Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably acceler... more Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably accelerated, mainly caused by excessive groundwater exploitation from shallow aquifers. To better understand the subsidence pattern and groundwater flow, investigating the structural setting of the Pingtung Basin is essential. The present investigation has revealed that the shallow-marine region off the most rapidly subsiding area of Linbian estuary and Dapeng Bay is characterised by extensive fault and fracture networks, along with a buried syncline, as evidenced by the seismic records. Nearshore, seismic records reveal tectonic fault blocks situated only a few meters beneath the modern seafloor, within the upper 200 m of the seafloor sediments, corresponding to the upper interval of the syncline's infill. This syncline has the same width as the Pingtung basin on land and likely represents its marine extension. Seaward of the most rapidly subsiding area, namely the Linbian estuary, a depression developed on the modern seafloor by both sagging above the syncline centre towards the western flank and extensional faults, which are indicative of recent sinking (= reactivation) of the syncline underneath. The faults, the submarine depression and the coastal subsidence are primarily manifest above the western flank and the centre of the syncline, possibly due to asymmetric reactivation prograding from the syncline's centre towards its western flank. The western flank is intersected by the Liuchu Hsu mud-diapir ridge, which started to rise further and thus, likely triggered the formation of a series of extensional faults above the syncline, followed by minor fault inversions. Previous studies have described freshwater leakage from land aquifers to the seafloor near the subsiding area and at the locations of faults. In fact, these aquifers extend to the adjacent seafloor. Furthermore, faults and fractures in the sub-seafloor deposits in vicinity to the subsiding land areas likely act as conduits in two ways: (1) saline water can infiltrate into the aquifers or (2) freshwater flows out of them. Therefore, these conduits facilitate flow of water from land towards the sea and vice versa. Consequently, the humaninduced groundwater overdraft at the Pingtung coast represents a primary factor, which causes seawater to intrude inland whereas tectonic subsidence of the Pingtung Basin is of subordinate importance. The extensive fault and fracture networks, however, have the potential to amplify seawater intrusion inland or seaward freshwater leakage by providing pathways, as highlighted by this study results.
Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably acceler... more Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably accelerated, mainly caused by excessive groundwater exploitation from shallow aquifers. To better understand the subsidence pattern and groundwater flow, investigating the structural setting of the Pingtung Basin is essential. The present investigation has revealed that the shallow-marine region off the most rapidly subsiding area of Linbian estuary and Dapeng Bay is characterised by extensive fault and fracture networks, along with a buried syncline, as evidenced by the seismic records. Nearshore, seismic records reveal tectonic fault blocks situated only a few meters beneath the modern seafloor, within the upper 200 m of the seafloor sediments, corresponding to the upper interval of the syncline's infill. This syncline has the same width as the Pingtung basin on land and likely represents its marine extension. Seaward of the most rapidly subsiding area, namely the Linbian estuary, a depression developed on the modern seafloor by both sagging above the syncline centre towards the western flank and extensional faults, which are indicative of recent sinking (= reactivation) of the syncline underneath. The faults, the submarine depression and the coastal subsidence are primarily manifest above the western flank and the centre of the syncline, possibly due to asymmetric reactivation prograding from the syncline's centre towards its western flank. The western flank is intersected by the Liuchu Hsu mud-diapir ridge, which started to rise further and thus, likely triggered the formation of a series of extensional faults above the syncline, followed by minor fault inversions. Previous studies have described freshwater leakage from land aquifers to the seafloor near the subsiding area and at the locations of faults. In fact, these aquifers extend to the adjacent seafloor. Furthermore, faults and fractures in the sub-seafloor deposits in vicinity to the subsiding land areas likely act as conduits in two ways: (1) saline water can infiltrate into the aquifers or (2) freshwater flows out of them. Therefore, these conduits facilitate flow of water from land towards the sea and vice versa. Consequently, the humaninduced groundwater overdraft at the Pingtung coast represents a primary factor, which causes seawater to intrude inland whereas tectonic subsidence of the Pingtung Basin is of subordinate importance. The extensive fault and fracture networks, however, have the potential to amplify seawater intrusion inland or seaward freshwater leakage by providing pathways, as highlighted by this study results.
ABSTRACT Surface trails of earthworms exhibit a similar pattern and geometrical arrangement at th... more ABSTRACT Surface trails of earthworms exhibit a similar pattern and geometrical arrangement at three different localities in southern, western, and central Europe and, hence, document distinct behavioral modes of the producers. Straight to slightly winding trails (gutters bounded by levees) are a record of normal behavior moving to a new habitat. Earthworms tend to use, at least for some distance, trails of other earthworms. In order to explore a new habitat, earthworms make blind-ending probings at an acute to sharp angle to either side of their course. When deviating from the main direction at a sharp angle, a pseudospreiten is produced, while the posterior part of the body is obliquely dragged to produce a shortcut. When earthworms leave subsurface tunnels they occasionally produce stellate probing structures. If the substrate is very soft, earthworms may use the anterior or posterior body part as anchor by bending it away from the direction of movement; the body may also be twisted to form meanders. Circular overcrossing, looping trails record the death throes of earthworms and dead producers are often found at the end of these trails. If the substrate is muddy and soft, subtle details can be preserved such as imprints parapodia (setae) or body segmentation. The fossilization potential of earthworm trails is like that of rain-drop imprints. Their occurrence characterizes temporarily wet surfaces in continental environments where the substrate contains some organic matter.
This report, and the Workshop discussions leading to it, stem from the growing realization that p... more This report, and the Workshop discussions leading to it, stem from the growing realization that physical events of short duration may have had frequent, significant, and lasting effects on the Earth’s biota. For the purposes of the report, physical events are considered relevant only if they are: a) relatively sudden, b) have a global or nearly global biologic effect, and c) are amenable to analysis through a combination of physical prediction and empirical observation. The time durations of the physical events themselves cannot be strictly defined, but most are short enough to be considered instantaneous on a geologic time scale. This generally means a duration of 104years or less, with a definite bias toward truly instantaneous events. The geographic scale of events and their geochemical, sedimentologic, and biologic effects can be determined from theoretical models and from the geologic record; there are, however, many uncertainties attached to the theoretical predictions and the incompleteness of the geologic record prevents a full understanding both of their cause and their effects.
Comparisons between Phycosiphon incertum Fischer-Ooster (1858) and Anconichnus horizontalis Kern ... more Comparisons between Phycosiphon incertum Fischer-Ooster (1858) and Anconichnus horizontalis Kern (1978) show that these two monotypic ichnogenera do not differ significantly in geometry, size, sediment fill, and environmental occurrence. Therefore, taxonomic priority has to be given to Phycosiphon and Anconichnus becomes a subjective junior synonym. The trace fossil is a small, highly lobed spreite structure produced by a zoned backfill consisting of a pale mantle and dark core. In a few cases, a meniscate structure is visible in the core. The spreite sediment is an extension of the mantle material; it commonly is poorly visible. The spreite-producing behavior may be locally interrupted, leaving a single tube of backfill. The spatial arrangement of the trace fossils seems to depend on the host sediment; in muddy and homogeneous material the lobes tend to be oriented randomly, including vertically, whereas in laminated sand and silty sediments they tend to lie parallel to bedding. This latter orientation is exaggerated by compaction. Textural differences between host sediment and spreite or mantle may be subtle and not always evident. Observations in modern sediments are in agreement with the type material of both ichnogenera.
In weakly indurated, nannofossil-rich, deep-sea carbonates compressional wave velocity is up to t... more In weakly indurated, nannofossil-rich, deep-sea carbonates compressional wave velocity is up to twice as fast parallel to bedding than normal to it. It has been suggested that this anisotropy is due to alignment of calcite c-axes perpendicular to the shields of coccoliths and shield deposition parallel to bedding. This hypothesis was tested by measuring the preferred orientation (fabric) of calcite c-axes in acoustic anisotropic, calcareous DSDP sediment samples by X-ray goniometry, and it was found that the maximum c-axis concentrations are by far too low to explain the anisotropies. The X-ray method is subject to a number of uncertainties due to preparatory and technical shortcomings in weakly indurated rocks. The most serious weaknesses are: sample preparation, volume of measured sample (fraction of a mm3), beam defocusing and background intensity corrections, combination of incomplete pole figures, and necessity of recalculation of the c-axis orientations from other crystallogra...
Several environmental parameters, sediment grain size and its total organic carbon (TOC) content,... more Several environmental parameters, sediment grain size and its total organic carbon (TOC) content, turbidity and salinity of water, have been measured, and burrows of the crab Macrophthalmus japonicus were studied by highresolution CT imaging of sediment cores sampled at 32 stations along transects from supratidal to subtidal settings of the Yellow River Delta in China. The burrows are present only at some stations in muddy and sandysilty sediments. They are concentrated in some patchy areas affected by low hydrodynamic conditions and high food abundance near a muddy tidal creek, exposed to slightly higher energy close to creeks, or far from tidal creeks. However, they are absent in other places with similar organic matter content and/or distance from tidal creeks, irrelevant to salinity, turbidity, and substrate consistency. The distribution and morphology of the burrows cannot be correlated with simple environmental parameters. Possibly, the crabs created their own environment the best suitable for their life. The burrows are unlined and show I-, J-, L-, U-and Y-shape resembling the small version of the trace fossil Psilonichnus, the Y-shaped Polykladichus, the U-shaped Arenicolites, whereas the complex, shallow M. japonicus burrows are similar to Pholeus bifurcatus, and the multi-branched, mostly inclined galleries superficially to Thalassinoides paradoxicus. These analogical trace fossils, although in the sediment record ascribed to occur in different ichnofacies and to have been probably produced by various animals, may occur together in the studied deposits wherein they have been produced by the same animal in the same habitat.
The Serbo-Macedonian Massif (SMM) represents a composite crystalline belt within the Eastern Euro... more The Serbo-Macedonian Massif (SMM) represents a composite crystalline belt within the Eastern European Alpine orogen, outcropping from the Pannonian basin in the north, to the Aegean Sea in the south. The central parts of the massif (i.e. southeastern Serbia, southwestern Bulgaria, easternMacedonia) consist of the medium- to high-grade Lower Complex, and the low-grade Vlasina Unit. New results of U–Pb LA-ICP-MS analyses, coupled with geochemical analyses of Hf isotopes onmagmatic and detrital zircons, andmain and trace element concentrations
in whole-rock samples suggest that the central SMM and the basement of the adjacent units (i.e. Eastern Veles series and Struma Unit) originated in the central parts of the northern margin of Gondwana. These data provided a basis for a revised tectonic model of the evolution of the SMM from the late Ediacaran to the Early Triassic. The earliest magmatism in the Lower Complex, Vlasina Unit and the basement of Struma Unit is related to the activity along the late Cadomian magmatic arc (562–522 Ma). Subsequent stage of early Palaeozoic igneous activity
is associated with the reactivation of subduction below the Lower Complex and the Eastern Veles series during the Early Ordovician (490–478 Ma), emplacement of mafic dykes in the Lower Complex due to aborted rifting in the Middle Ordovician (472–456 Ma), and felsic within-plate magmatism in the early Silurian (439 ± 2 Ma). The third magmatic stage is represented by Carboniferous late to post-collisional granites (328–304 Ma). These granites intrude the gneisses of the Lower Complex, in which the youngest deformed igneous rocks are of early Silurian age, thus constraining the high-strain deformation and peak metamorphism to the
Variscan orogeny. The Permian–Triassic (255–253 Ma) stage of late- to post-collisional and within-plate felsic magmatism is related to the opening of the Mesozoic Tethys.
Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably acceler... more Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably accelerated, mainly caused by excessive groundwater exploitation from shallow aquifers. To better understand the subsidence pattern and groundwater flow, investigating the structural setting of the Pingtung Basin is essential. The present investigation has revealed that the shallow-marine region off the most rapidly subsiding area of Linbian estuary and Dapeng Bay is characterised by extensive fault and fracture networks, along with a buried syncline, as evidenced by the seismic records. Nearshore, seismic records reveal tectonic fault blocks situated only a few meters beneath the modern seafloor, within the upper 200 m of the seafloor sediments, corresponding to the upper interval of the syncline's infill. This syncline has the same width as the Pingtung basin on land and likely represents its marine extension. Seaward of the most rapidly subsiding area, namely the Linbian estuary, a depression developed on the modern seafloor by both sagging above the syncline centre towards the western flank and extensional faults, which are indicative of recent sinking (= reactivation) of the syncline underneath. The faults, the submarine depression and the coastal subsidence are primarily manifest above the western flank and the centre of the syncline, possibly due to asymmetric reactivation prograding from the syncline's centre towards its western flank. The western flank is intersected by the Liuchu Hsu mud-diapir ridge, which started to rise further and thus, likely triggered the formation of a series of extensional faults above the syncline, followed by minor fault inversions. Previous studies have described freshwater leakage from land aquifers to the seafloor near the subsiding area and at the locations of faults. In fact, these aquifers extend to the adjacent seafloor. Furthermore, faults and fractures in the sub-seafloor deposits in vicinity to the subsiding land areas likely act as conduits in two ways: (1) saline water can infiltrate into the aquifers or (2) freshwater flows out of them. Therefore, these conduits facilitate flow of water from land towards the sea and vice versa. Consequently, the humaninduced groundwater overdraft at the Pingtung coast represents a primary factor, which causes seawater to intrude inland whereas tectonic subsidence of the Pingtung Basin is of subordinate importance. The extensive fault and fracture networks, however, have the potential to amplify seawater intrusion inland or seaward freshwater leakage by providing pathways, as highlighted by this study results.
Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably acceler... more Recently, subsidence at the coast of the Pingtung alluvial plain (SW Taiwan) considerably accelerated, mainly caused by excessive groundwater exploitation from shallow aquifers. To better understand the subsidence pattern and groundwater flow, investigating the structural setting of the Pingtung Basin is essential. The present investigation has revealed that the shallow-marine region off the most rapidly subsiding area of Linbian estuary and Dapeng Bay is characterised by extensive fault and fracture networks, along with a buried syncline, as evidenced by the seismic records. Nearshore, seismic records reveal tectonic fault blocks situated only a few meters beneath the modern seafloor, within the upper 200 m of the seafloor sediments, corresponding to the upper interval of the syncline's infill. This syncline has the same width as the Pingtung basin on land and likely represents its marine extension. Seaward of the most rapidly subsiding area, namely the Linbian estuary, a depression developed on the modern seafloor by both sagging above the syncline centre towards the western flank and extensional faults, which are indicative of recent sinking (= reactivation) of the syncline underneath. The faults, the submarine depression and the coastal subsidence are primarily manifest above the western flank and the centre of the syncline, possibly due to asymmetric reactivation prograding from the syncline's centre towards its western flank. The western flank is intersected by the Liuchu Hsu mud-diapir ridge, which started to rise further and thus, likely triggered the formation of a series of extensional faults above the syncline, followed by minor fault inversions. Previous studies have described freshwater leakage from land aquifers to the seafloor near the subsiding area and at the locations of faults. In fact, these aquifers extend to the adjacent seafloor. Furthermore, faults and fractures in the sub-seafloor deposits in vicinity to the subsiding land areas likely act as conduits in two ways: (1) saline water can infiltrate into the aquifers or (2) freshwater flows out of them. Therefore, these conduits facilitate flow of water from land towards the sea and vice versa. Consequently, the humaninduced groundwater overdraft at the Pingtung coast represents a primary factor, which causes seawater to intrude inland whereas tectonic subsidence of the Pingtung Basin is of subordinate importance. The extensive fault and fracture networks, however, have the potential to amplify seawater intrusion inland or seaward freshwater leakage by providing pathways, as highlighted by this study results.
ABSTRACT Surface trails of earthworms exhibit a similar pattern and geometrical arrangement at th... more ABSTRACT Surface trails of earthworms exhibit a similar pattern and geometrical arrangement at three different localities in southern, western, and central Europe and, hence, document distinct behavioral modes of the producers. Straight to slightly winding trails (gutters bounded by levees) are a record of normal behavior moving to a new habitat. Earthworms tend to use, at least for some distance, trails of other earthworms. In order to explore a new habitat, earthworms make blind-ending probings at an acute to sharp angle to either side of their course. When deviating from the main direction at a sharp angle, a pseudospreiten is produced, while the posterior part of the body is obliquely dragged to produce a shortcut. When earthworms leave subsurface tunnels they occasionally produce stellate probing structures. If the substrate is very soft, earthworms may use the anterior or posterior body part as anchor by bending it away from the direction of movement; the body may also be twisted to form meanders. Circular overcrossing, looping trails record the death throes of earthworms and dead producers are often found at the end of these trails. If the substrate is muddy and soft, subtle details can be preserved such as imprints parapodia (setae) or body segmentation. The fossilization potential of earthworm trails is like that of rain-drop imprints. Their occurrence characterizes temporarily wet surfaces in continental environments where the substrate contains some organic matter.
This report, and the Workshop discussions leading to it, stem from the growing realization that p... more This report, and the Workshop discussions leading to it, stem from the growing realization that physical events of short duration may have had frequent, significant, and lasting effects on the Earth’s biota. For the purposes of the report, physical events are considered relevant only if they are: a) relatively sudden, b) have a global or nearly global biologic effect, and c) are amenable to analysis through a combination of physical prediction and empirical observation. The time durations of the physical events themselves cannot be strictly defined, but most are short enough to be considered instantaneous on a geologic time scale. This generally means a duration of 104years or less, with a definite bias toward truly instantaneous events. The geographic scale of events and their geochemical, sedimentologic, and biologic effects can be determined from theoretical models and from the geologic record; there are, however, many uncertainties attached to the theoretical predictions and the incompleteness of the geologic record prevents a full understanding both of their cause and their effects.
Comparisons between Phycosiphon incertum Fischer-Ooster (1858) and Anconichnus horizontalis Kern ... more Comparisons between Phycosiphon incertum Fischer-Ooster (1858) and Anconichnus horizontalis Kern (1978) show that these two monotypic ichnogenera do not differ significantly in geometry, size, sediment fill, and environmental occurrence. Therefore, taxonomic priority has to be given to Phycosiphon and Anconichnus becomes a subjective junior synonym. The trace fossil is a small, highly lobed spreite structure produced by a zoned backfill consisting of a pale mantle and dark core. In a few cases, a meniscate structure is visible in the core. The spreite sediment is an extension of the mantle material; it commonly is poorly visible. The spreite-producing behavior may be locally interrupted, leaving a single tube of backfill. The spatial arrangement of the trace fossils seems to depend on the host sediment; in muddy and homogeneous material the lobes tend to be oriented randomly, including vertically, whereas in laminated sand and silty sediments they tend to lie parallel to bedding. This latter orientation is exaggerated by compaction. Textural differences between host sediment and spreite or mantle may be subtle and not always evident. Observations in modern sediments are in agreement with the type material of both ichnogenera.
In weakly indurated, nannofossil-rich, deep-sea carbonates compressional wave velocity is up to t... more In weakly indurated, nannofossil-rich, deep-sea carbonates compressional wave velocity is up to twice as fast parallel to bedding than normal to it. It has been suggested that this anisotropy is due to alignment of calcite c-axes perpendicular to the shields of coccoliths and shield deposition parallel to bedding. This hypothesis was tested by measuring the preferred orientation (fabric) of calcite c-axes in acoustic anisotropic, calcareous DSDP sediment samples by X-ray goniometry, and it was found that the maximum c-axis concentrations are by far too low to explain the anisotropies. The X-ray method is subject to a number of uncertainties due to preparatory and technical shortcomings in weakly indurated rocks. The most serious weaknesses are: sample preparation, volume of measured sample (fraction of a mm3), beam defocusing and background intensity corrections, combination of incomplete pole figures, and necessity of recalculation of the c-axis orientations from other crystallogra...
Several environmental parameters, sediment grain size and its total organic carbon (TOC) content,... more Several environmental parameters, sediment grain size and its total organic carbon (TOC) content, turbidity and salinity of water, have been measured, and burrows of the crab Macrophthalmus japonicus were studied by highresolution CT imaging of sediment cores sampled at 32 stations along transects from supratidal to subtidal settings of the Yellow River Delta in China. The burrows are present only at some stations in muddy and sandysilty sediments. They are concentrated in some patchy areas affected by low hydrodynamic conditions and high food abundance near a muddy tidal creek, exposed to slightly higher energy close to creeks, or far from tidal creeks. However, they are absent in other places with similar organic matter content and/or distance from tidal creeks, irrelevant to salinity, turbidity, and substrate consistency. The distribution and morphology of the burrows cannot be correlated with simple environmental parameters. Possibly, the crabs created their own environment the best suitable for their life. The burrows are unlined and show I-, J-, L-, U-and Y-shape resembling the small version of the trace fossil Psilonichnus, the Y-shaped Polykladichus, the U-shaped Arenicolites, whereas the complex, shallow M. japonicus burrows are similar to Pholeus bifurcatus, and the multi-branched, mostly inclined galleries superficially to Thalassinoides paradoxicus. These analogical trace fossils, although in the sediment record ascribed to occur in different ichnofacies and to have been probably produced by various animals, may occur together in the studied deposits wherein they have been produced by the same animal in the same habitat.
The Serbo-Macedonian Massif (SMM) represents a composite crystalline belt within the Eastern Euro... more The Serbo-Macedonian Massif (SMM) represents a composite crystalline belt within the Eastern European Alpine orogen, outcropping from the Pannonian basin in the north, to the Aegean Sea in the south. The central parts of the massif (i.e. southeastern Serbia, southwestern Bulgaria, easternMacedonia) consist of the medium- to high-grade Lower Complex, and the low-grade Vlasina Unit. New results of U–Pb LA-ICP-MS analyses, coupled with geochemical analyses of Hf isotopes onmagmatic and detrital zircons, andmain and trace element concentrations
in whole-rock samples suggest that the central SMM and the basement of the adjacent units (i.e. Eastern Veles series and Struma Unit) originated in the central parts of the northern margin of Gondwana. These data provided a basis for a revised tectonic model of the evolution of the SMM from the late Ediacaran to the Early Triassic. The earliest magmatism in the Lower Complex, Vlasina Unit and the basement of Struma Unit is related to the activity along the late Cadomian magmatic arc (562–522 Ma). Subsequent stage of early Palaeozoic igneous activity
is associated with the reactivation of subduction below the Lower Complex and the Eastern Veles series during the Early Ordovician (490–478 Ma), emplacement of mafic dykes in the Lower Complex due to aborted rifting in the Middle Ordovician (472–456 Ma), and felsic within-plate magmatism in the early Silurian (439 ± 2 Ma). The third magmatic stage is represented by Carboniferous late to post-collisional granites (328–304 Ma). These granites intrude the gneisses of the Lower Complex, in which the youngest deformed igneous rocks are of early Silurian age, thus constraining the high-strain deformation and peak metamorphism to the
Variscan orogeny. The Permian–Triassic (255–253 Ma) stage of late- to post-collisional and within-plate felsic magmatism is related to the opening of the Mesozoic Tethys.
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in whole-rock samples suggest that the central SMM and the basement of the adjacent units (i.e. Eastern Veles series and Struma Unit) originated in the central parts of the northern margin of Gondwana. These data provided a basis for a revised tectonic model of the evolution of the SMM from the late Ediacaran to the Early Triassic. The earliest magmatism in the Lower Complex, Vlasina Unit and the basement of Struma Unit is related to the activity along the late Cadomian magmatic arc (562–522 Ma). Subsequent stage of early Palaeozoic igneous activity
is associated with the reactivation of subduction below the Lower Complex and the Eastern Veles series during the Early Ordovician (490–478 Ma), emplacement of mafic dykes in the Lower Complex due to aborted rifting in the Middle Ordovician (472–456 Ma), and felsic within-plate magmatism in the early Silurian (439 ± 2 Ma). The third magmatic stage is represented by Carboniferous late to post-collisional granites (328–304 Ma). These granites intrude the gneisses of the Lower Complex, in which the youngest deformed igneous rocks are of early Silurian age, thus constraining the high-strain deformation and peak metamorphism to the
Variscan orogeny. The Permian–Triassic (255–253 Ma) stage of late- to post-collisional and within-plate felsic magmatism is related to the opening of the Mesozoic Tethys.
in whole-rock samples suggest that the central SMM and the basement of the adjacent units (i.e. Eastern Veles series and Struma Unit) originated in the central parts of the northern margin of Gondwana. These data provided a basis for a revised tectonic model of the evolution of the SMM from the late Ediacaran to the Early Triassic. The earliest magmatism in the Lower Complex, Vlasina Unit and the basement of Struma Unit is related to the activity along the late Cadomian magmatic arc (562–522 Ma). Subsequent stage of early Palaeozoic igneous activity
is associated with the reactivation of subduction below the Lower Complex and the Eastern Veles series during the Early Ordovician (490–478 Ma), emplacement of mafic dykes in the Lower Complex due to aborted rifting in the Middle Ordovician (472–456 Ma), and felsic within-plate magmatism in the early Silurian (439 ± 2 Ma). The third magmatic stage is represented by Carboniferous late to post-collisional granites (328–304 Ma). These granites intrude the gneisses of the Lower Complex, in which the youngest deformed igneous rocks are of early Silurian age, thus constraining the high-strain deformation and peak metamorphism to the
Variscan orogeny. The Permian–Triassic (255–253 Ma) stage of late- to post-collisional and within-plate felsic magmatism is related to the opening of the Mesozoic Tethys.