Browsing by Author "Gazzetti, Edward"

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    Autogenic signals in an experimental source-to-sink system
    (2015-12) Gazzetti, Edward
    Interpretations of the sedimentary rock record typically focus on allogenic forcing like fluctuations in relative sea-level and autogenic processes like fluvial avulsions and delta-lobe switching within the depositional system. I investigated the potential for drainage-basin-derived autogenic variability in sediment discharge to be preserved in the sedimentary rock record. I constructed a source-to-sink experimental apparatus to study the development of autogenic variability ‘signals’ in a net-erosional drainage basin and to trace these autogenic signals to a connected net-depositional basin (the ‘sink’), where they are preserved in a prograding fluvo-deltaic system. By maintaining constant tectonic uplift rate, climate (precipitation rate), and rock strength, I attempted to isolate and measure how allogenic forcing generates autogenic signals in the source terrane. Experimental results suggest that the interaction of landslides with channel processes in the drainage basin generates sediment-discharge variability. The scale of experimental landsliding is set by ridge relief, and landscapes with high rock strength, high uplift rate, and low precipitation rate have the potential to generate high-relief ridges. Thus, these systems can generate relatively large autogenic variability (+/- 10% from the mean) in sediment discharge. These experiments suggest that this autogenic variability in sediment supply propagates through the net-depositional fluvial system with minor time lags and can be preserved in the deltaic strata.