Featured Research

from universities, journals, and other organizations

The Mysterious Case Of Columbus's Silver Ore

Date:
February 20, 2007
Source:
University of Arizona
Summary:
What was thought to be the first evidence of successful prospecting for precious metals in the New World turns out to be something completely different, according to a University of Arizona-led research team. Silver-bearing ore found at the settlement founded by Christopher Columbus's second expedition was not mined in the Americas. Instead, the expedition members brought the ore with them to use in assaying the precious-metal-bearing ores they hoped to find.

Samples of galena, a silver-bearing lead ore and worked pieces of lead recovered from the archaeological dig at La Isabela. (Credit: Copyright 1998. James Quine, Florida Museum of Natural History, University of Florida)
Credit: Copyright 1998. James Quine, Florida Museum of Natural History, University of Florida

Silver-bearing ore found at the settlement founded by Christopher Columbus's second expedition was not mined in the Americas, new research reveals.

The ore that researchers excavated from the settlement, La Isabela, came from Spain, said Alyson Thibodeau, who analyzed the ores.

"What appeared to be the earliest evidence of European finds of precious metals in the New World turned out not to be that at all," said David J. Killick. "It's a very different story."

The explorers brought the Spanish ore to La Isabela to use for comparison when assaying the new ores they expected to find, the researchers surmise. The expedition's purpose was discovering precious metals.

But by 1497, La Isabela's remaining settlers, having found no gold or silver, were desperate to salvage something of value from the failed settlement. They were reduced to extracting silver from the galena they brought from Spain, the researchers said.

"This part of the story of Columbus's failed settlement is one that couldn't be found in the historical documents," said Thibodeau, a geosciences graduate student at The University of Arizona in Tucson. "We could never have figured this out without applying the techniques of physical sciences to the archaeological artifacts."

Thibodeau, Killick, a UA associate professor of anthropology, and their colleagues will publish their article, "The Strange Case of the Earliest Silver Extraction by European Colonists in the New World," in the early online edition of the Proceedings of the National Academy of Sciences during the week of February 19.

The other authors are UA's Joaquin Ruiz, John T. Chesley and Ward Lyman; Kathleen Deagan of the University of Florida in Gainesville; and Josι M. Cruxent (deceased). The National Science Foundation, Direccion Nacional de Parques de la Republica Dominicana, the National Endowment for the Humanities, the National Geographic Society and the Keck Foundation helped fund the research.

La Isabela, the first European town in the New World, was established by Columbus's second expedition in 1494 on the northern coast of the present Dominican Republic.

The approximately 1500 members of the expedition expected to make their fortunes by finding precious metals but instead found hurricanes, hunger and disease. Columbus was recalled to Spain in 1496, and the few hundred remaining inhabitants abandoned the town in 1498.

Archaeologists excavating the site in the late 1980s and early 1990s found about 100 pounds of galena, a silver-bearing lead ore, and more than 200 pounds of metallurgical slag. The ore and slag were associated with a small furnace near the alhσndiga, a building for the storage and protection of royal property.

Archaeologist Deagan sent pieces of the material to archaeometallurgist Killick for analysis.

The slag turned out to be lead silicate -- the end product of an improvised smelting process, Killick said, adding "Lead silicate is good for nothing." Other smelting processes used at the time could recapture the ore's lead so it could be used for musket balls and as cladding for ships.

"Why waste the lead?" Killick said. "Normally, they would smelt the galena to lead."

Killick and graduate student Ward Lyman examined the slag under a microscope and saw specks of silver, suggesting that Columbus's followers were trying to extract silver from the galena by removing all the lead.

"We thought, 'Fantastic!' The first evidence of Europeans prospecting for silver in the New World."

By reviewing the accounts of Columbus's second voyage, Thibodeau found the expedition had visited islands where geologists now know galena occurs.

It was puzzling that the documents made no mention of finding such ore, Killick said. Maybe it didn't seem to be enough metal to mention or maybe some members of the expedition were trying to hide the discovery.

Thibodeau then used lead isotope analysis to determine where La Isabela's galena originated. The ratio of the different forms, or isotopes, of lead provides a kind of fingerprint that can indicate the source of a rock.

"We're looking at something about the rock's chemistry and using that to tell us where it came from," she said. "It's like Antiques Roadshow where the appraiser looks at some characteristic of an antique and says, 'This was made by so-and-so at such-and-such a time.'"

Figuring out that the galena came from Spain led to the question, why bring ore? The documents report that the expedition also brought lead.

By contacting an expert in medieval chemistry, the scientists learned that a common practice of the time was mixing galena with powdered ores suspected of having gold or silver. The process provided an assay of the gold or silver in the newly discovered hunk of ore by comparing it with galena containing a known, small quantity of silver.

Given that the expedition purpose was discovering new sources of precious metals, it makes sense that the members toted along materials to assess their discoveries.

"It was a nice detective story," Killick said. "We think we've solved this one."

But there are more archaeological puzzles out there, Thibodeau said.

"Archaeology tells us what might be an interesting question to ask -- and the physical sciences gives us a way to answer the question," Thibodeau said.


Story Source:

The above story is based on materials provided by University of Arizona. Note: Materials may be edited for content and length.


Cite This Page:

University of Arizona. "The Mysterious Case Of Columbus's Silver Ore." ScienceDaily. ScienceDaily, 20 February 2007. <www.sciencedaily.com/releases/2007/02/070220020756.htm>.
University of Arizona. (2007, February 20). The Mysterious Case Of Columbus's Silver Ore. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2007/02/070220020756.htm
University of Arizona. "The Mysterious Case Of Columbus's Silver Ore." ScienceDaily. www.sciencedaily.com/releases/2007/02/070220020756.htm (accessed July 28, 2014).

Share This




More Fossils & Ruins News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did ISIS Destroy Jonah's Tomb?

Did ISIS Destroy Jonah's Tomb?

Newsy (July 25, 2014) — Unverified footage posted to YouTube purportedly shows ISIS militants destroying a shrine widely believed to be the tomb of the prophet Jonah. Video provided by Newsy
Powered by NewsLook.com
Richard III's Car Park Burial Site Opens to Public

Richard III's Car Park Burial Site Opens to Public

AFP (July 25, 2014) — Visitors will be able to look down from a glass walkway on the grave of King Richard III when a new centre opens in the English cathedral city of Leicester, where the infamous hunchback was found under a car park in 2012. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Mobile App Gives Tour of Battle of Atlanta Sites

Mobile App Gives Tour of Battle of Atlanta Sites

AP (July 25, 2014) — Emory University's Center for Digital Scholarship has launched a self-guided mobile tour app to coincide with the 150th anniversary of the Civil War's Battle of Atlanta. (July 25) Video provided by AP
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) — A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins