| Autor: |
Robert M. Reed, Stephen E. Laubach, Julia F. W. Gale, R. H. Lander |
| Rok vydání: |
2010 |
| Předmět: |
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| Zdroj: |
Journal of Structural Geology. 32:1201-1211 |
| ISSN: |
0191-8141 |
| DOI: |
10.1016/j.jsg.2009.04.018 |
| Popis: |
Opening-mode fractures in dolostones buried to depths of ∼1–5 km contain synkinematic dolomite cement, the amount and internal structure of which has a systematic relationship to fracture size. Narrow fractures ( We developed a geometric crystal growth model for synkinematic dolomite fracture fill in fractured dolostones, where periodic incremental fracture-opening events are introduced with concurrent cement growth. We assumed constant temperature and supersaturation with respect to dolomite. A key assumption in the model is that rapid dolomite accumulation within bridges is governed by high cement-growth rates on repeatedly broken grain surfaces during the process of crack seal. Slower cement-growth rates occur on euhedral crystals. This assumption is made on the basis of a comparison with quartz cement growth in fractured sandstones. Simulations with different fracture-opening rates mimic bridge and lining cement morphologies, including characteristic rhombic shapes of dolomite bridges. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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