AbstractThe Bransfield Strait (Antarctica) is an important region for evaluating changes in Weddell Sea shelf waters on geological time scales because of its restricted connections to the surrounding ocean. However, the detailed oceanographic consequen…
AbstractA threshold drainage area limits fluvial transmission of base-level fall and may be expressed in the form of a waterfall or a series of waterfalls, defined here as a knickzone. Knickzones on the west coast of Kaua‘i, Hawai‘i (USA), exhibit evid…
AbstractSand aprons are distinctive landforms that offer important insights into sedimentary dynamics for reef platform development. Here we link temporal and spatial scales of 21 sand aprons in the southern Great Barrier Reef to understand their Holoc…
AbstractChemical heterogeneities along grain boundaries in garnet occur across a wide range of metamorphic conditions, yet the processes underlying their development remain poorly understood. Here we integrate electron backscattered diffraction (EBSD) …
AbstractThe possibility that craton-like lithosphere may undergo subduction during convergence of major tectonic plates is still poorly investigated. We addressed this issue using ambient noise tomography of the Tarim Basin and the Tianshan (Central As…
AbstractPetrological data indicate that upper mantle and mantle plume temperatures diverged 2.5 b.y. ago. This has been interpreted as plate tectonics initiating at 2.5 Ga, with Earth operating as a single-plate planet before that time. We took an Occa…
AbstractThe crest of the Andes—the trace of the highest mountain topography—weaves back and forth, in places near the coastline, in others farther inland. Its position reflects the asymmetric distribution of orogen mass and coincides with asymmetry of …
AbstractThe Great Unconformity has been recognized for more than a century, but only recently have its origins become a subject of debate. Hypotheses suggest global Snowball Earth glaciations and tectonic processes associated with the supercontinent Ro…
AbstractPrevious studies of resurge sediments in drill cores from several marine-target impact craters indicated a relationship among the sedimentology, the target water depth, and the magnitude of the event. This offers a potentially valuable opportun…
AbstractMechanically weakened alteration zones in lava domes are thought to jeopardize their stability. Such zones can be hazardous when concealed within the dome, either because they formed by subsurface hydrothermal circulation or because they formed…