COUPLING LANDSCAPE EVOLUTION MODELS WITH CARBONATE PRODUCTION MODELS: HOW SEDIMENT FLUX COULD INFLUENCE CARBONATE PLATFORMS
| Main Author: | HUSSAIN ALQATTAN |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 2021
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/5017351 |
Daftar Isi:
- Terrigenous clastic sediment input is known to affect carbonate production and reef growth, which are primary elements of sedimentary studies. However, carbonate production models often use arbitrary sediment source inputs to capture such interactions. For sediment source information to be useful, it needs to include geometrical information about sediment transport pathways that are based on proximal erosion sources and incorporate flux and grain size data. For that, the coupling of a landscape evolution model with a rule-based carbonate model could provide a meaningful modeling workflow for clastic sediment flows and their interference in carbonate platforms. The LEM used is based on modeling erosion in mountain catchments and escarpments by fluvial, and hillslopes processes. Such a model is controlled by input parameters like uplift rate, lithology, and climate parameters, and it outputs channel network distribution along with discharge, and sediment flux information integrated from area accumulation and vertical erosion rate. Additional code is built to calculate grain size along the sediment pathways based on a simple degradation function of grain size with distance. In contrast, carbonate models are usually built with a turbidity threshold where the carbonate production distribution and rate are controlled by bathymetry and modulated by the incoming flux of sediments. Once LEM outputs are generated, they are put into the carbonate model at every time step. Also, while keeping the parameters constant, multiple sensitivity tests are performed on the influence of sediment input to the growth of carbonates based on different LEM parameters. The outputs from the LEM show that sediment flux is not simply an induced flow in the landscape but could be the result of drainage catchments expansion and competition. Once the incision of drainage basins reaches equilibrium with the uplift regime of the domain, the sediment flux stabilizes at a constant rate while grain sizes decrease as channels propagate, increasing their length farther into the mountain chain, or the retreating escarpment. The calculated velocity to steady-state drainage basins and constant sediment fluxes is shown to be dependent on the ratio of uplift to erodibility. This erodibility is also intrinsically dependent on how weakened the underlying rock is and the volume of annual precipitation rate. As a response, the carbonate production rate at the beginning is constant despite the penetration of coarse sediments into the system by early formed river channels. However, once the turbidity level is triggered, the production rate decreases exponentially at areas consistent with the sediment input pathways, while sediment transport spreads the influence of clastic input on carbonate production. These findings support the need for the application of this workflow to a case study where the incision of drainage basins near marine carbonate factories is tested for its effect on carbonate reservoirs.