Willwood Formation

Geology

Members: unnamed (728), "Gray Bull" beds (1), Sand Coulee beds (1), Sand Creek Facies (1), Wa-1 Zone (1)

Lithologies: not reported (82), "siliciclastic" (254), mudstone (13), "shale" (68), siltstone (12), sandstone (13), wackestone (2), "limestone" (2), "carbonate" (1)

Paleoenvironments: terrestrial indet. (321), fluvial indet. (6), fine channel fill (7), "channel" (5), wet floodplain (64), "floodplain" (41), crevasse splay (8), fluvial-lacustrine indet. (270), lacustrine - small (1), pond (4), lacustrine indet. (2)

Age range: base of the Sandcouleean to the top of the Early/Lower Eocene or 55.80000 to 48.60000 Ma
Collections

Time interval Ma Country or state Original ID and collection number
Late/Upper Paleocene - Early/Lower Eocene58.7 - 48.6USA (Wyoming) (57970 80579)
Clarkforkian56.2 - 54.9USA (Wyoming) (11378 11379 11386 11399 11420 15119 15171 15217 68476 133237 203361 231027)
Graybullian55.8 - 50.3USA (Wyoming) (11336 11337 11338 11339 11342 11343 11349 11350 11357 11360 11363 11364 11365 11370 11371 11387 11392 11394 11395 11396 11397 11398 11400 11436 11442 11448 11456 11463 11472 11473 11474 11475 11476 11477 11486 11489 11490 11493 11495 11496 11500 11502 11503 11504 11505 11506 15701)
Lostcabinian55.8 - 50.3USA (Wyoming) (11318 11319 11324 11325 11326 11327 11328 11329 11330 11344 11345 11346 11347 11354 11358 11388 11404 11450 11454 11455 11460 11461 11462 11464 11465 11466 11467 11468 11469 11470 11471 11484 11485 11498 11499 15997 15998 15999 16000 16001 16003 16005)
Lysitean55.8 - 50.3USA (Wyoming) (16002 16004 16061)
Sandcouleean55.8 - 50.3USA (Wyoming) (100280)
Wasatchian55.8 - 50.3USA (Wyoming) (11390 15458 15465 15466 15482 15487 15488 15489 15490 15491 15492 15493 15494 15495 15496 15497 15498 15499 15500 15501 15502 15503 15504 15505 15506 15507 15508 15509 15510 15511 15512 15513 15514 15515 15516 15517 15518 15519 15520 15521 15522 15523 15524 15525 15526 15527 15528 15529 15530 15531 15532 15533 15534 15535 15536 15537 15538 15539 15540 15541 15542 15543 15544 15545 15546 15547 15548 15549 15550 15551 15552 15553 15554 15555 15556 15557 15558 15559 15560 15561 15562 15563 15564 15565 15566 15567 15568 15569 15570 15571 15572 15573 15574 15575 15576 15577 15578 15579 15580 15581 15582 15586 15587 15588 15589 15590 15592 15593 15594 15618 15619 15620 15621 15622 15623 15624 15625 15626 15627 15628 15629 15630 15631 15632 15633 15634 15635 15636 15637 15638 15639 15640 15641 15647 15682 15683 15686 15687 15688 15689 15692 15694 15695 15696 15697 15698 15699 15702 15703 15704 15705 15706 15707 15726 15727 15728 15729 15730 15731 15732 15733 15734 15735 15736 15737 15738 15739 15740 15741 15742 15743 15744 15745 15746 15747 15748 15749 15750 15751 15752 15753 15754 15755 15756 15757 15758 15759 15760 15761 15762 15763 15764 15765 15766 15767 15768 15769 15770 15771 15772 15773 15774 15775 15776 15777 15778 15779 15780 15781 15782 15783 15784 15785 15786 15787 15788 15789 15790 15791 15792 15793 15794 15795 15796 15797 15798 15799 15800 15801 15802 15803 15804 15805 15806 15807 15808 15809 15810 15811 15812 15813 15814 15815 15816 15817 15818 15819 15820 15821 15822 15823 15824 15825 15826 15827 15828 15829 15830 15831 15832 15833 15834 15835 15898 27349 27352 27353 46636 46637 46638 46639 46640 46641 46642 46643 46644 46645 46646 46647 46648 46650 46652 46656 46657 46658 46659 46660 46661 46662 46663 46664 46665 46666 46667 46668 46669 46670 46671 46672 46673 46674 46675 46680 46681 46682 46683 46684 46685 46686 46687 46688 46689 46690 46691 46692 46693 46694 46695 46696 46697 46698 46699 46700 46701 46702 46703 46704 46705 46706 46707 46708 46709 46710 46711 46712 46713 46714 46715 46716 46717 46718 46719 46720 46721 46722 46723 46724 46725 46726 46727 46728 46729 46730 46731 46732 46733 46734 46735 46736 46737 46738 46739 46740 46741 46742 46743 46744 46745 46746 46747 46748 46749 46750 46751 46752 46753 46754 46755 46756 46757 46758 46759 46760 46761 46762 46763 46764 46765 46766 46767 46768 46769 46770 46771 46772 46773 46774 46775 46776 46777 46778 46779 46780 46781 46782 46783 46784 46785 46786 46787 46788 46789 46790 46791 46792 46793 46794 46795 46796 46797 46798 46799 46800 46801 46802 46803 46804 46805 46806 46807 46808 46809 46810 46811 46812 46813 46814 46815 46816 46817 46818 46819 46820 46821 46822 46823 46824 46825 46826 46827 46828 46829 46830 46831 46832 46833 46834 46835 46836 46837 46838 46839 46840 46841 46842 46843 46844 46845 46846 46847 46848 46849 46850 46851 46852 59890 59892 59893 59894 59895 59896 59897 59898 59899 59900 59901 59902 59903 59904 59905 59906 74333 74618 74619 74626 74631 75868 76066 76067 85438 85439 85440 85441 85442 85443 85444 87316 87317 88208 88209 88373 88374 88375 88376 109003 109254 109255 109302 141580 168284 168285 168286 168287 168288 168289 168290 168291 168292 168293 168294 168295 168296 168304 168305 168306 168307 168308 168309 168310 168311 168312 168313 168314 168315 168316 168317 168318 168319 168320 168340 177251 179977 180109 180111 180118 180119 180470 181617 191220 232917 232920)
Early/Lower Eocene55.8 - 48.6USA (Wyoming) (11393 13321 15081 15591 15679 15680 15681 15684 15685 15690 15691 15693 15700 15708 15709 27350 27351 80580 154253 154251 154252 154254 154255 154256 154257 154258 154259 154260 154261 154262 154263 154265 154264 154266 154268 154267 154269 154270 154271 154272 154273 154274 154275 154276 154277 154278 154279 154280 154281 154282 154283 154284 154285 154286 154287 154288 154289 154290 154291 154292 154293 176522 188084 226070)
Bridgerian50.3 - 46.2USA (Wyoming) (16290 16291)