Rivers in the western Gulf of Corinth have built gravelly fan deltas into waters 100-300 m deep. Seismic profiles (3.5 kHz) and gravity cores show that sand-filled channels extend seaward of modern distributary mouths and lead to sandy depositional lobes in deeper Water. Much of the fan delta slope is underlain by mud. Closely spaced gullies cut the [nterchannel ridges on either side of the main channels. Incised slope valleys occur on east-facing slopes, where the wave fetch is greatest, and may be formed by tip-currentinduced turbidity currents.

The Aegean area has experienced both extension and subduction throughout the Neogene and Quaternary. Small volcanic centres with a wide range of rock types occupy a ‘back-arc’ position with respect to the subduction zone, but their geochemistry and chronological correlation with local basin subsidence indicates that their origin is primarily the result of extension. The position of voluminous andesite-dacite volcanism in the modern south Aegean arc relative to the seismically defined Benioff zone is similar to that of other active subduction zones, although the timing of vigorous volcanic activity correlates with periods of most rapid basin subsidence. The voluminous early Miocene intermediate igneous rocks of the northeast Aegean also appear closely related to subduction. Variations in subduction-related products through time are correlated with changes in the rate and direction of subduction inferred from regional tectonic data. The island of Chios, in the eastern Aegean Sea, has several small, mid-Miocene (14–17 Ma) volcanic centres containing high-Mg calc-alkaline (adakitic) andesite, ne-normative basalt, and alkaline and calc-alkaline rhyolite. Both the ne-normative basalt and calc-alkaline andesite have Pb isotopic compositions similar to other Neogene volcanic rocks in the central Aegean region. The small size of the calc-alkaline centres (<10 −1 km 3 ) distinguishes them from the nearby voluminous (1000 km 3 ), 17–22 Ma, calc-alkaline to shoshonitic volcanic centres of Lesbos and Karaburum. The minor volcanism on Chios occurred near the site of earlier voluminous arc volcanism. The rapid decrease in the rate of subduction in the mid-Miocene reduced both the production of slab-derived volatiles and silicic melts, as well as the volume of mantle wedge from which arc-type magma was extracted. At the same time, extension resulted in decompression of the lithosphere and the generation of small-volume partial melts. Volcanic products are not found near the major extensional centres: rather, they are associated with minor basin subsidence, which provided brittle pathways for magma flow.

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