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Counterfeit silver appears to reflect economic decline in the late Bronze Age of the eastern Mediterranean.  The decline of Central Asian kingdoms in the Middle Ages now appears to be a result of protracted drought rather than the depredations of Genghis Khan.  Excavators in Mexico City have found more human skulls from the Aztecs’ Tower of Skulls.  And a silver cross from a Viking-age hoard in southwestern Scotland shows the highest level of craftsmanship.

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And now, here’s Laura Pettigrew with the Audio News from Archaeologica.  We hope you find this to be a valuable part of your day.

Welcome to the Audio News from Archaeologica!   I’m Laura Pettigrew, and these are the headlines in archaeological and historical news from December 13th to 19th, 2020. .

Our first story this week comes from Israel, where chemical studies of ancient silver from the Levant show several centuries of dirty money, or deliberate debasing of the metal content.  

Dates suggest that the collapse of several major civilizations after about 1250 BC caused such shortages of silver, the most common currency, that local rulers deliberately added copper and arsenic to make their silver stretch farther and hide their failing power. 

As reported by LiveScience.com, archaeologist Tzilla Eshel, a Ph.D. student at the University of Haifa, discovered the ancient counterfeiting.  While studying the chemical composition of thirty-five buried hoards of Bronze Age silver from sites around Israel, she found that the silver in eight of the hoards had been debased, by putting cheaper alloys of copper in the center of the pieces, and using arsenic to give the surface a sheen imitating silver. 

These hoards date from the time of the Late Bronze Age collapse, a period from about 1200 to 950 BC, when the region's most powerful kingdoms ended, often violently.  Disrupted trade led to shortages of silver in Canaan and other parts of the Levant, now occupied by Lebanon, Jordan, Palestine, Syria, and Israel.

During the Late Bronze Age, before the advent of coins, the leading form of currency across the eastern Mediterranean was silver.  Gold was also exchanged, but it was more costly and scarce.

Silver was often traded in scraps and broken bits of jewelry, but rulers also poured ingots to provide a more standardized form. 

The hoards that Eshel studied come from a time when ancient Egypt ruled over Canaan, the result of conquest by pharaohs of the New Kingdom about 1500 BC.  Canaan had no silver ores of its own, so it was imported by the Egyptians and used for trade with other powerful kingdoms like the Mycenaean world to the west, with Greece and its islands, and the Hittite Empire to the north.  Eshel’s discoveries show that the silver trade fell when all three civilizations declined between about 1200 and 1150 B.C.  

The hoards show sophisticated and systematic debasing of many pieces, suggesting it was executed by those who controlled the currency.  According to Eshel, the deception may have originated with the Egyptian rulers, possibly to hide the silver shortage as their power dwindled.

Two of the silver hoards that Eshel analyzed came from Beit Shean in northern Israel and from Megiddo, a Canaanite city.  The Beit Shean hoard contained ingots of only forty percent silver, alloyed with copper and other cheap metals.  The ingots showed silver on their surface, but were mainly copper in their core, achieved through a slow, controlled cooling process.

The Megiddo hoard had even less silver — around twenty percent.  Here, the debasement was disguised by the elemental metal arsenic, which gives copper a silvery shine that can pass as silver. 

According to Eshel, the debasing of silver continued long after Egypt's withdrawal from the region.  The practice must also have become accepted, because over the course of 250 years, people would have noticed.  One giveaway of high copper and arsenic content is that it corrodes and turns green over time.  

During this same period, cuts in the silver ingots became common.  This may have been from people testing to see how much copper was inside.

After about 950 BC, when new powers like the Neo-Assyrians, Persians, and Greek colonies arose, the raw silver used as currency regained its purity, signaling the restoration of wider trade networks that brought silver in from farther regions, like the western Mediterranean

. 

The reasons for the Late Bronze Age collapse in the eastern Mediterranean around 1200 BC are unclear.  Droughts, volcanic eruptions, earthquakes, economic failures, and piracy have all been suggested. 

Eshel’s research is published in the January 2021 issue of the Journal of Archaeological Science.

Our next story takes us to Central Asia, where new climate change research challenges the long-held view that the Mongols were the main cause of history’s changes here.  Central Asia held numerous river civilizations in the medieval era, but they collapsed around the time of the Mongol invasions of the area in the early thirteenth century AD.

The Aral Sea basin in Central Asia and the major rivers flowing through it were once home to many flourishing agriculture-based societies, which used floodwater irrigation to farm.  Their decline is often attributed to the devastating Mongol invasion, but the new research on long-term river dynamics and ancient irrigation networks shows that the cause may have been changing climate and dryer conditions, and the subsequent Mongol invasion was just an aftereffect.

As reported on the science news site Eurekalert.org, the University of Lincoln, in the United Kingdom, led the reconstruction research, in collaboration with VU University Amsterdam, University College London, the University of Oxford, and JSC Institute of Geography and Water Safety, in Almaty [ALL-meh-tee], Republic of Kazakhstan. 

The international team studied the effects of climate change on floodwater farming in the region and found that decreasing river flow effectively caused the abandonment of these previously flourishing city-states.

The project focused on the archaeological sites and irrigation canals of the Otrar oasis, a UNESCO World Heritage site that was once a Silk Road trade hub located at the meeting point of the Syr Darya and Arys rivers in present-day southern Kazakhstan.

The researchers identified the times when irrigation canals were abandoned, and studied the past dynamics of the Arys River, whose waters fed the canals.  The abandonment of irrigation systems matches a phase of riverbed erosion from AD 900 to 1300, that coincided with a dry period with low river flows, rather than corresponding with the Mongol invasion.

The environmental sequence showed a quick recovery following earlier droughts during the Arab invasions in the seventh and eighth centuries AD, because the climate swung back toward favorable wet conditions. 

But prolonged drought during and following the later Mongol destruction reduced the resilience of local populations, and prevented them from reestablishing the large-scale irrigation-based agriculture that had supported the earlier civilizations.

According to project leader Mark Macklin, director of the Lincoln Center for Water and Planetary Health at the University of Lincoln, the findings show that climate change, not Genghis Khan, was the ultimate cause for the demise of Central Asia's forgotten river civilizations.

The findings are published in Proceedings of the National Academy of Sciences of the United States.

Next, we go to Mexico, where archaeologists have discovered the skulls of more than 100 men, women and children in newly unearthed sections of an Aztec tower of skulls.

The tower was built between AD 1486 and 1502, and was first discovered five years ago by excavators from the National Institute of Anthropology and History.  It would have stood in the center of Mexico City near the Templo Mayor, called Hueteocalli [HWAY teh-oh-CAH-lee] by the Aztecs.  This great pyramid dominated the central sacred precinct of the Aztec capital, Tenochtitlan, with twin temples on top to the war god, Huitzilopochtli [HWEET-see-loh-POACHT-lee], and the rain god Tlaloc [TLAH-lohk].  After the invading Spanish conquistadors defeated the Aztecs, they destroyed the Templo Mayor in 1521, with some of its stones reused for a Catholic cathedral and some of it staying buried.

The conquistadors also tore down the tzompantli [tsohm-PAHNT-lee], or skull rack, in front of the pyramid, where priests displayed the skulls of their human sacrifices.  As the skulls decayed, they were moved to two skull towers on either side and embedded in the mortar.  

In 2015, archaeologists discovered the remains of one of these towers with several hundred skulls. 

Now analysis has concluded on another hundred and nineteen skulls excavated in March 2020, on the eastern side of the tower.  At least three skulls were from children.  As reported by the British newspaper The Independent, this brings the total number of skulls found there so far to six hundred and three.

It is thought that the cylindrical skull tower, part of the Huey Tzompantli [HWAY tsohm-PAHNT-lee], was one of seven such displays of human skulls in Tenochtitlan, now Mexico City.

Although it is unclear exactly who the individuals were, they were presumably killed during sacrifices to the gods.  According to lead archaeologist Raul Barrera, some or most of the victims were war captives.  The rituals of sacrifice made them sacred, either as gifts for the gods, or even personifications of deities themselves.

Human sacrifice occupied an important place throughout prehistoric Mesoamerica, and the Mexica [may-SHEE-ca], or Aztecs, brought it to its peak.  Like the Maya, the Mexica believed that the sacrifice of blood and human life nourished the gods.  Without it, the sun would cease to rise, and the world would end.  

We end this week in southwestern Scotland, where painstaking conservation of a silver cross in the Galloway Hoard, found in 2014, reveals a piece so spectacular that it must have belonged to a high-ranking cleric or a king.

The cross was under a thousand years of encrusted dirt when found in a plowed field in western Scotland.  The Anglo-Saxon object was just one part of the Galloway Hoard, the richest collection of rare and unique Viking-age artifacts ever found in Britain or Ireland.  

The National Museums of Scotland acquired the hoard in 2017, and have been researching it ever since.

A supreme example of late Anglo-Saxon metalwork, the cross has gold-leaf decoration on silver, and is shaped with four equal arms to commemorate the four evangelists who, according to tradition, wrote the gospels of the New Testament.  The four arms show their symbols:  a man for Saint Matthew, a lion for Saint Mark, a cow for Saint Luke, and an eagle for Saint John.

According to Dr. Martin Goldberg, the museum’s principal curator of early medieval and Viking collections, many ecclesiastical treasures were robbed from monasteries during the Viking age, and the cross is one of the rare survivors.  

As reported by The Guardian, the Galloway Hoard was buried in the late ninth century in Dumfries and Galloway, where a metal detectorist found it in 2014.  The hoard contains over a hundred items of gold, silver and other materials, including a gold pin shaped like a bird, and an entire vessel of silver-gilt. 

Galloway had been part of Anglo-Saxon Northumbria.  It was called the Saxon coast in the Irish chronicles as late as the tenth century AD.  

But this area was to become the Lordship of Galloway, named from the Gall-Gaedil, people of Scandinavian descent who spoke Gaelic and dominated the Irish Sea zone during the Viking age.

According to Goldberg, the mixed material of the Galloway Hoard exemplifies this complex and changing political and cultural environment.

To clean the cross, museum conservators carved a porcupine quill into a tool sharp enough to remove the dirt, yet soft enough not to damage the metalwork.

The results reveal a late Anglo-Saxon style of decoration, executed in the 800s AD.  

The apparent expense of the item suggests a commission by someone from an aristocratic family.  Oldest sons were usually kings and lords, and second sons would become high-ranking clerics.   

According to Goldberg, the cross likely belonged to one of these high-born men.

The pectoral cross has an intricate spiral chain, from which to be suspended from the neck, so it could be displayed across the chest.  The chain was carefully wrapped around the cross before burial. 

Why the burial even happened remains a mystery.  Goldberg said that the cross now raises many more questions, and that research continues.

The cross will be part of the touring exhibit of the Galloway Hoard starting in early 2021.

That wraps up the news for this week!

For more stories and daily news updates, visit Archaeologica on the World Wide Web at www.archaeologica.org where all the news is history!

I’m Laura Pettigrew and I’ll see you next week!