Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Weathering rind
open-in-new
<h2 id="dating-using-weathering-rinds">Dating using weathering rinds</h2> <p>Weathering rinds have a long history of being used to determine the relative age of either <a href="/facts/Quaternary/3cEgHAqc">Quaternary</a> <a href="/facts/Sediment/zsIH1A6U">sediments</a> or <a href="/facts/Landform/eI0tkDYB">landforms</a>. This is done by comparing the thickness of weathering rinds of <a href="/facts/Gravel/IwHG9JfI">gravel</a> composed of similar rock types. Deposits containing gravel with thicker weathering rinds are interpreted to be older than deposits containing rocks with thinner weathering rinds. Sedimentary deposits containing gravel with weathering rinds of the same thickness are interpreted to be approximately contemporaneous in age. The use of weathering rinds in <a href="/facts/Relative_dating/PyvmNRU6">relative dating</a> is widely used in <a href="/facts/Arctic/bxbuUz7Q">Arctic</a>, <a href="/facts/Antarctic/xPPVrxBE">Antarctic</a>, and alpine regions and in the correlation of <a href="/facts/Glacial/alIAm38r">glacial</a> <a href="/facts/Moraine/NUoWIpka">moraines</a> and <a href="/facts/Till/Wv7pJAsD">tills</a> and <a href="/facts/Fluvial/nkLrSheo">fluvial</a> sediments and <a href="/facts/Fluvial_terrace/2CSEIJfG">terraces</a>.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a><a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a><a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> </p><p>In addition, weathering rinds have been used to determine the absolute amount of time gravel-size rock has been exposed to the weathering processes. This technique was proposed by Cernohouz and Solc<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> who first argued that the relationship between the thickness of a weathering-rind thickness and the time it took to form is expressed by a logarithmic function. This is done by determining the absolute age of sedimentary deposits containing either gravel-size rocks or artifacts using absolute dating methods such as C14 and measuring the weathering-rind thickness of rocks of similar lithology. The dates obtained from absolute dating techniques and measurements of weathering rind thicknesses are then used to construct an age versus thickness curve for dating rocks in other sedimentary deposits. This dating method has often been applied to glacial deposits in alpine regions.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a><a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a><a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a><a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> </p> <h3>Obsidian hydration</h3> <p class="note">Main article: <a href="/facts/Obsidian_hydration_dating/soRWd0bY">Obsidian hydration dating</a></p> <p>Obsidian hydration dating is a type of dating that uses the weathering rind that develops within artifacts or gravel that are composed of <a href="/facts/Obsidian/GW1DI93A">obsidian</a>. When fresh obsidian is exposed to air it typically contains less than 1% water. Over time, a weathering rind, known as an <i>obsidian hydration band</i> and composed of hydrated glass forms, as water slowly diffuses from a broken surface, which is normally associated with manufacture of an artifact, into the obsidian. The thickness of this band can be seen, and measured, using various techniques such as a high-power <a href="/facts/Microscope/ldJp0CI3">microscope</a> with 40-80 power <a href="/facts/Magnification/ACFaV1Bd">magnification</a>, depth profiling with SIMS (<a href="/facts/Secondary_ion_mass_spectrometry/8JNqxqP6">secondary ion mass spectrometry</a>), and IR-PAS (infra red photoacoustic spectroscopy).<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a><a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a><a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> </p><p>The determination of absolute age from the thickness of an obsidian hydration band is complicated and problematic. First, the rate at which the hydration of glass occurs varies significantly with temperature. The rate at which the obsidian hydration band forms increases with temperature. Second, the rate of hydration and obsidian hydration band formation varies with the geochemistry of the obsidian, including the intrinsic water content, seems to affect the rate of hydration. Finally, water vapor pressure may also affect the rate of obsidian hydration. If the rate of obsidian hydration band can be controlled for the obsidian's geochemistry (e.g., the "source"), temperature (usually approximated using an "effective hydration temperature" or EHT coefficient) and other factors, it might be possible to date an artifact using the obsidian hydration technique.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a><a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> </p><p>The presence or absence of an obsidian hydration band has been used to distinguish prehistoric obsidian <a href="/facts/Debitage/Wmv1I1kc">debitage</a> from obsidian debitage produced by modern <a href="/facts/Knapping/FPPEFBvs">flintknappers</a>. This distinction can be made because it takes about 70 years for a band to enlarge sufficiently so that it is readily detectable on a freshly flaked surface of a piece of obsidian. For example, the basis of the lack of development of obsidian hydration bands, it was concluded that modern flintknappers brought specimens of obsidian to the <a href="/facts/Poverty_Point/QApWV0wq">Poverty Point</a> Site in <a href="/facts/Louisiana/2GvfFcKE">Louisiana</a>.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Liesegang_rings_(geology)/fQDW9Vhx">Liesegang rings</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Colman, SM, and KL Pierce (2001) Weathering rinds on andesitic and basaltic stones as a Quaternary age indicator, Western United States. Professional Paper no. 1210. United States Geological Survey, Reston, Virginia. <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Neuendorf, KKE, JP Mehl, Jr., and JA Jackson, eds. (2005) Glossary of Geology (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. ISBN 0-922152-76-4 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Oguchi, CT (2001) "Formation of weathering rinds on andesite." Earth Surface Processes and Landforms. 26(8):847–858. <a href="/wiki/Earth_Surface_Processes_and_Landforms" target="_blank">/wiki/Earth_Surface_Processes_and_Landforms</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Fairbridge, RW (1968) Spheroidal Weathering. in RW Fairbridge, ed., pp. 1041-1044, The Encyclopedia of Geomorphology, Encyclopedia of Earth Sciences, vol. III. Reinhold Book Corporation, New York, New York. <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Ollier, CD (1971). Causes of spheroidal weathering. Earth-Science Reviews 7:127-141. <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Goudie, AS, 2004, Rind, Weathering. in AS Goudie, ed., pp. 853-855, Encyclopedia of Geomorphology, vol. 2 J-Z Routledge, London-New York. ISBN 0-415-32738-5 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Wagner, GA (1998) Age Determination of Young Rocks and Artifacts: Physical and Chemical Clocks in Quaternary Geology and Archaeology. Springer Verlag, New York, New York. 466 pp. ISBN 9783540634362 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Anderson, LW, and DS Anderson (1981) Weathering Rinds on Quartzarenite Clasts as a Relative-Age Indicator and the Glacial Chronology of Mount Timpanogos, Wasatch Range. Arctic and Alpine Research. 13(1):25-31. <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Cernohouz, J, and I Solc (1966) Use of sandstone wanes and weathered basaltic crust in absolute chronology. Nature 212:806–807. <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Goudie, AS, 2004, Rind, Weathering. in AS Goudie, ed., pp. 853-855, Encyclopedia of Geomorphology, vol. 2 J-Z Routledge, London-New York. ISBN 0-415-32738-5 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Wagner, GA (1998) Age Determination of Young Rocks and Artifacts: Physical and Chemical Clocks in Quaternary Geology and Archaeology. Springer Verlag, New York, New York. 466 pp. ISBN 9783540634362 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Chinn, T (1981) Use of rock weathering-rind thickness for Holocene absolute age-dating in New Zealand. Arctic and Alpine Research 13(1):33–45. <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Knuepfer, RLK (1988) Estimating ages of late Quaternary stream terraces from analysis of weathering rinds and soils. Geological Society of America Bulletin. 100(1):1224–1,236. <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Walker, M (2005) Quaternary Dating Methods. John Wiley & Sons Ltd, Chichester, England ISBN 978-0-470-86926-0 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>Stevenson, C, I. Liritzis, and M. Diakostamation (2002) Investigations towards the hydration dating of Αegean obsidian. Mediterranean Archaeology & Archaeometry. 2(1):93–109. <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>Stevenson, C, and SW Novak (2011) Obsidian hydration dating by infrared spectroscopy: method and calibration. Journal of Archaeological Science. 3 (7):1716-1726. <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>Walker, M (2005) Quaternary Dating Methods. John Wiley & Sons Ltd, Chichester, England ISBN 978-0-470-86926-0 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>Anovitz, LM, M Elam, L. Riciputi, and D Cole (1999) The failure of obsidian hydration dating: sources, implications, and new directions. Journal of Archaeological Science. 26(7):735–752. <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>Boulanger, MT, MD Glascock, MS Shackley, C Skinner, and JJ Thatcher (2014) Likely Source Attribution for a Possible Paleoindian Obsidian Tool from Northwest Louisiana. Bulletin of the Louisiana Archaeological Society. no. 37:89-107. <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> </ol>