Abstract The objective of this work is to study the Mesozoic turbiditic sediments from the southern Tethys margin in Iran. These sediments are exposed as nappes in the Pichakun Mountains (i.e. the Zagros Mountains in the Neyriz area), which inverted during latest Cretaceous time. Radiolarians are used to both define and date four main lithostratigraphic formations: (1) the Bar Er Formation (undated, probably Late Triassic to Early Jurassic); (2) the Darreh Juve Formation (Aalenian–early Bajocian to middle Callovian–early Oxfordian); (3) the Imamzadeh Formation (middle Callovian–early Oxfordian to Aptian); (4) the Neghareh Khaneh Formation (late Aptian to Turonian–Coniacian). Most of the sediments are deep-sea gravity-flow lobe deposits. Channel deposits occurred during the Bajocian (i.e. the Darreh Juve Fm) and deeply incised channels (canyons?) occurred during the Albian (i.e. the Neghareh Khaneh Fm). Twenty-seven facies, grouped into eight facies associations, are defined. Based on a sequence stratigraphic study (i.e. the stacking pattern), five second-order cycles (10–30 Ma duration), defined between two successive distal facies time-intervals, are characterized: (1) the J2 (Toarcian?–middle Oxfordian, unconformity: Late Toarcian–Aalenian); (2) the J3 (middle Oxfordian–Berriasian, unconformity: middle? Tithonian); (3) the K1.1 (Berriasian–undated top); (4) the K1.2 (undated base–early Aptian, unconformity: late Hauterivian); (5) the K1.3 (early Aptian–at least Turonian–Coniacian, unconformity: Aptian–Albian boundary). The most important tectonic event recorded occurred at the Aptian–Albian boundary (a deposition of olistoliths, from a few metres to 100 m thick, in debris flows; related to Austrian deformations). The Arabian-scale late Toarcian and early Tithonian deformations have been recorded as unconformities. It is expected that another tectonic event occurred during the late Hauterivian. The unconformity of cycle K1.1 could be a late Valanginian eustatic fall of climatic origin.

Abstract The Bresse and Valence salt basins are in two adjacent segments of the West European Rift that cuts across the eastern part of France. They contain thick Paleogene halite sequences including intercalated and interfingering siliciclastic beds and carbonate and sulfate deposits. Source–rock samples were taken mainly from the depocenters because of maximum sampling coverage. Organic matter is generally immature and occurs primarily within intercalated nonhalitic beds. The amount of organic matter varies considerably with stratigraphic location and lithology. The Bresse basin contains organic matter in (1) the Intermediate Salt Fm (Priabonian), composed of alternating laminated carbonate and primary halite beds; (2) the upper part of the upper Salt Fm (brecciated clayey carbonate beds (Rupelian), affected by multistage halite solution penecontemporaneous with deposition; and (3) the solution breccia that immediately overlies the salt sequence. In the Valence basin, the layers richest in organic matter are in the Subsalt Fm (carbonate beds that are commonly laminated; Priabonian) and the upper part of the Lower Salt Fm (laminites; Rupelian). In both basins, type III kerogen is closely related to terrigenous material. Type I organic matter is abundant in the Valence basin (laminites). Type II seems to be more abundant in the Bresse basin, but its diagnosis remains uncertain. The main depositional environment favoring the preservation of organic matter is likely related to deposition beneath perennially stratified layers of water. Major salt–solution phenomena, which are evident, are supposed to be responsible for concentration of significant amounts of organic matter concurrently with the accumulation of nonsoluble, brecciated residues.