The modern Monterey submarine fan, which is one of the largest turbidite systems off the western US, is less than a million years old. The best-documented area of Monterey Fan is the northeastern quadrant, which is characterized by prominent channel-levee complexes. The most recent depositional area for Monterey fan is the southeastern distal part, with a succession of southward propagating lobes fed by rapidly shifting channels. The fan is composed of two major turbiditic systems with different feeding systems and timing of deposition: a Lower Turbidite System (LTS) and an Upper Turbidite System (UTS). The UTS, which comprises much less than half of the total fan volume, includes four channel-levee systems that show a complex history of channel switching resulting from allocyclic and, possibly, tectonic influences. The modern Monterey fan-valley is largely a by-pass zone funneling sediment to the southern lobe area, with a retrofit channel still evident in the transition from a leveed valley to the lobe depositional area. The UTS is underlain by the more extensive LTS, which comprises a series of less well-defined channel, overbank, and lower-fan/basin-plain elements. The age of the LTS is unknown but it is probably as old as late Miocene. No clear feeder system(s) has (have) been identified for the LTS, but it appears to lie north of the fan channels fed by the modern canyon systems in the adjacent Monterey Bay area. The inferred age of the LTS suggests that its initial source was in the area near the present Transverse Ranges.
SEPM: Intrabasinal Influence of Paleotopography on Deposition in Deep-Water Siliciclastic Settings