NM: Roosevelt Co.
General Description.—Hester 1972: Blackwater Loc. No. 1: 34°17' N, 103°19" W. SE1/4 Sec. 25, T1N, R34E. The locality was a pond intermittently between ca. 15,000 to 6,000 BP. The pond was oval in shape, ca. 100 yds E-W and 250 yds N-S. There was an outlet channel 50 yds in width at the S end, draining into the main body of the draw. The pond probably was never more than a few feet deep. A maximum of 12 to 15 feet of pond deposits were laid down. The pond was fed through much of its history by springs coming from the earlier riverine gravels intersecting the low escarpment of Blackwater Draw.
Hester 1972: Earliest unit of pond deposition is the Gray Sand, unit B1 (gravels below were deposited by the ancestral Brazos before beheading by the Pecos); presumed to be full pluvial in age, between 13,000 and 25,000 BP. Overlying the Gray Sand is the Brown Sand Wedge, deposited after a period of erosion; this includes units C0 and C1 of Haynes and Agogino (1966) of Clovis age with three radiocarbon dates (11,630 ± 400 [A-491], 11,170 ± 360 [A-481], and 11,040 ± 500 [A-490]); also known as the Brown Sand Wedge are units D1a and D1b, separated from below by a slight unconformity, and which are shoreward facies of the Diatomite and of Folsom age (dates of 10,170 ± 250 ± 250 [A-488] and 10,490 ± 200 [A-492]). The classic Diatomite (unit D2) lies toward the center of the pond (dates of 10,250 ± 320 [A-379 ∓ A-380] and 10,490 ± 900 [A-386]) and contains numerous bison kills of Folsom age. A strong unconformity lies at the top of the Diatomite.
Hester 1972: A strong unconformity separates the Diatomite from the overlying Carbonaceous Silt (unit E), with a date of 9,890 ± 290 (A-489). In the latter, spring action is greatly reduced and there was probably a shallow, stagnant pond or marsh; probably fed by intersection with the water table rather than by the springs. Eventually, drying and formation of a carbonaceous soil, followed by severe wind deflation, particularly in the center of the pond where completely removed in some places. Hand-dug wells by Archaic peoples during this time (indicated drop in water table between 5 and 8 ft). The Jointed Sand (unit F) is a massive quartz sand apparently representing a time of erosion possibly correlated with the Altithermal. A bison kill toward the base was dated at 4950 ± 150 BP. Above another unconformity is the Tan Aeolean Sand (unit G) with Recent Indian artifacts and with eolian activity still going on. Much more information in Hester 1972.
Age.—Wisconsinan and Holocene. 14C dates (Hester 1972:58-59): Carbonaceous silt, 6230 ± 150 (O-170) and 6300 ± 150 (O-169) on burned and unburned bone; Jointed Sand, 4950 ± 150 (O-157); Diatomite unit, Folsom occupation, 10,490 ± 900 (A-386); 9,900 ± 320 (on fine-grained carbonaceous matter in silt (A-379) and 10,600 ± 320 (on humic acid fraction) (A-380), average 10,250 ± 320 BP, transitional zone between diatomite and carbonaceous silt layers.
Comments.—Kurten and Anderson (1980) use this name for Blackwater Loc. No. 1, dividing into gray sand and brown sand wedge units. As used here, for taxa not assigned specifically to either of those two. Johnson (1987) notes that Milstead (1967) identified Terrapene ornata from Blackwater Draw Loc. No. 1, but that it came from the bottom of Well M at Station E, an aboriginal well dug during the Archaic period and thus Holocene. The "yellow sands" of Stock and Bode (1937) refer to the stratum under the gray sands (Hester 1972). The "Red Gravel" also refers to the statum under the gray sands; the "pink sand" also immediately underlies the gray sand. The "Blue Sand" of Stock and Bode is the Carbonaceous Silt and Diatomite units of more recent stratigraphic nomenclature.
Publications.—*Cotter 1937; Harris 1985; *Haynes and Agogino 1966; Hester 1967; (*Hester 1972); *Howard 1935; (*Johnson 1987); *Milstead 1967; Kurtén and Anderson 1980; *Slaughter 1975; *Stock and Bode 1937.
Fauna.—
Last Update: 4 September 1998.