Reply to ‘Calculation of depth to detachment and its significance in the Kuqa Depression: A discussion’

Abstract

This paper mainly replies to the discussion by Li et al (2009) on the calculation of the detachment depths in the Kuqa Depression. We think that viscous material fl owing into or out of the cross section can affect the validity of the calculation method, yet the number of detachment levels does not bring any drawbacks to the calculation. In the Kuqa Depression, the salt fl ow infl uenced the structural deformation to some extent, and affected slightly the accuracy of the calculated depths of the true detachment levels. However, it does not mean that the calculation method loses effectiveness in the study area. Therefore, the calculation results are still relatively believable.

Calculation of depth to detachment and its significance in the Kuqa Depression: A discussion

“…We agree with Yu et al (2006) in that "use of the excess area diagram makes it possible to predict the detachment level which cannot be discerned in seismic profiles and provides reference information for the interpretation of structural styles and design of balanced cross sections, etc". However, we would like to discuss some drawbacks that arise from their misinterpretation of Fig.…”

“…At this time, the line goes through the origin (Fig. 1(b)); that is, the line goes We used the data in Table 1 of Yu et al (2006) to fi t linear regression lines (Fig. 4).…”

“…Therefore, if without regard to other factors such as step fault, the true detachment level should be 115.74km below the reference level (Cretaceous bottom), which is impossible in Kela-2 area. Whereas, the 5.3km below the reference level of Yu et al (2006) is based on the line intersecting the h axis at S =16km 2 ; that is, h e = (16-16.806)/0.1452= -5.3km.…”

“…However, we would like to discuss some drawbacks that arise from their misinterpretation of Fig. 5 in Yu et al (2006). Epard and Groshong (1993) presented a linear graph method for using the excess area in a fold to determine the depth to detachment.…”

“…Using the data of Yu et al (2006) to fit linear regression lines, we obtain the depths to detachment of Kela-2, Misikantage anticline and 115.74km, 14.17km, and 75.48km below the reference level (Cretaceous bottom) respectively with the excess area intercept equal to zero. However, the calculation results of depth to detachment in Yu et al (2006) are based on excess area intercept unequal to zero. …”