Structures and tectonics of Tunisia

Burollet, P. F.

doi:10.1016/0040-1951(91)90221-d

Cited by 150 publications

(73 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Bou Grine Zn-Pb deposit is located on the northeastern flank of the Jebel Lorbeus Triassic evaporites dome, in the southern part of the Diapir Zone [8,12,42,57] (Figure 1). This is the largest known lead-zinc deposit in Tunisia [42], mined from 1993-2005 [4].…”

Section: Diapir Zonementioning

confidence: 99%

C–O Stable Isotopes Geochemistry of Tunisian Nonsulfide Zinc Deposits: A First Look

et al. 2018

View full text Add to dashboard Cite

A preliminary C-O stable isotopes geochemical characterization of several nonsulfide Zn-Pb Tunisian deposits has been carried out, in order to evidence the possible differences in their genesis. Nonsulfide ores were sampled from the following deposits: Ain Allegua, Jebel Ben Amara, Jebel Hallouf (Nappe Zone), Djebba, Bou Grine, Bou Jaber, Fedj el Adoum, Slata Fer (Diapir Zone), Jebel Ressas, Jebel Azreg, Mecella (North South Axis Zone), Jebel Trozza, Sekarna (Graben Zone). After mineralogical investigation of selected specimens, the C-O stable isotopic study was carried out on smithsonite, hydrozincite, cerussite and calcite. The data have shown that all the carbonate generations in the oxidized zones of Ain Allegua and Jebel Ben Amara (Nappe Zone), Bou Jaber, Bou Grine and Fedj el Adoum (Diapir Zone), Mecella and Jebel Azreg (North South Zone) have a supergene origin, whereas the carbonates sampled at Sekarna (Graben Zone) (and in limited part also at Bou Jaber) precipitated from thermal waters at moderately high temperature. Most weathering processes that controlled the supergene alteration of the Zn-Pb sulfide deposits in Tunisia had probably started in the middle to late Miocene interval and at the beginning of the Pliocene, both periods corresponding to two distinct tectonic pulses that produced the exhumation of sulfide ores, but the alteration and formation of oxidized minerals could have also continued through the Quaternary. The isotopic characteristics associated with the weathering processes in the sampled localities were controlled by the different locations of the sulfide protores within the tectonic and climatic zones of Tunisia during the late Tertiary and Quaternary.

show abstract

Section: Diapir Zonementioning

confidence: 99%

C–O Stable Isotopes Geochemistry of Tunisian Nonsulfide Zinc Deposits: A First Look

et al. 2018

View full text Add to dashboard Cite

show abstract

“…One shows a dominant strike-slip motion and limits the northwestern end of the Pantelleria trough (Gamberi & Argnani 1995;Argnani 2003), and the other is the north-south Axis of Tunisia that shows a complex deformation history throughout the Meso-Cenozoic (Burollet 1991). Finally, also the Malta trough appears to be affected in its evolution by the NNE-SSW Scicli-Ragusa strike slip fault that continues northward in the Hyblean Plateau (Gardiner et al 1995).…”

Section: Strait Of Sicily and Malta Escarpmentmentioning

confidence: 99%

Evolution of the southern Tyrrhenian slab tear and active tectonics along the western edge of the Tyrrhenian subducted slab

Argnani

2009

View full text Add to dashboard Cite

The evolution of the southern Tyrrhenian subduction has been possibly controlled by distinct episodes of slab break-off as indicated by a critical review of the geological literature and by the analysis of purposely acquired multichannel seismic profiles. Within the proposed interpretation the first episode occurred from 8.5 to 4.0 Ma and affected the segment of the slab located in the Sardinia Channel, causing the abandonment of the Adventure thrust front in western Sicily. The second episode occurred between 2.5 and 1.6 Ma, affecting the segment of slab located north of Sicily, and was preceeded by rifting in the Strait of Sicily. The space and time location of these episodes appear controlled by discontinuities pre-existing within the subducted African plate that trend at high angle to the advancing subduction front. These discontinuities delimit segment of subducted slab that can be affected by slab break-off and can act as wayouts for magma and mantle derived He. The major of these discontinuities, the Malta Escarpment, has been reactivated in the Quaternary as a trench-perpendicular tear (STEP faults). Ultimately, the hierarchy in strength of these trench-perpendicular features could have affected the timing and amount of trench retreat and backarc opening.

show abstract

“…Etna volcano were: (1) Mt. Climiti limestone (MCL), thick-bedded bio-calcarenites units in the Monti Climiti Formation of the Sortino Group in Southeast Sicily (Italy) (Pedley, 1981;Grasso and Lentini, 1982) and, (2) Thala limestone (TL), a micritic limestone from the Abiod limestones of Northwest Tunisia (Burollet, 1991). Their "as-collected" (i.e., before any thermal-stressing or deformation) chemical and physical properties are summarised in Tables 1 and 2, respectively A C C E P T E D M A N U S C R I P T…”

Section: Experimental Materialsmentioning

confidence: 99%

Thermal weakening of the carbonate basement under Mt. Etna volcano (Italy): Implications for volcano instability

Heap

Mollo

Vinciguerra

et al. 2013

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

The physical integrity of a sub-volcanic basement is crucial in controlling the stability of a volcanic edifice. For many volcanoes, this basement can comprise thick sequences of carbonates that are prone to significant thermally-induced alteration. These debilitating thermal reactions, facilitated by heat from proximal magma storage volumes, promote the weakening of the rock mass and likely therefore encourage edifice instability. Such instability can result in slow, gravitational spreading and episodic to continuous slippage of unstable flanks, and may also facilitate catastrophic flank collapse. Understanding the propensity of a particular sub-volcanic basement to such instability requires a detailed understanding of the influence of high temperatures on the chemical, physical, and mechanical properties of the rocks involved. The juxtaposition of a thick carbonate substratum and magmatic heat sources makes Mt. Etna volcano an ideal candidate for our study. We investigated experimentally the effect of temperature on two carbonate rocks that have been chosen to represent the deep, heterogeneous sedimentary substratum under Mt. Etna volcano. This study has demonstrated that thermalstressing resulted in a progressive and significant change in the physical properties of the two rocks. Porosity, wet (i.e., water-saturated) dynamic Poisson's ratio and wet Vp/Vs ratio all increased, whilst P-and S-wave velocities, bulk sample density, dynamic and static Young's modulus, dry Vp/Vs ratio, and dry dynamic Poisson's ratio all decreased. At temperatures of 800 °C, the carbonate in these rocks completely dissociated, resulting in a total mass loss of about 45% and the release of about 44 wt.% of CO 2 . Uniaxial deformation experiments showed that high in-situ temperatures (> 500°C) significantly reduced the strength of the carbonates and altered their deformation behaviour. Above 500 °C the rocks deformed in a ductile manner and A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTthe output of acoustic emissions was greatly reduced. We speculate that thermally-induced weakening and the ductile behaviour of the carbonate substratum could be a key factor in explaining the large-scale deformation observed at Mt. Etna volcano. Our findings are consistent with several field observations at Mt. Etna volcano and can quantitatively support the interpretation of (1) the irregularly low seismic velocity zones present within the sub-volcanic sedimentary basement, (2) the anomalously high CO 2 degassing observed, (3) the anomalously high Vp/Vs ratios and the rapid migration of fluids, and (4) the increasing instability of volcanic edifices in the lifespan of a magmatic system. We speculate that carbonate sub-volcanic basement may emerge as one of the decisive fundamentals in controlling volcanic stability.

show abstract

Structures and tectonics of Tunisia

Cited by 150 publications

References 2 publications

C–O Stable Isotopes Geochemistry of Tunisian Nonsulfide Zinc Deposits: A First Look

C–O Stable Isotopes Geochemistry of Tunisian Nonsulfide Zinc Deposits: A First Look

Evolution of the southern Tyrrhenian slab tear and active tectonics along the western edge of the Tyrrhenian subducted slab

Thermal weakening of the carbonate basement under Mt. Etna volcano (Italy): Implications for volcano instability

Contact Info

Product

Resources

About