How stylolite tips crack rocks

E. Aharonov*, Z. Karcz

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Stylolites are surfaces of localized dissolution, ubiquitous in sedimentary rocks. They belong to a family of sub-planar defects caused by localized volume reduction (LVR), alongside compaction bands, localized negative-volume phase transitions, and dehydration structures. In the past such LVR structures have been labeled as “anti-cracks”, but recent works showed that their stress field is actually that of an Eshelby Inclusion. This work first reviews the stress field near the tips of LVR's, focusing on the fact that while they induce significant compression at certain regions around their tip, they also induce significant extension and shear in other regions around the tip. We thus show that the stress field induced by the LVR tip may give rise to what seem to be counter-intuitive structures - specifically tension cracks, pull-aparts, and shear fractures. We demonstrate this by comparing the stress field of an LVR to a complex network of fractures, veins and sedimentary stylolites in a rock slab from the Calcare Massiccio Formation of the Umbria–Marche, Central Italy. We show that fractures near stylolite tips can be fully rationalized by the stress field induced by the tips, even though in some cases the veins and the stylolites are nearly parallel. Our work suggests that 1) stylolite tips may induce vein formation, creating interconnected network, 2) strain is accommodated in the coupled network, similarly to a mid-ocean ridge and transform fault system, and 3) tension and so-called “pressure-solution” may operate in unison and in the same direction, implying that sedimentary stylolites may sometimes form through textural/chemical heterogeneity, rather than by stress.

Original languageAmerican English
Pages (from-to)299-307
Number of pages9
JournalJournal of Structural Geology
Volume118
DOIs
StatePublished - Jan 2019

Bibliographical note

Publisher Copyright:
© 2018 Elsevier Ltd

Keywords

  • LVR (localized volume reduction)
  • Pressure solution
  • Stylolites
  • Veins
  • anti-crack

Fingerprint

Dive into the research topics of 'How stylolite tips crack rocks'. Together they form a unique fingerprint.

Cite this