Development of oblique-slip basement-cored uplifts
- 出版日期：2000.
- 页数：255 p. :
- 第一责任说明：Sarah Elizabeth Tindall.
- 分类号：a247
- ISBN：0599705582(ebk.) :
MARC全文
02h0023641 20110420155507.0 cr un||||||||| 110414s2000 xx ||||f|||d||||||||eng | AAI9965940 0599705582(ebk.) : CNY371.35 NGL NGL NGL a247 Tindall, Sarah Elizabeth. Development of oblique-slip basement-cored uplifts [electronic resource] : insights from the Kaibab uplift and from physical models / Sarah Elizabeth Tindall. 2000. 255 p. : digital, PDF file. Source: Dissertation Abstracts International, Volume: 61-03, Section: B, page: 1283. ; Director: George H. Davis. Thesis (Ph.D.) -- The University of Arizona, 2000. Detailed structural geologic mapping of the East Kaibab monocline in southern Utah, combined with results of physical analog modeling, demonstrate that basement-cored structures that form by oblique deformation exhibit a number of distinctive, characteristic features. Map relationships and stress inversion techniques reveal that Laramide growth of the East Kaibab monocline involved a previously unrecognized component of right-handed offset accommodated by reverse-right-lateral fault-propagation folding. Evidence for this new interpretation lies in a monocline-parallel shear zone that changes character with changing structural and stratigraphic level. Structural character and fault orientations within this shear zone resemble a ‘fault-tip process zone’ ahead of an upward- and northward-propagating basement-rooted fault tip. Moreover, fracture patterns in the fault-tip deformation zone resemble Riedel shear geometry normally identified with the map view perspective of pure strike-slip systems. Analysis of fault and slickenline orientations and recognition of the relationship of Riedel fracture geometry to principal stress and strain directions allow an estimate that the strike-slip to dip-slip ratio in the East Kaibab shear zone was between 2:1 and 6:1. The revised estimate of the sub-regional shortening direction during Laramide deformation is 078° or more easterly, as opposed to the 065° shortening direction calculated in previous studies of the Grand Canyon region.;Results of a new physical analog modeling technique complement field-based observations of structural features associated with oblique shortening. Physical analog models were constructed of wet clay overlying rigid basement forcing blocks in order to simulate cover deformation above strike-slip, dip-slip reverse, and oblique-reverse faults in underlying basement. The experiments were used to identify basic structural patterns characteristic of oblique shortening deformation. Features associated with oblique shortening experiments include basement-rooted faults in the cover section that strike obliquely to the fault boundary between underlying forcing blocks. These faults accommodate reverse-oblique slip in the cover section, and resemble the Riedel geometry mapped along the East Kaibab monocline. The most distinctive features formed by oblique shortening models are outer-arc extensional faults (on the crest of a basement-cored uplift) that strike obliquely to the trend of the uplift, the underlying basement fault orientation, and the horizontal shortening direction. A similar system faults has been mapped in detail by other geologists working along the crest of the East Kaibab monocline. The correspondence between physical model results and secondary structures mapped along the East Kaibab monocline indicates that these and other structural features provide convenient tools for recognizing and analyzing oblique deformation in other natural examples of oblique-slip basement-cored uplifts. Strike-slip faults (Geology) ; Faults (Geology) The University of Arizona. aCN bNGL http://proquest.calis.edu.cn/umi/detail_usmark.jsp?searchword=pub_number%3DAAI9965940&singlesearch=no&channelid=%CF%B8%C0%C0&record=1 NGL Bs197 rCNY371.35 ; h1 bs1104