Insights into the strain history of Neoproterozoic limestones in the Paraguay Belt using stylolites
Open Access
- 1 January 2021
- journal article
- research article
- Published by FapUNIFESP (SciELO) in Brazilian Journal of Geology
Abstract
Tectonic stylolites are indicators of compressive deformation episodes in rocks and are commonly studied in terms of their geometrical attributes' length (L), and maximum (D-max) and average (D-avg) amplitudes. These parameters were analyzed for vertical stylolites from a sinistral strike-slip fault zone in limestones from the Guia Formation, Paraguay Belt, and compared mathematically to scarce vertical stylolites away from the fault zone. The study aimed to understand the role of strain-induced stylolites on the thinning of faulted limestone layers. Stylolites range from 2.66 up to 28.15 mm in length and from 0.143 up to 1.378 mm in amplitude. The total contractional strain (is an element of) was calculated for 49 stylolites with maximum amplitude peaks of 0.762 mm, using the Kostrov formula. The strain produced layer thinning and growth of the stylolite population. Regions of high stylolite concentration accommodated 16.92% contractional strain, whereas strain values of 3.29% are present in portions with low stylolite density. Layer thinning is directly proportional to contractional strain (is an element of) values spatially induced by faulting. The stylolite morphology plays an essential role in the permeability structure at the reservoir scale, where it can act as a barrier or a channel for fluid flux.Keywords
This publication has 50 references indexed in Scilit:
- Morphological analysis of stylolites for paleostress estimation in limestonesInternational Journal of Rock Mechanics and Mining Sciences, 2014
- The influence of rock heterogeneity on the scaling properties of simulated and natural stylolitesJournal of Structural Geology, 2009
- Development and scaling relationships of a stylolite populationJournal of Structural Geology, 2006
- A study of compaction bands originating from cracks, notches, and compacted defectsJournal of Structural Geology, 2006
- The fractal geometry of some stylolites from the Calcare Massiccio Formation, ItalyJournal of Structural Geology, 2003
- Soft-sediment deformation at the base of the Neoproterozoic Puga cap carbonate (southwestern Amazon craton, Brazil): Confirmation of rapid icehouse to greenhouse transition in snowball EarthGeology, 2003
- Solution-mass-transfer deformation adjacent to the Glarus Thrust, with implications for the tectonic evolution of the Alpine wedge in eastern SwitzerlandJournal of Structural Geology, 2001
- Quantitative analysis of reservoir rocks by microfocus X-ray computerised tomographySedimentary Geology, 2000
- Geometric analysis and scaling relations of deformation bands in porous sandstoneJournal of Structural Geology, 1997
- Rock matrix structures in a zone influenced by a styloliteJournal of Structural Geology, 1992