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Rift-basins are the shallow effects of lithosphere-scale extensional processes often producing polyphase faulting. Their sedimentary evolution depends on the mutual interplay between tectonics, climate, and eustasy. Estimating the role of each factor is generally a challenging issue. This paper is focused on the tectono-sedimentary evolution of the Neogene Siena-Radicofani Basin, a polyphase structural depression located in the inner Northern Apennines. Since Miocene, this basin developed after prolonged extensional tectonics, first as a bowl-shaped structural depression, later reorganized into a half-graben structure due to the activation of high-angle normal faults in the Zanclean. At that time the basin contained coeval continental and marine settings controlled by the normal faulting that caused the development of local coarse-grained depositional systems. These were investigated to: (i) discriminate between the influences of tectonics and climate on sedimentation patterns, and (ii) provide detailed time constraints on fault activity. The analysed successions were deposited in an interval between 5.08 and 4.52 Ma, when a climate-induced highstand phase occurred throughout the Mediterranean. However, evidence of local relative sea-level drops is registered in the sedimentary record, often associated with increased accommodation space and sediment supply. Such base-level fluctuations are not connected to climate changes, suggesting that the faults generally control sedimentation along the basin margins. [ABSTRACT FROM AUTHOR]

The Middle Triassic epoch is the key to understanding the environment changes after the Permian–Triassic mass extinction. The Anisian Badong Formation is a carbonate and siliciclastic succession deposited on the Yangtze Platform, Upper Yangtze Block. In this paper, we use facies analysis combined with sequence stratigraphy of the Badong Formation in the Nashuixi section, Yangtze Block, to discuss the Anisian relative sea-level changes. Microfacies analyses were used to define ten microfacies in four depositional facies zones (tidal flat, restricted platform, restricted to open platform, and open platform) indicating an epeiric platform depositional environment. The lowstand, transgressive, and highstand systems tracts and two sequences were identified. Sequence stratigraphy interpretations indicate that relative sea-level at Nashuixi experienced two rises in the Middle Anisian, which is correlated with those in the Yangtze Block, confirming that sea-level changes during the Anisian were of eustatic origin. However, a distinct regression at Nashuixi occurred in the late Bithynian to IIIyrian while the global sea-level rose, which is likely to be caused by interference from regional tectonics during IIIyrian. The carbon and oxygen isotopic shifts in the Nashuixi section exhibit two negative-values stage in the time near end of Aegean and early Pelsonian, which is well correlated with the global typical sections, indicating two middle Anisian warming events. Our study indicated that the relative sea-level at Nashuixi was controlled by global sea-level change and regional tectonics (Indosinian Orogeny), and the C and O isotopes records respond to global climate change. [ABSTRACT FROM AUTHOR]

Deserts and sandylands that are located in the semi-arid and arid regions in the middle latitudes of the Northern Hemisphere are usually regarded as environmentally sensitive change belts which respond to global climatic change. In northern China, activation or immobilization of sand dunes is mainly influenced by humid and dry variation and is related to stronger or weaker Asian monsoons. In this paper, the history of Holocene millennial-scale climatic and environmental change is reconstructed by the systematic analysis of the geochemical element contents and parameters, along with the OSL and C chronologies, from the different lithologies of the palaeosol-aeolian sand sequence in the south-eastern Mu Us Desert, northern China. Our results indicate that the region was dominated by a dry climate with intensive aeolian activity before 7.2 ka BP, and there was an optimal humid climate and fixed desert in 7.2-4.6 ka. Afterwards, the dune fields became mobile again as the effective humidity declined. Additionally, six dry events were discovered with times of ~7.2, 7.0-6.8, 6.6-5.7, 4.6-4.1, 3.7-3.5, and 3.3-2.5 ka, which were not only coincident with the intervals of millennial-scale weaker Asian summer monsoons, but also accordant with the cold events evidenced in the ice cores and deep-sea deposits of the high latitudes in the Northern Hemisphere. In general, the Holocene climatic and environmental changes had the characteristics of the 'monsoonal mode' and 'abrupt millennial-scale oscillation' in the Mu Us Desert. [ABSTRACT FROM AUTHOR]