Kinematics of regional salt flow in the northern Gulf of Mexico

Abstract

International audienceThe kinematics of regional-scale salt flow in the northern Gulf of Mexico is analysed using: (i) a map of shelf-break contours at the termination of successive depositional episodes; (ii) the location and geometry of large-scale structures of the slope domain as imaged by seismics; and (iii) digital slope bathymetry. In the north margin, salt has flowed towards the SW since the Cretaceous with three main stages of development prior to, during and after a massive salt extrusion in the Early Miocene time. The corresponding sequence of structural development is discussed using a laboratory model. Contrary to all previous interpretations that invoked sedimentary loading as the main driving force, the analysis of regional-scale salt flow implies that the salt tectonics of the northern Gulf of Mexico is predominantly controlled by gliding above the margin dip. The SWdirected salt flow indicates that the north margin of the northern Gulf of Mexico trendsNW-SE, in agreement with plate kinematic models in which the Yucatan continental block has undergone a 45-608 dextral rotation relative to its present orientatio

Salt tectonics at passive margins: Geology versus models

“…The formation of frontal salt nappes is also obtained in this type of experiment when the sedimentation rate in the downdip contractional domain remains moderate (Fort and Brun, 2011). In the model shown in Figure 12, the contractional domain starts to develop (Day 6) in the same way as in Figure 10.…”

“…We recently mapped the regional direction of salt flow (Fort and Brun, 2011) using two types of data (Fig. 22): i) shelf break migration and ii) seafloor deformation in the slope domain.…”

“…For the purpose of the present paper, we will summarise below the major conclusions. The full data analysis can be found in Fort and Brun (2011).…”

Heterogeneity of folding in Zechstein (Upper Permian) salt deposits in the Kłodawa Salt Structure, central Poland

“…This in di cates that flow and fold ing of salt beds, in fact, be gins long be fore the ini ti a tion of salt pil low or diapir ini ti ation and that prob a bly only a min ute in cli na tion of beds trig gers salt flow. Also re cently, grav ity-driven slid ing, flow and fold ing of stratiform beds have been well-doc u mented by seis mic data in salt basins lo cated on con ti nen tal slopes (Davison et al, 2012;Fiduk and Ro wan, 2012;Fort and Brun, 2012;Adam and Krezsek, 2012;Quirk et al, 2012;Strozyk et al, 2012). These data show that in clined salt beds flow down wards in re sponse to grav ity and sed i ment load ing and that the grav ity-driven slid ing and flow leads to de for ma tion of the evaporite se quence as well as an in crease in its total thick ness down the slope, prior to diapirism.…”

Structure and origin of the rifted margin of the northern Gulf of Mexico

“…The vast amount of industry seismic-reflection data and decades of drilling results have created a detailed record of sediment routing and basin stratigraphy (Snedden et al, 2018;Zhang et al, 2018), postrift subsidence (Roure et al, 2009), heat flow (Christie and Nagihara, 2016), and salt tectonics (Fort and Brun, 2012;Dooley et al, 2013). However, a consequence of the thick overburden in the Gulf of Mexico is that it makes imaging of the underlying crust more challenging than at sediment-starved margins Bayrakci et al, 2016).…”