte 1-1/2 miles south of El Capitan; beds 11 to 20 farther north along same ridge, starting 1 mile south of El Capitan and proceeding up to great sandstone bench; higher beds on slope southeast of El Capitan, starting at top of sandstone bench and proceeding up to base of cliffs. (See pl. 6).


Feet

Capitan limestone:


42. Massive limestone, with faint, inclined bedding planes, extending to top of cliff

43. Massive white limestone, interbedded with thin. bedded, white limestone, containing large limestone lenses25


Delaware Mountain group:
   Bell Canyon formation:


40. Thin-bedded white limestone15

39. Soft, greenish-gray sandstone, parts of which weather red, with some interbedded white limestone30

      Pinery limestone member:


38. Dark gray, fine-grained, somewhat lumpy, thin-bedded limestone. Some thicker layers33

37. Light to dark gray, fine-grained or dense limestone in 3-inch to 1-foot beds. Stylolites prominent in places49

36. Grey to dark gray, fine-grained limestone in 6-inch to 1-foot beds, in part cherty, interbedded with layers of massive, granular, gray, fossiliferous limestone up to 5 feet thick 52

35. Gray, granular limestone in massive beds, containing silicified fossils and some chert masses32

34. Buff, thin-bedded sandstone, interbedded with dense, dark gray, flaggy limestone36

33. Hegler limestone member: Gray, fine-grained, lumpy, slabby limestone, with some traces of fossils, in two ledges, separated by pale, greenish-gray sandstone15

   Cherry Canyon formation:


32. Soft, pale greenish-gray, thin-bedded sandstone65

31. Manzanita limestone member: Pale buff or gray sandstone and sandy limestone in blocky, rounded ledges, weathering orange-brown, part of it full of geodic cavities. Several layers of apple-green, siliceous shale and bentonitic clay6

30. Massive, greenish-gray, fine-grained sandstone, without bedding planes44

29. Buff, thin-bedded, fine-grained sandstone, with some 1-foot beds, and occasional thin, discontinuous layers of dark, platy, shaly sandstone369

28. Black, dense, drab-weathering limestone in 6-inch to 1-foot beds, with some ammonoid imprints, interbedded with platy sandstone27

27. Thin-bedded, buff, fine-grained sandstone with some 6-inch beds70

      Getaway limestone member (very poorly developed):


26. Hard, platy, calcareous and quartzitic sandstone, forming bench10

25. Buff, fine-grained, thin-bedded sandstone, with thin beds of black sandy limestone and gray, hard, platy sandstone 100

24. Black, dense, sandy limestone, weathering brown, and gray platy sandstone. Forms bench6

23. Buff, thin-bedded, fine-grained sandstone, with some dark gray, platy, shaly sandstone115

22. Two 6-inch beds of brown, sandy, flaggy limestone, separated by thin-bedded sandstone23

21. Buff, fine-grained, thin-bedded sandstone, with some harder, platy beds99

   Brushy Canyon formation:


20. Calcareous sandstone, similar to bed 19. Cross-bedded and lenticular, with thin zones of conglomerate and casts of fusulinids36

19. Massive, very prominent ledge, forming projecting bench about halfway up mountain side toward El Capitan. Consists of medium-grained, buff sandstone, weathering brown, in beds several feet thick. Rests on channeled surface85

18. Fine to medium-grained buff sandstone in beds a few inches to several feet thick, with some platy beds at base96

17. Buff, fine-grained, thin-bedded sandstone, with some platy beds in lower part272

16. Medium-grained, buff sandstone in beds several feet thick, weathering brown, forming prominent ledge18

15. Buff, fine-grained, thin-bedded sandstone, with some thicker beds65

14. Thick-bedded, medium-grained, brown sandstone and some platy sandstone, forming prominent ledges9

13. Buff, thin-bedded, fine-grained sandstone, with some thicker beds, interbedded below with gray, platy or papery sandstone, which projects in ledges34

12. Buff, thin-bedded, fine-grained sandstone90

11. Buff, thin-bedded, fine-grained sandstone, interbedded with hard, gray, platy sandstone, which forms well-marked ledges at top71

10. Fine-grained, hard, platy sandstone, weathering brown, with some quartzitic beds at top. Forms prominent ledges at top of bench. Changes into massive, medium-grained sandstone to south, on hill 508720

9. Dark-gray, platy, shaly sandstone, interbedded with buff, thin-bedded sandstone81

8. Buff, thin-bedded, fine-grained sandstone31

7. Medium-grained buff sandstone in beds several feet thick, with ripple marks. Forms ledge17

6. Buff, thin-bedded, fine-grained sandstone, with some shaly sandstone below54

5. Fine- to medium-grained buff sandstone, forming ledges above and below38


Bone Spring limestone:
   Cutoff shaly member:


4. Thin-bedded, buff, fine-grained sandstone with a 1-foot bed of granular, fossiliferous limestone in middle40

3. Medium-grained buff sandstone in beds several feet thick5

2. Black, calcareous, papery shale, containing spherical limestone nodules an inch to a foot across2

   Black limestone beds:


1. Black limestone, mostly thin-bedded, cropping out in irregular ledges and bluffs, separated by slopes. Most of beds are a few inches to a foot thick, part are evenly bedded and laminated, others are lumpy, knotted, or even markedly lenticular. Near middle are lenses a foot or more thick containing silicified bryozoans. Lower beds are papery or platy, and in part sandy. Some contortion of beds and slickensiding on bedding planes242
Base concealed.


SECTION 21

Measured on hillside above Pine Spring, starting at the level of the spring and proceeding up the slope to the base of the Capitan limestone. (See pls. 6, 15.)


Feet

Capitan limestone:


19. Massive white to gray dolomitic limestone, extending up to crest of Pine Top Mountain

18. Massive, white dolomitic limestone in pinching and swelling beds up to 8 feet thick, interbedded with white limestone in beds a few inches thick25


Delaware Mountain group:
   Bell Canyon formation:


17. Light-gray, granular limestone in beds several feet thick, containing some brachiopods (fossil locality 7702)12

16. Buff, fine-grained, thin-bedded sandstone, interbedded with dark-gray, platy, shaly limestone, and with fine-grained, gray limestone. The last forms 1-inch to 6-inch beds, in part laminated, and contains chert and some fossils50

15. Buff, fine-grained, thin-bedded sandstone23

14. Gray, fine-grained limestone in beds several feet thick, containing chert lenses12

13. Buff, fine-grained, thin-bedded sandstone, interbedded with dark-gray, fine-grained, slabby limestone55

      Pinery limestone member (type section):


12. Soft, buff, sandstone, interbedded with 1-foot beds of gray fossiliferous limestone10

11. Fine-grained, dark-gray limestone in beds a few inches thick, containing fossils in some beds32

10. Light-gray, granular limestone in a single massive bed10

9. Light-gray, coarse- to medium-grained limestone, with some cherty lenses, in beds 2 feet or more thick, interbedded with slabby limestone26

8. Dark-gray, fine-grained limestone in beds a few inches to a foot thick, in part laminated, containing chert nodules and bands. Polydiexodina and a few other fossils (fossil localities 7703 and 7917)36

7. Light-gray, coarse-grained limestone in irregular, lenticular beds several feet thick, ending above in a very massive ledge. Contains small chert masses and numerous silicified fossils including Coenocystis, Domopora, and small brachiopods (localities 7477 and 7420)22

6. Fine-grained, gray limestone in straight beds a few inches thick, containing small chert masses, interbedded with sandstone15

5. Buff, fine-grained sandstone, with some thin layers of lumpy limestone17

4. Hegler limestone member: Dark-gray, fine-grained limestone in lumpy or nodular beds a few inches thick, forming two sets of ledges, separated by sandstone that forms a a slope in middle. Winding trails on bedding surfaces and some poorly preserved ammonoids 15

   Cherry Canyon formation:


3. Friable, fine-grained, pale-buff sandstone25

2. Manzanita limestone member: Pale-buff, calcareous sandstone and sandy limestone in 3- inch to 8-inch beds, weathering orange-brown and to blocky fragments; some beds contain geodic cavities. Contains two beds, each a foot or more thick, of apple-green chert or siliceous shale (altered volcanic ash), the first 18 feet above, and the second 30 feet above the base66

1. Buff, fine-grained sandstone in beds a few inches thick, weathering into slabs. Contains faintly marked, dark laminations. Best exposed in middle third111
Base of slope, at level of spring.


SECTION 23

Measured at head of Rader Ridge. Beds 1 to 7 measured on south side of ridge 1-1/4 miles west of Hegler Ranch; beds 8 to 23 on south side of ridge 1/2 mile farther west, but with some additional notes from first locality; higher beds measured on top of ridge, proceeding northwestward up face of escarpment. All beds above 23, and notably the sandstones of beds 25 and 27, interfinger or intergrade northwestward with massive Capitan limestone, which is exposed throughout the interval in the adjacent ravines. (See pls. 6, 15.)


Feet

Capitan limestone: Thick-bedded to massive dolomitic limestone, extending to top of escarpment.

Delaware Mountain group:
   Bell Canyon formation:
      Lamar limestone member:


29. Platy, gray, fine-grained limestone, in part laminated, containing numerous fossils in cross section. Dips 15 to 30 degrees southeastward, down the ridge. Corrected for dip50

28. Massive dolomite, in part sandy, with dip of about 15 degrees down the ridge75

27. Buff, medium-grained, friable sandstone, similar to bed 25. Sandy dolomite interbedded in middle80

26. Dark gray, fine-grained, laminated, slabby limestone, and thick-bedded, sandy dolomite, in part pebbly23

25. Buff, medium-grained, friable sandstone, in part cross-bedded, in rounded ledges, with a layer of brown, sandy dolomite in middle68

24. Buff, massive dolomitic limestone, interbedded with platy limestone and sandstone36

23. Dark gray, fine-grained, granular limestone in slabby beds, containing fusulinids and bryozoans, interbedded in middle with lighter gray, thicker-bedded limestone and dolomitic limestone (locality 7360)64

      Rader limestone member (type section):


22. Fine-grained, gray limestone in 6-inch to 1-foot beds, with some interbedded massive layers of light-gray limestone 28

21. Light gray to white, granular to dense limestone, containing silicified bryozoans and some small chert masses, forming massive, lenticular beds which weather into two sets of rounded cliffs. Parts contain angular cobbles and pebbles of limestone. Some interbedded lenses of thin-bedded white limestone. Rests irregularly on bed below (locality 7668)58

20. Light gray, fine-grained limestone in 6-inch to 1-foot beds, containing silicified fossils4

19. Soft, platy sandstone, with some thin limestone beds19

      Pinery limestone member:


18. Fine-grained, light-bray limestone, beds several feet thick, containing some chert, passing into thinner-bedded, darker-gray limestone toward top. Forms ledges16

17. Dark gray, fine-grained limestone, in part laminated, in part lumpy, in 3-inch to 8-inch beds, with some chert. Near middle, a 5-foot bed of massive, light gray, granular limestone 50

16. Brown, fine-grained, platy sandstone, interbedded with dark gray, fine-grained, well-laminated limestone, in beds a few inches thick. Contains fossils at top of ridge 1-1/4 miles west of Hegler Ranch (locality 7705)53

15. Light gray, granular limestone in beds up to 3 feet thick. Forms bench15

14. Fine-grained, gray to dark-gray limestone In 3-inch to 1-foot beds, containing nodules and bands of chert12

13. Buff to greenish, fine-grained, soft sandstone, interbedded with dark-gray, laminated limestone in beds a few inches thick32

12. Hegler limestone member: Dark gray, fine grained limestone in lumpy, slabby beds a few inches thick, projecting in two ledges, separated by a slope of sandstone. Contains poorly preserved ammonoids at nearby localities on the ridge16

   Cherry Canyon formation:


11. Buff, fine-grained, thin-bedded sandstone33

     Manzanita limestone member:


10. In section to east, a buff calcareous sandstone like bed 8; in section to west, a lumpy gray limestone like bed 123

9. Buff, soft, fine-grained sandstone9

8. Gray, fine-grained, sandy limestone, containing geodic cavities, in 2-inch to 6-inch beds. Some bedding planes are knobby. Weathers blocky and orange brown. Interbedded with soft, thin-bedded, fine-grained sandstone. In section to east, contains 1-foot bed of apple green chert 45 feet above base61

7. Massive, pale greenish, fine-grained sandstone in rounded ledges, with some thin-bedded sandstone38

6. Buff, thin-bedded, fine-grained, friable sandstone 21

5. Thin-bedded, fine-grained, calcareous buff sandstone, in part standing in rounded ledges, containing poorly preserved fusulinids in places15

      South Wells limestone member:


4. Massive gray dolomite in thick beds, containing flat, angular pebbles and abundant, poorly preserved fossils. Weathers to gray-brown, jagged surfaces. Inter bedded with flaggy, laminated gray, dolomitic limestone22

3. Buff sandstone5

2. Fine-grained, laminated, buff, sandy dolomite in 1-foot beds, overlain by massive ledge of sandy dolomite which weathers to jagged surfaces7

1. Buff, thin-bedded, fine-grained sandstone38
Base of slope.


SECTION 28

Measured on south side of McKittrick Canyon at its entrance. Beds 1 to 3 measured along the stream channel; beds 4 to 5 up slope of projecting bench; beds 6 to 7 up slope above the bench toward Capitan limestone escarpment. (See pl. 6.)


Feet

Capitan limestone:


7. Light gray, somewhat dolomitic limestone, containing occasional Squamularia and Composita, with poorly developed bedding planes, forming rounded ledges. Beds rise northwestward up slope of peak. Probable maximum thickness is100


Delaware Mountain group:
   Bell Canyon formation:
      Lamar limestone member:


6. Light gray, fine-grained limestone in 1-foot to 3-foot beds, with some interbedded sandy limestone40

5. Dark gray, fine-grained or dense limestone in beds a few inches thick, interbedded with some sandstone in lower part, and higher up with many beds 1 to 5 feet thick of lighter gray, granular limestone, containing abundant silicified and somewhat fragmented fossils. These are mostly brachiopods nearly all of which are Capitan species (locality 7401). Upper few feet are slabby or nodular. Forms steep cliff, top of which is a flat bench that exposes some of fossiliferous layers. Changes into massive Capitan limestone a few hundred yards up the canyon to northwest130

4. Pale brown or yellowish, fine- to medium-grained sandstone in thin to thick beds. A few thin limestone layers interbedded. This and bed 3 interfinger abruptly with massive Capitan limestone a few hundred yards up the canyon140

3. Thin-bedded, laminated, dark-gray limestone, resting on channeled surface of sandstone below, so that it thickens and thins on the eroded surface. Some beds have thin trail marks on their upper surfaces. Some bedding surfaces are wavy. Several lenses of granular, fossiliferous limestone are interbedded, which contain brachiopods and bryozoans (locality 7608)10

2. Brown, fine-grained sandstone in slabby beds, with ripple marks on many bedding surfaces. Bedding is irregular, with dips in various directions and some channeling35

1. Gray, dolomitic limestone in lenticular, massive beds a few feet to 15 feet thick, forming bouldery ledges. Contains some brachiopods. Interbedded are layers of white or gray, laminated limestone in beds a few inches to several feet thick, and some darker-gray, more granular limestone, full of fossil fragments (locality 7708). Downstream, near where bed dips beneath channel, it becomes more regularly bedded, with fewer thick layers, and is interbedded with sandstone in upper part50
Sandstone beneath, exposed farther northwest, up the canyon.


SECTION 33

Section west of Guadalupe Summit radio station. Starts at base of Delaware Mountain escarpment in ravine on north side of projecting spur that is capped by a turretlike remnant of limestone. Proceeds up escarpment to radio station at top.


Feet

Delaware Mountain group:
   Cherry Canyon formation:
      Getaway limestone member:


25. Buff sandstone, with several layers of dark gray, granular limestone, containing fusulinids. Top limestone bed forms summit of escarpment19

24. Dark gray, fine- to medium-grained limestone, in part well laminated, in beds up to 1 foot thick, with a 2-foot ledge of very granular, black, fossiliferous limestone in middle (fossil locality 7468). Forms ledges52

23. Platy sandstone and limestone5

22. Dark gray, irregularly bedded limestone, in part thinly laminated, in part massive, with some granular, fossiliferous lenses (locality 7474). Forms ledges16

21. Platy sandstone, with 1-foot bed of conglomeratic limestone in middle22

20. Dark gray to black, fine-grained to dense, well-laminated limestone, in 1-inch to 1-foot beds15

19. Thin-bedded sandstone, in part papery and shaly, with 1-foot bed of fine grained, dark gray limestone in middle19

18. Several beds up to 5 feet thick of very massive, granular, dark gray, sandy limestone, containing pebbles, fusulinids, and other fossils. Weathers to rough, brown-colored surface. Interbedded with thicker layers of black, papery limestone and sandy limestone29

17. Platy buff sandstone, containing thin limestone lenses18

16. Medium-grained sandstone in 1- to 2-foot beds, weathering brown6

15. Mostly buff, fine-grained sandstone, with some interbedded platy sandstone. In lower part are several beds up to 10 feet thick of sandy, friable limestone, crowded with fusulinids, but also containing crinoid stems and brachiopods, mostly somewhat water worn (locality 7423) Member rests on channeled surface of lower division, and thins northward and southward by overlap100

   Brushy Canyon formation:


14. Medium-grained sandstone, forming brown, massive ledges, containing some fusulinids. Higher beds of this member are present nearby, beneath erosion surface10

13. Dark gray, platy, shaly sandstone, with some thicker beds of ripple-marked sandstone6

12. Buff, fine-grained sandstone in beds a few inches thick, forming rounded ledges or slopes, with some thin beds of platy, shaly sandstone, and a few layers containing fusulinids66

11. Dark gray, platy, shaly sandstone6

10. Buff, medium-grained sandstone in beds several feet thick, forming massive ledges, and weathering brown. Some beds contain fusulinids (locality 7920)5

9. Black, platy, shaly sandstone4

8. Buff, fine-grained, thin-bedded, laminated sandstone38

7. Dark gray to black, platy or papery, shaly sandstone, standing in ledges6

6. Buff, fine-grained sandstone in beds a few inches to a foot thick, in part laminated, with ripple marks on some bedding surfaces, interbedded with black, shaly sandstone, especially toward top 36

5. Fine- to medium-grained buff sandstone in beds several feet thick, with some thinner partings, forming great rounded ledges in upper half which extend for long distances along escarpment. Some fusulinids in lower part59

4. Buff, fine-grained, thin-bedded, laminated sandstone, with some calcareous beds in lower part10

3. Massive sandstone in prominent ledges; buff, medium-grained, friable, weathering brown, in beds several feet thick. Top part is a calcareous sandstone, containing some sandstone pebbles, and crowded with calcareous tests of fusulinids21

2. Dark gray, well laminated, shaly sandstone, passing upward into black, hard, papery, sandy shale3

1. Gray, fine-grained, friable sandstone in 1-inch to 6-inch beds, weathering buff. Marked by light and dark laminae a few millimeters apart, suggestive of varves. Some thinner bedding in upper part62
Base of section cut off by fault.


SECTION 34

Section along and northeast of Lamar Canyon near old route of U. S. Highway 62. Beds 1 to 9, or section 34—a, measured on south side of Lamar Canyon 3 miles east of Hegler Ranch, ending on top of butte 1 mile east-northeast of B. M. 4923. Section of higher beds begins 1 mile to northeast, near crossing of highway over Bell and Lamar Canyons, and proceeds north-northeastward to top of limestone cuesta 1-1/2 miles distant. (See pl. 6.)


Feet

Castile formation:


20. Dark gray, papery, very thinly laminated sandstone. Elsewhere passes up into laminated anhydrite, within a few feet. Here it is overlain by older Quaternary gravel2


Delaware Mountain group:
   Bell Canyon formation:


19. Platy, brown-weathering, fine-grained sandstone, forming scattered remnants at top of cuesta26

18. Lamar limestone member: Gray to dark-gray, fine-grained limestone, mostly in beds a few inches thick, with some thicker layers. Weathers gray-brown and to rather rough surfaces. Some beds contain small chert nodules. Bedding planes undulatory, some layers lenticular, and some appear to be contorted. Thin partings of platy sandstone in lower part. Forms rim of prominent line of cuestas30

17. Massive, buff sandstone with some faint laminations. Bedding planes widely spaced and mostly very smooth. One, however, shows faint ripple marks, and in places the laminae are cross-bedded. Overlain with sharp contact by Lamar member. Crops out in prominent ledges and rocky buttes, bare of vegetation138

16. Platy, brown-weathering sandstone, underlying broad valley and poorly exposed. Thickness corrected for dip160

15. Flaggy limestone bed: Hard, fine-grained limestone, in part sandy, in straight, even beds a few inches thick, making four or five layers, interbedded with sandstone10

14. Platy, brown-weathering sandstone10

13. Buff, fine-grained sandstone, thin-bedded in lower half, in upper half standing in massive, rounded ledges several feet thick90

      Rader limestone member:


12. Thin beds of gray limestone, interbedded with platy sandstone5

11. Buff, fine-grained sandstone, thin-bedded below, passing upward into rounded ledges several feet thick???

10. Thin-bedded, fine-grained limestone, overlain by thick ledge of light-gray, granular, conglomeratic limestone, containing fossil fragments (locality 7600 at top of section 34—a). At base, a bed of apple-green chert is locally developed33

9. Buff, fine-grained, thin-bedded sandstone, forming thick, rounded ledges at top. Ripple marks in bed of Bell Canyon nearby 8

8. Pinery limestone member: Dark gray, laminated limestone in beds several inches thick, with some chert bands, interbedded with sandstone in upper part. Several ledges of lighter gray, more granular limestone up to 3 feet thick, containing fossils. In section to northeast, limestones are all thin bedded, and there is much more sandstone30

7. Fine-grained, yellowish sandstone in thin or platy beds54

6. Hegler limestone member: Dark gray, dense, laminated limestone in beds several inches thick, with some chert bands, interbedded with platy sandstone. Contains three beds up to 2 feet thick of gray, granular, cherty limestone, with pebbles and silicified fossils (locality 7601)37

   Cherry Canyon formation:


5. Soft, pale buff, platy sandstone, weathering brown 14

      Manzanita limestone member:


4. Fine-grained, sandy limestone, weathering brown, in beds up to 1 foot thick, interbedded with sandstone12

3. Fine-grained, pale-yellow sandstone in massive, rounded ledges with thinner-bedded sandstone below35

2. Pale buff, compact, sandy limestone and calcareous sandstone in 2-inch to 1-foot beds, weathering brown, and containing geodic cavities. Some ammonoid casts. Interbedded with soft, buff sandstone, and with 3 or 4 thin beds of green, bentonitic clay38

1. Fine-grained, pale-yellow sandstone in massive, rounded ledges. Below base of section is some interbedded dark shaly sandstone32
Lower beds, exposed farther northwest up Lamar Canyon, not measured.


SECTION 40

Getaway Gap section. Beds 1 and 2 measured in channel of Getaway Canyon, starting at fault at west end of gap. Higher beds measured up south wall of canyon a few hundred yards east of its western end. (See pl. 6.)


Feet

Delaware Mountain group:
   Cherry Canyon formation:
      Getaway limestone member (type section):


19. Platy gray limestone, forming rim of canyon3

18. Platy buff sandstone, quartzitic above10

17. Granular, conglomeratic, fossiliferous limestone, interbedded with sandstone8

16. Buff, platy sandstone14

15. Granular limestone, containing fusulinids, passing up into platy limestone5

14. Platy sandstone in beds up to 5 feet thick, interbedded with three layers a foot or more thick of granular, somewhat conglomeratic limestone25

13. Granular, dark gray to black limestone, full of fusulinids and other fossils, in lenticular, irregular ledges. Some beds contain limestone pebbles18

12. Buff, platy sandstone with some thin limestone beds8

11. Dark gray to black, granular to dense limestone, some of which contains abundant fossils, in lenticular beds up to several feet thick, but with platy beds between. Forms ledges16

10. Platy or papery sandstone, containing sandy limestone nodules, and with two beds of granular, conglomeratic limestone52

9. Gray, granular limestone, crowded with fusulinids and crinoid stems, with numerous limestone cobbles and pebbles in lower part. Rests on channeled surface. To southwest, around hill, thickens to ten feet (fossil locality 7632 at latter place)4

8. Buff, thin-bedded, fine-grained sandstone in beds up to 4 feet thick, interbedded with dark gray, papery, shaly sandstone, and with 2 beds of nodular limestone21

7. Buff, thin-bedded, fine-grained sandstone, with two beds of nodular limestone in upper part23

6. Dark gray, sandy limestone, forming nodular bed 1

5. Buff, fine-grained, thin-bedded sandstone, interbedded with dark gray, shaly sandstone in middle. Some channeling at base22

4. Gray, thinly laminated limestone in nodular bed 1

3. Buff, fine-grained, friable sandstone in beds a few inches thick, marked by thin, dark laminae, with a bed of dark gray, platy, shaly sandstone in middle26

2. Mostly covered in flood plain and lower slopes of valley. Some exposures of buff, fine-grained, platy sandstone, and, of darker, shaly beds. Some beds ripple-marked41

   Brushy Canyon formation:


1. Reddish-brown, quartzitic medium-grained sandstone 6
Lowest beds exposed; cut off by fault to west.


SECTION 42

Section between Pinyon Canyon and Long Point. Parts were measured at several places, as follows: a) beds 1 to 9 on south side of Pinyon Canyon 2-3/4 miles south-southeast of Getaway Gap, and continuing to hilltops 1/2 mile to east; b) beds 10 to 16 on south side of Pinyon Canyon 1-1/2 miles west of Long Point, and up slope of butte to south; c) beds 17 to 24 on west slope of Long Point, and beds 25 to 28 on higher hill 3/4 mile east of end of point. (See pl. 6.)


Feet

Delaware Mountain group:
   Bell Canyon formation:


28. Hegler limestone member: Limestone in 3-inch to 1-foot beds, in part dense, in part finely granular, containing some silicified fossils and chert bands. Interbedded with platy sandstone 33

   Cherry Canyon formation:


27. Hard, platy, brown-weathering sandstone4

      Manzanita limestone member:


26. Dark gray, lumpy limestone in beds a few inches thick5

25. Greenish-buff, friable sandstone, forming massive, rounded ledges, but with some thinner beds62

24. Limestones resembling typical facies of Hegler member as exposed in foothills of Guadalupe Mountains. Gray to dark gray, lumpy limestone, interbedded with greenish, marly sandstone, forming slabby beds a few inches to a foot or more thick. Contains numerous poorly preserved ammonoids. Forms prominent cliff at end of Long Point, but separates elsewhere into several groups of ledges46

23. Fine-grained, pale-buff or greenish sandstone in massive, rounded ledges, with some thinner-bedded layers. Forms slopes of Long Point117

22. Platy brown sandstone, poorly exposed above 74

      South Wells limestone member:


21. Dark gray, fine-grained limestone3

20. Brown, fine-grained, platy sandstone10

19. Dark gray, granular, sandy limestone, weathering light gray, containing small pebbles and numerous fossils (locality 7641 from this and nearby beds)6

18. Buff, fine-grained sandstone in beds several inches thick, interbedded with dark shaly sandstone18

17. Buff, fine-grained, sandy limestone in 1-foot to 2-foot beds, forming rounded ledges. Forms top of section (b) and base of section (c)6

16. Thin-bedded, fine-grained, buff sandstone, with some interbedded limestone58

15. Gray, fine-grained, in part sandy limestone, in 6-inch beds, forming a bench3

14. Thin-bedded to platy, brown-weathering sandstone, with some lenticular beds of limestone, especially in upper part32

13. Buff, fine-grained sandstone in thick, rounded ledges, bare of vegetation42

12. Buff, calcareous sandstone in prominent, blocky ledge3

11. Thin-bedded to platy, fine-grained, buff sandstone weathering brown59

10. Fine-grained, gray limestone, with some more granular and fossiliferous parts, and some beds of reddish quartzite. Forms top of section (a), where it is mostly quartzite. In section (b), it crops out 67 feet above bed of Pinyon Canyon6

9. Thin-bedded to platy, fine-grained, buff sandstone, with several thin limestone beds39

8. Reddish quartzite and slabby, fine-grained limestone, with some lenses of granular limestone. Forms prominent bench 7

7. Thin-bedded, fine-grained buff sandstone, with some limestone in middle57

      Getaway limestone member:


6. Gray, fine-grained limestone, with some granular seams that are crowded with fusulinids. In places, bed is much silicified. Forms prominent ledge4

5. Buff, thin-bedded, fine-grained sandstone, with some interbedded limestone32

4. Dark gray, granular limestone, containing numerous fusulinids and crinoid stems, and some other fossils, in 1-foot beds 5

3. Thin-bedded brown sandstone and gray sandy limestone17

2. Thin-bedded, fine-grained, dark-gray limestone, and massive, granular, fossiliferous limestone, in irregular, lenticular beds, with some interbedded sandstone31

1. Fine-grained, gray, brown-weathering, platy sandstone, standing in ragged ledges in lower half, interbedded with softer buff sandstone, and containing nodular beds of gray, fine-grained sandy limestone88
Base of section; lower beds cut off by fault to west.

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Last Updated: 28-Dec-2007