Haynes. 10.1073/pnas.0800560105

Fig. 6. Black mats of Younger Dryas age (locality nos. refer to Fig. 1 and SI Table 2). Photographs are by the author unless indicated otherwise. (a) The black mat at the Murray Springs Clovis site in Arizona (locality 1a) is a black algal mat that blankets the Clovis occupation surface. (b) At the Naco Clovis site (locality 1b) the mammoth bones and artifacts are directly overlain by laminated marls and clay bands that are pond facies of the San Pedro Valley black mat. (c) The type Clovis site in Blackwater Draw, New Mexico (locality 5) has a dark-gray diatomite stratum D containing Folsom artifacts and bones of Bison bison antiquus overlying a "brown sand wedge" (stratum C) with Clovis artifacts and mammoth bones over a "gray sand" (stratum B) with Clovis artifacts and bones of mammoth and B. bison antiquus beyond where stratum C pinches out. Photograph courtesy of Glen L. Evans. (d) At the Lubbock Lake site in Texas (locality 6) a black and white diatomite (stratum 2A) (2d in SI-8) contains Folsom artifacts and bones of extinct bison and directly overlies a gray fluvial sand (stratum 1B). Photograph courtesy of Vance T. Holliday. (e) Folsom, Goshen-Plainview, and Agate Basin artifacts are found in situ in the lower portions of the Leonard paleosol at several sites in the Knife River - Lake Ilo region of North Dakota (locality 7). Photograph by Stanley A. Ahler. Published courtesy of the Center for the Study of the First Americans. (f) The Lindenmeier Folsom site in Colorado (locality 8) has Folson artifacts and bison bones covered by a black cumulic mollisol overlying Peoria loess.

Fig. 7. Black mats of Younger Dryas age (Locality numbers refer to Fig. 1 and SI Table 2). Photographs are by the author unless indicated otherwise. (a) The Goshen paleosol at the Hell Gap site (locality 9) is a cumulic mollisol as seen here and an aquall in lower elevations. (b) At the Agate Basin site (locality 10a) multiple black bands are separated by slope wash alluvium. (c) Dennis Stanford (on left) and Adrian Hannus examine a Clovis point in situ on an erosion surface covered by a cumuli mollisol of YD age at the Lange-Ferguson site (locality 12). Note truncation of the mollisol on the right. (d) The Domebo mammoth skeleton (locality 13) is buried by dark gray organic clayey sand. Photograph courtesy of Frank C. Leonhardy. (e)The Clovis occupation surface at the Aubrey site locality 14) is overlain by a facies of the lacustrine organic clay and marl. Photograph courtesy of C. Reid Ferring.(f) At the Feterman mammoth site (locality 15) a black cumulic mollisol of probable YD age overlies mammoth bones on older terrace alluvium.

Fig. 8. Black mats of Younger Dryas age (locality numbers refer to Fig. 1 and SI Table 2). Photographs are by the author unless indicated otherwise. (a) At the Carter/Kerr-McGee site (locality 16) a black aquoll overlies an erosional surface and contains Goshen and Folsom artifacts in its basal portion. (b) The black cumulic mollisol at the Jim Pitts site (locality 17a) contains Goshen, Folsom, and Agate Basin artifacts and overlies a surface with preYD charcoal that is apparently not cultural. (c) Dissection of Gilcrease Spring mound (locality 19b) revealed a black peat of YD age. Figures in the background are excavating mammoth tusks in the stratum directly under the peat. (d) Black peaty lens of "Black Mat 1" of YD age on the Kaibito Plateau (locality 37) represents one of several localized wet land relicts. (e) At the Wilson-Leonard site (locality 27) a dark gray cienega soil of YD age underlies the Leanne paleosol shown here and overlies what is believed to be a Clovis horizon. Photograph courtesy of Vance T. Holliday. (f) At the Indian Creek site (locality 29) multiple black organic stringers of YD age contain Folsom artifacts upstream and overlie a Clovis horizon above Glacier Peak tephra downstream. Leslie Davis, the principal investigator, provides scale at the Clovis locality.

Fig. 9. Black mats of Younger Dryas age (locality numbers refer to Fig. 1 and SI Table 2). Photographs by the author unless indicated otherwise. (a) The Arlington Springs site on Santa Rosa Island (locality 30) contains the oldest human skeletal remains in North America. Human bones occur near the bottom of a channel, to the right of the menu board, and below a lens containing bones of an extinct large mouse (Peromyscus nesodytes). The overlying black layers are of YD age. Photograph courtesy of G. James West. (b) Clovis artifacts at the Arc site (locality 31a) near Lake Erie occur at the base of the black peaty layer of YD age and on a late glacial diamicton. Photograph by Kenneth Tankersley. Published courtesy of the Center for the Study of the First Americans. (c) At the Frazier site (locality 23a) Agate Basin artifacts occurred at the base of a black cumulic mollisol of YD age. The pick rests on the top of the mollisol. (d) A Cody-complex bone bed at the Jurgens site (locality 23b) occurred both on and in a black cumulic mollisol of YD age. (e) At Lamb Spring (locality 38) YD strata included the channel fill at lower left and the overlying dark gray strata. (f) A dark brown to black mollisol of YD age at the Flaming Arrow site (locality 40a) is highly bioturbated.

Fig. 10. Black mats of Younger Dryas age (locality nos. refer to Fig. 1 and SI Table 2). Photographs are by the author unless indicated otherwise. (a) Pleistocene terrace gravels in the Streifel gravel pit (locality 40b) north of Bismarck, North Dakota, are overlain by loess with the Leonard Paleosol on top. (b) Sheep Mountain Table, South Dakota (locality 41), is a large mesa capped by the Oahe Formation with the black Leonard Paleosol at the base. (c) A waste pit of the Apache Power plant on the west edge of Wilcox Playa, Arizona (locality 42) exposed a YD black mat over storm beach deposits of Pluvial Lake Cochise of late Pleistocene age. (d) The Sunshine Paleoindian site in Nevada (locality 44) contains a black paleosol of YD Age. Photograph courtesy of George T. Jones. (e) The Nall site (locality 48) in the Oklahoma panhandle produced many Paleoindian artifacts during the 1930s dust bowl years. The lower dark gray paleosol of YD age is the Nall paleosol and underlies the Baker paleosol. Photograph courtesy of Vance T. Holliday. (f.) At the JB Spring site, East Rainey Butte (locality 49), several YD black mats are separated by colluvium shed from an adjacent sandstone cliff.
Table 2. Localities with black sediments of Younger Dryas age
|
Map No.*
Site No. |
Locality† |
YD stratum β2a 14C age, yrs B.P.§ |
Z1-2 contact and/or Clovis stratum
|
Ref.
|
||
|
Archaeology |
Extinct fauna |
14C age, yrs BP§ |
||||
|
1a 1 |
Murray Springs site, AZ SI Fig. 6a (1) |
Black organic clay = Stratum F2 , 9700 to 10,700 (A)†† |
Clovis |
Mammoth Bison Horse Dire wolf American Lion |
10,885 ± 50 (av. of 8) |
37 14 |
|
1b 2 |
Escapule site, AZ (1) |
Black organic clay = Stratum F2 , same age as at Murray Springs (F) |
Clovis |
Mammoth
|
None |
S-1 |
|
1c 3 |
Schaldack Mammoth, AZ (1) |
Black organic clay = Stratum F2 , same age as at Murray Springs (F) |
None |
Mammoth Horse |
None |
35 |
|
1d 4 |
Donnet Mammoth, AZ (1) |
Black organic clay = Stratum F2 , same age as at Murray Springs (F) |
None |
Mammoth |
10,530±520 |
35 |
|
1e 5 |
BLM V-005 Mammoth, AZ (1) |
Black organic clay = Stratum F2, same age as at Murray Springs (F) |
None |
Mammoth |
None |
35 |
|
2 6 |
Lehner site, AZ (1) |
Black organic clay = Stratum F2 9700 to 10,700 (A) |
Clovis |
Mammoth Bison Horse Camel Tapir |
10,950±40 (av. of 12) |
S-2 S-3 14 |
|
3a 7 |
Naco site, AZ SI Fig. 6b (1) |
Muddy marl facies Stratum F2b, with solid carbon age of 9250 ± 300 (A-9 & A-10) (E) |
Clovis |
Mammoth |
8980 ± 270 (A-195), inaccurate bone date (unpublished) |
S-4 |
|
3b 8 |
Leikem site, AZ (1) |
Dark gray mud = Stratum F2 (F) |
Clovis ? |
Mammoth |
None |
S-5 |
|
3c 9 |
Navarrete site, AZ (1) |
Brownish gray mud = Stratum F2 (F) |
Clovis ? |
Mammoth |
None |
S-6 |
|
4 10 |
Red Peak Valley, AZ (1) |
Cumulic mollisol = Stratum β2, 9660 ± 150, 10,510 ± 510 (A) |
None |
None |
None |
S-7 |
|
5 11 |
Clovis site, Blackwater Draw, NM SI Fig. 6c (1 & 5) |
Diatomite = Strata D & E, 9600 to 10,740 (A) |
Clovis in B3 and C below Folsom and Agate Basin in D |
Mammoth Bison Horse |
New date of 10,914 ± 72 (AA-30454) on carbonized plants in Stratum B3 |
38 39 |
|
6 12 |
Lubbock Lake site, TX SI Fig. 6d (1) |
Diatomaceous marsh deposits = Stratum 2A, 16 dates between 9720 ± 80 and 10,530 ± 90 on humates, 10,540 ± 100 on charcoal (A) |
Clovis (?) under Folsom in Stratum 1B |
Mammoth Bison Horse Camel Short-faced Bear Giant Armadillo |
11,100 ± 100 and 11,100 ± 80 both on wood |
S-8 S-9 14 |
|
7 13 |
Lake Ilo Basin, Knife River area, ND SI Fig. 6e (1) |
Leonard paleosol, >18 dates between 7000 and 13,000, mostly on humates, but 9700 to 11,000 believed to be most accurate (C) |
Folsom, Goshen, and Agate Basin above basal contact |
Bison with Folsom and Agate Basin occupations |
15,220 ± 130 below Leonard paleosol |
S-10 |
|
8 14 |
Lindenmeier site, CO SI Fig. 6f (1 & 2) |
Cumulic mollisol = Lower stratum D, 9460 ± 180 for top to 10,600 ± 60 (av. of 3) for Folsom occupation at base (B) |
Folsom in lower stratum D |
Bison in D |
New date for stratum B, top of Peoria loess = 12,170 ±8 0 (AA-51988) |
S-11 |
|
9 15 |
Hell Gap site, WY SI Fig. 7a (1 & 4) |
Cumulic mollisol = Lower Stratum E, 40 dates between 8630 and 11,250 for post Z1-2 occupation (B) |
Folsom, Goshen, Agate Basin, Hell Gap above basal contact |
Bison |
6 samples between 10,878 and 12,170 for base of E contact |
S-12 |
|
10a 16 |
Agate Basin site, WY SI Fig. 7b (1 & 4) |
Multibanded aquoll = Stratum B, 13 samples dated 9350 to 10,780 (B) |
Folsom, Agate Basin, and Hell Gap above basal contact |
Bison |
None |
S-13 18 |
|
10b 17 |
Sheaman site, WY (1 & 2) |
Haplaquoll = Stratum B, 13 samples dated 9086 to 11,810. Antler or bone foreshaft = 10,305 ± 15 av. of 3 (C) |
Clovis (?) on basal contact, unidentified occupation above |
Bison |
11,224 ± 50 (av. of 3) |
S-14 14 |
|
11 18 |
Medicine Creek area, NE (1) |
Paleosol YY = Brady Paleosol with > 7 samples between 9120 and 10,850 (B) |
Plainview and Paleosol YY |
Bison |
Between 10,850 ± 670 and 13,720 ± 530 |
S-15 |
|
12 19 |
Lange/Ferguson site, SD SI Fig. 7c (1 & 6) |
Cumulic mollisol = Stratum D with basal date of 10,670 ± 300 (B) |
Clovis in stratum C and on D/B contact = Z1-2 |
Mammoth in Stratum C with 2 bone dates of 10,710 ± 130 11,110 ± 40 |
Stratum C with 3 dates, average = 11,080 ± 40 |
S-16 14 |
|
13 20 |
Domebo site, OK SI Fig. 7d (1) |
Dark gray organic clayey sand = Strata C1 and C2 with dates between 10,123 ± 280 and 11,090 ± 110 (D) |
Clovis in Stratum C2 on C2/C3 contact = Z1-2 |
Mammoth in Stratum C2 with three AMS bone dates averaging 11,040 ± 255 |
Stratum C3 below Mammoth dates 12,350 ± 100 (AA-13026) |
S-17 S-18 14 |
|
14 21 |
Aubrey site, TX SI Fig. 7e (1) |
Strata E & G with 4 dates from 10,084 ± 80 to 10,937 ± 80 (B) |
Clovis on G/A2 and E1/D contact = Z1-2 |
Bison Mammoth Ground sloth |
2 charcoal dates av. 11,570 ± 70 |
S-19 14 |
|
15 22 |
Feterman Mammoth, WY SI Fig. 7f (2) |
Cumulic mollisol (F) |
Flaked tool and several flakes in questionable association |
Mammoth |
None |
S-20 S-21
|
|
16 23 |
Carter-Kerr-McGee site, WY SI Fig. 8a (1) |
Argiaquoll over Haplaquoll and 10,400 ± 600 on Goshen age bison bone (E) |
Goshen, Folsom, Agate Basin, Hell Gap, Cody in Aquolls |
Bison Camel |
Stratum 3/Stratum 2 contacted not dated |
S-22 S-23 18 |
|
17a 24 |
Jim Pitts site, SD SI Fig. 8b (2) |
Leonard paleosol = Stratum II with 7 dates of 9855 to 10,280 on basal Level 9 (C) |
Goshen, Folsom, Agate Basin and Cody in paleosol |
Bison |
11,597 ± 200 av. of 2 |
S-24 |
|
17b 25 |
Sewright site, ND (1) |
Leonard paleosol with 5 dates from 9890 ± 60 to 10,850 ± 40 with inversions (A) |
Goshen-Plainview base in 2Akb above Leonard paleosol in T-2 terrace |
Bison |
>10,320 ± 70 |
S-25 |
|
18 26 |
Trout Creek site, CO (1) |
Cumulic mollisol with date of 10,600 (E) |
Folsom in mollisol |
Bison |
None |
S-26 |
|
19a 27 |
Southern Great Basin, NV (1, 2 & 5) |
Wet meadows, springs, and shallow ponds 17 dates between 8400 and 11,760. YD age dominates (C) |
None reported |
Rancholabrean |
11,800 ± 180 at Corn Creek Flat |
7 |
|
19b 28 |
Gilcrease Spring Mound, NV SI Fig. 8c (5) |
Black peat dates 9920 ± 150 at top and 10,810 ± 460 at base (A) |
None |
Mammoth |
<12,100 ± 200 |
S-27 |
|
20 29 |
Black Mountain site, CO (2) |
Cumulic mollisol with charcoal date of 10,631 ± 84 (E) |
Folsom in mollisol |
None |
None |
S-28 |
|
21 30 |
Elgin mammoth, AZ (1) |
Cumulic mollisol (F) |
None |
Mammoth below mollisol |
None |
S-29 |
|
22 31 |
Pounds Playa, NM (6) |
Mollic aquoll with basal dates of 9623 ± 87 (AA-66775L) and 11,690 ± 73 (AA-66775H) (E) |
None |
None |
None |
S-30 |
|
23a 32 |
Frazier site, CO SI Fig. 9c (2) |
Mollic aquoll with date of 9600 ± 130 (av. of 2) (E) |
Agate Basin in Aquoll |
Bison |
None |
S-31 S-32 |
|
23b 33 |
Jurgens site, CO SI Fig. 9d (2) |
Mollic aquoll with date of 9070 ± 90 (E) |
Cody in aquoll |
Bison |
None |
S-31 |
|
24a 34 |
Jones-Miller site, CO (2) |
Hell Gap artifacts with date of 10,020 ± 320 in Argialboll (E) |
Hell Gap |
Bison |
None |
S-33 |
|
24b 35 |
Dutton site, CO (2) |
Argialboll over older Argialboll (F) |
Clovis on Z1-2 surface on lower argialboll |
Mammoth of questionable association with Clovis |
Mammoth bone date of 11,710 ± 150 |
S-34 17 |
|
25 36 |
Bram's site, SD (1) |
Leonard paleosol with 7 basal bulk soil dates from 8570 ± 90 to 11,670 ± 120 (C) |
None in the Leonard paleosol |
None |
> 11,670 unless contamination or bioturbation involved |
28 S-35 |
|
26 37 |
Huntington Canyon , UT (6) |
Dark grayish-brown lacustrine clayey silt with 4 dates from 8430 to 10,020 over peat with mammoth (B) |
None in clear association |
Mammoth and short faced bear on marsh peat between two lacustrine strata |
4 dates between 11,020 and 12,340 on mammoth fecal material and bone |
S-36 |
|
27 38 |
Wilson-Leonard site, TX SI Fig. 8e (1) |
Stratum I = cienega deposit (lcl) overlain by Leanne paleosol (lsi) Stratum I dates 9500 to 11,400 (C) |
Clovis (?) overlain by nondiagnostic artifacts |
Not identifiable |
11,500 |
S-37 |
|
28 39 |
Cow Catcher locality, ND (1) |
Leonard paleosol with bulk soil date of 11,130 ± 80 on basal 10 cm (E) |
None in the Leonard paleosol |
None |
None |
28 |
|
29 40 |
Indian Creek site, MT SI Fig. 8f (1) |
Black organic streaks in alluvium over Glacier Peak tephra dated 11,125 ± 130 (A) |
Folsom at 10,410 ± 60 stratigraphically over Clovis at 10,980 ± 110 downstream |
Bison |
Z1-2 contact between 10,980 ± 110 and ash dated 11,125 ± 130 |
S-38 14 |
|
30 41 |
Arlington Springs site, Santa Rosa Island, CA SI Fig. 9a (1) |
"Black Band," above human bone, with 2 dates of 10,315 ± 40 and 10,725 ± 40 in stratigraphic order (A) |
Human skeleton with bone date of 10,960 ± 80 |
Peromyscus nesodytes |
Contact Z1 between 10,725 ± 40 and 11,250 ± 40 |
S-39 14 |
|
31a 42 |
Arc site, NY SI Fig. 9b (1) |
Black peat with basal date of 10,370 ± 108 (av. of 2) on wood (E) |
Clovis or Gainey in silt under peat and over diamicton |
None |
11,700 ± 110 on Z1-2 pre-Clovis surface |
S-40 |
|
31b 43 |
Hiscock site, NY (5) |
Upper Fibrous Gravelly Clay (FGC) dated 9250 to 9475 over lower FGC dated 10,200 to 11,450 (C) |
Clovis in bioturbated Fibrous Gravelly clay |
Disarticulated mastodon bones in bioturbated FGC |
FGC/ till contact about 11,450 |
S-41 |
|
32 44 |
Sisters Hill site, WY (1) |
Aquoll with black carbaceous bands = stratum C dated 9550 ± 130 and 9650 ± 130 (E) |
Hell Gap in Stratum C |
None |
Erosional surface on Ucross Formation = Z1-2 |
S-42 |
|
33 45 |
Richard Beene site, TX (1) |
Perez paleosol with 4 dates from 9780 to 10,780 (A) |
Late Paleoindian above paleosol |
None |
13,480 ± 360 below Perez paleosol |
S-43 |
|
34 46 |
Thunderbird site, VA (1) |
"Clovis" clay on buried terrace (F) |
Post Clovis, fluted points on "Clovis" clay |
None |
None |
S-44 |
|
35 47 |
Chapo Ranch, AZ (1 & 5) |
Mollisol = Stratum F2 with dates of 9580 ± 170 (AA-53781), 10,516 ± 75 (AA-52885) and 10,696 ± 57 (AA-52886) overlies Strata E1 and E2 (B) |
None |
Mastodon in Stratum E2 marl below Stratum F2 |
12,750 ± 460 (A-1786) on Stratum E1 below E2 |
S-45 |
|
36 48 |
South Whitlock site, SD (1) |
Leonard paleosol with bulk soil dates of 5590 ± 60 and 9190 ± 90 over 11,860 ± 60 on charcoal (C) |
None reported |
Bison |
> 11,670 unless bioturbation involved |
28 |
|
37 49 |
Kaibito Plateau, AZ SI Fig. 8d (6) |
Black mats = cienega soils in depressions with dates from ~ 8000 to ~ 11,000 (B) |
Paleoindian surface finds include Clovis points |
None |
None |
S-46 |
|
38 50 |
Lamb Spring, CO SI Fig. 9e (5) |
Mollic cienega paleosol with date at 9330 ± 50 over channel fill with 6 dates from 10,810 ± 60 to 11,080 ± 50 (C) |
Cody above Clovis-age cienega channel but no Clovis artifacts |
Mammoth |
11,260 ± 60 at base of channel |
S-47 |
|
39 51 |
Roosevelt National Park, Little Missouri Badlands, ND (3) |
Leonard paleosol with 7 dates from 8800 ± 77 (AA-49044) to 11,135 ± 61 (AA-45980) (C) |
None |
None |
None |
S-48 |
|
40a 52 |
Flaming Arrow site, ND SI Fig. 9f (2) |
Leonard paleosol with 4 dates from 9588 ± 53 (AA-49048) to 11,860 ± 270 (AA-53770) (C) |
None |
None |
11,860 ± 270 |
S-49 S-50 |
|
40b 53 |
Streifel Gravel Pit, ND SI Fig. 10a (3) |
Leonard paleosol with 4 dates from 8300 ± 150 (AA-56335) to 11,400 ± 120 (AA-53762) (C) |
Cody above paleosol |
None |
11,400 ± 120 |
S-50 |
|
41 54 |
Sheep Mountain Table, Badlands National Park, SD SI Fig. 10b (3) |
Mollic paleosol = Stratum 2 with 8255 ± 70 near top and 12,010 ± 80 near Base (C) |
None |
None |
None |
S-51 S-52 |
|
42 55 |
Wilcox Playa, AZ SI Fig. 10c (6) |
Mollic paleosol = Stratum C with bulk sediment date of 8910 ± 280 = minimum age (E) |
None |
Mammoth in Stratum B5 |
12,970 ± 480 in Stratum B3 below mammoth |
S-53 |
|
43 56 |
MacHaffe site, MT (1) |
"Black soil" with 2 dates from 10,090±50 to 10,390±40 (A) |
Folsom in "black soil," Cody above it |
Bison |
None |
S-54 |
|
44 57 |
Sunshine site, NV SI Fig. 10d (6) |
Dark brown marsh deposit = Stratum C with 4 dates from 9800 to 10,000 (A) |
Fluted point in Stratum E below Strata C and D |
Camel in Stratum E |
Between 10,340 ± 60 and 11,390 ± 60 |
S-55 |
|
45 58 |
Vermillion Lakes Site, Alberta, Canada (4) |
Multiple black layers with numerous dates from 9500 to 10,500 (B) |
Agate Basin |
|||