Seismic‐reflection data show that most deepwater (>200 m water depth) basins are filled by sand and mud dispersed across clinoformal geometries characterized by gently dipping topsets, steeper foresets and gently dipping bottomsets. However, the entire geometry of these ubiquitous clinoforms is not always recognized in outcrops. Sometimes the infill is erroneously interpreted as “layer cake” or “ramp” stratigraphy because the topset‐foreset‐bottomset clinoforms are not well exposed. Regional 2‐D seismic lines show clinoforms in the Lower to Middle Jurassic Challaco, Lajas, and Los Molles formations in S. Neuquén Basin in Argentina. Time equivalent shelf, slope and basin‐floor segments of clinoforms are exposed, and can be walked out in hundreds of metres thick and kilometres‐wide outcrops. The studied margin‐scale clinoforms are not representing a continental‐margin but a deepwater shelf margin that built out in a back‐arc basin. Lajas‐Los Molles clinoforms have been outcrop‐mapped by tracing mudstones interpreted as flooding surfaces on the shelf and abandonment surfaces (low sedimentation rate) in the deepwater basin. The downslope and lateral facies variability in the outcrops is also consistent with a clinoform interpretation. The Lajas topset (shelf) is dominated by fluvial and tidal deposits. The shelf‐edge rollover zone is occasionally occupied by a 40–50‐m‐thick coarse‐grained shelf‐edge delta, sometimes incising into the underlying slope mudstones, producing oblique clinoforms expressing toplap erosion on seismic. A muddy transgressive phase capping the shelf‐edge deltas contains tidal sandbodies. Shelf‐edge deltas transition downslope into turbidite‐ and debris flow‐filled channels that penetrate down the mud‐prone Los Molles slope. At the base‐of‐slope, some 300m below the shelf edge, there are basin‐floor fan deposits (>200 m thick) composed of sandy submarine‐fan lobes separated by muddy abandonment intervals. The large‐scale outcrop correlation between topset–foreset–bottomset allows facies and depositional interpretation and sets outcrop criteria recognition for each clinoform segment.
Fossil microfloral assemblages from five sedimentary successions of the Dacian Basin (Eastern Paratethys) are used to reconstruct the palaeovegetation and palaeoclimate of SE Romania during the Late Miocene to Early Pliocene (regional stages Khersonian, Meotian, Pontian, and Dacian). The studied microfloras were deposited under brackish to freshwater conditions in a fairly distal area of the Dacian Basin and are interpreted to reflect changes in the terrestrial ecosystems at a regional scale. The results show that the vegetation dynamic of the area was driven by the interplay of palaeogeographical and climatic changes. Broadleaved deciduous trees characteristic of temperate climatic regimes and a variety of gymnosperms dominated the vegetation during the Khersonian and the Meotian. This type of vegetation underwent a gradual decline throughout the studied time span, probably associated with a long‐term cooling and drying trend. Thermophilous taxa were virtually absent in the area, with the exception of Engelhardia and Taxodioideae, which probably inhabited lowland swamp forests. The effect of an arid phase, which had its acme during the late Khersonian and extended, in an attenuated mode, during the earliest Meotian, is reflected in the palynological assemblages. This event resulted in the development of a xeric flora including Ephedra and Lygeum. The latter genus is cited for the first time in the Neogene flora of the Eastern Paratethys. Although mesic herbaceous taxa generally occur in low numbers throughout the successions, its signal becomes more relevant in the Pontian, suggesting drier conditions favourable for open ecosystems to develop. During the Dacian substage, the transition from brackish to freshwater settings in the basin favoured the development of shallow, freshwater marshes and led to the spread of a diverse hygrophytic flora. At the same time, a significant increase in Celtis pollen is interpreted to represent increased seasonality of precipitation.
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