Fort Union Formation, Group

Geology

Formations: unnamed (1), Sentinel Butte (2), Tullock (3)

Members: unnamed (478), Atwell Gulch (4), China Butte (1), Ekalaka (2), Lebo (21), lower Ludlow (3), Ludlow (85), Ludow (1), Overland (4), Rock Bench Quarry (1), Sentinel Butte (5), Shotgun (3), Somber beds (3), Tongue River (14), Tullock (23), upper Ludlow (1)

Lithologies: not reported (136), "siliciclastic" (138), claystone (36), mudstone (49), "shale" (84), siltstone (58), sandstone (96), marl (2), coal (41), lignite (5), ironstone (1)

Paleoenvironments: terrestrial indet. (215), deltaic indet. (1), fluvial indet. (249), fine channel fill (11), "channel" (3), wet floodplain (89), "floodplain" (2), crevasse splay (8), mire/swamp (13), fluvial-lacustrine indet. (14), pond (49), lacustrine indet. (2)

Age range: base of the Lancian to the top of the Graybullian or 70.60000 to 50.30000 Ma
Collections

Time interval Ma Country or state Original ID and collection number
Cretaceous - Tertiary145.0 - 2.588USA (Montana) (32513)
Lancian70.6 - 66.0USA (North Dakota) (24902 25011 25059 25414 25421 25422 25437 25445 25448 25461 25465 25468 25472 25473 25474 25475 25476 25477 25478 25498 48268 48269 48270 48271)
Pu166.0 - 63.3USA (North Dakota) (105890)
Puercan66.0 - 63.3USA (North Dakota) (24973 24974 25004 25005 25006 25007 25008 25009 25010 25012 25026 25415 25420 25423 25424 25425 25426 25427 25440 25441 25442 25443 25446 25447 25449 25450 25451 25453 25454 25455 25456 25457 25458 25459 25460 25462 25463 25464 25466 25467 25469 25470 25471 25499 48177 48178 48179 48180 141585 192238)
Puercan66.0 - 63.3USA (Wyoming) (11334 11335 11340 11359 11366 11368 11389 11401 174233)
Puercan66.0 - 63.3USA (Montana) (14693 14738 14744 14745 168332 168333 168334 168335 168336 168337 176681 176682 176683 176684 176685 176686 176687 176698 176699 177319 183112 183113 183114 185209 193844)
Early/Lower Paleocene66.0 - 61.7USA (North Dakota) (129230)
Early/Lower Paleocene66.0 - 61.7USA (Montana) (34106 129028)
Paleocene66.0 - 56.0USA (North Dakota) (40103 40124 40145 40389 40390 40426 40427 40430 40533 43284 58010 58012 58014 58016 58017 58019 58020 58021 58022 58023 58027 58028 58029 58030 58032 58033 58035 58036 58037 58038 58046 58082 58083 58084 58085 58086 58087 58088)
Paleocene66.0 - 56.0Canada (Saskatchewan) (45729)
Paleocene66.0 - 56.0USA (South Dakota) (34038 58007 58008 58009 58026 58039)
Paleocene66.0 - 56.0USA (Montana) (31538 33433 40082 40084 40092 40094 40098 40100 40104 40272 40274 40275 40277 40279 40280 40284 40436 40440 40445 40531 40532 40739 40671 40740 40741 40742 40743 40744 40745 40746 40779 40781 40782 40889 40891 40931 40932 40933 40934 40935 43250 43251 43252 43253 43313 43314 43401 43403 43404 43407 53526 53527 53528 53529 53532 53534 53535 53536 53537 53538 53539 53600 53601 53603 53604 53606 53608 53687 53689 53690 53693 53694 53838 53839 53841 53842 53843 53844 53845 53846 53939 53940 53941 53942 53943 53948 53949 53953 53954 53955 53956 53959 53960 53961 53963 53964 53965 55850 55851 55852 55853 55854 55855 55857 55858 55859 128448 133583)
Paleocene66.0 - 56.0USA (Wyoming) (31006 31219 31220 31221 31222 31289 31291 31292 31293 31294 31295 31296 40083 40085 40090 40146 40276 40535 40578 40669 40670 40775 40776 40778 40780 40783 40819 40822 40825 40829 40833 40836 40841 40847 40882 40884 40885 40886 40888 40937 40938 40940 41227 43240 43248 43301 43303 43304 43305 43310 43311 43312 52867 52868 52869 52928 57928 57929 57930 57931 57932 57933 57934 57935 57936 57937 57938 57939 57954 57955 57956 57957 57961 57962 57963 57964 57968 57973 57974 57976 57977 57984 57986 57987 57990 57991 57992 57993 57994 57995 57996 57997 57998 58001 58002)
Paleocene66.0 - 56.0USA (New Mexico) (43161 43246 43247)
Paleocene66.0 - 56.0USA (Colorado) (53061 53062 53076)
Paleocene66.0 - 56.0USA (Utah) (39885)
Paleocene - Eocene66.0 - 33.9USA (Wyoming) (138874 138875 138876 138877 138878 138879)
Paleogene66.0 - 23.03USA (Wyoming) (52866)
Torrejonian63.3 - 61.7USA (Montana) (14874 14875 14885 14906 14907 14908 14909 14913 14914 14915 14916 14917 14918 14919 14920 14921 14922 14923 176690 176691 176692 176693)
Torrejonian63.3 - 61.7USA (North Dakota) (24953 24954 24957 24962 24964 24965 24970 24971)
Torrejonian63.3 - 61.7USA (Wyoming) (11332 11351 11367 11402 14879 14880 14881 14882 14886 14911 128433)
To3 - Ti163.3 - 56.8USA (Montana) (15022)
Torrejonian - Tiffanian63.3 - 56.8USA (Montana) (131899)
Ti161.7 - 56.8USA (Montana) (15021 15023 15026)
Ti561.7 - 56.8USA (Wyoming) (46654 46655)
Tiffanian61.7 - 56.8USA (Wyoming) (11331 11333 11341 11361 11362 11383 11403 11478 14952 14974 14979 14980 14981 14982 14983 14984 14985 14986 14987 14988 15007 15017 15027 15036 15067 26569 28632 28633 28634 28635 28636 28637 28638 28639 28640 28641 28642 28643 28644 28645 46653 53059 176696 176697 187515 190402 190403 190404 190405 190406 190407 190408 190409 190410 190411 190412 190413 190414 190417 190418 190419 190420 190421 190423 190424 190425 190426 190427 190428 190429 190435 190436 190437 190438 190439 190440 190441 190442 190443 190444 190445 190446 190447 190448 190449 190452 190456 190457 190458 190459 190461 190462 190463 190464 190465 190466 190467 190468 190469 190470 190471 190472 190473 190474 190475 190476 190477 190478 190479 190481 190482 190483 190484 190487 190488 190489 190490 190491 190492 190493 190494 190495 198262 198263 198264 198265)
Tiffanian61.7 - 56.8USA (Montana) (15008 15019 15020 15037 15038 15039 15040 15041 15042 15043 15044 15045 15047 15048 15050 15051 15052 15053 15070)
Tiffanian61.7 - 56.8USA (Colorado) (174227 176834)
Thanetian59.2 - 56.0USA (Montana) (124225)
Late/Upper Paleocene58.7 - 55.8USA (North Dakota) (78394)
Late/Upper Paleocene58.7 - 55.8USA (Wyoming) (15018 15024 15082 28656 28670 64106 129153 129222 129223 129224)
Cf156.8 - 55.8USA (Wyoming) (46649)
Cf256.8 - 55.8USA (Wyoming) (46651 46679)
Cf356.8 - 55.8USA (Wyoming) (46676 46678)
Clarkforkian56.8 - 55.8USA (Montana) (137834)
Clarkforkian56.8 - 55.8USA (North Dakota) (21372)
Clarkforkian56.8 - 55.8USA (Colorado) (176832 176833)
Clarkforkian56.8 - 55.8USA (Wyoming) (11348 11352 11355 11356 11372 11373 11374 11375 11376 11377 11380 11381 11382 11384 11444 11445 11446 11457 11458 11459 15072 15216 15218 28646 28647 28648 28649 28650 28651 28652 28653 28654 28655 28657 28658 28659 28660 28661 28662 28663 28664 28665 28666 28667 28668 28669 28671 28672 28673 28674 28675 28676 28677 28678 28679 28680 28681 28682 28683 28684 28685 28686 28687 28688 28689 28690 28691 28692 28693 28694 28898 28899 28900 28901 28902 28903 28904 28905 28906 28907 46677 154182 154225 154236 190415 190416 190422 190430 190431 190432 190433 190434 190450 190451 190453 190454 190455 190460 190480 190485 190486)
Graybullian55.8 - 50.3USA (Wyoming) (11406)