9614752 Sahagian We propose to develop a self-consistent depositional model of the West Siberian Basin by sequence stratigraphic analysis of the Jurassic-Neocomian section. Existing stratigraphic models have led to inconsistencies in basin stratigraphy. We also propose to test the validity of the Quantified Eustatic Curve (QEC) developed in our previous study by comparing against the stratigraphy of tectonically independent regions. We will then apply the QEC to quantify the subsidence history of various parts of the West Siberian Basin. Motivation to conduct this proposed study stems from the following: -- No basin-scale sequence stratigraphic analysis of West Siberia has ever been performed, although copious stratigraphic information has already been accumulated. -- The depositional history of West Siberia is not well understood because most previous investigations have been focused on local petroleum exploration. -- Basin subsidence has not been well constrained because it has been impossible to separate the eustatic signal from basin stratigraphy. -- The recently developed Quantified Eustatic Curve (QEC) based on Russian Platform stratigraphy must be tested on tectonically independent basins before it can be used as a globally applicable tool. West Siberia provides an ideal test case because of its well-established biostratigraphic correlation with the Russian Platform. -- It will be possible to use the newly constructed Quantified Eustatic Curve to filter the eustatic signal from tectonic and sedimentary factors for any basin, once it has been tested. -- No quantified eustatic input has been available for synthetic stratigraphic models. Inclusion of the Quantified Eustatic Curve will enhance their applicability to basin analysis. Our plan of attack includes: -- Data Compilation -- Sequence stratigraphic analysis -- Backstripping and construction of relative sea-level curves -- Further testing of the Quantified Eustatic Curve -- Application of eustatic cu rve to basin stratigraphy and determination of subsidence history -- Utilization of synthetic stratigraphic simulations to fine-tune parameters and test system sensitivity to parameter uncertainties. We will first compile a database including geophysical, lithostratigraphic, and paleontologic information from published literature and unpublished data housed in Siberian Institutes. We will then apply sequence stratigraphic techniques to selected regions in West Siberia in order to develop a consistent model of basin stratigraphy and depositional history. The next part of the proposed project involves construction of local relative sea-level curves by backstripping individual points in the stratigraphic database. Our previously constructed Quantified Eustatic Curve will be tested and then applied to the local relative sea-level curves, making it possible to quantify the subsidence and sedimentation histories of the different parts of the basin. Finally, we will construct synthetic stratigraphy of West Siberia using standard modelling packages. The results of the project will be significant on local and global scales in that the project will: -- include the first basin-scale sequence stratigraphic analysis of West Siberia (basin-scale), thus providing a better understanding of its depositional history. -- reconcile the differences between presently existing, parochial depositional models. -- produce a quantified history of basin subsidence more reliably than previously possible. -- provide a test of the applicability of the recently constructed Quantified Eustatic Curve for filtering the eustatic signal from basin stratigraphy. -- be the first use of the Quantified Eustatic Curve in synthetic stratigraphic computer models.
