MeetingOfInterest:Meeting-363

From CSDMS

CLAST 2019 - Climatic controls on continental erosion and sediment transport
Juneau Alaska, United States
04 - 10 August 2019
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The physical and chemical breakdown of continental crust into sediments by solid Earth tectonic and climatically modulated forces are key steps in many global geochemical cycles. These processes control the compositional evolution of the continental crust, and ultimately the recycling of material back into the upper mantle via subduction zones. The products of erosion and weathering are supplied to sedimentary basins within continents and to continental margins where they may be preserved, allowing reconstruction of tectonic and environmental histories of adjacent landmasses through the application of suitable proxies. Although tectonic forces are known to be a strong primary control on the generation of sediment, this meeting focuses on assessing the dynamic role of global and regional climate in controlling the production, transport, and deposition of sediments to basins over millennial to million-year timescales. How does climate mediate the sedimentary record and under what conditions can paleoenvironmental and paleoclimatic change be unambiguously deconvolved from the erosional signals preserved in the rock record?

There is no doubt that accelerated rock uplift can drive faster erosion rates of bedrock source terrains. What remains less clear, however, is how erosion and transport efficiency can be governed by climatic and earth surface processes independent of tectonics, especially when changes in these processes often occur as a consequence of tectonic forcing. Although it has typically been argued that stronger precipitation results in faster bedrock erosion, this relationship can be much more complex in many systems. This is because the simple model ignores factors such as seasonality and intensity/duration of precipitation, degree of soil and vegetation development, and/or topographic steepness among many others. Often, understanding of several critical processes, their relative rates, and distributions is required to define any relationship between climatic change and sediments produced as a result from that change. Yet, many equations for fundamental relationships in sediment transport and erosion still remain in the earliest stages of development. Furthermore, whether the same rules and conditions observed between climate, erosion, and sediment transport can be applied across different time scales is a source of considerable contemporary debate.

We solicit talks that aid in understanding how climate can drive erosion and exhumation of source terranes, as well as the earth surface processes that transport and deposit sediments in basins. Global Cenozoic climate, fluctuating sea level, and largescale glaciation have pivotally affected our planet, from the physical evolution of mountain belts to the chemical breakdown of sediments distributed across margins. How do longer- and shorter-term climatic phenomena dictate rates of sediment supply and records of provenance? Sediments are rarely transferred immediately from bedrock to the deep sea because of intermittent storage and release. To what extent and over what timescales do environmental conditions mediate the periodic storage and transport of sediments between sources and final depocenters? Climatic control over sediment transport certainly extends to the offshore, so how do earth surface processes dictate the supply, loading, and stratigraphic architecture along margins and into the deep sea? When, where, how is it possible to isolate the erosional signals produced by tectonic forcing from those linked to climatic processes? And, under what conditions and timescales can precise and accurate climatic records be reconstructed from sediments?

This conference seeks to discuss these challenging questions. We particularly solicit contributions addressing erosion and/or environmental change from all earth surface process disciplines that permit robust correlation between changes in climate, erosion, and sediment transport. Separating drivers and processes continues to be difficult but are much improved in recent years as field studies are coupled with novel spatial and temporal control and further tested with dynamic landscape and stratigraphic models. This transdisciplinary meeting is intended bring together sedimentologists, geomorphologists, landscape and stratigraphic modellers, as well as paleoclimatologists to showcase the current state of research, demonstrate contemporary evidence and methods from studies worldwide, and underline the research concerns remaining in our community.

Of interest for:
  • Terrestrial Working Group
  • Geodynamics Focus Research Group