Moderators: MichelleH, Minimalist, JPeters
However, I fail to understand how the freezing process can create a percussion strike,
Title: Geoarchaeological Investigations at the Topper and Big Pine
Sites, Allendale County, Central Savannah River, South Carolina
Authors: Michael R. Waters, Steven L. Forman, Thomas W. Stafford
Jr., John Foss
I'll preface this review of Waters et al. (2009) by saying there is
not a lot new here. Much of this information has been released
informally via various media outlets. But now at least we have a peer-
reviewed paper acknowledging the info that has been released
informally.
"…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…"
So no hearth in the > 50kya strata according Waters et al.
"…The age of the deposition is unknown, but the infinite radiocarbon
ages from this unit indicate that deposition occurred before 55,000
yr. B.P. A period of floodplain stability and soil formation followed
the deposition of fine-grained overbank deposits (unit 1b). This was
followed by a period of fluvial scouring when the soil developed on
unit 1b was truncated. 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…"
This indicates that the proposed, younger preClovis artifacts can be
no younger than 15kya.
"…Below the Clovis horizon, Goodyear (2005a) reports the presence of
what he believes are pre-Clovis artifacts. This "Topper assemblage"
is buried within units 2b and 1. The stratigraphic position of
the "Topper assemblage" indicates an antiquity older than Clovis, but
how much older remains unresolved…"
Except not younger than 15kya.
"…Stratigraphic relationships show that a moderately-well developed
paleosol (Bw horizon) formed in colluvial deposits (unit 3a) that lie
between the Clovis horizon and the "Topper assemblage" that reflect a
few hundreds to a few thousands of years of deposition and
pedogenesis. Two OSL ages, 14,400 + 1200 yr B.P. (UIC-763) and 15,200
+ 1500 yr B.P. (UIC-764), are from the top of unit 2b and provide a
provisional minimum age for the proposed pre-Clovis material. The
base of this sand remains undated…"
"…Even older "Topper assemblage" material has been reported in the
older unit 1a and 1b sediments and are associated with dates of
>50,000 14C yr B.P…"
"…The "Topper assemblage", consisting of a smashed core and
microlithic industry(Goodyear 2005a), is typologically and
technologically unique among New World archaeological sites. Goodyear
(2005a) believes that spalls and flakes were modified into small
unifacial tools and bend-break tools that were used to work wood and
other organic materials. The human origin of the "Topper assemblage"
has not yet been unequivocally demonstrated. Alternatively, the
pieces making up the "Topper assemblage" could have been produced
naturally as a result of thermal fracturing (forest fires and freeze-
thaw cycles) or physical fracturing during stream transport. Finally,
the "Topper assemblage" is highly diachronous, occurring in sediments
ranging in age from >50,000 to 15,000 yr B.P. It is unusual that
there was no lithic technological change for ca. 35,000 years…"
Is it? Acheulean? Mousterian?
Also, it seems only one category of artifacts are being addressed by
Waters et al. How about the proposed core tools, large flake tools
and microblade cores:
http://tinyurl.com/dxpftq
http://tinyurl.com/boph3s
http://tinyurl.com/ajhzzq
http://tinyurl.com/a9mvhj
http://tinyurl.com/b4pbvq
http://tinyurl.com/attgae
"…The timing of the first change from meandering to braided is
unknown, with only dates in excess of 50,000 yr B.P. being reported
from the upper portion of the deposits of the first meandering stream
package. This study of the terraces at the Topper site yielded
similar minimum limiting ages (>55,000 yr B.P.) for the initial
meander period. Leigh and others (2004) have suggested that the shift
from meandering to a braided stream regime occurred in other streams
in the Southeast possibly as early as 70,000 yr B.P. and as late at
30,000 yr B.P., though this age span may reflect precision limits on
radiocarbon dating…"
This discounts the proposed physical fracturing during stream
transport:
"…The shortest distance; that is, a straight channel, results in the
highest energy per unit of length, disrupting the banks more,
creating more sediment and aggrading the stream. The presence of
meanders allows the stream to adjust the length to an equilibrium
energy per unit length in which the stream carries away all the
sediment that it produces…"
http://en.wikipedia.org/wiki/Meander#Equilibrium_theory
"…Meandering streams develop in relatively flat areas, such as a
floodplain, and where sediment consists primarily of fine sands,
silts, and muds…"
http://www.thefreedictionary.com/meandering+stream
Can somebody please show me specimens derived from thermal
fracturing, or fracturing due to stream transport, that exhibit the
characteristics of these specimens:
http://tinyurl.com/dxpftq
http://tinyurl.com/boph3s
http://tinyurl.com/ajhzzq
http://tinyurl.com/a9mvhj
http://tinyurl.com/b4pbvq
http://tinyurl.com/attgae
Lets be fair: the specimens should come from Piacenzian strata or
older.I've never once had someone demonstrate this to me, whether
the control specimens be Topper or Calico. Special pleading?
"…A meandering pattern has characterized the Savannah River and other
southeast streams from 14,000 – 16,000 B.P. to present…"
"…The period of downcutting and return to meandering conditions is
linked with another abrupt vegetation and climate change along the
central Savannah River at about 16,000 yr B.P. (Leigh 2008). The
previous boreal vegetation was rapidly replaced with a temperate-wet
forest of mixed deciduous trees and a climate that was warmer and
wetter than the previous climate and that of today (Watts, 1980;
Jackson et al., 2000). This switch to mesic and warmer conditions and
concomitant vegetation change resulted in lower sediment yields and
lower, more uniform stream discharge that favored meandering stream
environments (Leigh et al., 2004; Leigh, 2006, 2008)…"