Depositional systems, sequence architecture, and controlling factors of an Eocene stratigraphic sequence at Minfeng steep margin of Dongying depression, eastern China

“This study is carried out in Minfeng area, the steep margin of Dongying half graben, eastern China, by integrating 3-D seismic, wireline log, and core data, and aims to interpret the depositional systems, reconstruct sequence stratigraphic architecture, and understand the controlling processes and factors at the steep margin of a rift basin. In the first part of this work, an Eocene stratigraphic sequence is divided into three systems tracts, corresponding to different stages of lake evolution, as early expansion (EEST), late expansion-early contraction (LEECST), and late contraction (LCST). EEST is the thickest and diagnostic by the best-developed marginal and basinal fan systems, displaying a prominent retrogradational stacking pattern. LEEST has the largest basin size with most widespread profundal-sublittoral deposits, but limited fan development. LCST is the thinnest with poorly-developed fan systems, and characterized by significant erosion at basin margin by fluvial incision during lake latest contraction. The differential thickness and development of individual depositional systems in the three systems tracts are resulted from interplay between sediment supply and accommodation space. In the second part of this work, two contrasting depositional styles are recognized above two temporally-adjacent sequence boundaries, as perched lake and incised valley. Their infills are interpreted as fan-lacustrine deposition and fluvial-shoreface-deltaic-lacustrine deposition, recording variable sedimentation during lake lowstand and early expansion. The development of two contrasting depositional styles is a function of multiple allo- and auto-genic processes and factors. This study provides a lake expansion-contraction approach in sequence stratigraphic study in lacustrine steep margin. The results may serve as an ancient counterpart for other studies in lacustrine rift basins”--Abstract, page iv.

Name thesis:degree_name

Ph. D. in Geology and Geophysics

Grantor

Missouri University of Science and Technology

Author dc:creator

• Li, Zhixin

• Controlling Factors
• Depositional Systems
• Lacustrine
• Rift Basin
• Sequence Architecture
• Steep Margin
• Geology

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/3101

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-4106