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surface of the underlying limestone. The middle member and much of the upper member were deposited in a river system that reworked the
Coalbank Hill Member sediments, while the upper member includes some marine beds. The boundary between the middle and upper members is set where
515:
and Ernest Howe in 1905 for deposits near Molas Lake. Sherman
Wengerd and John Strickland first divided the formation into three informal members in 1954, and William Merrill and Richard Winar formally designated the Coalbank Hill Member in 1958.
393:, and conglomerate, that is typically around 40 feet (12 m). The upper member is typically around 25 feet (7.6 m) that includes maroon to light gray sandstone. The upper member grades into the overlying
567:
Evans, James E.; Reed, Jason M. (March 2007). "Integrated loessite-paleokarst depositional system, early
Pennsylvanian Molas Formation, Paradox Basin, southwestern Colorado, U.S.A.".
740:
540:"Geologic framework of pre-Cretaceous rocks in the Southern Ute Indian Reservation and adjacent areas, southwestern Colorado and northwestern New Mexico"
702:
Merrill, William M.; Winar, Richard M. (1958). "Molas and
Associated Formations in San Juan Basin-Needle Mountains Area, Southwestern Colorado".
675:
Wengerd, Sherman A.; Strickland, John W. (1954). "Pennsylvanian
Stratigraphy of Paradox Salt Basin, Four Corners Region, Colorado and Utah".
276:
304:
603:
189:
735:
182:
468:
456:
394:
123:
377:. The lowermost Coalbank Hill Member is up to 56 feet (17 m) of purplish-red to reddish-brown
105:
358:
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604:"Stratigraphy of the Mississippian System, South-Central Colorado and North-Central New Mexico"
382:
170:
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483:
The
Coalbank Hill Member is devoid of fossils, but the upper member contains some marine
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U.S. Geological Survey
Geologic Atlas of the United States Folio, Silverton Folio
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Armstrong, Augustus K.; Mamet, Bernard L.; Repetski, John E. (1992).
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385:. This is overlain by an informal middle member, consisting of
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647:"Description of the Silverton quadrangle [Colorado]"
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601:
349:. Its age is poorly constrained but is thought to be
674:
369:The Molas Formation is a sequence of continental
727:
741:Carboniferous southern paleotropical deposits
471:. It exists in the subsurface throughout the
16:Geologic formation found in the United States
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533:
531:
529:
716:10.1306/0BDA5BAC-16BD-11D7-8645000102C1865D
689:10.1306/5CEAE07C-16BB-11D7-8645000102C1865D
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641:
619:
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544:U.S. Geological Survey Professional Paper
526:
546:. Professional Paper. 1505-A: A22-A23.
503:indicating a middle Pennsylvanian age.
311:
283:
728:
537:
511:The formation was first designated by
428:. It has also been interpreted as a
291:Molas Formation (the United States)
13:
400:The Coalbank Hill Member may be a
14:
752:
451:The formation is exposed in the
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608:U.S. Geological Survey Bulletin
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294:Show map of the United States
589:10.1016/j.sedgeo.2006.07.010
7:
444:becomes more abundant than
404:(a residual soil formed by
373:. It is divided into three
10:
757:
538:Condon, Steven M. (1992).
478:
469:Glenwood Springs, Colorado
457:Sangre de Cristo Mountains
319:Molas Formation (Colorado)
395:Pinkerton Trail Formation
269:
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124:Pinkerton Trail Formation
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26:
21:
507:History of investigation
645:; Howe, Ernest (1905).
143:37 m (120 ft)
736:Carboniferous Colorado
513:Charles Whitman Cross
418:Log Springs Formation
341:that is found in the
322:Show map of Colorado
115:Coalbank Hill Member
33:Bashkirian–Moscovian
581:2007SedG..195..161E
569:Sedimentary Geology
410:Leadville Limestone
201: /
134:Leadville Limestone
28:Stratigraphic range
453:San Juan Mountains
408:of the underlying
339:geologic formation
205:37.748°N 107.683°W
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432:trapped on the
422:Jemez Mountains
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335:Molas Formation
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22:Molas Formation
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643:Cross, Whitman
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473:San Juan basin
461:Mosquito Range
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359:Pennsylvanian
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658:. Retrieved
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625:. Retrieved
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399:
383:conglomerate
368:
343:Four Corners
334:
332:
262:Year defined
241:Type section
225:Four Corners
171:conglomerate
497:echinoderms
489:brachiopods
402:terra rossa
365:Description
208: /
196:107°40′59″W
183:Coordinates
730:Categories
520:References
487:beds with
426:New Mexico
412:) and may
406:weathering
357:to middle
249:Molas Lake
193:37°44′53″N
493:bryozoans
485:limestone
467:, and at
439:kaolinite
416:with the
414:correlate
391:sandstone
379:siltstone
246:Named for
167:Sandstone
148:Lithology
140:Thickness
120:Underlies
112:Sub-units
106:Formation
371:red beds
351:Namurian
254:Named by
177:Location
130:Overlies
660:27 July
577:Bibcode
479:Fossils
420:in the
387:mudrock
375:members
231:Country
157:Mudrock
153:Primary
627:21 May
501:forams
499:, and
463:, the
459:, the
455:, the
448:clay.
446:illite
353:(late
221:Region
434:karst
430:loess
337:is a
163:Other
662:2021
629:2019
612:1787
442:clay
381:and
333:The
265:1905
102:Type
38:PreꞒ
712:doi
685:doi
655:120
616:doi
585:doi
573:195
548:doi
424:of
361:).
732::
710:.
708:42
706:.
683:.
681:38
679:.
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528:^
495:,
491:,
475:.
397:.
389:,
169:,
88:Pg
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718:.
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687::
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631:.
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591:.
587::
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556:.
550::
93:N
83:K
78:J
73:T
68:P
63:C
58:D
53:S
48:O
43:Ꞓ
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