George Harlow: Solving a Geological Puzzle in Guatemala

by AMNH on

Research posts

In November 2010, Museum Curator George E. Harlow embarked on a Constantine S. Niarchos Expedition to the Montagua Valley in central Guatemala, a fault zone rich in the precious mineral, jadeite jade. Dr. Harlow, whose work was recently featured in the New York Times, went with a team of geologists. They hiked along riverbeds and steep outcrops, collecting rock samples that might provide clues to the evolution of the Caribbean region.

A video describes the expedition.

The Caribbean originated 120 million years ago, when areas of volcanic islands and ocean floor squeezed past Mexico and South America. In what’s known as the Guatemala suture zone, the boundary between the North American and Caribbean tectonic plates, geologists have found remnants of both a plate collision and a subduction zone, where an oceanic plate plunged into Earth’s mantle. The high pressures of subduction zones help form minerals like jadeite and its host rock, serpentinite.

Jadeite jade
This slab of jadeite jade is now on display in the Museum's Grand Gallery.
© AMNH/R. Mickens

By following the trail of jade in this region, Dr. Harlow and his team are gaining an understanding of the subduction and collisions that occurred throughout the history of Caribbean plate tectonics.

Harlow Niarchos Guatemenal Quiriga archological park
The team visited Quiriguá Archeological Park, where there are some great stelae, giant tombstonelike carvings recording great events of the rulers of the Late-Classic Maya site. This stela shows a rule with jade earspools and a string of large jade beads hanging from a belt.
Jamie Newman

During the expedition, the team studied an ophiolite—a piece of sea floor crust emplaced on top of the continent that had not previously been recorded on geological maps.

Back at the Museum, Dr. Harlow’s team, including Dr. Kennet Flores, a Davis Postdoctoral Scholar in the Department of Earth and Planetary Sciences, is conducting geochemical studies of the rock samples gathered during the expedition. Dr. Harlow anticipates that the results will provide insight into the geological puzzle of Guatemala and open windows for research in other parts of the world. 

George Harlow’s Constantine S. Niarchos Expedition was generously supported by the Stavros Niarchos Foundation. 

The research described here has been supported in part by the National Science Foundation (NSF) under grant numbers EAR0309116 and EAR1119403.