GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 205-9
Presentation Time: 9:00 AM-6:30 PM

WARREN HAMILTON AND THE BLUE APRON


SALES (POSTHUMOUSLY), John K., Mobil’s Research Lab and AAPG Distinguished Lecturer, 125 Sherwood Drive, Montpelier, VT 05602

NASA’s Gravity Recovery and Climate Experiment (GRACE) satellite map shows significant anomalies in the Earth's gravity field interpreted to represent large scale and deep seated density variations at the 650-km discontinuity.

The most striking feature referred to here as the “Blue Apron”, is the highest gravity variation that girdles almost the entire Pacific Ocean basin plus all of North and South America. The Blue Apron defines the original location and size of the Panthalassa Ocean before it evolved into the Pacific. As the oceanic crust of the Panthalassa plate subducted, North and South America shifted westward and Eurasia and Africa eastward opening the modern Atlantic. The Blue Apron represents a vast accumulation of high-density subducted slabs over which the overlying continental crust migrated.

This is consistent with density differences providing the driving force for plate tectonics, not mantle plumes, as suggested by Warren Hamilton decades ago. The upwelling arms of mantle convection are the result, not the cause of plate tectonics. Morgan-type deep mantle plumes, suggested as possible drivers for plate tectonics, do not exist.

Large-scale gravity anomalies beneath the Scotia Arc, south of the tip of South America, and beneath the Indian Ocean, Hudson Bay and the Gobi Desert are all examples of locations where the observations can be accounted for by the Blue Apron tectonic model.