Archean dome-and-basin style structures form during growth and death of
intraoceanic and continental margin arcs in accretionary orogens
Timothy Kusky a,b,* , Brian F. Windley a,c , Ali Polat a,d , Lu Wang a , Wenbin Ning a , Yating Zhong a
a State Key Lab for Geological Processes and Mineral Resources, Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan 430074,
China
b
Three Gorges Research Center for Geohazards, China University of Geosciences, Wuhan 430074, China
c
Department of Geology, University of Leicester, Leicester LE1 7RH, UK
d Department of Earth and Environmental Sciences, University of Windsor, Ontario, Canada
Abstract
Determining whether plate tectonics or some other mode of planetary dynamics operated in the early Archean is
one of the most contentious and debated areas of Earth Sciences today. The Paleo- Mesoarchean dome-and-basin
structures of the Eastern Pilbara craton are widely used as an example of an early Archean terrane supposedly
unlike any produced by plate tectonics in the current mode of active-lid plate tectonics on Earth. In contrast, we
produce a synthesis of the structural, magmatic and sedimentological development of the Eastern Pilbara craton
from 3600 to 2800 Ma, and through comparative tectonic analysis, show that the craton developed following a
typical orogenic sequence from an immature oceanic arc-dominated accretionary orogen, with the oldest rocks of
the craton represented by slabs of primitive circa 3590 Ma gabbro - anorthosite - ultramafic rocks, and
3522
–
3426 Ma oceanic crust and overlying dominantly hydrothermal deep-water cherts imbricated in thrust
piles and giant recumbent nappes. These were intruded by juvenile arc magmas including gabbros, diorites, and
TTG suites, most of which intruded as sills into structurally favorable sites between 3484 and 3416 Ma. These
oceanic crust and overlying sedimentary litho-tectonic assemblages of gabbro/ basalt/ komatiite/ chert, and
TTG-diorite-dominated plutonic rocks were deformed into imbricate and antiformal thrust stacks intruded by
suites of sheet-like TTG magmas during late regional shortening-related deformation at 3318
–
3290 Ma, then
soon-after, folded by upright folds during continued contractional deformation. The intrusive style, composi
tions, and relationships to structures suggest that the late magmatic suites represent a massive slab-failure
magmatic event similar to those formed during arc accretion and slab failure events in the North and South
American Cordilleras, and older orogens of all ages. Late-orogenic shortening deformed these sheet intrusions
into large domal structures, synchronous with or soon-after late- to post-orogenic cross-cutting steep-walled circa
3274
–
3223 Ma plutons vertically intruded the cores of some of the domes, forming nested plutons akin to the
Cretaceous Sierra CresSuite of the Sierra Nevada batholith, and deformed equivalents in Phanerozoic orogens.
In a much younger magmatic event, a wide swath of the craton was affected by circa 2851
–
2831 monzogranite
intrusions, after which the magmatic events of the Archean of the Eastern Pilbara were terminated by the circa
2772 Ma Black Range dolerite dike swarm, that preserves evidence for rapid APW drift during its intrusion.
The Eastern Pilbara represents only a very small preserved Paleo-Mesoarchean crustal remnant, measuring a
mere 200
×
200 km
2
, yet has been frequently used to model the presumed tectonic behavior of the entire planet
for much of the Archean. In this synthesis, we show that the scale of the craton renders its significance in this
literature greatly exaggerated. The Eastern Pilbara is only 1/3 the size of just the Sierra Nevada batholith.
Considering the entire Eastern, Central and Western Pilbara belts, the scale and tectonic zonation of lithotectonic
assemblages is remarkably similar to that of the California section of the North American Cordillera, from arc
root (Eastern Pilbara. cf. Sierra Nevada), to fore-arc overlap basin (de Gray Basin, cf. Great Central Valley
Sequence), to an accretionary complex (Western Pilbara, cf. Franciscan). The duration of different magmatic and
deformational events, confined to three main pulses in 300 Ma, including about six total magmatic suites over
500 Ma, is similar to that of different pulses and/or accretionary events in the western American Cordilleran
Keywords:
Archean plate tectonics
Gneiss dome
Dome-and-basin structure
Pilbara craton
Accretionary orogen
