sheeteddikekompleks

The sheeted dike complex is a characteristic structural unit within ophiolites, representing the uppermost part of the oceanic crust that forms at mid-ocean ridges. It consists of a dense network of closely spaced sheeted dikes that cut into underlying layered gabbro and are overlain by volcanic rocks in the preserved ophiolite sequence.

Geologically, the sheeted dikes are typically basaltic to diabase in composition and form as magma streams ascend from a crystallizing magma chamber in the crust. The dikes intrude as nearly vertical to steeply dipping sheets, often with chilled margins where they contacted hot host rocks. The arrangement records repeated injections of magma that fed seafloor eruptions, creating a braided pathway from the magmatic chamber to the spreading axis.

The sheeted dike complex is important because it provides a direct fossil record of oceanic crust formed at fast- or slow-spreading ridges, enabling studies of magmatic processes, crustal accretion, and the thermal and chemical evolution of the crust. Its preserved geometry allows researchers to infer magma supply rates, dike propagation mechanisms, and timing of intrusion events in ancient oceans.

Global occurrences include several well-studied ophiolites, with the Semail ophiolite in Oman and the Troodos ophiolite in Cyprus among the most cited examples. Across these exposures, the sheeted dike complex is a key indicator of ancient sea-floor spreading and oceanic crust formation.