LITHOSPHERIC STRENGTH: A POTENTIAL CONTROLLING FACTOR OVER DIFFERENTIAL SUBSIDENCE IN THE EARLY TRIASSIC SONOMA FORELAND BASIN (WESTERN USA)?
Based on an integrated study within a high-resolution timeframe and using georeferenced data from sedimentological, paleontological, structural and cartographic approaches, we propose to discuss the controlling factor(s) responsible for spatial variations in sedimentary thickness. Regional palinspastic reconstruction and high time-resolution subsidence analyses are thus conducted to obtain an accurate image of the basin by the time of the deposition.
We notably show that sedimentary overload in the basin and heterogeneity of the topographic load exerted by the Golconda Allochthon, when emplaced, are not sufficient to explain the significant discrepancy observed within the Early Triassic sedimentary record. We therefore argue that the age and thus, the rheological properties of the terranes that compose the basin basement are of paramount importance in controlling both the subsidence and thickness spatial distribution across the Sonoma Foreland Basin.