Figure 21.--Photographs of sedimentary features in the Sangre de Cristo Formation along the line of the principal reference section (Lindsey and Schaefer, 1984), stop 5. Photographs A-C show features at or near the mouth of Groundhog Basin; D-G show features that can be reached by climbing the ridgeline on the south side of Groundhog Basin.

[Photograph of diamictite interbedded with sandstone]

A) Diamictite interbedded with sandstone, upper part of lower member, Sangre de Cristo Formation, mouth of Groundhog Basin (near bottom of unit 33, Lindsey and Schaefer, 1984). Diamictite interpreted as mudflow deposit.

[Photograph of planar lamination, low-angle crossbedding in sandstone]

B) Planar lamination and low-angle crossbedding in sandstone, upper part of lower member, mouth of Groundhog Basin (unit 33, Lindsey and Schaefer, 1984). Sandstone interpreted as sheetflood deposit.

[Photograph of clast-supported cobble conglomerate]

C) Unsorted clast-supported cobble conglomerate, erosional base over crossbedded sandstone, lower part Crestone Conglomerate Member, mouth of Groundhog Basin (base of unit 50, Lindsey and Schaefer, 1984). Note boulders inclined at large angle to bedding, supporting interpretion of conglomerate as a debris-flow deposit.

[Photograph of stratified pebble conglomerate and sandstone]

D) Stratified pebble conglomerate and sandstone, Crestone Conglomerate Member, ridgeline, south side Groundhog Basin (upper part. unit 54, Lindsey and Schaefer, 1984). Note erosional contact below conglomerate beds at pick and at lower right. Interpreted as possible stream or sheetflow deposits.

[Photograph of thick debris-flow conglomerate]

E) Thick bed of unsorted clast-supported conglomerate (unit 96, interpreted as debris-flow deposits) overlying stratified sandstone and conglomerate (units 95-91, interpreted as braided alluvial deposits), Crestone Conglomerate Member. Note channeled base of unit 96, which cuts out underlying bed (arrows).

[Photograph of channeled base cut in debris flows]

F) View to north of unit 96, showing channeled base (arrows) cut into debris-flow deposits (no unit numbers--these units are missing at the line of section) and stratified sandstone and conglomerate of units 99-91. Note that the top of unit 96 in upper left is parallel to bedding in underlying units. These relationships indicate that unit 96 fills an incised channel, possibly a fanhead trench.

[Photograph of thick debris-flow conglomerate]

G) Thick (9 m) bed of poorly sorted cobble and boulder conglomerate, upper part of the Crestone Conglomerate Member (unit 114, near top Peak 13054, Lindsey and Schaefer, 1984). Interpreted as debris-flow deposit. Pebble count shows approximately 72 percent distinctive red felsite and syenite clasts from unknown source. Note faint stratification to left of man, base of cliff.