The advancement of seismic attributes and visualization techniques has allowed the study of seismic geomorphology from 3D reflection data. The study of deepwater deposits denes and characterizes architectural elements depending on their genesis, morphology, and position along the slope and basin floor. However, every individual basin’s geological configuration determines the dimensions, morphology, and lithological composition of its architectural elements. To understand how seismic attributes help characterize geological settings, we employ multiple datasets with variable qualities since few studies elaborate on compiling and discussing the differences between basins. We explore and compare the use of seismic attributes to highlight deepwater architectural elements in three different basins around the world: The Ceará Basin in Equatorial Brazil, The Taranaki Basin in New Zealand, and The North Carnarvon Basin in Australia, focusing on the deepwater sedimentary section in each case. Although the first two datasets are examples of siliciclastic environments and the North Carnarvon, a mixed carbonate-siliciclastic exponent, the architectural elements identified in all the datasets are similar, as well as their attribute response. The results show that the most robust attributes to characterize deepwater elements such as incised channels, channel-levee systems, and lobes are a combination of geometric, amplitude derived, frequency, and textural attributes. These seismic attributes indicate morphological, lithological, bed stacking, and help to define the stratigraphic architecture. Moreover, we found that the co-rendering of RMS (lithology-proxy), coherence (morphology indicator), and curvature attributes help to define the internal configuration for most of the deepwater architectural elements. While each basin is unique, our results and comparisons serve as a guide for seismic interpreters to use in deepwater seismic geomorphology characterization.

The factors that promote stability of Archean cratons are investigated from a combined geodynamic, geological, and geophysical perspective in order to evaluate the relative importance of nature—the initial conditions of a craton—versus nurture—the subsequent tectonic processes that may modify and destabilize cratonic lithosphere. We use stability regime diagrams to understand the factors that contribute to the intrinsic strength of a craton: buoyancy, viscosity, and relative integrated yield strength. Cratons formed early in Earth history when thermal conditions enhanced extraction of large melt fractions and early cratonization (cessation of penetrative deformation, magmatism and metamorphism) promote formation of stable Archean cratonic lithosphere. Subsequent processes that may modify and weaken cratonic lithosphere include subduction and slab rollback, rifting, and mantle plumes –processes that introduce heat, fluids, and partial melts that warm and metasomatize the lithosphere. We examine tomographic data from eight cratons, including four that are thought to be stable and four that have been proposed to be modified or destroyed. Our review suggests that continental lithosphere formed and cratonized prior to the end of the Archean has the potential to withstand subsequent deformation, heat, and metasomatism. Survivability is enhanced when cratons avoid subsequent tectonic processes, particularly subduction. It also depends on the extent and geometry of modification. However, because craton stability decreases as the Earth cools, marginally stable cratons that undergo even modest modification may be set on a path to destruction. Therefore, preservation of Archean cratons depends both on nature and nurture.

A comprehensive North American upper mantle seismic-tomographic model, NA13, was inferred from a combination of several decades of seismic data from early North American seismic models and USArray data. This data-driven modeling inverted a combination of regional waveform misfits, teleseismic S delay times, and constraints on Moho depths. The joint inversion model combines the contrasting and overlapping resolving power of the different data sets, and demonstrates enhanced resolution over regional models created with a single geophysical dataset. Resolution in the upper mantle is achieved on the scale of ~100km, although travel time delay studies suggest that anomalies in parts of the western United States are smaller. In NA13, velocities beneath the Yellowstone plume are low enough to require the presence of partial melt. NA13 also models a variety of smaller scale velocity variations beneath the Central and Eastern United States that reveal remnant velocity anomalies in the upper mantle from Mesozoic and Cenozoic tectonics.