P4: Sedimentologic, stratigraphic, and morpho-tectonic mapping of the western North American Cordillera bearing on its broad-scale uplift history

Supervisors

Prof. Anke Friedrich, Prof. Stuart Gilder

Advisors (int.)

Dr. Simon Kübler (LMU), Dr. Sara Carena (LMU)

Advisors (ext.)

Prof. Danny Stockli (Univ. Texas, Austin), Prof. Cari Johnson (Univ. Utah)

Description

The geological model is constructed by mapping the geological effects observed across the dynamically active target region and its distal sediment sinks through an event- and physical process-based stratigraphic framework (Friedrich et al. 2018, Friedrich 2019). First, distinct geological features (volcanic deposits, dikes, faults, sediments) and their published ages will be mapped to identify rosettastone locations for geochronological sampling and provenance analysis. Second, stratigraphic field mapping, provenance analysis and analysis of published data bearing the timing and rate of erosion of the dynamically uplifted target region will provide empirical knowledge about the space-time patterns of erosion and the origin of sediments. Third, construction of hiatus surface area and hiatus intensity (parameter quantity of Myr) will be constructed. Fourth, event-based stratigraphic mapping allows to construct sequential maps of space-time patterns of geological events and their interrelationships across the target region. Finally, the geological model must be corrected for the cumulative effects of erosion by calibrating the hiatus surfaces with published (P4), new (P3 and P4), and modeled (P7) constraints on erosion rates. The mapping approach will be designed to construct working hypotheses to identify the most likely process-based causes of paleotopography, event size and duration. These geological models will serve as a basis to test and calibrate the global dynamic model over the extent of the interregional target region. 

Timing constraints will be synthesized by thermo- and geochronological analysis and through the stratigraphic framework mapping approach, thereby combining existing data with newly collected samples of targeted areas in North America. Thermo-chronological sample preparation will be carried out at LMU while geochronological analyses will be carried out at our partner laboratories. 

Main objectives

• Produce sequential hiatus area maps at a resolution of stages (wherever possible), correcting them for the erosional history by calibrating them with empirical erosion rates from P3 and through acquisition of new empirical data gathered through field work in the target region. 
• Construct and interpret the geological model as an integrated plate-plume-mode chronostratigraphic map of the CR-Y plume-head event (RTG phase I) 
• Derive knowledge about the event duration, process speed, and rate of exhumation and the changes in the rates of exhumation from the geological model.
• Understand the spatial interrelationships of hiatal surfaces and the causative geological processes in the source region. 

RTG coupling

Input: 

• Empirical gravity/geoid (P1, P2) and geological data (P3).
• The landscape evolution tool, Landlab (P7), will be applied to maintain lateral internal consistency of sedimentary and erosional budgets.

Output: 

• Sequential integrated plate-plume-mode maps (geological model) yielding parameters bearing on spatiotemporal evolution of paleotopography and mass flux based on geological constraints for P1, P2, P6, P7 and P8, including uncertainties (P9).
• Phase I: Generalized integrated plate- and plume stratigraphic map of North America.
• Providing expertise on the sampling site selection for P3.