Shedding New Mild On Early Turquoise Mining In Southwest US

turquoise nuggets FROM Dyer Blue Mine, Nevada

Turquoise is an icon of the desert Southwest, with enduring cultural significance, particularly for Native American communities. But, comparatively little is understood concerning the early historical past of turquoise procurement and change within the area.

College of Arizona researchers are beginning to change that by mixing archaeology and geochemistry to get a extra full image of the mineral’s mining and distribution within the area previous to the sixteenth-century arrival of the Spanish.

In a brand new paper, revealed within the November concern of the Journal of Archaeological Science, UA anthropology alumnus Saul Hedquist and his collaborators revisit what as soon as was believed to be a comparatively small turquoise mine in japanese Arizona. Their findings recommend that the Canyon Creek mine, situated on the White Mountain Apache Indian Reservation, was truly a way more vital supply of turquoise than beforehand thought.

With permission from the White Mountain Apache Tribe, Hedquist and his colleagues visited the now primarily exhausted Canyon Creek supply — which has been recognized to archaeologists because the Nineteen Thirties — to remap the world and acquire new samples. There, they discovered proof of beforehand undocumented mining areas, which recommend the output of the mine might have been 25 % larger than previous surveys indicated.

“Pre-Hispanic workings at Canyon Creek have been a lot bigger than beforehand estimated, so the mine was clearly an necessary supply of turquoise whereas it was lively,” stated Hedquist, lead writer of the paper, who earned his doctorate from the UA Faculty of Anthropology within the School of Social and Behavioral Sciences in Might.

As well as, the researchers measured ratios of lead and strontium isotopes in samples they collected from the mine, and decided that Canyon Creek turquoise has a singular isotopic fingerprint that distinguishes it from different recognized turquoise sources within the Southwest. The isotopic evaluation was carried out within the lab of UA School of Science Dean Joaquin Ruiz within the Division of Geosciences by research co-writer and UA geosciences alumna Alyson Thibodeau. Now an assistant professor at Dickinson School in Pennsylvania, Thibodeau did her UA dissertation on isotopic fingerprinting of geological sources of turquoise all through the Southwest.

“When you decide up a bit of turquoise from an archaeological website and say ‘the place does it come from?’ you must have some technique of telling the totally different turquoise deposits aside,” stated David Killick, UA professor of anthropology, who co-authored the paper with Hedquist, Thibodeau and John Welch, a UA alumnus now on the school at Simon Fraser College. “Alyson’s work exhibits that the main mining areas could be distinguished by measurement of main lead and strontium isotopic ratios.”

Based mostly on the isotopic evaluation, researchers have been capable of confidently match turquoise samples they collected at Canyon Creek to a number of archaeological artifacts housed in museums. Their samples matched artifacts that had been uncovered at websites all through a lot of east-central Arizona — some greater than one hundred kilometers from the mine — suggesting that distribution of Canyon Creek turquoise was broader than beforehand thought, and that the mine was a big supply of turquoise for pre-Hispanic inhabitants of the Mogollon Rim space.

The researchers additionally have been capable of pinpoint when the mine was most lively. Their samples matched artifacts discovered at websites occupied between A.D. 1250-1400, suggesting the mine was primarily used within the late thirteenth and/or 14th centuries.

“Archaeologists have struggled for many years to seek out dependable technique of sourcing archaeological turquoise — linking turquoise artifacts to their geologic origin — and exploring how turquoise was mined and traded all through the higher pre-Hispanic Southwest,” stated Hedquist, who now lives in Tempe, Arizona, and works as an archaeologist and ethnographer for Logan Simpson Inc., a cultural assets consulting agency. “We used each archaeology and geochemistry to doc the extent of workings on the mine, estimate the quantity of labor spent on the mine and determine turquoise from the mine in archaeological assemblages.”

Analysis Paves Approach for Future Research

Turquoise is a copper mineral, discovered solely instantly adjoining to copper ore deposits. Whereas detailed documentation of pre-Hispanic turquoise mines is restricted, the work at Canyon Creek might pave the best way for future investigations.

“I feel our research raises the bar a bit by combining archaeological and geochemical analyses to realize a extra full image of operations at one mine: when it was lively, how intensely it was mined and the way its product moved concerning the panorama,” Hedquist stated. “Researchers have solely lately developed a dependable technique of sourcing the mineral, so there’s loads of potential for future analysis.”

Comparable work involving the UA is already underway to discover the origin of turquoise artifacts discovered on the Aztec capital of Tenochtitlan in Mexico.

“Canyon Creek is however certainly one of many historic turquoise mines,” Hedquist stated. “This research supplies a normal for the detailed documentation of historic mineral procurement and a framework for linking archaeological turquoise to particular geologic places. Constructing on different archaeological patterns — the circulation of pottery and flaked stone artifacts, for instance — we will piece collectively the social networks that facilitated the traditional circulation of turquoise in several occasions and locations.”

A greater understanding of the pre-Hispanic historical past of turquoise is necessary not solely to archaeologists and mining historians however to trendy Native People, Killick stated.

“It is of nice curiosity to trendy-day Apache, Zuni and Hopi, whose ancestors lived on this space, as a result of turquoise continues to be ritually necessary for them,” he stated. “They actually have proven a substantial amount of curiosity on this work, they usually’ve inspired it.”

The above story is predicated on Materials offered by University of Arizona. Unique written by Alexis Blue

Geology IN

This entry was posted in Geology and tagged , , , , , . Bookmark the permalink.

Leave a Reply