Differentiating geology and tectonics using a spatial autocorrelation technique for the hypsometric integral

Abstract

[1] Hypsometry is thought to be sensitive to tectonic uplift rates and lithology differences. In this study we calculated hypsometric integrals (HIs) using as topographic sources two digital elevation models of 10 and 90 m of pixel resolution in the Granada basin (SE of Spain). The HI spatial distributions do not show clear spatial patterns and do not correlate with basin parameters as mean elevation or relief amplitude. However, when exploratory spatial data analysis is applied to the data distributions through local indices of spatial autocorrelation, clear hot spots are visible that improve the geologic meaning of the HI. The distributions are robust and independent of the model resolution but are scale influenced. The application of this new method to the Granada basin shows a strong correlation between the main distribution of active normal faults in the basin and the clusters of high or low HI values obtained in our analysis. Clusters with high HI values define the uplifted footwalls of these faults and regions uplifted in relation with rollover anticlines or where epeirogenic uplift has not been counteracted by local extension. Once the method was adjusted in the Granada basin, we tested its applicability in an area of known contractive tectonic activity, central Otago, New Zealand, showing that the meaning of HI values is improved by using the autocorrelation techniques.

Active tectonics in the central and eastern Betic Cordillera through morphotectonic analysis: the case of Sierra Nevada and Sierra Alhamilla

“…The hypsometry analysis in the Granada basin reveals also the same pattern; a NE border being uplifted by the activity of the NW-SE normal fault (Pérez-Peña et al, 2009c) (Fig. 5).…”

“…5). The use of LISA to the HI value distribution shows that the NE border of the Granada basin is affected by differential uplift related with the NW-SE normal faults, thus having a different drainage pattern system than the rest of the basin (Pérez-Peña et al, 2009c). This drainage pattern, which presents deep incised V-shaped valleys, is similar to the Guadix-Baza drainage system.…”

Geomorphic analysis of transient landscapes in the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American–Caribbean–Cocos plate boundary

“…Recent tectonic or climatically induced base-level fall are associated with the propagation of an erosion wave, which represents the limit between an upper-relict landscape and a lower adjusting zone (e.g., Reinhardt et al, 2007;Pérez-Peña et al, 2015). As a result, relict portions of landscapes (i.e., where uplift is not yet counterbalanced by fluvial erosion) may persist though time (e.g., Burbank and Anderson, 2001;Clark et al, 2005;Legrain et al, 2014;Giletycz et al, 2015).…”

“…This index proved to be efficient in evaluating the response of landscapes to active tectonics (e.g., Pérez-Peña et al, 2009;Mahmood and Gloaguen, 2012;Siddiqui and Soldati, 2014;Andreani et al, 2014;Domínguez-González et al, 2015). According to Pike and Wilson (1971), the HI for a given area can be approximated with Eq.…”

“…Tectonic or climatically induced base-level falls modify the equilibrium of the drainage. The result is an erosion wave propagating upstream and the areas not yet affected by the erosion wave form an upper-relict landscape (e.g., Clark et al, 2005;Reinhardt et al, 2007;Pérez-Peña et al, 2015). The reconstruction of the original stream profile downstream of the convexity provides an estimate for the amount of base-level change and subsequent incision (Schoenbohm et al, 2004;Clark et al, 2005;Gallen et al, 2013).…”