Study Reveals Faster Cooling and Sinking of Continental Margins Off US East Coast

A new study from the University of Haifa has found that the Earth's crust off the eastern coast of the United States has cooled up to 1.6 times faster than previously estimated by standard geological models. This accelerated cooling has caused the crust to become denser, leading to faster sinking of the continental margin and the accumulation of thicker sediment layers. The research, published in Communications Earth & Environment, challenges long-held assumptions about passive cooling processes at continental margins.

The study focused on a region between the American continent and the Atlantic Ocean, known as a magma-rich passive continental margin, where large amounts of molten rock intruded and erupted during the breakup of continents. Traditionally, models have struggled to explain why these margins sink more rapidly and accumulate thicker sediments than expected. Researchers Dr. Guy Lang, Prof. Itzik Makovsky, and Prof. Uri Ten Brink developed a new mathematical model incorporating crustal stretching, volcanic rock addition, and changes in heat transfer rates.

Comparing their model to seismic data and sediment thickness measurements from the past 26 million years, the team found sediment layers up to 8 kilometers thick, far exceeding the 3 kilometers predicted by earlier models. The model only matched observations when a faster cooling rate was included, which the researchers attribute to water flowing through porous basalt rocks, transporting heat upward more efficiently. Similar processes are observed today in Iceland and East Africa.

The findings have broader implications beyond this specific region, potentially affecting interpretations of sediment thickness, ancient sea-level changes, and the thermal history of sedimentary basins important for oil and gas exploration. The researchers emphasize that understanding the true cooling and sinking rates of continental margins is crucial for reconstructing Earth's geological history more accurately.