Researchers led by Matthew Siegler, a research professor at SMU and a scientist with the Planetary Science Institute, have made an intriguing discovery regarding a large granite formation beneath the lunar surface. Their study, published in Nature, utilized microwave frequency data to measure heat below the moon’s surface in an area known as Compton-Belkovich, suspected to be a volcanic feature. The team found that the heat emanating from beneath the surface is generated by a concentration of radioactive elements unique to the moon and indicative of granite.
Granite is an igneous rock typically found in the remnants of plumbing systems below extinct volcanoes. When lava cools without erupting, it forms a granite batholith. Similar to Earth, where granite bodies are associated with volcanic systems like the Cascade volcanoes, this lunar batholith likely resulted from volcanoes that were active as early as 3.5 billion years ago.
This lunar batholith, located in a region previously identified as a volcanic complex, is surprisingly large, estimated to have a diameter of approximately 50 kilometers. While granite is relatively common on Earth due to water and plate tectonics playing a role in its formation, it is exceptionally rare on the moon, where these processes are absent.
The discovery of this granite formation provides valuable insights into the early formation of the lunar crust. It raises intriguing questions about the presence of water on the moon and whether it played a role in the formation of this particular granite body, or if alternative mechanisms, such as extreme heat, were involved.
In summary, the study’s findings shed light on the unique geological processes that shaped the moon’s early history and provide further evidence of its complex volcanic past.
Source: Southern Methodist University