The mafic and felsic Haertaolegai intrusions crop out in Urad Zhongqi, western Inner Mongolia and are dominated by monzogranite, porphyritic granite, and gabbroic diorite intrusions. We investigate the tectonic setting, geochronology, and anorogenic characteristics of the western Inner Mongolia through field investigation, microscopic and geochemical analyses of samples from the Haertaolegai bimodal intrusions and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) zircon U–Pb dating of gabbroic diorite and adakitic granites. Petrographic and geochemical studies of the bimodal intrusions indicate that the gabbroic diorites formed from a primary magma generated by the partial melting of lithospheric mantle material that had previously been modified by subduction-related fluids. The felsic rocks are high-K calc-alkaline and metaluminous, have characteristics of adakitic rocks and were generated during the partial melting of juvenile crustal material. Zircon U–Pb dating indicates that the felsic portion of this pluton was emplaced during late Carboniferous – early Permian time, with the mafic portion of the pluton emplaced during early Permian time. The zircons of adamellites have ɛHf(t) values and TDM2 ages of +1.0 to +2.7 and 1032–1128 Ma, respectively, suggesting that they formed from magmas generated by partial melting of juvenile Mesoproterozoic lower crust. These data, combined with the geology of the region, indicate that the late Carboniferous – early Permian bimodal intrusive rocks in western Inner Mongolia record a transitional period from collisional compression to post-collisional extension. These results indicate that the Paleo-Asian Ocean in western Inner Mongolia closed before 300 Ma.

A Lower Devonian silicified ostracod fauna has been recovered from limestone interbeds in the Büyükdere section of the Kozyatağı Member of the Pendik Formation. Forty-one species belonging to 33 genera have been recognized. Twenty-three are already known, and 15 are described in open nomenclature. One genus and three species (Omerliella rectangulata gen. et sp. nov., Microcheilinella istanbulensis sp. nov. and Roundyella goekchenae sp. nov.) are described. Silicified larval stages of trilobites, agglutinated foraminifers and conodonts co-occur with the ostracods. The ostracod assemblages are ‘mixed faunas’, between the epineritic Eifelian Mega-Assemblage, representative of high-energy environments, and the basinal Thuringian Mega-Assemblage, representative of low-energy environments. The conodont faunas of the Pendik Formation represent the serotinus, patulus and partitus biozones of the late Emsian – earliest Eifelian. The Emsian ostracods of NW Turkey show numerous species-level links between the Western Pontides (Istanbul Terrane) and assemblages of contemporaneous faunas of the Cantabrian Mountains (Spain), Morocco and Thuringia (Germany), and of similar biofacies. This supports the notion that the Istanbul Terrane, Armorican terrane-collage and northern margins of Gondwana were in geographical proximity in late Early Devonian time.

A thick Ordovician intra-rhyolitic palaeosol was studied to investigate the peculiarities of early Palaeozoic continental environments, shortly before the development of vascular plants, and to compare its pedogenic patterns with those of previously studied intra-basaltic profiles from the same succession. Well-defined K-eluviation from the top of the palaeosol is proportionally met by K-illuviation at the base of the profile, a pedogenic behaviour that was masked in the underlying intra-basaltic profiles due to subsequent eodiagenetic K-enrichment associated with rhyolite emplacement. Greater stability of K (and eventually Mg) than Si in the intra-rhyolitic profile suggests high pH soil water at the time of pedogenesis despite the low base contents of the acidic host rock, and despite evidence for humid weathering conditions. We also observe that, at the base and at the top of the profile, Al2O3/Zr ratios are substantially lower than those of the host rock, suggesting Al-leaching and therefore extreme weathering conditions, whereas the middle portion of the profile shows Al2O3/Zr ratios that are similar to those of the host rock, suggesting Al stability and therefore less extreme conditions. We interpret these variations in Al2O3/Zr ratios as signatures of a cyclic change from sub-humid periods during which Al was stable throughout the profile, to more humid periods with a well-defined seasonality, during which only the juvenile zone of weathering at the base of the profile could have developed sufficiently high pH during dry seasons for Al to be leached, leaving the Al2O3/Zr signatures from previous stages untouched higher in the profile.

A gastropod fauna has been studied from upper Pliensbachian – upper Toarcian deposits of two sections of the Causses Basin (southern France) in order to investigate the mode of recovery after the early Toarcian anoxic event. The fauna consists of 15 species, one of which is new (Bathrotomaria kronzwilmesorum sp. nov.). Their stratigraphical distribution shows two peaks of diversity – in the Bifrons Zone (Bifrons Subzone) and in the Aalensis Zone (Mactra Subzone) – which reflect brief times during which the oxygen content and bottom consistency favoured the settlement of a relatively diversified fauna. In the Variabilis–Pseudoradiosa zones, gastropods are only represented by two species. This probably indicates more severe and unstable environmental conditions, only allowing the survival of gastropod taxa with wide adaptive capacities. The very low species diversity and the discontinuous and slow faunal recovery were probably determined by physiographic factors. The Causses area was a small basin confined by exposed lands and open towards the central part of western Tethys. Gastropods described here occur exclusively in the Toarcian – early Aalenian communities of the European epicontinental seas, whereas species from the central region of western Tethys are absent. Geographic isolation and marginal location of the Causses Basin restricted faunal exchange with the western European epicontinental seas, preventing fast recovery after the anoxic event. Gastropods of the central region of the western Tethys were probably unable to settle and colonize that area due to the strongly different environment.

The Diguva Sonaba area (Vishakhapatnam district, Andhra Pradesh, South India) represents part of the granulite-facies terrain of the Eastern Ghats Mobile Belt. The Precambrian metamorphic rocks of the area predominantly consist of mafic granulite (±garnet), khondalite, leptynite (±garnet, biotite), charnockite, enderbite, calc-granulite, migmatic gneisses and sapphirine–spinel-bearing granulite. The latter rock type occurs as lenticular bodies in khondalite, leptynite and calc-granulite. Textural relations, such as corroded inclusions of biotite within garnet and orthopyroxene, resorbed hornblende within pyroxenes, and coarse-grained laths of sillimanite, presumably pseudomorphs after kyanite, provide evidence of either an earlier episode of upper-amphibolite-facies metamorphism or they represent relics of the prograde path that led to granulite-facies metamorphism. In the sapphirine–spinel-bearing granulite, osumilite was stable in addition to sapphirine, spinel and quartz during the thermal peak of granulite-facies metamorphism but the assemblage was later replaced by Crd–Opx–Qtz–Kfs-symplectite and a variety of reaction coronas during retrograde overprint. Variable amounts of biotite or biotite+quartz symplectite replaced orthopyroxene, cordierite and Opx–Crd–Kfs–Qtz-symplectite at an even later retrograde stage. Peak metamorphic conditions of c. 1000°C and c. 12 kbar were computed by isopleths of XMg in garnet and XAl in orthopyroxene. The sequence of reactions as deduced from the corona and symplectite assemblages, together with petrogenetic grid and pseudosection modelling, records a clockwise P–T evolution. The P–T path is characteristically T-convex suggesting an isothermal decompression path and reflects rapid uplift followed by cooling of a tectonically thickened crust.

Elasmosauridae constitutes one of the most immediately recognizable plesiosaurian radiations. Their distinctive body plan represents the popular model for Plesiosauria, and is typified by an osteological morphology especially adapted for hyper-elongation of the neck. Nevertheless, many archetypal elasmosaurids are known only from incomplete and/or inadequately documented material, a problem that has contributed to their uncertain intra-clade relationships. A prime example of this is Libonectes morgani from the Upper Cretaceous of Texas, USA, which is frequently presented as an elasmosaurid structural proxy because of its three-dimensionally preserved holotype skull. Perplexingly though, both the taxonomic diagnosis and phylogenetic placement of L. morgani rely primarily upon the cervical vertebrae, together with the pectoral girdle and forelimb, yet most of these elements are now lost and figured only as line drawings. We therefore reviewed the remnant postcranial skeleton of L. morgani first-hand with the objective of clarifying its defining character states. Our observations showed that the existing diagnosis of L. morgani is indeed inadequate. Moreover, the only identifiable autapomorphies occurred within the axial skeleton. This concurred with an examination of character scores used in published plesiosaurian phylogenies, and highlights the persistent significance of postcranial elements for discriminating elasmosaurid taxa.

The Doba gabbro was collected from an exploration well through the Cretaceous Doba basin of southern Chad. The gabbro is composed mostly of plagioclase, clinopyroxene and Fe–Ti oxide minerals and displays cumulus mineral textures. Whole-rock 40Ar–39Ar step-heating geochronology yielded a Late Permian plateau age of 257 ± 1 Ma. The major and trace elemental geochemistry shows that the gabbro is tholeiitic in composition and has trace element ratios (i.e. La/YbN > 7; Sm/YbPM > 3.4; Nb/Y > 1; Zr/Y > 5) indicative of a basaltic melt derived from a garnet-bearing mantle source. The moderately enriched Sr–Nd isotopes (i.e. ISr = 0.70495 to 0.70839; ɛNd(T) = −1.0 to −1.3) fall within the mantle array (i.e. OIB-like) and are similar to other Late Permian plutonic rocks of North-Central Africa (i.e. ISr = 0.7040 to 0.7070). The enriched isotopic composition of the Doba gabbro contrasts with the more depleted compositions of the spatially associated Neoproterozoic post-Pan-African within-plate granites. The contrasting Nd isotope composition between the older within-plate granites and the younger Doba gabbro indicates that different mantle sources produced the rocks and thus may mark the southern boundary of the Saharan Metacraton.

Root-associated stalactites (rootsicles) in Galeria da Queimada lava tube have a mineralogical composition and developmental association with microbes that render them unique. Samples were examined by X-ray diffraction, micro-Raman spectrometry and scanning electron microscopy/X-ray energy-dispersive spectroscopy. Three types of rootsicle were defined: incipient; hard (white and red); and black spongy. The incipient rootsicles still contained rotten organic material and showed the beginning of mineralization by allophane. The white hard and black spongy types were also composed of allophane, while the red hard type was composed of hydrous ferric oxi-hydroxide minerals (HFO). The allophane and HFO in the andisol covering the cave roof precipitated out of the dripwater running along the roots to form the studied rootsicles. All three types of rootsicle showed black layers, coatings, spots or patches composed of manganese oxide minerals and, occasionally, hisingerite (iron (III) phyllosilicate). An alternation of organic precipitation caused by filamentous bacteria and inorganic precipitation (the latter facilitated by pH changes in the dripwater and the cave's temperature) built up both the porous and compact rings observed in the white and red hard rootsicles. The largely straight filaments seen in the porous rings of the white hard rootsicles may be indicative of the previous presence of Leptothrix spp., while the helical morphologies seen in the red hard rootsicles may be indicative of that of Gallionella spp. The manganese oxide minerals detected probably formed via microbial activity. This study reflects the important role of filamentous bacteria in rootsicle formation, independent of their mineralogy.

The uppermost metavolcanic layer of the Cambro-Ordovician Ollo de Sapo Formation, the largest accumulation of pre-Variscan igneous rocks in the Iberian Peninsula, have been dated in its northernmost part using U–Pb SHRIMP-RG zircon age techniques at 479.0 ± 4.7 Ma. The age obtained is the youngest age found so far in the metavolcanic facies of Ollo de Sapo Formation and represents the cessation of the rifting-related Cambro-Ordovician Ollo de Sapo volcanism at the northernmost tip of the Iberian Peninsula. Our results show that the Cambro-Ordovician volcanism in the NW of the Iberian Peninsula is not as short-lived as previously thought and confirm the correlation between the Cambro-Ordovician volcanic sequences that crop out in the Central Iberian Zone and the French Southern Armorican Massif. Finally, our study suggests that the cessation of the Cambro-Ordovician volcanism along the Ibero-Armorican Arc was synchronic or, less probably, slightly diachronic with younger ages towards the north (in present-day geographical coordinates).

The fabric of sedimentary rocks in lacustrine archives usually contains long and continuous proxy records of biological, chemical and physical parameters that can be used to study past environmental and climatic variability. Here we propose an innovative approach to sedimentary facies analysis based on a coupled geomicrobiological and sedimentological study using high-resolution microscopic techniques in combination with mineralogical analyses. We test the applicability of this approach on Lake Son Kul, a high alpine lake in central Tien Shan (Kyrgyzstan) by looking at the mineral fabric and microbial communities observed down to the nanoscale. The characterization of microbe–mineral interactions allows the origin of four carbonate minerals (e.g. aragonite, dolomite, Mg-calcite, calcite) to be determined as primary or diagenetic phases in Lake Son Kul. Aragonite was mainly of primary origin and is driven by biological activity in the epilimnion, whereas diagenetic minerals such as Mg-calcite, calcite, dolomite and pyrite were triggered by bacterial sulphate reduction and possibly by methanotrophic archaea. A new morphotype of aragonite (i.e. spherulite-like precursor) occurs in Unit IV (c. 7100–5000 cal. BP) associated with microbial mat structures. The latter enhanced the preservation of viral relics, which have not yet been reported in Holocene lacustrine sediments. This study advocates that microbe–mineral interactions screened down to the nanoscale (e.g. virus-like particles) can be used successfully for a comprehensive description of the fabric of laminated lake sediments. In this sense, they complement traditional facies sedimentology tools and offer valuable new insights into: (1) the study of microbial and viral biosignatures in Quaternary sediments; and (2) palaeoenvironmental reconstructions.

A new genus and new species of primitive eucryptodiran turtle, Phunoichelys thirakhupti gen. et sp. nov., is described on the basis of shell remains from the lower part of the Phu Kradung Formation, at Phu Noi locality, Kalasin Province, NE Thailand. It is assigned to Xinjiangchelyidae on the basis of the marginals covering the lateral end of the costals and the anal scutes invading the hypoplastra. The new taxon is further characterized by a low and rounded carapace without a cervical notch; the whole carapace and plastron covered with a clear ornamentation consisting of tiny irregular vermiculated furrows; a complete neural series that reaches the suprapygal; a very wide and short cervical scute; relatively wide vertebral scutes; and a long first thoracic rib that extends along the full width of the first costal. The sutured plastron/carapace connection and the marginals covering the lateral end of the second to seventh costals suggest that the turtles from Phu Noi may be related to some primitive xinjiangchelyids from the Sichuan Basin. The discovery of a xinjiangchelyid turtle in the lower part of the Phu Kradung Formation supports a Late Jurassic age for that part of the formation.

Andros is a key island for understanding both the timing of high-pressure–low-temperature (HP-LT) metamorphism and the dynamics of crustal-scale detachment systems exhuming high-grade units in the Cyclades (Greece). Using phengite 40Ar–39Ar geochronology coupled with thermobarometry, as well as data from literature, we constrain the pressure–temperature–time (P-T-t) paths of the Makrotantalon and Attic–Cycladic Blueschist units on Andros. Peak conditions of the HP-LT episode in the Makrotantalon unit are 550°C and 18.5 kbar, dated at 116 Ma. We correlate this episode with Early Cretaceous blueschist facies metamorphism recognized in the Pelagonian zone of continental Greece. This is a new argument favouring a Pelagonian origin for the Makrotantalon unit. In the Attic–Cycladic Blueschist unit, the P-T-t path is characterized by: (1) exhumation after peak conditions in HP-LT conditions between 55 and 35 Ma; (2) isobaric heating at 7 kbar until 30 Ma; and (3) isothermal decompression until 21 Ma. This thermal evolution and timing are similar to those of the neighbouring Tinos Island, emphasizing major thermal re-equilibration at the transition between stable and retreating subduction. Modifications of the crustal thermal state played a major role in the evolution of the North Cycladic Detachment System, below which Andros HP-LT units were exhumed.

The planktonic foraminifera assemblage across the Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage defined at Mont Risou (Haute-Alpes in France) is here restudied to clarify the identification and stratigraphic distribution of Thalmanninella globotruncanoides ( = Rotalipora globotruncanoides Sigal, 1948) and Pseudothalmanninella tehamaensis ( = Rotalipora tehamaensis Marianos & Zingula, 1966) whose appearance levels are primary and secondary criteria for placing the Albian/Cenomanian boundary. Since the ratification of the GSSP in 2002, the identification of the foraminifera index species across the Albian/Cenomanian boundary has been reported to be sometimes difficult either because of their rarity or uncertainty in the taxonomic identifications. We discuss the taxonomic status of Thalmanninella brotzeni Sigal 1948, a species regarded for a long time to be a junior synonym of Th. globotruncanoides, through images of Sigal's type materials deposited at the Musée National d’Histoire Naturelle (Paris), and elucidate the taxonomically important characters that enable unequivocal identification of Th. brotzeni, Th. globotruncanoides and Ps. tehamaensis. Planktonic foraminifera marker species from Mont Risou are compared with well-preserved specimens from Blake Nose Plateau (ODP 171B, North Western Atlantic Ocean) to verify the reliability and stratigraphic distribution of these marker taxa outside the Mediterranean Tethyan area.

Results from a high-resolution study of δ13Ccarb, δ18Ocarb, δ34SCAS, δ34SCRS and elemental concentrations (Ca, Fe, Mg, Mn and Sr) in the Furongian Kyrshabakty section, southern Kazakhstan, are reported here. The investigated interval covers the Drumian to Jiangshanian stages of the Cambrian Period, respectively the regional Ptychagnostus atavus to Ivshinagnostus ivshini-Irvingella major trilobite zones. δ13Ccarb data include the Steptoean positive carbon isotope excursion (SPICE) with a local peak value of +5‰. The onset of SPICE corresponds to the Kormagnostus simplex – Glyptagnostus stolidotus zones and pre-dates the base of the Paibian Stage/Furongian Series. δ34SCAS data already increase during the Lejopyge armata biozone culminating in three positive excursions prior and after the SPICE maximum. Differences in onset, peak values and shape of the δ13Ccarb and/or δ34SCAS excursions at Kyrshabakty, but also in almost all sections characterized by the SPICE, are pointing towards Furongian seawater that was low in sulphate concentration and heterogeneous in its carbonate carbon and sulphate sulphur isotopic composition. The occurrence of benthic faunal elements in almost all SPICE-related sections strongly supports oxygenated conditions at the seafloor, therefore excluding widespread anoxia or euxinia. Regional anoxic conditions are most probable. A positive δ18Ocarb excursion parallel to the SPICE could probably be explained by a decline in seawater pH associated with a sea-level rise. Again, no euxinic conditions would be mandatory for explaining the SPICE event.

The ‘Purana’ basins were long considered Neoproterozoic basins until geochronology and palaeomagnestism showed parts of the Chattisgarth and lower Vindhyan basins to be a billion years older. Historically, the successions in the Chattisgarth Basin are correlated with similar successions in the Pranhita–Godavari and Indravati basins. In India, differentiating between early–late Mesoproterozoic rocks and those spanning the Mesoproterozoic–Neoproterozoic boundary is possible by comparing magnetic declination and inclination; palaeomagnetism is therefore a very useful correlation tool. Here we report a new Stenian-aged palaeopole (50.1°N, 67.4°E, radius of cone of 95% confidence A95 = 12.4°, precision K = 30.1) from carbonate and shale successions of the Pranhita–Godavari and Chattisgarth basins (the C+/– magnetization). In addition, an early diagenetic remagnetization (component A) was identified. No primary or early diagenetic magnetizations were identified from the Indravati Basin. Here, as well as in stratigraphically higher parts of the other two successions, widespread younger magnetic overprints were identified (B+ and B– magnetic components). Our C+/– palaeopole is constrained by palaeomagnetic stability field tests, is different from known 1.4 Ga and 1.0 Ga Indian palaeopoles, but similar to a 1.19 Ga palaeopole. Penganga Group (Pranhita–Godavari Basin) deposition was probably initiated at around 1.2 Ga. A similar palaeomagnetic signature confirms its correlation with the Raipur Group (Chattisgarth Basin), of which the deposition spans most of the Stenian period (c. 1.2–1.0 Ga). Sedimentation in these groups began significantly later than c. 1.4 and c. 1.6 Ga, as suggested by ages reported from below the Raipur and Penganga groups, respectively.

The stratigraphic succession exposed in the Karaburun area (southern Black Sea coast, NW Turkey) records multiple changes in depositional and tectonic settings during Cenozoic times. It starts with the Middle–Upper Eocene Soğucak Formation of reef limestone that across a normal fault, omitting the lower part of the Lower Oligocene Ceylan Formation (deep-marine shale unit), abuts the upper part of the Ceylan Formation that is made up of two facies: (1) shallow-marine sandstone and (2) shallow-marine limestone units containing horizons of submarine slumps. Both facies are unconformably overlain by the fluvial Upper Miocene Çukurçeşme Formation. The tectonic record includes: (1) latest Eocene – Early Oligocene NE–SW extension, (2) Early Oligocene NE–SW shortening and (3) Late Miocene NW–NE extension. The earliest normal faults cutting the Soğucak and the lower part of the Ceylan formations are associated with clastic dykes injected into the deep-marine shale. These structures suggest a disruption of the Eocene carbonate platform and are also known in the neighbouring Thrace Basin. The following NE–SW shortening created the NE-vergent Karaburun Thrust that is synchronous with the shallowing and inversion of the Ceylan Basin. Rotation of the stress field is recorded by changes in clastic dyke orientation and their deformation. Compression caused multiple westerly directed submarines slides from uplifts in easterly located regions. This event is not recorded in the Thrace Basin. Finally, the Miocene tectonic activity formed NW- and NE-striking normal faults. The outlined tectonic history includes Early Oligocene extensional and compressional episodes recorded in the southern margin of the Black Sea that had hitherto not been known.

The Weeks Formation preserves a diverse, yet largely undescribed, exceptionally preserved fauna of late Guzhangian age. Here I describe Notchia weugi gen. et sp. nov., a new arthropod characterized by a short cephalon, a trunk with 12 tergites and weakly differentiated into two morphological regions, and a spine-bearing rectangular telson. This combination of characters is incompatible with its assignment to any known groups. The new taxon also adds to examples of convergent evolution of ramified digestive glands in arthropods, possibly as an adaptation to infrequent feeding.

Bradoriids are small bivalved arthropods that had global distribution for about 20 million years beginning at Cambrian Epoch 2 (c. 521 Ma). The majority of bradoriids are considered to be benthic, favouring oxygenated waters, as suggested by their anatomy, lithofacies distribution, faunal associates and provinciality. Most bradoriids were extinct by the end of the Drumian Age (middle of Cambrian Epoch 3). The post-Drumian is characterized by widespread dysoxic shelf lithofacies in southern Britain and Scandinavia and by the abundance of phosphatocopid arthropods. This interval is also associated with two bradoriid species with wide intercontinental distribution: Anabarochilina primordialis, which had a geographical range from the palaeo-tropics to high southern palaeo-latitude, and Anabarochilina australis, which extended through the palaeo-tropics from Laurentia to Gondwana. The wide environmental and geographical range of these species, coupled with a carapace anatomy that suggests an active lifestyle, is used to infer a zooplanktonic lifestyle. A possible driver of this widespread Cambrian bradoriid zooplankton was sea-level rise coupled to the periodic spread of low oxygen conditions onto continental shelves, acting in tandem with anatomical pre-adaptations for swimming. Parallels exist with the myodocope ostracod colonization of the water column during Silurian time, which may also have been influenced by extrinsic environmental controls acting on anatomical pre-adaptations for swimming. Similar biological and environmental mechanisms may have facilitated arthropod zooplankton colonizations across Phanerozoic time.

Paired isotope dilution – thermal ionization mass spectrometry (ID-TIMS) and secondary ion mass spectrometry (SIMS) zircon U–Pb data elucidate geochronological relations in the historically important Knaben molybdenum mining district, Sveconorwegian Orogen, south Norway. This polyphase district provided c. 8.5 Mt of ore with a grade of 0.2%. It consists of mineralized quartz veins, silica-rich gneiss, pegmatites and aplites associated with a heterogeneous, locally sulphide-bearing, amphibolites facies gneiss called Knaben Gneiss, and hosted in a regional-scale monotonous, commonly weakly foliated, granitic gneiss. An augen gneiss at the Knaben I deposit yields a 1257±6 Ma magmatic zircon age, dating the pre-Sveconorwegian protolith of the Knaben Gneiss. Mineralized and non-mineralized granitic gneiss samples at the Knaben II and Kvina deposits contain some 1488–1164 Ma inherited zircon and yield consistent intrusion ages of 1032±4, 1034±6 and 1036±6 Ma. This age links magmatism in the district to the regional 1050–1020 Ma Sirdal I-type granite suite, corresponding to voluminous crustal melting during the Sveconorwegian orogeny. A high-U, low-Th/U zircon rim is present in all samples. It defines several age clusters between 1039±6 and 1009±7 Ma, peaking at c. 1016 Ma and overlapping with a monazite age of 1013±5 Ma. The rim records protracted hydrothermal activity, which started during the main magmatic event and outlasted it. This process was coeval with regional high-grade Sveconorwegian metamorphism. Molybdenum deposition probably started during this event when silica-rich mineralizing fluids or hydrous magmas were released from granite magma batches. An analogy between the Knaben district and shallow, short-lived porphyry Mo deposits is inappropriate.

The Central Asian Orogenic Belt is an accretionary orogen with many distinct terranes including the Chinese Central Tianshan, whose Precambrian tectonic affinity is not yet clearly known. We present Precambrian age spectra of inherited/xenocrystic zircons from magmatic rocks in the Chinese Central Tianshan, collected from published papers. The age patterns are dominated by zircons with ages ranging from 3261 to 541 Ma. These spectra provide robust clues regarding the Precambrian affinity of the Chinese Central Tianshan. The age spectra record two major tectonothermal events, represented by salient age peaks of c. 950 and 900 Ma within the ‘Grenville Orogeny’ period, and age peaks at c. 750 and 630 Ma, synchronous with magmatic events corresponding to Rodinia break-up. These results are consistent with the hypothesis that the Chinese Central Tianshan was part of the Tarim craton during Precambrian time as well as documenting its incorporation into, and separation from the Rodinia landmass.