Stylolites and stylolite networks as primary controls on the geometry and distribution of carbonate diagenetic alterations

Autor: J. Neilson, Enrique Gomez-Rivas, Daniel Koehn, Elliot Humphrey, Juan Diego Martín-Martín, Anna Travé, Albert Griera, Paul D. Bons, Maria-Gema Llorens
Přispěvatelé: Ministerio de Ciencia e Innovación (España), Generalitat de Catalunya, German Society for Petroleum and Coal Science and Technology, Gomez-Rivas, Enrique [0000-0002-1317-6289], Griera, Albert [0000-0003-4598-8385], Travé, Anna [0000-0002-2735-3733], Llorens, Maria-Gema [0000-0002-6148-2600], Gomez-Rivas, Enrique, Griera, Albert, Travé, Anna, Llorens, Maria-Gema
Rok vydání: 2022
Předmět:
Zdroj: Dipòsit Digital de la UB
Universidad de Barcelona
Digital.CSIC. Repositorio Institucional del CSIC
instname
DOI: 10.31223/x5061v
Popis: There is ongoing debate on whether stylolites act as barriers, conduits, or play no role in fluid transport. This problem can be tackled by examining the spatial and temporal relationships between stylolites and other diagenetic products at multiple scales. Using the well-known Lower Cretaceous Benicàssim case study area (Maestrat Basin, E. Spain), we provide new field and petrographic observations of how bedding-parallel stylolites can influence different diagenetic processes during basin evolution. The results reveal that stylolites can serve as baffles or inhibitors for different carbonate diagenetic reactions, and act as fronts for dolomitization, dolomite recrystallization and dolomite calcitization processes. Anastomosing stylolites that pre-date burial dolomitization probably acted as a collective baffle for dolomitization fluids in the study area, resulting in stratabound replacement geometries at the metre-to-kilometre scale. The dolomitization front coincides with stylolites, and can be traced along consecutive anastomosing ones. Such anastomosing stylolites are typical of mud-dominated facies that characterize limestone-dolostone transition zones. Conversely, dolostone bodies tend to correspond to more grain-dominated facies characterized by parallel (non-anastomosing) stylolites. Stylolites subsequently acted as fluid flow conduits and barriers when the burial and stress conditions changed. Stylolitic porosity enhanced by dissolution within dolostones close to faults appears filled with saddle dolomite riming the stylolite pore, and high-temperature blocky calcite cements filling the remaining porosity. The fluids responsible for these reactions were likely released from below at high pressure, causing hydraulic brecciation, and were channelised through stylolites, which acted as fluid conduits. Stylolites are also found acting as baffles for subsequent dolomite calcitization reactions during meteoric diagenesis and occasionally appear filled with iron oxides likely released by calcitization. This example demonstrates how the same type of stylolites (bedding-parallel) can act as barriers/inhibitors and/or conduits for different types of diagenetic reactions through time, and how important it is to consider their collective role when they form networks.
This research was carried out within the framework of the Spanish Ministry of Science and Innovation Projects PGC2018-093903-B-C22 and PID2020-118999GB-I00, the Grup Consolidat de Recerca “Geologia Sedimentària” (2017-SGR- 824, funded by the Agency for Management of University and Research Grants, Catalan government, Spain) and the DGMK (German Society for Petroleum and Coal Science and Technology) project 718, funded by the companies ExxonMobil Production Deutschland GmbH, GDF SUEZ E&P Deutschland GmbH, RWE Dea AG, and Wintershall Holding GmbH. EGR acknowledges funding by the Spanish Ministry of Science, Innovation and Universities (“Ramón y Cajal” fellowship RYC2018-026335-I), and the Geological Society of London Elspeth Matthews Fund 2015 grant. MGL acknowledges funding by the Spanish Ministry of Science, Innovation and Universities (“Juan de la Cierva-Incorporación” fellowship IJC2018-036826-I).
Databáze: OpenAIRE
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