In the Earth’s lithosphere, fungi are of fundamental importance as decomposer organisms, animal and plant pathogens and symbionts (e.g. lichens and mycorrhizas), being ubiquitous in sub-aerial and subsoil environments. The ability of fungi to interact with minerals, metals, metalloids and organic compounds through biomechanical and biochemical processes, makes them ideally suited as biological weathering agents of rock and building stone. They also play a fundamental role in biogeochemical cycling of nutrients, (e.g. C, N, P and S) and metals (e.g. Na, Mg, Ca, Mn, Fe, Cu, Zn, Co and Ni) essential for the growth of living organisms in the biosphere. In addition they play an integral role in the mobilization and immobilization of non-essential metals (e.g. Cs, Al, Cd, Hg and Pb). Most studies on mineral-microbe interactions and microbial involvement in geological processes have concentrated on bacteria and archaea (Prokaryota): fungi (Eukaryota) have, to a certain extent, been neglected. This article addresses the role of fungi in geomicrobiological processes, emphasizing their deteriorative potential on rock, building stone and mineral surfaces and involvement in the formation of secondary mycogenic minerals. Such roles of fungi are also of importance for the global carbon reservoir and have potential biotechnological applications, e.g. in the bioremediation of xenobiotic-, metal- and/or radionuclide-contaminated soils and wastes, and metal/radionuclide recovery.

The Harsin–Sahneh serpentinized peridotites are widely exposed along the Zagros suture zone in the western region of Iran and are considered to represent remnants of Neo-Tethys oceanic lithosphere at the junction of the Arabian and Iran Plates. These rocks are characterized by low contents of SiO2 (38.8–43.5 wt%), Al2O3 (0.1–3.8 wt%), CaO (0.2–8.2 wt%) and TiO2 (< 1 wt%) and high MgO contents (31.1–46.0 wt%). Their enrichments of large ion lithophile elements and light rare earth elements, with high 87Sr/86Sr(i) values (0.7036–0.7109) and relatively high variations in their εNd(t) (–7.5 to +7.8) values, indicate that the Harsin–Sahneh peridotites were metasomatized by flux released from the oceanic subducting slab in an active margin. The chemical compositions and isotopic ratios of these rocks suggest that they were formed as residue of mid-oceanic ridge basalt in the lithosphere that was then subsequently re-melted and metasomatized in a supra-subduction zone system. The occurrence of both mid-oceanic ridge and supra-subduction zone-type peridotites suggests that the heterogeneity of the upper mantle may have occurred due to the different ratios of partial melting and melt–rock reaction processes in different tectonic settings within the Neo-Tethys realm. The Harsin–Sahneh peridotites provide a good explanation of multistage melt extraction as well as melt–rock and metasomatic reactions in the mantle sequence of the Zagros ophiolite complex.

Gem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.

The Wilkes Subglacial Basin (WSB), the largest subglacial basin in East Antarctica, is a topographic depression of continental proportions that lies beneath the East Antarctic continental ice sheet. Discovered by the US Victoria Land Traverse 1959–60, the origin of the WSB and the influence of palaeoclimate on its overlying continental ice sheet have remained uncertain since the time of its discovery. Most explanations of origin favour lithospheric structural control as a function of tectonic activity. Lithospheric flexure due to thermally or isostatically induced uplift of the Transantarctic Mountains was suggested in the 1980s. Lithospheric extension and rifting was proposed in the 1990s. More recent investigations have revealed the presence of fold and thrust belts, casting doubt on flexural and extensional hypotheses as the primary mechanisms, suggesting instead a compressional scenario. While remaining inconclusive, these tectonic mechanisms in one form or another, or in combination, are now believed to have provided the structural control for the origin of the WSB. Not yet comprehensively examined, however, is the role of non-tectonic processes in the formation of the WSB, as they may have influenced the size, configuration, subglacial sedimentation and subglacial topography of the WSB. In this paper we review the tectonic hypotheses and examine post-tectonic climate change along with glacial and marine processes as potentially significant factors in the present condition and configuration of the WSB. In the process, we find that there are a number of features not included in previous investigations that may have been major factors in the modification of the subglacial basin.

Dyke swarms traverse Neoproterozoic rocks in the Hawashiya region in the extreme northern part of the Eastern Desert of Egypt. They are a suite of basaltic andesite and andesite mafic dykes, and dacitic and rhyolitic felsic dykes. The mafic dyke suite is more abundant in the younger granites (577 ± 6 Ma) than in the older granitoids (614 Ma), in which the felsic dykes are the most common. The dyke swarms trend predominantly NE–SW, and the felsic dyke suite is older than the mafic dyke suite. Both dyke suites are calc-alkaline (alkaline dykes are rare) and are relatively poor in TiO2 and Nb but enriched in the incompatible elements and HFSE. The felsic dyke suite is enriched in REE and is strongly LREE fractionated relative to the mafic dyke suite. Although the Hawashiya dykes were emplaced at the end of the Neoproterozoic era in an extensional tectonic setting, they have geochemical characteristics that are consistent with a subduction-related regime. These chemical signatures were inherited from the lithospheric rocks that produced their host Hawashiya granitoids. The felsic dyke suite magma may be derived from crustal rocks (essential source component) by partial melting. The mafic dyke suite magma was generated from a lithospheric mantle and has undergone fractional crystallization of plagioclase, amphibole, clinopyroxene and magnetite, as documented by major and trace elements fractionation modelling.

We have analysed 129 stratigraphic sections from the Timan–Pechora basin, from its adjacent continental shelf and from the South Barents Sea basin, in order to determine whether existing models of extensional sedimentary basin formation can be applied to these intracratonic basins or whether new mechanisms of formation need to be invoked. The subsidence history of each section has been calculated using standard backstripping techniques. An inverse model, based on finite-duration lithospheric stretching, has then been used to calculate the distribution of strain rate as a function of time required to fit each subsidence profile. Results demonstrate an excellent fit between theory and observation. By combining our analysis with independent field-based and geophysical observations, we show that the Timan–Pechora basin underwent at least four phases of mild lithospheric stretching during the Phanerozoic (β<1.2). These phases occurred in Ordovician, Late Ordovician–Silurian, Middle–Late Devonian and Permian–Early Triassic times. Growth on normal faults, episodes of volcanic activity and regional considerations provide corroborative support for the existence of all four phases. Although less well constrained, subsidence data from the South Barents Sea basin are consistent with a similar Early–Middle Palaeozoic history. The main difference is that Permian–Early Triassic extension is substantially greater than that seen onshore. This similarity implies structural connectivity throughout their respective evolutions. Finally, subsidence modelling demonstrates that rapid foreland basin formation, associated with the Uralian Orogeny, was initiated in Permo-Triassic times and is confined to the eastern margin of the Timan–Pechora basin. Coeval foreland subsidence does not occur on the eastern margin of the South Barents Sea basin, supporting the allochthonous nature of Novaya Zemlya. The most puzzling result is the existence of simultaneous lithospheric extension and foreland loading in Permian–Early Triassic times. This juxtaposition is most clearly seen within the Timan–Pechora basin itself and suggests that convective drawdown may play a role in foreland basin formation.

Many late Mesozoic lamprophyre dykes occur in the Taihang Mountains (north China). These lamprophyres are rich in large ion lithophile elements (e.g. Rb, Sr, Ba and K) and light REE, and have highly differentiated REE patterns. They show large but regular variations in chemical and Nd–Sr isotopic compositions. All these suggest that the lamprophyres were produced from differentiation of a parental magma, coupled with contamination by lower crust. The parental magma was derived from melting of a long-term enriched sub-continental lithospheric mantle source as is indicated by the highly enriched isotopic signatures of the lamprophyres. Mantle enrichment in the area was probably produced by interaction of volatile-rich melts released from the asthenosphere with the above lithosphere in middle Proterozoic times.

Ultramafic xenolith lithologies representative of the mantle beneath the Midland Valley of Scotland comprise magnesian peridotite (predominantly spinel lherzolite) and cumulate wehrlites and clinopyroxenites. The lherzolites are typical of the worldwide type I (Cr-diopside) xenolith suite; their textures and mineral chemistry record a complex thermal and deformational history. The petrographical and mineralogical features of the wehrlite-clinopyroxenite suite can be interpreted within the context of a sequence of cpx + ol ± sp cumulates that have undergone a protracted period of subsoli dus re-equilibration. Mineral compositions are similar to those of type II (Al-augite) ultramafic xenolith suites.

Although xenolith populations imply widespread lower crustal heterogeneity, meta-igneous basic granulites form a major component of this region beneath the Midland Valley. They are principally composed of pi + cpx + mt ± opx ± ap; a modal continuum exists from clinopyroxenite to anorthosite, skewed towards plagioclase-rich lithologies. Garnet is rare. Locally, evidence indicates re-equilibration from garnet granulite precursors. Rock densities range from c. 2·8 to c. 3·2 gm . cm−3, implying P-wave velocities in the range 6·5–7·5 km . s−1 consistent with the known seismic properties of the lower crustal layer beneath the Midland Valley. Phase relations are also consistent with equilibration of primary assemblages at depths of 20–35 km. Retrograde reactions indicate that portions of the crust may have had a complex pressure-temperature-time evolution. Major element compositions of the granulites are broadly basaltic, ranging from ne to hy normative with the mean corresponding to alkali olivine basalt. They are distinct, chemically, from basic granulites of the Lewisian complex of NW Scotland.