Submagmatic to Solid-State Deformation Microstructures Recorded in Cooling Granitoids during Exhumation of Late-Variscan Crust in North-Eastern Sicily

Late-Variscan granitoid rocks of trondhjemitic and granitic composition, intruded in migmatitic paragneisses in the north-eastern Peloritani Mountains (southern Italy) at ~310 Ma and ~300 Ma, respectively, exhibit a range of deformation microstructures developed under a shear regime at decreasing temperatures. Non-coaxial deformation is documented by sigmoidal feldspar porphyroclasts, mica fish, and asymmetric boudins affecting tiny andalusite crystals. Late-Variscan shearing during granitoid cooling is constrained by largely represented chessboard patterns in quartz and, especially, submagmatic fractures in plagioclase, indicating deformation at high-temperature conditions (T > 650 °C), in the presence of melt. Submagmatic deformation was extensively superseded by deformation at lower temperatures. Examples of solid state-high temperature deformation-related microstructures (T > 450 °C) include feldspar bulging, quartz grain boundary migration, and subgrain rotation recrystallization. Finally, low temperature subsolidus microstructures (T < 450 °C) consist of quartz bulging, mica kinks, and feldspar twinning and bending. A complete sequence of deformation, operating from submagmatic to low-temperature subsolidus conditions is recorded in both the older and younger granitoids, suggesting a duration of ~20 Ma for shear zone activity during post-collisional exhumation of the Variscan middle crust in southernmost Italy

Contrasting Styles of Inter-Caldera Volcanism in a Peralkaline System: Case Studies from Pantelleria (Sicily Channel, Italy)

The recent (&lt;190 ka) volcanic history of Pantelleria is characterized by the eruption of nine peralkaline ignimbrites, ranging in composition from comenditic trachyte to comendite to pantellerite. The ~46 ka Green Tuff (GT) was the last of these ignimbrites, which was followed by many effusive and explosive low-volume eruptions of pantellerite from vents within the caldera moat and along the caldera rim. Although recent studies have shed additional light on the age, petrochemistry, and volcanology of the older ignimbrites, there is very little knowledge of magmatism that occurred between these older ignimbrites, primarily due to the very scarce exposures. In this paper, we present new field descriptions and geochemical data for three local peralkaline centers never studied before, two pre-GT and one post-GT, which share a similar setting with respect to the caldera scarps but differ in terms of their age, composition, and eruptive style. These centers include: (i) the older (~125 ka) Giache center (comenditic trachyte), (ii) the ~67 ka Attalora center (comendite, pantellerite), and (iii) the younger (~14 ka) Patite center (pantellerite)

Poly-Orogenic Melting of Metasedimentary Crust From a Granite Geochemistry and Inherited Zircon Perspective (Southern Calabria-Peloritani Orogen, Italy)

Inherited zircon ages and geochemical features of late Cadomian and late Variscan granitoids from the north-eastern Peloritani Mountains (NE Sicily) and the western Aspromonte Massif (SW Calabria) shed new light on the sources and processes involved in poly-orogenic granitoid magmatism. The two groups of strongly peraluminous granitoids have similarities in trace element abundance patterns, and Sr and Nd isotopic compositions consistent with both being derived from crustal sources, possibly with a minor contribution from mantle-related components. Comparison of the granite compositions with those of experimental melts derived from various metaigneous and metasedimentary sources indicates that both groups of granitoids originated exclusively from different degrees of melting of similar greywacke-dominated turbidite. Abundant inherited zircon cores from representative samples of metamorphosed late Cadomian (545 ± 5 Ma) granite and late Variscan (300 ± 4 Ma) leucogranodiorite have the same range of U–Pb ages, from Early Paleoproterozoic to latest Neoproterozoic, with main age clusters at ∼0.55 and ∼0.63 Ga, and minor age clusters at ∼0.95 and ∼2.5 Ga. The pattern of detrital zircon ages from a paragneiss, host rock to the late Cadomian granite, is the same, indicating, in conjunction with the geochemistry, that both granites originated by partial melting of deeper crustal equivalents of those paragneisses. The same crustal sequence melted during successive orogenies under different thermal regimes and in different post-collisional tectonic settings, giving rise to granitoid associations with different ages and geochemical features largely reflecting the melting conditions. On the other hand, the zircon inheritance patterns and specific chemical features of S-type granitoids reflect the nature of their crustal magma sources, independently from the effects of the thermal regime or tectonic setting at the time of magmatism

Contrasting Styles of Inter-Caldera Volcanism in a Peralkaline System: Case Studies from Pantelleria (Sicily Channel, Italy)

The recent (\u3c190 ka) volcanic history of Pantelleria is characterized by the eruption of nine peralkaline ignimbrites, ranging in composition from comenditic trachyte to comendite to pantellerite. The ~46 ka Green Tuff (GT) was the last of these ignimbrites, which was followed by many effusive and explosive low-volume eruptions of pantellerite from vents within the caldera moat and along the caldera rim. Although recent studies have shed additional light on the age, petrochemistry, and volcanology of the older ignimbrites, there is very little knowledge of magmatism that occurred between these older ignimbrites, primarily due to the very scarce exposures. In this paper, we present new field descriptions and geochemical data for three local peralkaline centers never studied before, two pre-GT and one post-GT, which share a similar setting with respect to the caldera scarps but differ in terms of their age, composition, and eruptive style. These centers include: (i) the older (~125 ka) Giache center (comenditic trachyte), (ii) the ~67 ka Attalora center (comendite, pantellerite), and (iii) the younger (~14 ka) Patite center (pantellerite)

Exploring Response to Immunotherapy in Non-Small Cell Lung Cancer Using Delta-Radiomics

Delta-radiomics is a branch of radiomics in which features are confronted after time or after introducing an external factor (such as treatment with chemotherapy or radiotherapy) to extrapolate prognostic data or to monitor a certain condition. Immune checkpoint inhibitors (ICIs) are currently revolutionizing the treatment of non-small cell lung cancer (NSCLC); however, there are still many issues in defining the response to therapy. Contrast-enhanced CT scans of 33 NSCLC patients treated with ICIs were analyzed; altogether, 43 lung lesions were considered. The radiomic features of the lung lesions were extracted from CT scans at baseline and at first reassessment, and their variation (delta, 06) was calculated by means of the absolute difference and relative reduction. This variation was related to the final response of each lesion to evaluate the predictive ability of the variation itself. Twenty-seven delta features have been identified that are able to discriminate radiologic response to ICIs with statistically significant accuracy. Furthermore, the variation of nine features significantly correlates with pseudo-progression

Late-Proterozoic to Paleozoic history of the peri-Gondwana Calabria–Peloritani Terrane inferred from a review of zircon chronology

U–Pb analyses of zircon from ten samples of augen gneisses, eight mafic and intermediate metaigneous rocks and six metasediments from some tectonic domains along the Calabria–Peloritani Terrane (Southern Italy) contribute to knowledge of peri-Gondwanan evolution from Late-Proterozoic to Paleozoic times. All samples were equilibrated under amphibolite to granulite facies metamorphism during the Variscan orogeny. The zircon grains of all considered samples preserve a Proterozoic memory suggestive of detrital, metamorphic and igneous origin. The available data fit a frame involving: (1) Neoproterozoic detrital input from cratonic areas of Gondwana; (2) Pan-African/Cadomian assemblage of blocks derived from East and West African Craton; (3) metamorphism and bimodal magmatism between 535 and 579 Ma, within an active margin setting; (4) rifting and opening of Ordovician basins fed by detrital input from the assembled Cadomian blocks. The Paleozoic basins evolved through sedimentation, metamorphism and magmatism during the Variscan orogeny involving Palaeozoic and pre-Paleozoic blocks. The Proterozoic zircon records decidedly decrease in the high grade metamorphic rocks affected by Variscan pervasive partial melting. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40064-016-1839-8) contains supplementary material, which is available to authorized users

Timescales and mechanisms of batholith construction: Constraints from zircon oxygen isotopes and geochronology of the late Variscan Serre Batholith (Calabria, southern Italy)

The late Variscan Serre Batholith in central Calabria represents the middle portion, c. 13-km-thick, of a tilted crustal section continuously exposed from lower-crustal granulites to upper-crustal phyllites. The batholith is zoned, consisting of several granitoid types that were emplaced at depths ranging from c. 23 to c. 6 km. Deep, strongly foliated quartz diorites and tonalites were emplaced into migmatitic metapelites, the intermediate level granitoids are weakly foliated to unfoliated porphyritic granodiorites and monzogranites, and the shallowest bodies are two-mica granodiorites and granites, grading upward to biotite ± amphibole granodiorites, emplaced into paragneisses and phyllites. Five samples, representative of the main granitoid types in terms of both composition and emplacement depth, have been dated by SHRIMP. Zircon from a lower-crustal quartz diorite gave an emplacement age of 297.3 ± 3.1 Ma; two middle-crustal strongly peraluminous K-feldspar megacrystic granites were emplaced at 296.1 ± 1.9 Ma and 294.9 ± 2.7 Ma; a middle- to upper-crustal two-mica monzogranite was emplaced at 294.2 ± 2.6 Ma and finally, an upper-crustal weakly peraluminous granodiorite from the batholith roof was emplaced at 292.2 ± 2.6 Ma. These results are consistent with the development of the batholith by incremental multipulse overaccretion, each granitoid body being in a dominantly rigid state before intrusion of the next, with little or no possibility of magma mixing. The difference in age between the oldest and youngest granitoids, from the batholith floor and roof, respectively, is 5.1 ± 4.0 Ma, providing an upper limit of about 9 Ma on the time taken for batholith construction. The presence in the c. 296–294 Ma granitoids of c. 305–302 Ma anatectic zircon with varied Th/U and oxygen isotope compositions indicates a time interval of 8–9 Ma between incipient partial melting in the lower crust and magma emplacement in the middle crust. The emplacement of the first granitoid bodies into the top of the lower crust was controlled tectonically by the activation of a deep-seated shear zone. The shallowest granodiorites were emplaced during the waning stages of the shear zone activity, producing late-to post-tectonic contact metamorphism in the upper-crustal phyllites and mylonitic paragneissesThis work was supported by PRIN 2009, PRA 2012 and FIR 2014 grants, and carried out in large part while PF was visiting RSES, ANU, in 201

The augen gneisses of the Peloritani Mountains (NE Sicily): Granitoid magma production during rapid evolution of the northern Gondwana margin at the end of the Precambrian

The medium- to high-grade polymetamorphic basement rocks of the Peloritani Mountains, northern Sicily, include large volumes of augen gneiss of controversial age and origin. By means of a geochemical and SHRIMP zircon study of representative samples, th

Crustal Contributions to Late Hercynian Peraluminous Magmatism in the Southern Calabria-Peloritani Orogen, Southern Italy: Petrogenetic Inferences and the Gondwana Connection

Sensitive high-resolution ion microprobe (SHRIMP) analyses of zircon from granites of the medium-high grade Aspromonte-Peloritani Unit, Calabria-Peloritani Orogen (CPO), southern Italy, show that one of the minor trondhjemites (313·7 ± 3·5 Ma) represe