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Field observations of the crossing relationships of fractures have been used to explain the sequence of fractures. Based on field observations from Fuyang-Lin’an anticline, located near Hangzhou, Zhejiang Province, this paper proposes that the formation of synfolding fractures was influenced dominantly by one fracture set, which developed prior to folding and the orientation was nearly parallel to the bedding. The length of the prefolding fractures is longer than the synfolding fractures. These prefolding fractures cut thicker strata into small pieces and form a dense network of fractures in thicker strata. Most synfolding fractures, which are oblique to the bedding, are truncated by prefolding fractures in thicker strata. The synfolding fractures, which result from local stress, are inferred to form during folding. Here, the mechanism of truncation was analyzed using finite-element models. The approach was based on the idea that natural fractures can be interpreted or inferred from stress distribution. The presence or absence of prefolding fractures is shown to strongly control the distribution of stress, and this control has an important implication for interpreting the fracture truncation mechanism from geomechanical models.
Field observations of the crossing relationships of fractures have been used to explain the sequence of fractures. Based on field observations from Fuyang-Lin’an anticline, located near Hangzhou, Zhejiang Province, this paper Proponent that the formation of synfolding fractures was influenced dominantly by one fracture set, which developed prior to folding and the orientation was nearly parallel to the bedding. The length of the prefolding fractures is longer than the synfolding fractures. These prefolding fractures cut thicker strata into small pieces and form a dense network of fractures in thicker Most synfolding fractures, which are oblique to the bedding, are truncated by prefolding fractures in thicker strata. The synfolding fractures, which result from local stress, are inferred to form during folding. Here, the mechanism of truncation was analyzed using finite- element models. The approach was based on the idea that natural fractures can be interpreted or inferred from st ress distribution. The presence or absence of prefolding fractures is shown strongly control the distribution of stress, and this control has an important implication for interpreting the fracture truncation mechanism from geomechanical models.