Plate tectonics, the hypothesis of multiple crustal plates which float on a viscous layer called the "asthenosphere," provides reason for viewing the earth's outer shell as a system of shifting continents and changing ocean basins. The idea of diverging plates (or seafloor spreading) implies that plates converge elsewhere at compatible rates. Estimated convergence rates range up to 10 cm/yr, or 224 km in the 2 million years since the beginning of Pleistocene time.

Convergence between oceanic and continental crust may result in thermal generation of oil and gas in sediments as young as Pleistocene because of rapid deep burial associated with subduction. Mountainous source areas for sediment plus steep continental slopes favor rapid burial of organic material with turbidites. Rapid subduction of oceanic crust under continental margins may carry sediments to depths which provide requisite thermal environments for generation of oil and gas from organic matter disseminated in the sediment. Continued subduction of oceanic crust under continental slopes may cause reverse faulting such that oil and gas accumulations are uplifted toward the ocean bottom.

Core samples obtained adjacent to the Aleutian Trench in the western Gulf of Alaska apparently show effects of subduction and reverse-fault uplift on a Pleistocene sedimentary sequence. Although this Pleistocene sequence lies only a few hundred feet below the ocean bottom, organic-matter carbonization suggests previous burial of at least 8,500 ft (2,600 m) and a late pregeneration state for petroleum. In contrast, noncommercial oil production from uplifted deep-water strata of early Tertiary age at Katalla, Alaska, suggests that formerly significant accumulations may have been dissipated by faulting, uplift, and erosion. Late Tertiary rocks beneath outer continental shelves and/or upper continental slopes at convergent margins may be in the optimum stage of current petroleum expulsion but still buried deeply enough for entrapment of giant oil accumulations.

On the continent side of volcanic ridges and mountain trends, parallel with subduction zones, geographic coincidence of intermediate and deep-focus earthquakes with regions of high earth heat and giant petroleum accumulations suggests an empirical means of predicting earth heat trends that would favor petroleum accumulation in block-fault basins.