Tensional Faults Research Articles

Source mechanism of mining induced seismic events — Resolution of double couple and non double couple models

Traditional assumption about a seismic source as a double couple (DC) can represent a serious limitation for describing mechanisms of mining induced seismic events. In mining conditions more general process than a shear slip can occur due to stress concentration on mined-out areas. We assume both non-DC components within the dipole description of the source — the moment tensor, and a single force. We processed five seismic events recorded at Driefontein gold mine in South Africa to demonstrate that waveform modeling is not successful enough due to poor information about the medium. Inversion of amplitudes of direct P- and S-waves is more prospective due to their smaller sensitivity to detail of the medium and possibility to correct them for ray bending and shear wave splitting prior to the inversion. Moreover, we are able to estimate the error of the resulting mechanism due to neglect of ray bending. All five events processed display non-DC mechanisms which are significant at 95% considering the mismodelling of the rock mass by a homogeneous isotropic medium. The source mechanisms are in agreement with the underground mining and geological structures. One event has a sub-vertical pressure single dipole complemented by an implosion, which is the body force equivalent of a collapsing horizontal crack or a burst of a pillar supporting the hangingwall of a mined-out area. Two events have mechanisms close to a pressure single couple. All three events are located on pillars. Two out of these three events can be assigned with a downward single force as an alternative mechanism, which matches the amplitude data successfully. It is the force equivalent of a mined-out area collapse, when a rock mass falls from the hangingwall to the footwall. The events are however rather strong, which would require too large rock mass fallen. One of the remaining events is a nearly horizontal tensile single couple, corresponding to a vertical tensional fault. It could be originated by a break of the hangingwall of a mined-out area, however the hypocenter of this event is deep into the footwall were there is no mining taking place. The last event is mostly DC accompanied by a compensated compressive dipole, which may be associated to nearly vertical dip–slip along a fault in the hangingwall. This event is located on the margin of a wide pillar which supports the interpretation.

Centroid depth and mechanism of trench-outer rise earthquakes

Trench-outer rise earthquakes occur by reactivation or creation of normal faults caused as the oceanic lithosphere approaches a subduction zone and bends into the deep-sea trench. These faults may cut deep enough into the mantle to allow sea water to penetrate into the lithosphere, causing serpentinization. The amount of water carried into the mantle is linked to the maximum depth that the tensional faults cut into the lithosphere, which in turn is directly linked to the maximum focal depths of outer rise normal faulting earthquakes. We analysed teleseismic P and S waves of seven earthquakes from the trench-outer rise offshore of Central America using teleseismic waveform inversion of broad-band data. For the computation of Green's functions for waveform inversion, probabilistic earthquake locations were calculated. To study the rupture process, earthquake centroid depths and focal mechanisms for a sequence of subevents were calculated. Both, hypocentral depths from the relocation process and the estimated centroid depths from the waveform inversion show that all events occur at shallow depths (<30 km). Furthermore, the locations of the subevents relative to each other suggest that fault planes for Mw∼ 6 are in the order of 50 km in length and only 5–10 km in width. Rupture generally propagates downdip and the focal mechanisms change for most events from normal faulting to strike-slip or oblique thrusting with time. The depth at which this mechanism change is observed may represent the depth of the nodal plane between tensional and compressional regions in the incoming plate.

Geochemical characteristics of the fluid inclusions in the Gangxi Fault Belt, Huanghua Depression, Bohai Bay Basin, China

We studied the geochemical characteristics of the fluid inclusions in the Ordovician carbonates and the Oligocene Shahejie Formation sandstones from 15 wells in the Gangxi Fault Belt, Huanghua Depression. The fluid inclusions are all sec- ondary with gas/liquid ratio of 5%~10%. Base on Raman they are mainly composed of H2O, CO2 and CH4. The homogenization temperatures, combined with burial and geothermal history of the host rock, indicate that the fluid flows in the Shahejie Formation and the Ordovician carbonates were trapped in Neocene. Using a VG5400 mass spectrometer, the helium isotopic compositions were analyzed. Interpretation of results suggested a significant amount of mantle-derived helium mainly accumulating in the intersections of the NWW trending Xuzhuangzi and NE trending Gangxi faults. The maturity of hydrocarbon decreases from the intersection to the outside pointing out that the fluid related to the NWW trending Xuzhuangzi and NE trending Gangxi faults. These factors implied the fluid inclusions have a close relationship to the local tectonic setting. Gangxi Fault Belt experienced intensive Neo-tectonic activities in Cenozoic. Widespread faulted-depressions and strong volcanic eruptions manifested its tec- tonic status of extensional stress field. Mantle uplift caused the movement of magma that carried mantle-derived gases and deep heat flows, the deep-rooted tension faults provided the passages for the gases and heat flows to shallow crust levels.

Features and Formation Mechanism of Faults and Potash‐forming Effect in the Lop Nur Salt Lake, Xinjiang, China

Abstract: The Lop Nur Salt Lake, located in the eastern part of the Tarim Basin, Xinjiang, China, has become a playa in the Quaternary. Rhombic in shape, the Lop Nur depression is mainly controlled by the NE‐striking and nearly N‐S‐striking sets of faults. Since 1995, a superlarge brine potash deposit with potash resources of 2.50times108t has been found in the Luobei subbasin in the northeastern part of the Lop Nur. We intensively studied the features and formation mechanism of faults inside the Lop Nur through satellite images, geomorphologic survey and continuous conductivity imaging and found seven subparallel graben faults formed under the action of nearly N 10° E principal compressional stress during deposition of the Lop Nur Salt Lake. These faults are up to &gt;60 km long and 1–4 km wide and may extend downward for 1000 m or more. It is just under the action of these tensional faults that potash subbasins formed. The largest subbasin is the Luobei subbasin and the smaller ones are the Luoxi hollow, Erbei hollow and Tienan hollow. Investigation also indicates that the graben faults in the Lop Nur not only control the origin of the potash subbasins, but they themselves are also good brine reservoir structures, in which abundant potash‐rich brines are stored. Therefore, The faults had played an important role in the potash formation of the Lop Nur.

Helium isotopic compositions in fluid inclusions of the Gangxi fault belt in the Huanghua Depression, Bohai Bay Basin

The authors obtained 30 core samples from 15 wells in Gangxi fault belt, Huanghua Depression. Using a VG5400 mass spectrometer, the helium isotopic compositions in fluid inclusion of these samples were analysed. Interpretation of results suggests a significant amount of mantle-derived helium in the inclusions, which were likely trapped during Neocene. Mantle-derived helium have mostly accumulated in the intersections of the NWW trending Xuzhuangzi and NE trending Gangxi faults, and decreased away from the intersections. This pattern implied a close relationship to the local tectonic setting. Gangxi fault belt experienced intensive neo-tectonic activities in the Cenozoic. Widespread faulted-depressions and strong volcanic eruptions manifested its tectonic status of extensional stress field. Mantle uplift caused the movement of magma that carried mantle-derived gas, and the deep-rooted tension faults provided the passages for the gases to shallow crust levels. High-content abiogenic CO2 pools occurred in the study area, hence, using the helium isotopic compositions is of great significance to the exploration of abiogenic natural gases.

Numerical Simulation of Fluid Migration during Ore Formation of Carboniferous Exhalation‐Sedimentary Massive Sulfide Deposits in the Tongling District, Anhui Province

Abstract Numerical simulation of fluid migration during the ore‐forming process of the Carboniferous exhalation‐sedimentary (Sedex) massive sulfide deposits in the Tongling district shows that fluid and thermal activities in lying‐wall rocks were limited to a small area around the main draining passage, which led to weak mineralization and alteration in the lying‐wall rock. Temperature and fluid fields indicate that mineralization and alteration in the lying‐wall rock of the Sedex‐type deposits are usually weaker than those of volcano‐hosted massive sulfide deposits. Fluid migration involves the following processes: seawater penetrating and leaching the lying‐wall rocks, then mixing with ascending hydrothermal fluids in the main draining passage, and finally jetting into seafloor. Although fluid activity‐influenced area is rather small, the content of metals leached out from the lying‐wall rocks is high enough to form large‐scale ore deposits. Tensional contemporaneous faults accompanied with strong heat flows controlled the formation and distribution of Sedex deposits. The tensional tectonic regime on the northern margin of the Yangtze block during the Hercynian provided Sedex deposits with a prerequisite geodynamic condition.

Ground cracks in Ethiopian Rift Valley: facts and uncertainties

No accurate relationship has been obtained in this study between ground cracks in Ethiopian Rift Valley and the most common causes of earth fissures such as aquifer-system compaction and increased horizontal seepage stresses. This is due to the fact that the level of groundwater withdrawal responsible for these processes is still negligible in Ethiopia. If aquifer-system compaction and increased horizontal seepage stresses have a certain role, then it should be through the long-term effect of groundwater flow from basins to neighboring lakes. The ground cracks appeared also not to have a direct link with active faulting or distant earthquakes. Structurally, the Ethiopian Rift Valley is dominated by NE–SW-trending tensional faults, but no evidence is obtained in this study to associate the process of surface cracking with major tectonics. However, an aseismic elastic strain, which originates at depth and propagates upward through sediments without the formation of bedrock faults, could result in conditions conducive to the development of cracks. Then, fissures might ultimately be created after heavy rainfalls by near-surface processes such as piping and hydrocompaction along water-line sources.

Tharsis Tholus: an unusual martian volcano

Tharsis Tholus is unusual martian shield volcano in that the edifice is cut by a series of large normal faults that appear to penetrate the entire volcano. Northeast-trending narrow graben also cut the flank. The large normal faults may be caused by loading of a ductile subsurface layer allowing failure of the edifice; the narrow graben are typical tensional faults. The flank is heavily mantled by aeolian material. Despite the bulbous appearance, the overall morphology of Tharsis Tholus suggests it is a basaltic shield. Crater counts indicate an age of early Hesperian placing Tharsis Tholus in the middle of the period of activity that built the other small Tharsis volcanoes.

Seismic wave velocity of Archaeozoic felsic rocks from North China and its existing location in the crust

This paper contains two contents. The first is seismic velocity of felsic crystalline rocks of North China at room temperature and high pressures and at both high temperatures and pressures. The second is heating acoustic emission of felsic rocks at atmosphere pressure and the temperature of the quartz α-β transition. The results of these experiments show that velocities of the felsic crystalline rocks are obviously lower than that of the basic rocks and no visible relationship with metamorphic phase. The velocity curves of rocks containing quartz display peaks of the α-β phase reaction, which are different from other rocks in configuration. When the heating temperature is up to the phase transition temperature of quartz at the atmosphere pressure, felsic hypometamorphic rocks and magma granite produce acoustic emission. While the other kind of the granite generated by metasomatism does not produce acoustic emission. These results have the following implications. It explains the crustal constitution of the North China craton in combination with other geoscientific data, and clarifies the existing space of α quartz and β quartz. It also indicates that the α-β quartz transition and dehydration melting of amphibole and biotite in the lower crustal rocks of the Cenozoic tectonic subsidence area are likely associated with faulting (tensional fault) and seismic activities.

Thermal History Recovery and Comparative Research on Jiuquan Basin Group

Jiuquan basin group is formed by the superposition of two-stage different property and different generation basins. It was a tensional fault basin in Late Jurassic-Early Cretaceous and a compression depression basin since Cenozoic. The present geothermal gradient and heat flow are low in Jiuquan basin group, where the present geothermal gradient is mainly between 2.5 and 3.00 °C/100m, and the heat flow value is mainly between 50 and 57mW/m2. Jiuquan basin group is tensional fault basins and their palaeothermal gradients are higher in late Mesozoic, which reached 3.75–4.50 °C/100m. Thermal gradient of Jiuquan basin group has gradually decreased since Cenozoic. Huahai basin and Shibei depression of Jiuxi basin have subsided at a small scope since Cenozoic, the palaeotemperature of Lower Cretaceous source rock is higher than present, the maturity of Lower Cretaceous source rock is controlled by paleotemperature. It only has one stage of main oil generation, which is Early Cretaceous. Qingxi depression of Jiuxi basin and Yinger depression of Jiudong basin have subsided at a big scope since Cenozoic, and the maturity of Lower Cretaceous source rock is mainly controlled by present temperature. It has two stage of main oil generation, one is late of Early Cretaceous and another is since Late Tertiary, and main stage of oil generation is since Late Tertiary. The difference of tectonic thermal history in different basin and different units of a basin results in difference of stage of main oil generation and difference of oil-gas exploration prospect.

Contrôle tectonique de l'édification des récifs Dévonien moyen de Mechra ben Abbou (Rehamna, Maroc)

In the carbonated platform of Upper Emsian to Givetian age, the reef edification is previous to, and contemporaneous with, a tilted block tectonic that has favoured the bioconstruction in its upper part. The tectonic expression is illustrated by several instability marks, such as tension faults, progressive unconformity and the resulting landslide, observed in both the reef development zone and the external platform.

Mesozoic mesothermal quartz‐gold‐scheelite lodes, Wakamarina, Marlborough, New Zealand

In the Wakamarina valley, Marlborough, ribbon‐banded quartz lodes fill tensional faults in Caples Terrane‐derived, Marlborough Schist and Wakamarina Quartzite. The largest of the lodes, the Golden Bar, has a strike length of at least 1.8 km and an average width of 2 m. It fills a steeply dipping normal fault which separates pumpellyite‐actinolite fades psammitic schists on the footwall from stilpnomelane‐pumpellyite‐spessartine quartzite (Wakamarina Quartzite) and metabasites on the hanging wall. The lode consists of bands of buck quartz separated by thin chlorite‐sericite‐rich laminae that have been split off the wall‐rock schist. Five deformation events are recognised. The first two are linked with early Jurassic metamorphism, the younger event producing the earliest scheelite, whereas in early Mid Jurassic (illite/sericite K‐Ar age of c. 175 Ma), the third event produced late metamorphic transtensional mylonites with minor quartz‐scheelite veining. As uplift of the schist belt continued through the brittle‐ductile transition zone, the fourth deformation created tensional faults across the mylonites which localised deposition of the quartz‐scheelite ± gold lodes (Golden Bar and Alfords). Internal lode structures indicate that internal pulsed fluid inflow and ductile vein deformation continued during this deformation. The fifth deformation, again with minor quartz‐scheelite veining, created late brittle fracturing and compressional deformation of the lodes and country rocks. Fluid P‐T conditions are probably comparable to those in similar mesothermal quartz‐scheelite lodes at Glenorchy in Otago (1.5–3.5 kbar and 275–330°C), but co‐existing albite and calcic plagioclase in Alfords lode implies that fluid temperatures at Wakamarina may have been locally higher. An extensive zone of sericitic hydrothermal alteration characterised by sericite and K‐feldspar (sericite K‐Ar age of c. 140 Ma — earliest Cretaceous) and loss of pumpellyite, stilpnomelane, and actinolitic amphibole surrounds the Golden Bar lode. The potassic enrichment, the stability of albite and chlorite in both wall rocks and the lodes, and a low sulphide content indicate that the fluids at Wakamarina had a higher aK+/aH+ than in the Otago lodes, and a more neutral pH with a low capacity to carry gold in solution.

Late Neoproterozoic periglacial aeolian sand sheet, Stuart Shelf, South Australia*

The late Neoproterozoic (ca 600 Ma) Whyalla Sandstone covers 25 000 km2 in outcrop and subcrop on the Stuart Shelf, South Australia, and is coeval with the Marinoan glaciogenic succession in the adjacent Adelaide Fold Belt. The flat‐lying formation is up to 165m thick and comprises mainly reddish brown, medium‐ to very coarse‐grained, well‐rounded, commonly bimodal quartzose sandstone that shows regional south‐southeastward fining. Low‐angle (≤15°) strata form the principal stratification type. Large‐scale cross‐bedded sets up to 7 m thick occur mainly in the central area; cross‐strata usually have dips of ≤20–23° and rarely up to 30°, and display grainfall and grainflow deposits, inversely graded subcritically climbing translatent strata, and pin stripe lamination’. Periglacial cryogenic structures in the basal 5 m of the formation include two generations of primary sand wedges, drop involutions, periglacial injections, frost‐heaved blocks, water‐escape structures, and thermokarst microtopography. Small‐scale tensional faults suggest collapse caused by snow melt. The sedimentary features of the Whyalla Sandstone together indicate an aeolian origin and the periglacial structures imply a cold, arid and strongly seasonal climate. The preponderance of low‐angle strata accords with a periglacial sand‐sheet environment, with dune forms confined mostly near the centre of the sand sheet. Cross‐bedding attitudes and the direction of regional fining, together with palaeolati‐tudes inferred from palaeomagnetic data for Marinoan glaciogenic strata in the Adelaide Fold Belt, imply the movement of cold, dry palaeowinds obliquely toward or across the palaeoequator during the Marinoan glaciation.

Deception Island (Antarctica): a new target for exploration of Fe-Mn mineralization?

Abstract This work correlates the submarine volcanic and hydrothermal structures detected through seismic profiles on Deception Island (DI) with geochemical distribution patterns of the volcanic sediments which make up the seafloor of the island. A comparison of subaerial and submarine volcanic events is also carried out and three groups of submerged seismo-depositional units are defined. A model is proposed according to which the highest contents of Fe-Mn-Zn are related to volcanic cones, mounds and vents formed in relation with extensional normal low-angle faults. The As-Ba anomalies, active fumaroles and hot-springs are associated to later tensional faults.

Synchronous very low-grade metamorphism, contraction and inversion in the central part of the Welsh Lower Palaeozoic Basin

A metamorphic map (white mica crystallinity) based on 663 data points has been generated for the recently published British Geological Survey 1:50 000 geological sheets 178 (Llanilar) and 179 (Rhayader). Epizone, upper anchizone, lower anchizone and sub-anchizone are delineated. Metamorphic cross-sections are drawn and superimposed on structural cross-sections. Assumptions made in order to draw metamorphic cross-sections are: (1) the anchizone spans 100°C; (2) the metamorphic field gradient was 36°Ckm −1 ; (3) metamorphic surfaces were initially generated parallel to the contemporary ground surface. Restoration of the sections indicates that at the time of metamorphism a contractional phase had begun because reverse movement on earlier extensional faults, development of back-thrusts, footwall short-cuts and limited growth of precursor folds had taken place. Metamorphism continued locally during later stages of the contractional phase as a strain-related phenomenon. Finally, tensional faulting followed the cessation of folding and metamorphism.

Tectonic Influence on Depositional Sequence Development, Columbus Basin, Eastern Offshore Trinidad and Tobago: ABSTRACT

The Columbus Basin is located off the eastern coast of Trinidad and the northeastern coast of Venezuela, along the margins of the converging Caribbean and Atlantic plates. Post-Miocene tectonics have resulted in transpressional structures oriented NE-SW and tensional faults oriented NW-SE. Sea level has undergone high frequency fluctuations throughout the Plio-Pleistocene. The Orinoco River, which drains the Andean Highlands, has fed enormous quantities of sediment into the basin since the late Miocene (>30,000[prime]). Several observations from an Integrated Depositional Sequence Analysis of the Columbus Basin are applicable to basins in similar settings, such as the Nile and Niger deltas. These include the following: (1) Limited shelf development, associated with limited shelf subsidence, may be an indicator of shelf bypass and slope Canyon development. (2) United basin-floor and slope fan development may be an indicator of shelf aggradation, associated with subsidence at the shelf-break. (3) Extensional and compressional structures focus feeder systems and localize accommodation space. (4) Drill deeper; the basal deepening of a regressive package may be in response to localized tectonics and indicate only temporary loss of good reservoir. (5) Limited transgressive systems tract development is associated with limited transgressive-time accommodation space, and creates better reservoir-seal relationships. (6) Interactively,more » integrating data sets provides the best chance for discerning: sequence relationships across the basin, local versus basinwide chronologic events, sediment bypass versus aggradation zones, reservoir trends and TRUE age of the section. (7) Interpreting the rock record in terms of accommodation space and sediment supply provides a much more practical methodology in tectonically active areas than traditional sequence stratigraphic techniques using the classic eustatic-driven model.« less

Sedimentary evolution models of Lower Triassic deep-water carbonate rocks of west Qinling Mts.

Based on the study of Lower Triassic deep-water carbonate rock sequence of west Qinling Mts . deep-water carbonate rock sequence is divided into lower fine-grain euxinic deposits of a carbonate gentle slope type and upper bathyal and abyssal sediments of carbonate steep slope type. The upper member is emphatically analysed and synthesized into five fades associations. They comprise four fining- and thinning-upward megacycles, each of them representing a sedimentary column which accumulated after a tensional fault subsidence event, which recorded a whole rifting process of west Qinling ocean trough during Lower Triassic.

Late Neogene kinematics of intra‐arc oblique shear zones: The Petilia‐Rizzuto Fault Zone (Calabrian Arc, Central Mediterranean)

The kinematics of intra‐arc shear zones play a key role in the secondary shaping of orogenic arcs such as the Calabrian Arc (central Mediterranean). Comparison of the Neogene structural development of the Petilia‐Rizzuto Fault Zone and the basement structure of the bordering Sila massif reveals that the fault zone is the surface expression of a deep NW–SE trending sinistral crustal oblique shear zone. This shear zone continues over a length of more than 130 km across the northern segment of the Calabrian Arc and shows a post‐Eocene sinistral displacement of about 50 km. The late Neogene forearc basin development and syndepositional tectonics along the fault zone are reconstructed in great detail by analyzing the middle Miocene‐Recent tectonic sequence stratigraphy. A strike‐slip cycle can be recognized whereby the subsequent activity of Riedel shears, tensional faults, and P shears, positive flower structures and principle displacement wrench faults, can accurately be traced in time. Observed phenomena are discussed in terms of the activity of a conjugate system of oblique thrust zones within the growing accretionary complex. The evolution of special types of thrust belt basins is illustrated. These include oblique thin‐skinned pull‐apart basins, oblique rhomboidal “harmonica” basins, and “detached slab” basins (new terms introduced here), evolving one into the other. A new feature illustrated is the recurrent basin inversion which generated passive roof duplexes through back‐shear motion and out‐of‐sequence thrusting along the wedge. The fault patterns and the style of inversion tectonics imply an E–W directed axis of effective compressive stress in this part of the arc. This resulted from an interaction of (1) local E–W directed compression related to a differential displacement of two parallel segments of the arc (generated by the migration to the southeast of the Calabrian Arc and opening of the Tyrrhenian backarc basin); (2) alternating NW–SE directed compression and extension (related to pulsating thrust wedge dynamics with phases of accretion and underthrusting respectively) and (3) regional, compressive interplate stress (middle Messinian‐middle Pliocene). All structures are overprinted by post middle Pleistocene extensional faulting (related to rapid uplift of intra‐arc massifs) and reversal along thrust planes and transcurrent faults. This extensional collapse reflects isostatic adjustments in response to plate rupture which was provoked by regional compressive stress.

Tectonic evolution of northern Wadi Araba, Jordan

In the area east of northern Wadi Araba several phases of tectonic fracturing can be distinguished. The oldest is of Precambrian age and is represented by a system of dikes. A second, pre-Cretaceous, tectonic phase is represented by a distinct joint system, which is restricted to the Cambrian sediments and has not cut the Cretaceous sediments. The major tectonic movements which lead to the formation of the Dead Sea rift produced faults and joint systems which cut all rock sequences. The major deformation of the area started in the early Tertiary, when the accumulation of the SE-NW directed compressive stresses produced fold structures which are older than the rift movements. As a result of this stress a conjugate system of fractures was produced; ESE-trending right-lateral (antithetic) faults and SSE-trending left-lateral (synthetic) faults. A major group of tensional faults and fractures, trending 130°, was produced due to this compression. The major displacement along the rift followed the formation of the above mentioned faults. These fault systems dissected the area into different blocks. As the compression continued, the faults and the blocks between them were rotated relative to each other. Two phases of rotational movements were recorded, contemporaneous with the two phases of the rift formation. During its northward movement, the Arabian plate came into collision with the Sinai-Palestine plate in the Dahal area in northern Wadi Araba. Various indications prove that the Wadi Araba fault is still active and the northward displacement of the Arabian plate along this fault continues in recent time.

Neogene tectonostratigraphy and kinematics of Calabrian basins; Implications for the geodynamics of the Central Mediterranean

Abstract A new structural model for the Calabrian Arc (Southern Italy) is presented, based on a systematic analysis of basin kinematics combined with a review of the literature on basement structure. Three tectonic patterns can be distinguished: (A) NW-SE trending oblique thrust zones, determining a set of N130 trending segments, (B) SW-NE to E-W trending thrust zones, and (C) radial and concentric tensional fault systems in the southern Tyrrhenian back-arc area. These faults, combined with dome-shaped uplift centres determine the actual arc. Patterns A and B can be regarded as the on-shore representation of the Calabrian accretionary-wedge system. The kinematics of various types of basins such as piggy-back, pull-apart and complex-oblique-strike-slip basins are connected to these patterns. The patterns A and B can be linked to the Middle Miocene-Early Pliocene development of oblique, convergent crustal shear zones (“strike-slip cycle”), whereas pattern C can be linked to the Pleistocene collapse of the Southern Tyrrhenian basin and concentric uplift of the arc. Our structural model has considerable implications for the understanding of the kinematic evolution of the Central Mediterranean. We propose a model in which the evolution is characterized by an alternation of the translation of the Calabrian lithosphere element either to the southeast (gravitationally) or to the northeast (compression). Combining (a) our analyses of basin evolution, (b) the structural model and (c) some considerations concerning kinematics of the Central Mediterranean, with the geodynamic mechanisms as proposed in literature, we present a model which consists of a geodynamic cycle comprising the following three stages: (1) a tension stage with back-arc basin opening related to the diapiric inflow of asthenosphere material and roll-back of the subducted Ionian slab, resulting in gravitational displacement of the Calabrian Element to the southeast, (2) a transpression stage with oblique overthrusting towards the northeast upon the Southern Apennines, and (3) a compression stage with NE-SW compression due to oblique dextral shear along the North African margin, plate rupture/lithosphere split and back-arc basin collapse.