Bifacial Flake-Core Reduction Strategies and Related Aspects of Early Paleoindian Lithic Technology

2021 ◽  
pp. 345-370
Author(s):  
Philip J. Wilke
2003 ◽  
Vol 14 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Georges A. Pearson

AbstractAn archaeological survey on the Azuero Peninsula in Panama has recently discovered a Paleoindian quarry/workshop at the base of a quartz outcrop. The Nieto site contains seldom-seen preforms and flake blanks that provide new information on early-stage reduction strategies used by Clovis-like point makers in the Neotropics. Finished tools recovered at the site include gravers, side scrapers, and large scraper planes. The production of flake blanks followed a core reduction and rejuvenation strategy already observed at other Paleoindian sites in Costa Rica and Florida. Although the quartz outcrop is located only a few kilometers away from better-quality sources of jasper and chert, Paleoindians appear to have preferred this translucent stone for their weaponry. This new information, when combined with late-stage production strategies previously recorded from other Panamanian sites, brings us closer to tracing a complete manufacturing trajectory for Clovislike points on the Isthmus. It is hoped that data from the Nieto quarry/workshop will eventually help archaeologists determine if the presence of the fluting technique in Central and South America is attributable to a migration of Clovis-related people or a technological diffusion among pre-established southerly populations.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257041
Author(s):  
Berrin Çep ◽  
Benjamin Schürch ◽  
Susanne C. Münzel ◽  
Jens Axel Frick

The branched reduction system at the Heidenschmiede described here is hitherto exceptional for the Middle Paleolithic of the Swabian Jura. By means of refits and supporting objects, we are able to describe a superordinate reduction system that combines several individual reduction concepts, such as Levallois and blade production, within one volume. In the Middle Paleolithic of the Swabian Jura, blade technology has thus far played a rather minor role. On the one hand, it is possible to split a selected volume (nodule) into three parts, which are reduced separately according to individual concepts. On the other hand, it is also possible to reduce parts of a volume with one concept first and then with another. The hypothetical reduction system can be branched or linear, thus emphasizing the technological flexibility in core reduction, which requires a high degree of cognitive skills of three-dimensional imagination.


2014 ◽  
Vol 17 ◽  
pp. 1 ◽  
Author(s):  
Grant W.G. Cochrane

<p>An analysis of stone artefacts from the Arcadia Valley in south central Queensland is used to develop a core reduction sequence model for the region. During the initial construction of this model, core types are identified that reflect phases or end points in reduction trajectories. The model shows that core reduction methods employed in the Arcadia Valley during the mid-to-late Holocene included Levallois, discoidal, prismatic and burin blade core methods, along with less formal reduction strategies. In recognition of the equifinality of many reduction processes, the model has a flexible structure. Hence the prevalence of the various core reduction methods, and their relationships to each other, may be the subject of a range of hypothetical scenarios which can be tested by employing multiple lines of additional evidence. Following this procedure, it is concluded that Levallois and discoidal methods may account for close to half of the artefact assemblage, while less formal methods were also very common.</p>


Antiquity ◽  
2002 ◽  
Vol 76 (292) ◽  
pp. 397-412 ◽  
Author(s):  
Xing Gao ◽  
Christopher J. Norton

The Chinese Palaeolithic has traditionally been divided into three distinct cultural periods: Lower, Middle, and Upper. Analysis of four stone tool criteria (raw material procurement, core reduction, retouch, and typology) to determine if a distinct Middle Palaeolithic stage existed in China suggests that very little change occurred in lithic technology between the Lower and Middle Palaeolithic. Accordingly, a two-stage progression is proposed: Early and Late Palaeolithic. The transition between these two cultural periods occurred with the development of more refined stone tool making techniques (e.g. introduction of blade and microblade technology) and the presence of other archaeological indicators of more modern human behaviour (e.g. presence of art and/or symbolism) (c. 30,000 years ago).


2010 ◽  
Author(s):  
Michael T. Sliter ◽  
Scott A. Withrow ◽  
Michelle H. Balzer ◽  
Michelle H. Brodke ◽  
Jennifer Z. Gillespie ◽  
...  
Keyword(s):  

2011 ◽  
Author(s):  
Erin E. Bonar ◽  
Harold Rosenberg ◽  
Erica Hoffmann ◽  
Shane W. Kraus ◽  
Elizabeth Kryszak ◽  
...  

2016 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Sara C Martinez ◽  
◽  
Sharonne N Hayes ◽  

The physiologic demands of pregnancy may either trigger or uncover ischemic heart disease (IHD) via largely unknown mechanisms, leading to an increased mortality compared with nonpregnant individuals. Risk factors for IHD in pregnancy are age, smoking, multiparity, and prior cardiac events. A multidisciplinary team at a referral center is key to coordinating medical or invasive management and inpatient observation. Etiologies may be revealed by experienced angiographers, and are predominantly spontaneous coronary artery dissection, followed by atherosclerotic disease and thrombus, while a significant percentage of women are found to have normal coronary arteries by angiogram. The management of these conditions is varied and, in general, conservative management is preferred with adequate coronary flow and stable hemodynamics. A woman with a history of IHD in pregnancy is at a substantial risk for further complications in future pregnancies and beyond; therefore, aggressive risk factor-reduction strategies and regular cardiology follow-up are imperative to decrease adverse events.


2010 ◽  
Vol 5 (1) ◽  
pp. 104
Author(s):  
Daniel S Menees ◽  
Eric R Bates ◽  
◽  

Coronary artery disease (CAD) affects millions of US citizens. As the population ages, an increasing number of people with CAD are undergoing non-cardiac surgery and face significant peri-operative cardiac morbidity and mortality. Risk-prediction models can be used to help identify those patients at increased risk of peri-operative cardiovascular complications. Risk-reduction strategies utilising pharmacotherapy with beta blockade and statins have shown the most promise. Importantly, the benefit of prophylactic coronary revascularisation has not been demonstrated. The weight of evidence suggests reserving either percutaneous or surgical revascularisation in the pre-operative setting for those patients who would otherwise meet independent revascularisation criteria.


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