Thermal Alteration of Bald Eagle Jasper: Authors' Reply to Patterson

1984 ◽  
Vol 49 (1) ◽  
pp. 173-177 ◽  
Author(s):  
Debra L. Schindler ◽  
James W. Hatch ◽  
Conran A. Hay ◽  
Richard C. Bradt
1982 ◽  
Vol 47 (3) ◽  
pp. 526-544 ◽  
Author(s):  
Debra L. Schindler ◽  
James W. Hatch ◽  
Conran A. Hay ◽  
Richard C. Bradt

The aboriginal thermal processing of Bald Eagle Jasper in Central Pennsylvania is described in terms of the chemical and physical changes that occur in this material. Heat treatment is shown to transform the jasper's geothite component to hematite and to improve its workability by reducing its fracture toughness by one-half. This is accompanied by a yellow to red color change. The role of thermal alteration in the local lithic technology is inferred from laboratory heating experiments and from an analysis of lithic artifacts from the Houserville Site (36 Ce 65), a jasper workshop. The prehistoric utilization of this material is analyzed from a regional perspective. The results have implications for aboriginal social organization in Central Pennsylvania.


1984 ◽  
Vol 49 (1) ◽  
pp. 168-173 ◽  
Author(s):  
Leland W. Patterson

Comments are offered on heat treating experiments and archaeological studies by Schindler, Hatch, Hay and Bradt concerning Bald Eagle Jasper from central Pennsylvania. Their conclusions concerning aboriginal patterns of use of Bald Eagle Jasper are critiqued. Their explanations for the effects of thermal alteration on jasper fracture properties are also questioned.


1990 ◽  
Author(s):  
D.J. Varnes ◽  
D. H. Radbruch-Hall ◽  
K.L. Varnes ◽  
W.K. Smith ◽  
W.Z. Savage
Keyword(s):  

2020 ◽  
Author(s):  
Jeffrey Osterhout ◽  
◽  
J. William Schopf ◽  
Anatoliy B. Kudryavtsev ◽  
K.D. McKeegan

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
E. Pop ◽  
F. H. Reidsma ◽  
T. Reimann ◽  
M. J. Sier ◽  
C. E. S. Arps ◽  
...  

AbstractThroughout (pre)history, non-flint rocks have been used to structure fireplaces, to retain heat, to boil liquids, and to cook food. Thus far, the identification of heated non-flint rocks in archaeological contexts largely depends on a visual (macroscopic) assessment using criteria thought to be diagnostic for thermal alteration. However, visual identification can be subject to observer bias, and some heat-induced traces can be quite difficult to distinguish from other types of weathering or discolouration. In this paper, we present feldspar luminescence analysis as an independent, objective way to identify heated non-flint rocks and to evaluate the results against the established visual macroscopic method for the identification of such pieces. This is done by submitting manuported rocks with and without inferred macroscopic characteristics of heating, originating from the Last Interglacial, Middle Palaeolithic site Neumark-Nord 2/2 (Germany), to feldspar luminescence analysis (pIRIR290). Results of the feldspar luminescence analysis are compared with the visual assessments. This proof of concept study demonstrates the potential of luminescence analyses as an independent, quantitative method for the identification of heated rocks—and their prehistoric applications like hot-stone cooking, specifically for cases where macroscopic assessment cannot provide reliable determinations.


1965 ◽  
Vol 2 (5) ◽  
pp. 442-484 ◽  
Author(s):  
Donald Carlisle ◽  
Takeo Susuki

The highly deformed section at Open Bay is one of the few good exposures of a thick sedimentary unit within the prebatholithic rocks along coastal British Columbia. It provides new structural information relating to emplacement of a part of the Coast Range batholith and it contains an important Upper Triassic fauna unusually well represented. Structural and paleontological analyses are mutually supporting and are purposely combined in one paper.Thirteen ammonite genera from 14 localities clearly substantiate McLearn's tentative assignment to the Tropites subbullatus zone (Upper Karnian) and suggest a restriction to the T. dilleri subzone as defined in northern California.Contrary to an earlier view, the beds are lithologically similar across the whole bay except for variations in the intensity of deformation and thermal alteration. Their contact with slightly older relatively undeformed flows is apparently a zone of dislocation. Stratigraphic thicknesses cannot be measured with confidence, and subdivision into "Marble Bay Formation" and "Open Bay Group" cannot be accepted. Open Bay Formation is redefined to include all the folded marble and interbedded pillow lava at Open Bay. Lithologic and biostratigraphic correlation is suggested with the lower middle part of the Quatsino Formation on Iron River, 24 miles to the southwest. Basalt flows and pillowed volcanics west of Open Bay are correlated with the Texada Formation within the Karmutsen Group.The predominant folding is shown to precede, accompany, and follow intrusion of numerous andesitic pods and to precede emplacement of quartz diorite of the batholith. Structural asymmetry is shown to have originated through gentle cross-folding and emplacement of minor intrusives during deformation.


1985 ◽  
Vol 16 (35) ◽  
Author(s):  
Y. NAKANO ◽  
T. A. FOGLIA ◽  
H. KOHASHI ◽  
T. PERLSTEIN ◽  
S. SEROTA

2007 ◽  
Vol 42 (3) ◽  
pp. 357-372 ◽  
Author(s):  
Takaaki Noguchi ◽  
Tomoki Nakamura ◽  
Kyoko Okudaira ◽  
Hajime Yano ◽  
Seiji Sugita ◽  
...  

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