![using flac3d for modeling sediments prograding wedge using flac3d for modeling sediments prograding wedge](http://docs.itascacg.com/flac3d700/_images/damfoundation.png)
2007 Mulugeta and Koyi 1992 Naylor and Sinclair 2007 Wenk and Huhn 2013). 1999 Konstantinovskaia and Malavieille 2005 Stockmal et al. Previous studies have investigated the trajectory of particles in the wedges (e.g., Willett et al. In this study, the trajectory of the sediments and their thermal histories during wedge formation were examined using a numerical simulation. Thus, the unique trajectory of the sediments cannot be inferred by only using the observed thermal maturity indices because of the tradeoff between the exposed temperature and its duration. Therefore, these indices can reveal the thermal history either as a function of the heating temperature or as a function of the duration. 2017), which are most frequently used as preservation indices of thermal history, is the integration of the entire history of the material (c.a., temperature and exposed time). 2003 Sakaguchi 1996 Sweeney and Burnham 1990 Yamamoto et al. The thermal maturity recorded in vitrinite reflectance or in the Raman spectrum of carbonaceous materials (e.g., Beyssac et al. The difficulty that is encountered while defining the temporal development of thermal maturity and the associated structures originates from the fact that thermal maturity represents an integration of the exposed temperature and its duration during structural deformation. The temporal development of thermal maturity and their relationships to the associated structures in accretionary wedges have been investigated to date (Barr and Dahlen 1989 Barr et al. In order to represent these observations, various conceptual models have been proposed to interpret the relation between the recorded thermal maturities and geological structures (e.g., Underwood et al. 1992) as well as about the duration of thrusting (e.g., Sakaguchi 1996 Yamamoto et al. The observations of these recorded thermal maturities and geological structures (e.g., intrusion and fault) have promoted a better understanding about the formation of the geological structures and the associated igneous activity (Underwood et al. Thermal history (e.g., peak heating and its duration) is recorded in an organic material in the form of thermal maturity. Previous studies have depicted that the relative duration of peak heating within any accretionary wedge, especially during specific stages of deformation, can be ascertained by determining whether any discordance exists between megascopic structural geometries and paleothermal gradients. The large step of thermal maturity is formed by long-term displacement along an out-of-sequence thrust (OOST) in the deep portion of the wedge. However, the step is overprinted and is observed to disappear through the deep high thermal maturity pathway. The small step of thermal maturity is formed by the frontal thrusting and can be preserved as a function of the shallow low thermal maturity pathway. Simultaneously, a geological deformation event, such as faulting, defines the steps of thermal maturity. However, the sediments subducted in the deep portion of the wedge experience high temperatures and obtain high thermal maturity as a function of the deep high thermal maturity pathway. These shallow path sediments, which move into the shallow portion of the wedge during wedge growth through accretion, rarely experience high temperatures therefore, their thermal maturity is low. We propose two end-member pathways of sediment movement in the accretionary wedge during wedge growth: a shallow, low thermal maturity pathway and a deep, high thermal maturity pathway. This study revealed the variability in the thermal maturity even though sediments are observed to originate at an identical initial depth and thermal conditions. The thermal maturity, which is described in terms of vitrinite reflectance, is determined using the temperature and duration of exposure based on the particle trajectories within the accretionary wedge. This study investigates the thermal maturity structure of the accretionary wedge along with the thermal history of sediments during wedge formation using a numerical simulation.