Nemuro Belt

The Nemuro Belt is a Late Cretaceous to Paleogene accretionary complex located in eastern Hokkaido, Japan. It is a significant geological feature characterized by its complex structure and varied lithology, reflecting its formation through the accretion of oceanic materials onto the continental margin.

The belt primarily consists of sedimentary rocks, including turbidites, cherts, and mudstones, along with volcanic rocks, serpentinites, and metamorphic rocks. These rock types represent different oceanic environments, such as deep-sea basins, seamounts, and oceanic plateaus, that were sequentially accreted.

The Nemuro Belt is important for understanding the tectonic evolution of the western Pacific margin. Its formation is linked to the subduction of the Pacific Plate beneath the Eurasian Plate. Studies of the belt's stratigraphy, geochemistry, and structural geology provide insights into the timing, mechanisms, and paleogeographic setting of accretionary processes.

Researchers use various methods, including detailed geological mapping, biostratigraphy, radiometric dating, and geochemical analyses, to reconstruct the history of the Nemuro Belt. Understanding its evolution is crucial for interpreting the broader tectonic framework of the region and the development of the Japanese archipelago. The belt has been subject to multiple phases of deformation and metamorphism, further complicating its geological interpretation. The study of these deformational events helps unravel the complex tectonic history of this region.