Yellowstone plume drives drainage reorganization in the early Miocene.

ABSTRACT: The rise of the Yellowstone plume coincided with a shift from orogenic collapse of the Cordillera to Basin and Range extension in the northern Rocky Mountains, yet its impact on regional uplift, sediment dispersal, and drainage patterns remains largely unexplored. Here, we present rock magnetic analyses from eight Oligo-Miocene sedimentary sections in southwestern Montana. Using two complementary datasets, we identify a sharp increase in magnetic mineral concentration immediately after the early Miocene unconformity [~20 million years ago (Ma)], concurrent with a shift in detrital zircon ages, indicating a major provenance shift. We identify bimodal volcanism of the Columbia River Basalt Group as the dominant Miocene source, requiring that the early Miocene Continental Divide lay ~400 kilo

SUBMITTER: Gerritsen D 

PROVIDER: S-EPMC12629190 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature