Whole-Earth Decompression Dynamics

The weight of 300 Earth-masses of primordial gases gravitationally compressed the non-gases: the original rock-plus-alloy kernel that became Earth to some 64% of its present diameter, sufficient compression for solid continental-rock crust to cover the entire rocky part of the planet. As thermonuclear reactions in the sun ignited, the violent T-Tauri solar wind stripped Earth of its Jupiter-like gas envelope. What remained was a solid, smaller Earth whose surface consisted entirely of continental rock, without ocean basins. At the onset of the Hadean eon, one ancient supercontinent existed: the 100% closed contiguous shell of continental-rock I name Ottland in honor of Ott Christoph Hilgenberg, who first conceived its existence.  

What was Earth like at this point? The core had already formed; in fact, the core was the first part of Earth to form. The crust and perhaps into the upper mantle was initially quite cold, having formed just before the sun ignited and began stripping away 300 Earth-masses of primordial gases by the super-intense solar wind, which may have cooled the crust even more. There must have been intense bombardment by meteorites and comets in the final stages of Earth formation and after primordial gases were removed; these emplaced iron and iron-loving elements, like nickel, in the upper mantle and in the crust. After the gases had blown away and the violent T-Tauri phase had ended, water began to collect that was brought to Earth's surface by comets, perhaps the small comets described by Louis A. Frank in scientific literature (moreover, in The Big Splash he asserts that these continue to bring water to Earth today). Volcanic eruptions may have contributed water as well. In the absence of ocean basins, inland seas eventually covered much of the Earth's surface. Oceanic features, such as banded ironstone deposits and pillow basalts from underwater volcanic eruptions, may be found within continent confines.

Banded ironstone from North America, formed 2.1 billion years ago, presumably during a transition period from less available oxygen to more available oxygen. Photo courtesy of André Karwath.

Meanwhile, deep within the Earth, pressures were building. Occasionally there would be a blow out. Pressure would force a column of matter from within the mantle at a depth of about 100 km or more to puncture a narrow hole a few meters in diameter through all of the overlying rock and explode at the surface in a funnel shape as wide as 200 meters. These are the diamond-bearing kimberlite pipes. Sporadic energetic events such as this, though, were just the serenely whispered overture to the global catastrophic violence that would occur again and again, splitting the continual crust, creating a new ocean basin, wreaking havoc, and causing widespread extinction of the species that had developed on this watery planet.

Decompression of Earth (WEDD) from Hadean to present. From left to right, same scale: 1) Ottland, 64% of present Earth diameter, fully covered with continental-rock crust; 2), 3), & 4) Formation of primary and secondary decompression cracks that progressively fractured Ottland to open new ocean basins. Timescale not precisely established; and 5) Holocene Earth.

During Earth's formation as a Jupiter-like gas giant, the rocky kernel was compressed to about 64% of its present diameter, and two things happened: (1) the interior got hot due to the heat of compression, and (2) the protoplanetary energy of compression due to the weight of about 300 Earth-masses of primordial gases was stored in the compressed kernel. That energy remained trapped within the kernel, that we now call Earth, contained by the rigid crust (and augmented by the properties of crust and mantle material). For the Earth to begin to decompress, two things had to happen: (1) heat had to be supplied (by natural radioactive decay and nuclear fission) to replace the lost heat of compression (otherwise decompression would cool the kernel which would impede decompression) and (2) internal pressures had to build sufficiently to produce the force needed to crack the rigid crust. Much more force is required to initiate a crack than for its subsequent propagation.

My Whole-Earth Decompression Dynamics (WEDD) concept envisions decompression as causing the formation of two types of surface cracks. Primary cracks occur in the rigid crust and are underlain by heat sources capable of extruding lava. Primary decompression cracks are identified with the mid-ocean ridge system. WEDD as well envisions secondary decompression cracks, typically found along continent margins; they are identifiable as submarine trenches.

Primary decompression cracks, with their underlying heat sources, extrude basalt-rock, whereas secondary decompression cracks lack heat sources. They became ultimate repositories for extruded basalt-rock. Basalt-rock, extruded from mid-ocean ridges, traverses the ocean floor by gravitational creep. Ultimately, in a process of subduction that lacks any mantle convection, seafloor basalt, with its carbonate sediment, fills in secondary decompression cracks. Seismically imaged "down-plunging slabs", I submit, are in-filled secondary decompression cracks.

Ocean floor topography formed by Whole-Earth Decompression Dynamics. As the Earth decompresses by WEDD, primary cracks with underlying heat sources and secondary cracks that lack heat sources are produced to increase surface area to accommodate decompression increased planetary volume. Basalt-rock, extruded at mid-ocean ridges, creeps across the ocean basins (black arrows) to fill in secondary decompression cracks often located at continental margins. As the Earth decompresses by WEDD (vertical green arrows), crustal extension (lateral red arrows) forms secondary decompression cracks into which seafloor falls; the dynamic processes require no invocation of mantle convection, but their outcomes resemble subducted tectonic plates.

Whole-Earth Decompression Dynamics extends plate tectonic concepts as it is responsible for Earth's well-documented features. fold mountain formation does not exclusively require plate collisions. Partially in-filled secondary decompression cracks uniquely explain oceanic troughs, inexplicable by plate tectonics. Also, compression heating at the base of the rigid crust is a direct consequence of mantle decompression. Plate tectonic meanings and terminology are to a great extent preserved in my new paradigm. For example, transform plate boundaries are identical; divergent plate boundaries are similar, but with a different driving mechanism; convergent plate boundaries likewise are similar, but down-plunging plates neither create oceanic trenches, which are secondary decompression cracks, nor are they recycled through the mantle by conveyor-like mantle convection; and Wadati-Benioff earthquake zones are quite similar, with the possible exception of why mantle melting occurs that is responsible for sometimes associated volcanic eruptions. Many of the plethora of observations, taken to support plate tectonics, support Whole-Earth Decompression Dynamics as well.

This NOAA representation of the age of the seafloor clearly shows the chain of primary decompression cracks (where seafloor basalt is erupted) that form the mid-ocean ridge system that encircles Earth like the stitching on a baseball.

Chain of secondary decompression cracks, also called oceanic trenches, encircle the Pacific, where seafloor subducts and in-fills the trenches. The deepest spot in the ocean, called the Challenger Deep (10,902 meters), is indicated.

NOAA representation of the topology of the Puerto Rico Trench, colored purple, at the western boundary of the North American Plate in the Atlantic Ocean.