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Abstract: A Late Cretaceous tempestite in the northern Songliao Basin, China, was studied based on thin-section and granularity analyses of borehole samples. The results indicated that the local tempestite can be categorized into several clastic constituent types, which include bottom erosion structures, graded beds, hummocky cross stratification (HCS), parallel beds, wave marks, and bioturbation structures. Based on these sedimentary characteristics and vertical sequence combinations, four tempestite sedimentary models were developed: (I) an autochthonous tempestite facies, (II) an allochthonous tempestite facies (the proximal subfacies), (III) a second allochthonous tempestite facies (the distal subfacies), and (IV) a turbidite facies. [Copyright &y& Elsevier]

Shell beds in the uppermost Xiangshuyuan Formation and its coeval Upper Shihniulan Formation (Lower Silurian), northern Guizhou, SW China, are interpreted as tempestites occurring on the Upper Yangtze Platform. The shells are dominated by two endemic and transient virgianid (brachiopod) taxa, Paraconchidium shiqianensis and Virgianella glabera, which vary in relative abundance and deposited as fragments of valves with cemented micrite that differs from the surrounding sediment, demonstrating that the shells were not originally preserved in growth positions. The thicknesses of individual shell layers vary from ten centimeters to more than four meters. Shells had been strongly stirred up by high-energy currents, mainly caused by ocean storm events and probably related to the profile of the geographic shape of the coastline. Fragmentation of shells, in particular, their thinning anterior parts of ventral and dorsal valves are more intensive. The benthic assemblages are from lower BA2 to upper BA3 in depth, assigned to near shoal belt in geographic background. Breakage and stacking density are of the indexes of proximal and distal transportations. Northern Guizhou was located within the lower latitudes of the Southern Hemisphere during the Silurian time, and obviously affected the depth of the virgianid inhabitation. Most of these shells were disturbed repeatedly by surges. It is inferred that on average, several ten thousand years of growth of shells were required for development of shell layers, followed by storm disruption. [ABSTRACT FROM AUTHOR]

This paper contributed three academic results for a deep-water fan-related sedimentary system formed in the Lijin Sag, China: First, the sedimentary characteristics of the sublacustrine fan and the lobe were reported. The shape and internal architecture of sublcustrine fan and lobe complexes were interpreted by the seismic data. The reasoning for the mound-shaped lobe complexes in the seismic profile was explained. The relationship between the sublacustrine fan and the lobe complexes and their sedimentary processes were discussed. Second, the sublacustrine fan was formed by sandy debris flow, and the lobes were reworked sands formed by wind-driven bottom flow. According to the characteristic and the principle of the hypopycnal plume, the academic view that the extrabasin sandy turbidity flow can't be formed in the saltwater lake was discussed. The deep-water sandstone characterized by the sedimentary structure related to traction flow was explained to be formed by the wind-driven bottom current in the continental saltwater basin. Third, three factors controlling the distribution of deep-water sandstones were analyzed: provenance, basin topography and strong wind stress. • The external shapes and internal architecture of sublacustrine fan and the lobes are quantitatively investigated. • The reason why the lobe complexes are mounded-shaped in seismic profile is explained. • Three factors controlling the distribution of deep-water sandstones was analyzed. • The academic view that the extrabasin sandy turbidity flow can't be formed in the saltwater lake was discussed. • In the saltwater lake, the sandy debris flow and the wind-driven bottom flow reworked deep-water sands distribution. [ABSTRACT FROM AUTHOR]