Fluvial-derived Turbidites in the Los Molles Formation (Jurassic of the Neuquen Basin): Initiation, Transport, and Deposition

This chapter is about an almost uninterrupted exposure of the Jurassic Los Molles Formation in the Arroyo La Jardinera region in the southern Neuquen Basin (western Argentina). It is based on the analysis of high-resolution satellite images linked with extensive field data. Its main goal is to present a conceptual model for the studied turbidite system capable of explaining how sand and gravel were brought onto and removed from the shelf margin and how these coarse-grained sediments were transported along and deposited on the slope and basin plain. The facies tract ascribed to this turbidite system represents high-frequency lowstand system tracts. From proximal to distal, it includes the record of fluvial channels incised into mid- to outer-shelf deposits, turbidite channels scoured on slope strata, turbidite lobes resting on slope rise facies, and poorly developed turbidite lobe fringes enclosed within basin-plain strata. These gravity flow strata were assigned to short-lived (surges) moderately efficient turbidity currents derived from the almost continuous failure of delta-front deposits (sand and gravel) during ordinary fluvial floods.