Geological Society of America

T227 Do Carbon Sources or Sinks Drive the Phanerozoic Carbon Cycle?: Understanding Geobiologic Forcings and Feedbacks

Wednesday, 12 October 2022
8:00 AM - 12:00 PM
506

TOPOGRAPHY, PRECIPITATION AND EROSION IN THE MARITIME CONTINENT INCREASED SILICATE WEATHERING EFFICIENCY IN THE LAST 15 MYR

Paper number: T227-10
Program: Technical Sessions
Time: 10:15 AM – 10:30 AM

Authors

Pierre Maffre Presenting Author
University of California Berkeley, Berkeley, CA
John Chiang
University of California Berkeley, Berkeley, CA
Nicholas Swanson-Hysell
University of California, Berkeley, Berkeley, CA
Peter Martin
University of Colorado Boulder, Boulder, CO
Francis Macdonald
University of California Santa Barbara, Santa Barbara, CA
Rebecca Flowers
University of Colorado Boulder, Boulder, CO

Abstract

The Maritime Continent contributes to ~12 % of modern global silicate weathering flux, owing to the extreme rainfall and the intense exhumation and erosion in this region. Precipitation in the Maritime Continent are due largely to the interaction of topography with seasonal northward and southward large-scale atmospheric circulation. The topography of the Maritime Continent is related to arc-continent collisions that started in the Neogene, which are also responsible of the high exhumation and erosion rates of the region. Using the CESM climate model, coupled to the weathering module DynSoil of the geochemical cycle model GEOCLIM, we quantify the relations between topography growth, precipitation, erosion and silicate weathering, and compare the relative contribution of climate dynamics and exhumation to the increase of silicate weathering efficiency. Recent constraints on the topography and exhumation/erosion history of a transect in New Guinea allow us to go further than these sensitivity experiments and provide a first-order estimate of the temporal evolution of silicate weathering efficiency due to progressively increased precipitation and erosion rates during the last 15 Myrs.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-380982

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