"...Currently, the oldest claim for occupation of
North America is at the Topper site, located on
a Pleistocene terrace overlooking the Savannah
River. Clovis artifacts at Topper are found at
the base of a colluvial deposit, and older artifacts
are reported in underlying sandy alluvial sediments
dated to about 15 ka (68). The proposed
early assemblage is a smashed core and microlithic
industry. Cores and their removals show
no negative bulbs, and flakes and spalls were
modified into small unifacial tools and “bendbreak
tools,” possibly used for working wood
or bone. In 2004, similar-looking material was
found in older alluvial deposits dating in excess
of 50 ka (69). Given that the assemblage was
not produced through conventional Paleolithic
technologies and that the putative artifacts
could have been produced through natural
processes (specifically thermal spalling), evaluation
of this site must await a complete lithic
analysis..."
Goebel, Waters, O’Rourke 2008
I think Goebel et al. need to define what they consider to be "conventional Paleolithic technologies". Here are examples of specimens recovered in secure geological contexts at Topper:
These are without a doubt anthropogenic. I'm not sure why these non-"smashed core", microlithic, “bendbreak tools” weren't addressed?
Here are examples of "bendbreak", "smashed core" (I assume they mean bipolar reduction), microlithic specimens:
An overview of the stratigraphy:
"...Hypothesized pre-Clovis artifacts derive from several stratigraphic units below the Clovis horizon at Topper..."
"...This is overlain by unit 3b (Figures 2, 4, 5, and 6) which is ubiquitous across the site. This unit consists primarily of silty sand with occasional angular gravels that become more abundant toward to the slope. In some places, the angular gravels close to the slope become 10 cm thick and grade downslope into a stone line (Figure 6). The upper 60 cm of unit 3b is pedogenically altered into a weak Bw horizon with a 15-20 cm thick A or AP horizon. Unit 3b immediately overlies units 3a and 2b. The contact between units 3b and 2b is sometimes difficult to clearly identify due to their similar textures. Clovis artifacts occur at the base of unit 3b. Above the Clovis horizon is a stratigraphically coherent cultural sequence that ranges from early, middle, and late Archaic to Woodland near the top (Goodyear 2001)..."
"...Sometime after this erosional period, colluvium (unit 2a) accumulated locally next to the channel edge and the alluvial sands were deposited (unit 2b) across most of the site. These sediments appear to have been deposited in arcuate channels, potentially part of a braided stream system. Swales at the top of this unit are
filled with fine-grained overbank deposits (unit 2c) and represent the last episode of fluvial deposition at the site. Luminescence dating suggests that fluvial deposition ceased around 15,000 yr B.P. At this point, the river downcut and abandoned the floodplain, creating Terrace 2…”
Waters et al. 2009
This indicates that the preClovis artifacts recovered from Unit 2a can be no younger than 15kya.
"...Pedogenic processes have altered the upper portion of unit 1 creating a weak Bt, which was later truncated by erosion. Goodyear (2005a, 2005b) has recovered chert pieces that he identifies as pre-Clovis artifacts and a charcoal concentration (feature 91) that had the appearance of a possible hearth in unit 1..."
"...This technique was used on a sample of organic matter from unit 1a. The “humic acids” isolated from the first extraction from this sample yielded dates of 44,300 + 1700 14C yr B.P. (CAMS-77496) and 45,800 + 1000 14C yr B.P. (CAMS-78601). The second humic acid extraction was discarded and not dated. Humates from the third extraction yielded dates of 48,700 + 1500 14C yr B.P. (CAMS-78602) and 49,900 ± 1300 14C yr B.P. (CAMS-80534). These dates are evidence that negligible younger humate contamination existed in the samples. However, the dates from the third extractions yield more reliable ages. Regardless, these dates are all minimum ages because the dates are at the maximum limits of the radiocarbon method..."
"...Six samples of wood, nutshell, and humic acids were dated from unit 1a (Figures 4 and 5). These dates represent minimum ages for unit 1a and indicate that this unit dates in excess of 50,000 14C yr B.P. A date of >54,700 14C yr B.P. (CAMS-79022) was obtained on a Hickory (Carya) nutshell and a date of >55,500 B.P. 14C yr B.P. (CAMS-19023) on a pied of fir wood (Abies) from an organic horizon within unit 1a underlying the reported oldest cultural horizon at the Topper site. The lens containing the Carya, Abies, and other plant species is interpreted to be woody plant material that accumulated naturally in a shallow swale in the stream bed. Two dates, >50,300 14C yr B.P. (UCIAMS-11682) and >51,700 14C yr B.P. (UCIAMS-11683) were obtained on reduced woody plant remains from a low-relief, thin, lenticular accumulation of physically well preserved plant material within the fluvial sands of unit 1. Goodyear defined this as feature 91 and *SUGGESTED* that this *MAY* represent a hearth-like feature (Goodyear, 2005b). Although the plant remains were black, there is no evidence the plant material had been combusted or that the plant fossils had been emplaced secondarily into the fluvial sands. The organic-carbon rich lens was lithologically conformable vertically and horizontally with enclosing stream channel sands, there was no evidence of heat-caused oxidation (hematite development) in sand immediately below the organic matter, and the plant remains were soft, retained excellent cellular structure, and reacted immediately and strongly with weak KOH used during the radiocarbon pretreatment process..."
* Emphasis added
Waters et al. 2009
"...Evidence is emerging for an even earlier human entry into the Americas, prior to 15,500 CALYBP. Presentations and discussions concerning Miles Point and similar localities on the Delmarva Peninsula, Cactus Hill, La Sena, Lovewell, Burnham, Topper, Monte Verde I, and others suggesting the possibility of a human presence in the Americas before the Last Glacial Maximum is increasingly intriguing and may develop rapidly in the near future..."
Collins and Waters et al. 2008
Current Research in the Pleistocene 25:195-197
"...Excavations here consisted of one-meter squares dug to the depth of the 50,000-year radiocarbon dates, or about 95.40 meters. The goal is to recover chert artifacts from the top of the terrace at approximately 97.30 meters, downward two meters to the level of the dates (Fig. 2). Numerous examples of the distinctive bend break tools have been found through out the terrace including one with an obvious graver spur (Fig. 3). This artifact is considered of unquestionable human manufacture and was found in the upper portion of the terrace (Fig. 2). Another exciting find was a reddish core of unweathered chert with four areas of battering and several flake detachments (Fig. 4). This artifact was recovered in situ at a depth of 96.05 meters, some 60 centimeters above the 50,000-year dates (Fig. 2). Like the spurred piece, it is considered a definitive artifact.
Figure 3
Figure 4
..."
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