Details

Autor(en) / Beteiligte

• Feng, Zhiqiang
• Graham, Stephan A.

Titel

From foredeep to orogenic wedge-top: The Cretaceous Songliao retroforeland basin, China

Ist Teil von

• Di xue qian yuan., 2023-05, Vol.14 (3), p.101527, Article 101527

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Quelle

Elsevier ScienceDirect Journals Collection

Beschreibungen/Notizen

• [Display omitted] •Songliao Basin, NE China, initiated as a backarc rift in the late Jurassic.•Songliao Basin evolved to a foreland basin after 88 Ma due to changing plate dynamics.•Songliao foredeep progressively deformed after 81.6 Ma, as Songliao evolved to a wedge-top basin.•Much of Songliao foreland basin evolved into the orogenic wedge and eroded by 65 Ma. Songliao Basin, the largest Mesozoic intracontinental nonmarine basin in eastern China, initiated during the latest Jurassic as a backarc extensional basin; rifting failed and thermal cooling controlled subsidence through the early Late Cretaceous. Integrating 2-D and 3D reflection seismic and borehole data with regional geological studies, we interpret sedimentary sequence and structural patterns of the Coniacian-Maastrichtian fill of Songliao Basin as defining a retroforeland basin system developed after 88 Ma (marked by the T11 unconformity in the basin), including (1) significant increase in the thickness of the Nenjiang Formation eastward towards orogenic highlands of the Zhangguangcai Range and the convergent continental margin; (2) a shift of detrital provenance in the basin from north to southeast; and (3) propagation of E-W shortened structures, increasing eastward in amplitude, frequency, and degree of inversion toward the orogen. During latest Cretaceous, foreland basin fill progressively deformed, as the foredeep evolved to a wedge-top tectonic setting, marked by the basin-wide T04 unconformity within the upper Nenjiang Formation at 81.6 Ma. Much of the basin was brought into the orogenic wedge and eroded by the end of the Cretaceous. Late Jurassic/Early Cretaceous backarc rifting of uncratonized basement comprised of accreted terranes likely facilitated and localized the foreland. Synrift normal faults reactivated and extensively inverted as thrust faults are prominent in the eastern 1/3 of the basin, whereas folds developed above detachments in shaley early post-rift strata dominate the western 2/3 of the basin. Songliao foreland development likely was driven by changing plate dynamics and collision along the Pacific margin after 88 Ma.