Dolomite cementation and recrystallisation of sedimentary breccias along the Musandam Platform margin (United Arab Emirates)

Breesch, Liesbeth; Swennen, Rudy; Vincent, Benoı̂t; Ellison, R.A.; Dewever, Ben

doi:10.1016/j.gexplo.2010.02.005

Cited by 20 publications

(17 citation statements)

References 36 publications

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“…They have more elongated forms with purple luminescent to non luminescent cores overgrown by pink to yellow luminescent rims. Stable isotope analyses show a covariant trend between δ 18 O and δ 13 C from marine (−4.2 to −1.8 and +0.8 to +2.1‰ VPDB, respectively) towards depleted values (−10.2‰ and −8.9‰ VPDB, respectively; Breesch et al 2006Breesch et al , 2010a. This depletion is explained by recrystallisation during type 2 dolomitisation and it is interpreted in terms of high temperatures during precipitation and the incorporation of light carbon as hydrocarbons matured.…”

Section: Hot Dolomitizing Fluidmentioning

confidence: 95%

“…Because most of the analytical results have been published in detail elsewhere (Breesch 2008;Breesch et al 2006Breesch et al , 2009Breesch et al , 2010a, only a summary of the regional carbonate paragenetic sequences is presented and discussed below. The detailed analytical results are presented in Table 1.…”

Section: Petrographic Studies Aiming At Paleo-fluids Characterisationmentioning

confidence: 99%

“…Either way, whether this part of the Musandam Platform unit was located close to the slope, or was instead underlain by a high-angle fault inherited from the former rift, it is dominated by the presence of patchy dolomite breccia ( Fig. 6; Breesch et al 2010a, b).…”

Section: Hot Dolomitizing Fluidmentioning

confidence: 99%

“…These dolomites are planar-s, have crystal sizes ranging from 5 to 25 μm and exhibit an orange to pink and sometimes zoned red-yellow luminescence. This dolomite phase was formed shortly after deposition by fluids of marine or slightly modified marine composition (Breesch et al , 2010a. The second dolomite phase (type 2) mainly affected dolomite type 1 breccias by recrystallisation, dolomite cementation and replacement.…”

Section: Hot Dolomitizing Fluidmentioning

confidence: 99%

“…Based on the main results of this project, some of which have already been described in previous publications (e.g. Breesch 2008;Breesch et al 2006Breesch et al , 2009Breesch et al , 2010aRoure et al 2010) this paper first documents the successive/ alternating episodes of interaction between meteoric and/or hydrothermal fluids with the rock matrix, as evidenced by field and petrographic studies. These analytical data are further discussed and compared with results of basin modelling, in order to better understand the spatial and temporal changes observed in the regional fluid flow and its incidence on diagenetic processes operating in an open system.…”

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confidence: 93%

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Paleo-fluids characterisation and fluid flow modelling along a regional transect in Northern United Arab Emirates (UAE)

et al. 2010

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In the Northern Emirates, Jurassic and Lower Cretaceous platform carbonates of the Musandam parautochthonous units are tectonically overlain by siliciclastic units of the Hawasina-Sumeini allochthon, which derive from the former paleo-slope domain and a more distal basinal portion of the Arabian margin of the Tethys, respectively. All these tectonic units display numerous evidences of paleo-fluid circulations, accounting for dolomitisation and recrystallisation of the rock matrix (Musandam Platform units), as well as cementation of fractures. Polymict breccias of Upper Cretaceous Ausaq Formation which underlay the sole thrust of the Hawasina-Sumeini allochthon also record episodes of hydraulic fracturing, whereas fluid inclusion data indicate precipitation at high temperature in relation to paleo-fluid flow. Petrography of thin-sections (conventional and cathodoluminescence microscopic techniques) as well as fluid inclusion and stable isotopes analyses, were combined with microtectonic studies. These analytical data document (1) the paragenetic sequence of diagenetic products for the Musandam Platform (which constitutes a carbonate reservoir analogue) and Sumeini units of the Dibba Zone, as well as (2) the nature of the paleo-fluids circulating along fractures and the sole thrust of the Hawasina-Sumeini allochthon. The main results of this petrographic approach are qualitative, evidencing (1) the rapid and vertical transfer of hot fluids in the vicinity of the former slope to platform transition, accounting for episodes of hydrothermal dolomitisation, as well as (2) early (i.e. pre-orogenic) and late (i.e. post-orogenic) episodes of emersion of the carbonate units, accounting for additional interactions with meteoric fluids and karstification. In order to better link these diagenetic events with the overall burial, thermal and kinematic evolution of the Arabian margin, basin modelling with Ceres2D, including fluid flow and pore-fluid pressure modelling, was subsequently performed along a regional transect (D4) located in the vicinity of the samples localities and cross-cutting the Northern Oman Mountains from Dibba in the east up to the Arabian Gulf in the west. New subsurface constraints provided by deep seismic profiles were used to constrain the architecture of the cross-section, and to test various hypotheses on the lateral and vertical connection, timing and hydrodynamic behaviour of the faults. This Ceres basin modelling also provides new quantitative estimates of the paleo-fluid pathways, of the timing and velocities of the fluid transfers and of the evolution of pore-fluid pressures. Ultimately, this integration of petrographic studies on surface samples and coupled kinematic and fluid flow basin modelling provides an updated scenario for the succession of tectonically controlled episodes of fluid rock interactions, namely dolomitisation and karstification recorded in the Mesozoic platform carbonates of the Northern Emirates.

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Section: Hot Dolomitizing Fluidmentioning

confidence: 95%