Geologia estrutural em ambiente ruptil

TERRÆ DIDATICA 7(1):75-85, 2011

H. Zerfass, F. Chemale Jr.

Geologia Estrutural em ambiente rúptil: fundamentos físicos, mecânica de fraturas e sistemas de falhas naturais
Henrique Zerfass1, Farid Chemale Jr.2
Petróleo Brasileiro S/A, Univ. Petrobras, Escola de Ciência e
Tecnologia de E&P-Rua Julio do Carmo 323, 8º andar- CEP 20211260. Rio de Janeiro - RJ, [e-mail].
2
Instituto de Geociências, Universidade de Brasília, Campus Darcy
Ribeiro, Brasília, DF, [e-mail].

1

abstract
Structural geology is a basic discipline in Geology courses, and has a wide application in different areas of a geologist´s work field, either in the academy or industry. The traditional approach of structural geology is geometric-kinematic, in which rock stresses are induced from the geometry of structures. As a mean of enhancing the knowledge of the process-product relationship, this paper aims to add concepts of mechanics of solids to the study of brittle structures – fractures, joints and faults. It is discussed as an inverse reasoning the way natural structures can be deduced or predicted from the principles of mechanics. The starting points are the concepts of force, stress and strain. In the following are presented the principal ideas on initiation and propagation of fractures. This knowledge was constructed by theoretical principles (Mohr-Coulomb Theory) as well as through observation and measuring by performing laboratory tests. In addition, the role of fracture linkage in the formation of joints and faults systems is discussed. Natural fault systems of extensional, compressional and transcurrent environments are briefly revised based on the concepts previously presented. The principles of the mechanics of solids herein discussed yield a relevant contribution to interpret the natural brittle structures.
Citation: Zerfass H., Chemale jr. F. 2011. Geologia estrutural em ambiente rúptil: fundamentos físicos, mecânica de fraturas