Abstract

The understanding of each geological-structural aspect in the field is fundamental to be able to reconstruct the geological history of a region and to give a geological meaning to the data acquired in the outcrop. The description of a brittle extensional environment, which is dominated by normal fault systems, is based on: (I) image interpretation, which aims to find evidence suggestive of an extensional geological environment, such as the presence of scarp lines and fault scarps, horst, graben and/or half-graben, among others, that allow the identification of the footwall and hanging wall blocks; ii) definition of the sites of interest for testing; and iii) analysis of the outcrops, following a systematic procedure that consists of the observation and identification of the deformation markers, their three-dimensional schematic representation, and their subsequent interpretation, including the stereographic representation in the outcrop. This procedure implies the unification of the parameters of structural data acquisition in the field, mentioning the minimum fields necessary for the registration of the data in tables. Additionally, the integration of geological and structural observations of the outcrop allows to understand the nature of the geological units, the deformation related to the extensional environment and the regional tectonic context of the study area.

Highlights

  • The observations of geological structures in the field allow the understanding of the geological processes that occur in the earth’s crust, product of the dynamics of tectonic plates through geological time (Frisch et al, 2011; Moores and Twiss, 2000)

  • The description of a brittle extensional environment, which is dominated by normal fault systems, is based on: (i) image interpretation, which aims to find evidence suggestive of an extensional geological environment, such as the presence of scarp lines and fault scarps, horst, graben and/or half-graben, among others, that allow the identification of the footwall and hanging wall blocks; ii) definition of the sites of interest for testing; and iii) analysis of the outcrops, following a systematic procedure that consists of the observation and identification of the deformation markers, their three-dimensional schematic representation, and their subsequent interpretation, including the stereographic representation in the outcrop

  • The integration of geological and structural observations of the outcrop allows to understand the nature of the geological units, the deformation related to the extensional environment and the regional tectonic context of the study area

Read more

Summary

Introduction

The observations of geological structures in the field allow the understanding of the geological processes that occur in the earth’s crust, product of the dynamics of tectonic plates through geological time (Frisch et al, 2011; Moores and Twiss, 2000). The deformation can be homogeneous or heterogeneous (Fossen, 2010; Ragan, 2009; Tanner and Brandes, 2020; van der Pluijm and Marshak, 2004). Homogeneous deformation without volume change can be decomposed into pure shear and/or simple shear (Fossen, 2010; Ragan, 2009; Twiss and Moors, 2007; van der Pluijm and Marshak, 2004) (Figure 2b). Those structural levels of deformation from brittle to ductile level present intrinsic characteristics depending on the temperature and pressure at which the deformation occurred (Forero-Ortega et al, 2021; Fossen and Cavalcante, 2017; Hatcher, 1995; Sibson, 1980)

R ecognition of extensional environments in the field
C onclusions

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.