Abstract A collection of large data sets from different orogenic belts was compiled for a correlation between organic matter (OM) versus clay mineral (CM) indices calibrated with the vitrinite reflectance, (VR) vs Kübler-Indices (KI) method. Data selection was based on a normal geothermal gradient (25 to 35 °C/km) as determined in previous studies, e.g. by maturity modelling and clay mineral reaction progress calculations. In the Lower Austroalpine (Eastern Switzerland, European Alps) a 20 myr lasting metamorphic overprint caused an OM–CM thermal equilibrium among the indices used. The observed correlation enables to determine gradual changes in metamorphic factors such as pressure, temperature and time causing sensitive shifts of the gradient slope in the range of normal gradients. For New Caledonia, an identical correlation has been determined. Prior to re-equilibration of the VR/KI indices, sediments in New Caledonia of diagenetic to incipient metamorphic grade underwent a high-pressure subduction event. VR/KI indices are in or close to equilibrium, while slight differences in OM vs CM indices allow for a better understanding of polyphase conditions, especially with respect to pressure. Temperature estimations are identical despite of their poly-phase metamorphic history, which was mainly controlled by the last orogenic thermal event lasting > 5 to < 10 myr. In the eastern Helvetic Alps and Northern Calcareous Alps similar correlations were found with slightly different slopes. Comparison between different regions is possible when using KI standardization and same data discrimination. In both parts of the Alps a complex thermal history of short durations (< 5.0 myr for the Northern Calcareous Alps to 10 myr for the Helvetic Alps) caused similar VR/KI trends, but disequilibrium is suggested by weaker regression parameters. The following correlation is calculated for a moderate geotherm (55 to 74 mWm2, mean = 61 mWm2) and normal temperature gradient conditions (25 to 35 °Ckm−1): KI = 1.134e−0.305VR, (R2 = 0.880, n = 462) with VR given as %Rmax, KI as Δ°2θ (limited to values between 0.2 to 1.0 Δ°2θ). With increasing depth (z) a VR gradient of 1.4 ± 0.2%Rmaxkm−1 is determined and a KI gradient of 0.09 ± 0.002 Δ°2θ km−1 is observed. The study illustrates that a normal geotherm can be described by VR/KI correlation, even if different heating episodes may occur. For the detection of a poly-phase or plurifacial thermal history, several indices of clay minerals and organic matter with very different kinetics should be used, as e.g. demonstrated by strong differences in smectite content at equal VR/KI values versus structural depth. A specific interest is given to the correlation of vitrinite like solid bitumen reflectance as an alternative method to VR, the persistent preservation of liptinite macerals and the stability range of clay minerals and sub-greenschist facies critical minerals compared with VR/KI data. Until now, despite the Alps in this study, systematic liptinite maceral studies have not been published in other orogenic settings.

There are numerous contradictory models concerning the reconstruction of the Palaeozoic palaeogeography of the Central European Variscides. A key region is the suture zone, the Northern Phyllite Zone, between the southern continent Gondwana including Armorica and the northern continent Laurussia including the continents Avalonia and Baltica. The Northern Phyllite Zone hosts the Silurian volcanic arc of the Rheic Ocean. This volcanic arc has been interpreted as an island arc that was accreted together with the northern part of Armorica against Laurussia in the Lower Devonian. Our results of U–Pb age dating of detrital and magmatic zircon grains give constraints on the provenance of metasedimentary rocks and the extrusion age of the volcanic rocks of the Rhenish Massif and adjacent Northern Phyllite Zone of the Central European Variscides. These help to validate the geodynamic models. U–Pb data of zircon grains indicate that the Silurian arc of the Northern Phyllite Zone is a continental arc. It received detritus from the East Avalonian basement that points to a position at the southern plate boundary of Laurussia. This Silurian arc cannot be correlated with the Silurian to Devonian magmatic arc of the Mid-German Crystalline Zone, because the host rocks of the Silurian plutons received detritus from Armorica or Baltica. The volcanic rocks of the Northern Phyllite Zone are dated with the U–Pb zircon method from 442 to 431 Ma. During the latest Silurian (Pridolian), the volcanism vanished and Devonian shelf sediments accumulated on top of the continental arc. At the same time, numerous Devonian plutons intruded into the magmatic arc of the Mid-German Crystalline Zone. Palaeogeographic reconstructions suggest that the Brabant High, the eastern most part of Avalonia, is the most obvious source area for the Devonian sediments of the Rhenohercynian Basin. The U–Pb data of the detrital zircon grains of the Rhenohercynian Basin do not fit the Avalonian age spectrum of the Brabant High, which is characterized by a high proportion of Ediacaran zircon grains. The detritus of the Rhenohercynian Basin is dominated by Mesoproterozoic zircon grains. Ediacaran zircon grains are absent. This limits the possible source area of the Rhenohercynian Basin to West Baltica and to the early Palaeozoic sediments of South Norway, Sweden and Denmark. Our data, along with published results, indicate that there was no collision between the northern part of Armorica and Laurussia during the Lower Devonian in the German part of the Rhenohercynian Zone.

Concerning their provenance and age, the nappes of the Uppermost Unit of Crete are counted among the most enigmatic constituents of the Eastern Mediterranean. U–Pb dating of zircons separated from metavolcanic rocks of the Preveli nappe exposed near Lefkogia yielded Triassic emplacement ages at 237.3 ± 1.8, 241.5 ± 1.2 and 242.1 ± 1.2 Ma. U–Pb grandite dating of subvolcanic barren skarn of this area yielded the same age at 239.3 ± 2.3 Ma. The skarn is dominated by hydrous phases (ferri-actinolite, hydro-grandite, epidote), which developed at T = 400–450 °C in a marine extensional setting due to fluid-assisted metasomatic reactions between chert-bearing limestone and igneous veins. The fluids and their composition played a significant role for the complex oscillatory zoning of the grandite, which largely results from antithetic variations in Fe3+ and Al. The new U–Pb ages suggest that—similar to deep-seated skarns—U–Pb grandite dating of shallow-seated skarns allows dating the complementary record of hydrothermal activity related to the causative melt. Although the development of skarn is regarded as a short-lived process on geological time scales, the skarn formation of the Preveli nappe lasted for more than 20 m.y. as is indicated by additional U–Pb grandite ages obtained from skarn exposed near Kerames (232.7 ± 1.5 Ma) and near Gerakari (218.0 ± 3.5 Ma). The new ages and published data suggest the Uppermost Unit of Crete to be derived either from the peri-Rhodope domain of the Internal Hellenides or from the Pontides of northern Turkey.

Abstract We present kinematic, radiometric, geochemical and PT data, which help to constrain the tectonometamorphic evolution of the Tripolitza Unit (TPU). The age of both the metamorphic peak (P = 0.4 ±0.2 GPa, T = ca. 310 °C) and top-to-the WNW mylonitic thrusting, attributed to the emplacement of the hanging Pindos nappe, has been constrained at 19 ±2.5 Ma using Rb-Sr on synkinematic white mica of a basal mylonite of NW Crete. This early tectonic event is also documented by the oldest generation of veins, which cut through less metamorphic (T = 240 ±15 °C) late Bartonian/Priabonian Nummulite limestone exposed as olistolith in TPU flysch of central Crete. Calcite of these veins yielded a similar U-Pb age at 20 ±6 Ma. U-Pb dating of matrix calcite, on the other hand, reflect the time of sedimentation (38.4 ±5.7 Ma and 37.6 ±1.2 Ma), which is in line with the faunal content of the black limestone. Geochemical data and U-Pb calcite ages of fibres of the Nummulite test (32.3 ±3.1 Ma and 34.6 ±0.9 Ma) suggest unexpected pseudomorphic fibre replacement during late Priabonian/early Rupelian diagenesis. Additional calcite veins, which developed at ca. 10–11 and 7 – 9 Ma (U-Pb on calcite), are attributed to top-to-the S thrusting and subsequent extension, respectively. The resulting anticlockwise rotation of the shortening direction within the TPU from WNW-ESE at ca. 20 Ma to N-S at ca. 10 Ma has significant implications for the geodynamic evolution of the External Hellenides.

Knowledge about the initial tectonic and depositional dynamics, as well as the influence of early rifting on climate and environmental evolution remains speculative to a large extent, because sediments are usually deeply buried. Within the East African Rift System, inversion tectonics uplifted a few of these successions to the surface hence presenting rare windows into the pre-rift depositional history. One such example, an exceptional 700m long and up to 60m high fresh road cut provided the opportunity to study in detail initial rift successions of the southern Albertine Rift (Western Uganda). This focusses on the basal and poorly known Middle to Late Miocene in order to unravel the climatic, environmental, hydrological and tectonic evolution of the initial Albertine Rift. A large and robust multi-proxy dataset was gathered comprising 169 m of stratigraphic thickness, which spans from 14.5 to 4.9 Ma according to a revised lithostratigraphic model. Fieldwork comprised logging of the sedimentary record, spectral gamma ray, magnetic susceptibility and 2D wall mapping with photomosaics. Additionally, the sections were sampled for bulk mineral and clay mineral analysis. The succession exposes a suite of lithofacies and architectural elements detailing the evolution of a fluvio-lacustrine system. Five depositional environments were identified which show an overall back-stepping trend from an alluvial plain to a delta plain and finally palustrine/shallow lacustrine conditions. Mesoscale base-level cycles, preservation potential of architectural elements, and stacking pattern exhibit limited accommodation space. However, it increases over time. This overall trend indicates increasing tectonic subsidence, which can be explained by flexural downwarp within the pre-rift phase and in the upper part grading into fault-controlled crustal extension of the syn-rift phase, which more and more disrupted a large-scale river system. From the Middle Miocene up to the early Pliocene, this study revealed that palaeoclimate trends become marked by increasing and more fluctuating Th concentrations, loss of feldspar, intercalated lenses of hydroxosulphate minerals, and a shift from smectite-dominated to kaolinite-dominated clays. These signals are all interpreted as detrital except for the hydroxosulphates, and they mirror the increasing intensity of chemical weathering and stripping of soils in the catchment. A trend towards increasing humidity is supported by an increase in lacustrine sediment facies and a lake-level rise. Nevertheless, intercalation of hydroxosulphate, ferricretes and pedogenised horizons prove ongoing seasonality and dry intervals. Finally, based on a revised stratigraphic model a sequence stratigraphic correlation of the outcrop's depositional cycles with basinscale cycles is presented. According to these cycles, transition from the pre-rift to the syn-rift stage is marked by an unconformity and a tectonic pulse in the latest Miocene. However, the response of fluvial supply, the depositional system as well as climate conditions are less punctuated and characterised by gradual trends and temporal delays. The long pre-rift phase (Ca 10 Myr) and the gradual transition to the syn-rift phase is in accordance with the active rifting model, which is based on thermal thinning of the lithosphere by asthenospheric upwelling.

The sampling of fluvial sediment is subject to many sources of uncertainty, for example, time and location, and the number of samples collected. It is nevertheless commonly assumed that a sample taken at one time and location provides a somewhat averaged compositional signal. Any spatial or temporal variability of this signal is often neglected. This study investigates how the composition of bed load sand changes over an observation period of 1 year in four river basins with differing bedrock geology in southwestern Germany. Up to 12 bulk sediment samples were taken at the same locations using the same approach and analyzed for their granulometry and geochemistry. The results indicate that (a) different grain sizes yield different compositions due to source rock composition and hydraulic sorting effects, (b) bulk sediment composition changes temporally due to changing grain‐size distribution, and (c) compared to the bulk sample, the composition of narrow grain sizes is temporally more stable but nevertheless has an average variability of 15%. Because heavy mineral‐bound elements such as Zr have the highest variability, we relate a major component of compositional variability to temporally varying heavy mineral concentrations in response to hydrodynamic processes. Mixing modeling demonstrates that the fluvial sand faithfully reflects its catchment geology and that the sediment sources do not change substantially during the observation period, even during a flooding event. We conclude (a) that the causes for compositional variability may be disentangled using chemical and granulometric time series data and (b) that narrow grain sizes yield representative source rock contributions.

The modern precipitation balance in southeastern (SE) Brazil is regulated by the South American summer Monsoon and threatened by global climate change. On glacial-interglacial timescales, monsoon intensity was strongly controlled by precession-forced changes in insolation. To date, relatively little is known about the spatiotemporal distribution of tropical precipitation in SE Brazil and the resulting variability of fluvial discharge on glacial-interglacial timescales. Here, we present X-ray diffraction-derived mineralogical data for the 150–70 ka period (marine isotope stage (MIS) 6 to MIS 5) from the Doce River basin. This area was sensitive to changes in monsoonal precipitation intensity due to its proximity to the South Atlantic Convergence Zone. The data, obtained from a marine sediment core (M125-55–7) close to the Doce river mouth (20°S), show pronounced changes in the Doce River suspension load’s mineralogical composition on glacial-interglacial and precessional timescales. While the ratio of silicates to carbonates displays precession-paced changes, the mineralogical composition of the carbonate-free fraction discriminates between two assemblages which strongly vary between glacial and interglacial time scales, with precession-forced variability only visible in MIS 5. The first assemblage, dominated by high contents of kaolinite and gibbsite, indicates intensified lowland erosion of mature tropical soils. The second one, characterized by higher contents of the well-ordered illite, quartz and albite, points to intensified erosion of immature soils in the upper Doce Basin. High kaolinite contents in the silicate fraction prevailed in late MIS 6 and indicate pronounced lowland soil erosion along a steepened topographic gradient. The illite-rich mineral assemblage was more abundant in MIS 5, particularly during times of high austral summer insolation, indicating strong monsoonal rainfall and intense physical erosion in the upper catchment. When the summer monsoon weakened in times of lower insolation, the mineral assemblage was dominated by kaolinite again, indicative of lower precipitation and runoff in the upper catchment and dominant lowland erosion.

A nonconformity refers to a hiatal surface located between metamorphic or igneous rocks and overlying sedimentary or volcanic rocks. These surfaces are key features with respect to understanding the relations among climate, lithosphere and tectonic movements during ancient times. In this study, the petrological, mineralogical and geochemical characteristics of Variscan basement rock as well as its overlying Permian volcano-sedimentary succession from a drill core in the Sprendlinger Horst, Germany, are analyzed by means of polarization microscopy, and environmental scanning electron microscope, X-Ray diffraction, X-ray fluorescence and inductively coupled plasma mass spectrometry analyses. In the gabbroic diorite of the basement, the intensity of micro- and macro-fractures increases towards the top, indicating an intense physical weathering. The overlying Permian volcanic rock is a basaltic andesite that shows less intense physical weathering compared with the gabbroic diorite. In both segments, secondary minerals are dominated by illite and a mixed-layer phase of illite and smectite (I–S). The corrected chemical index of alteration (CIA) and the plagioclase index of alteration (PIA) indicate an intermediate to unweathered degree in the gabbroic diorite and an extreme to unweathered degree in the basaltic andesite. The τ values for both basaltic andesite and gabbroic diorite indicate an abnormal enrichment of K, Rb and Cs that cannot be observed in the overlying Permian sedimentary rocks. Accompanying minerals such as adularia suggest subsequent overprint by (K-rich) fluids during burial diagenesis which promoted the conversion from smectite to illite. The overall order of element depletion in both basaltic andesite and gabbroic diorite during the weathering process is as follows: large-ion lithophile elements (LILEs) > rare earth elements (REEs) > high-field-strength elements (HFSEs). Concerning the REEs, heavy rare earth elements (HREEs) are less depleted than light rare earth elements (LREEs). Our study shows that features of supergene physical and chemical paleo-weathering are well conserved at the post-Variscan nonconformity despite hypogene alteration. Both can be distinguished by characteristic minerals and geochemical indices. Based on these results, a new workflow to eliminate distractions for paleoclimate evaluation and evolution is developed.

Hydrothermally altered rhyolite rocks in the Permian Donnersberg Formation of a geothermal borehole in the Northern Upper Rhine Graben (Germany) were investigated to find out answers for the low hydraulic conductivity of the rocks. The composition of clay minerals and the temperature of smectite–illite transformation were carried out using X-ray diffraction, X-ray fluorescence, transmission electron microscopy, Fourier transform infrared spectroscopy, and polarized-light microscopy analyses. Clay mineral (CM) composition includes illite/muscovite (1 M and 2 M 1 polytypes), illite–smectite interstratifications (IS-ml), smectite, and chlorite; and non-clay minerals such as quartz, feldspars, epidote, calcite, dolomite, and hematite were detected. The 2 M 1 -polytype mica might be the only primary sheet silicates from the parent rocks, while the others occur as authigenic neo-formed CMs under heat flow and geothermal gradient. The development of CMs indicates different mechanisms of illitization and smectitization. Based on the texture, morphology, structure/polytype, and chemistry of rocks and minerals, in particular CMs, the study grouped the CM formation into three transformation processes: smectitization during magma cooling and possible contact metamorphisms with decreasing and low temperature, smectite illitization controlled by burial diagenesis and hydrothermal alteration, and illite smectitization followed exhumation and Cenozoic subsidence with decreasing temperature. The rhyolites were altered to all of the orders IS-R0, IS-R1, and IS-R3 by the dissolution-precipitation and layer-to-layer mechanisms. The first one supported small xenomorphic plates and flakes of 1 M d , elongated particles of 1 M , and pseudo-hexagonal forms of 2 M 1 . The second one could lead to the platy particles of 1 M d and 2 M 1 polytypes. The dominant temperature range for the transformation in the area has been 140–170 °C– ~ 230 °C.

We present geochronological, thermobammetric and computertomographic data from a composite sill exposed in the Weschnitz pluton of the Variscan Odenwald. The wall rock consists of quartzmonzodiorite, which intruded at deep structural levels (P = ca. 0.50 GPa, ca. 18 km depth) in a continental arc setting. Zircons and titanites of the quartzmonzodiorite yielded similar U-Pb ages at 344.3 +/- 0.6 and 343.2 +/- 2.1 Ma, respectively, reflecting fast initial cooling (>= 76 degrees C/m.y.) until the solidus was attained at ca. 680 degrees C. Under these conditions, the quartzmonzodiorite was cut by a spessartite sill, which yielded a U-Pb titanite age at 342.0 +/- 1.0 Ma. The short period between wall rock and sill emplacement (<= 3.9 m.y.) suggests that both are genetically related. The quartzmonzodiorite situated adjacent to the spessartite sill is enriched in quartz and plagioclase and depleted in hornblende. As geothermobarometric data of these felsic parts yielded T = ca. 710 degrees C and P = 0.42 GPa (ca. 15 km depth), they are interpreted as contact melt, which invaded into shrinkage cracks of the cooling sill resulting in thin felsic veins. The migration of contact melt from the wall rock into the shrinkage cracks was suction-induced because of volume gain by contact melting in the wall rock and volume loss by cooling of the sill. The formation of such Sederholm-type composite veins seems to be very fast. Titanites of the felsic veins yielded a U-Pb age at 341.8 +/- 1.5 Ma, which is the same like that of the sill. Moreover, results of thermal modelling indicate a maximum period of 4 months between sill emplacement and the time when both the quartzmonzodiorite and the sill had attained the ambient temperature. The modelling further explains, why Sederholm-type veins, described from several places around the world, are restricted to deep crustal levels. We present geochronological, thermobammetric and computertomographic data from a composite sill exposed in the Weschnitz pluton of the Variscan Odenwald. The wall rock consists of quartzmonzodiorite, which intruded at deep structural levels (P = ca. 0.50 GPa, ca. 18 km depth) in a continental arc setting. Zircons and titanites of the quartzmonzodiorite yielded similar U-Pb ages at 344.3 +/- 0.6 and 343.2 +/- 2.1 Ma, respectively, reflecting fast initial cooling (>= 76 degrees C/m.y.) until the solidus was attained at ca. 680 degrees C. Under these conditions, the quartzmonzodiorite was cut by a spessartite sill, which yielded a U-Pb titanite age at 342.0 +/- 1.0 Ma. The short period between wall rock and sill emplacement (<= 3.9 m.y.) suggests that both are genetically related. The quartzmonzodiorite situated adjacent to the spessartite sill is enriched in quartz and plagioclase and depleted in hornblende. As geothermobarometric data of these felsic parts yielded T = ca. 710 degrees C and P = 0.42 GPa (ca. 15 km depth), they are interpreted as contact melt, which invaded into shrinkage cracks of the cooling sill resulting in thin felsic veins. The migration of contact melt from the wall rock into the shrinkage cracks was suction-induced because of volume gain by contact melting in the wall rock and volume loss by cooling of the sill. The formation of such Sederholm-type composite veins seems to be very fast. Titanites of the felsic veins yielded a U-Pb age at 341.8 +/- 1.5 Ma, which is the same like that of the sill. Moreover, results of thermal modelling indicate a maximum period of 4 months between sill emplacement and the time when both the quartzmonzodiorite and the sill had attained the ambient temperature. The modelling further explains, why Sederholm-type veins, described from several places around the world, are restricted to deep crustal levels. We present geochronological, thermobammetric and computertomographic data from a composite sill exposed in the Weschnitz pluton of the Variscan Odenwald. The wall rock consists of quartzmonzodiorite, which intruded at deep structural levels (P = ca. 0.50 GPa, ca. 18 km depth) in a continental arc setting. Zircons and titanites of the quartzmonzodiorite yielded similar U-Pb ages at 344.3 +/- 0.6 and 343.2 +/- 2.1 Ma, respectively, reflecting fast initial cooling (>= 76 degrees C/m.y.) until the solidus was attained at ca. 680 degrees C. Under these conditions, the quartzmonzodiorite was cut by a spessartite sill, which yielded a U-Pb titanite age at 342.0 +/- 1.0 Ma. The short period between wall rock and sill emplacement (<= 3.9 m.y.) suggests that both are genetically related. The quartzmonzodiorite situated adjacent to the spessartite sill is enriched in quartz and plagioclase and depleted in hornblende. As geothermobarometric data of these felsic parts yielded T = ca. 710 degrees C and P = 0.42 GPa (ca. 15 km depth), they are interpreted as contact melt, which invaded into shrinkage cracks of the cooling sill resulting in thin felsic veins. The migration of contact melt from the wall rock into the shrinkage cracks was suction-induced because of volume gain by contact melting in the wall rock and volume loss by cooling of the sill. The formation of such Sederholm-type composite veins seems to be very fast. Titanites of the felsic veins yielded a U-Pb age at 341.8 +/- 1.5 Ma, which is the same like that of the sill. Moreover, results of thermal modelling indicate a maximum period of 4 months between sill emplacement and the time when both the quartzmonzodiorite and the sill had attained the ambient temperature. The modelling further explains, why Sederholm-type veins, described from several places around the world, are restricted to deep crustal levels.

The present-day hydrological cycle in southeastern Brazil depends on the intensity of the South American Summer Monsoon (SASM) with strong monsoonal precipitation during austral summer (DJF) and weak precipitation during austral winter (JJA). On glacial-interglacial timescales, monsoonal intensity was mainly controlled by precession-forced changes in insolation.Relatively little is known to date about the spatial distribution of precipitation in the hinterland and coastal areas of SE Brazil and the resulting variability of the fluvial discharge on glacial-interglacial timescales. The Doce River basin is situated at the northern boundary of the present-day South Atlantic Convergence Zone (SACZ), wherefore its run-off and suspension load respond sensitive to changes in both summer monsoon and coastal winter precipitation. The soil and rock distribution of the basin allows for the study of the relative proportions of terrigenous up- and lowland sources among the transported fluvial sediments.We studied the mineralogical composition and crystallinity of the non-carbonate fine fraction from late Marine Isotope Stage (MIS) 6 to MIS 5 (150-70 ka) in a marine sediment core obtained in the proximity of the Doce river mouth (20° S, 38° W, 2 km water depth). The main non-carbonate mineral content comprises quartz, albite, illite, kaolinite and gibbsite. The relative abundances of the mineral assemblage show distinct changes relative to changes in summer insolation as well as across the MIS 6-5 transition. Thereby, the mineral assemblage shows a distinct end-member pattern, with high contents of illite (80 % 2M-polytype) and high illite crystallinity as a proxy for stronger physical erosion of the parent rocks in the steep upland, and high contents of kaolinite and gibbsite as proxy for intense tropical soil erosion in the lowlands.During MIS 5, the insolation dependent cyclicity seen in the mineral assemblage shows high illite/kaolinite ratios when austral summer insolation is high and low illite/kaolinite ratios in low insolation phases. This pattern is not visible in late MIS 6, when very low illite/kaolinite ratios are present during high austral summer insolation.We consider the spatial changes in erosion intensity to be caused by variations in the regional precipitation pattern. Thereby, pronounced upland erosion is caused by severe precipitation and discharge events during a strong SASM. A relatively increased lowland erosion indicates both increased austral winter precipitation due to stronger trade wind forcing and a weaker monsoonal system in the upper discharge area. The lack of a strong insolation-control on illite/kaolinite ratios during MIS 6 is interpreted as an overall weakening of the SASM system during glacial periods, when austral winter precipitation exerted a stronger control on the hydrological budget of the Doce River.

A 601 m long sedimentary sequence was drilled in Lake Acigol, located in the lakes region of SW Anatolia, near the Denizli travertine from which the oldest hominin of Turkey was unearthed. Among all dating methods applied to the sedimentary sequence, paleomagnetism, through the recognition of geomagnetic chrons, was the most successful and led to a quasi linear age model, with the 601 m long sedimentary record covering the last 2.3 Ma. An attempt to use the atmospherically deposited Be-10 as a dating method was not very successful but provides interesting clues on this new method. Long-term lake level changes are depicted through lithological variations, in particular the carbonates and evaporites abundance. This change could be influenced by both long term cooling during the last 2 Ma and tectonic activity, which may in particular be responsible for a maximum water depth at around 1.8 Ma. Despite active tectonic influence, the sedimentary facies description and the magnetic susceptibility record (cleaned from tephra intervals) show that climate fluctuations (i.e., glacial-interglacial alternations) are likely recorded in the sedimentary succession, with warm periods marked by enhanced carbonate precipitation and cold and dry periods characterized by more detrital input linked to reduced vegetation cover and consequently more erosion in the catchment area. Preliminary pollen data, used to interpret magnetic susceptibility fluctuations, show that an average dry and open landscape prevailed around Acigol lake during the whole record.

The continental settings of Central Asia witnessed increased desertification during the Cenozoic as a result of mountain uplift and the Paratethys retreat. The interaction of these tectonic‐scale processes with orbitally forced climate change and their influence on Asia's atmospheric moisture distribution are poorly constrained. A Miocene succession of continental mudflat deposits, exposed in the Aktau Mountains (Ili Basin, south‐east Kazakhstan), has great potential as a terrestrial palaeoclimate archive. About 90 m of the 1700 m thick succession comprise alluvial mudflat deposits and appear as cyclic alternation of coarse sheet floods, mudflat fines and semi‐arid hydromorphic soils. In this study, bulk‐sediment mineralogy and geochemistry, magnetic susceptibility, sediment colour and palynology are used to reconstruct environmental conditions by determining changes and forcing mechanisms in the intensity of sediment discharge, weathering and pedogenesis. The results presented here indicate four major periods of arid soil formation and one palustrine interval characterized by higher evaporation rates under highly alkaline/saline conditions. A positive correlation between weathering indices and the Mg/Al ratio suggest that these horizons correspond to maximum rates of evapotranspiration and aridity. The formation of mudflat fines is, instead, interpreted as representing higher detrital sediment production by more intense alluvial fan activity during times of higher precipitation. Time series analysis of weathering indices, colour and magnetic susceptibility data yields cycle‐to‐frequency ratios with the potential to represent Milankovitch cyclicity with short and long eccentricity as dominant periodicities. Periods of pronounced aridity, paced by long eccentricity forcing, reflect changes in moisture availability. On longer tectonic timescales, the persistent appearance of gypsum indicates a shift towards more arid conditions. This trend in climate is considered to result from the closure of the eastern gateway of the Mediterranean to the Indian Ocean that restricted circulation and enhanced salinity within the Eastern Paratethys.

While the use of Egyptian blue (EB) as the earliest artificial pigment was common amongst ancient Mediterranean cultures throughout Egypt, Mesopotamia, Greece, and the Roman Empire, little is known about ancient production centres and the sources of raw materials. Variations in lead isotope (LI) ratios can be useful for fingerprinting the geological sources of copper metal, which has the potential to indicate local production or importation. This method is here applied to copper- and silica-rich EB pigments in order to investigate the provenance of the copper component. The investigated EB pigments were sampled from nine ancient artefacts of Egyptian, Etruscan, Canosan, and Roman origin (dating from between the 5th century BCE to the early 1st century CE) that are part of the archaeological collection of the Ny Carlsberg Glyptotek (NCG), Denmark. For the first time, copper isotope analysis was also applied to EB pigments to facilitate future studies of copper isotopes in such materials. Variations in copper isotopes hold the potential to complement lead isotope-based provenance considerations. The lead isotope data (LID) of the investigated EB pigments were compared to reference LID of copper minerals of European, Near and Middle Eastern, and North African ores that have been exploited at a time relevant for the studied EB pigments. In support of (i) a previously postulated scenario where the import of copper for producing EB dominated over the use of local resources (Shortland, 2006) and (ii) consistent with the preference for lead isotope-based exclusion of unlikely sources rather than the determination of certain provenance, copper ore deposits pertaining to Egyptian and Italian LI fields show no significant overlap with the LID of the studied EB pigments. Instead, we propose that copper sourced from various European (Aegean, Balkan, Iberian, Central European) deposits potentially supplied the production of the studied EB pigments. For example, (i) the studied Egyptian EB pigments show no overlap with Egyptian copper, but instead with Aegean sources; (ii) based on the highly variable copper provenance of the studied Etruscan EB pigments, we tentatively propose that this might argue for the importation of copper raw materials and a subsequent local production in Etruria, analogous to previously reported Etruscan glass production; (iii) we propose that Iberian copper was used for local EB production at a time when the known large-scale EB production facilities in the Bay of Naples were already active. While the testimony of ancient trade in EB is a difficult topic to unravel, the potential copper sources involved in producing EB pigments of the few investigated archaeological artefacts suggests that a few (EB) pigment workshops/production centres were highly actively trading raw materials and/or manufactured EB pigments with several different Mediterranean civilizations. Many EB pigment producing workshops and distribution sites may have existed throughout the Mediterranean facilitating a highly complex and diverse network of trade in this widely distributed ancient pigment.

The Asterousia Crystalline Complex consists of Late Cretaceous amphibolite facies metamorphic rocks and associated granitoids, which can be found in exposures on Crete and the Cyclades (Greece). It is attributed to the Uppermost Unit and therefore to the Pelagonian domain of the Internal Hellenides. The tectonometamorphic evolution of this unit is still a matter of debate. We present new structural and petrological data of Asterousia-type rocks and greenschist facies metamorphic rocks from the island of Anafi in the southern Aegean Sea as well as U–Pb zircon ages of granitoids from Anafi. The crystalline sequence of Anafi rests on top of Eocene flysch and comprises from bottom to top: (a) Anafi Greenschist; (b) Anafi Amphibolite Group (orthoamphibolite with intercalations of metasedimentary rocks at the base); and (c) Chalepa Group (amphibolite facies metasediments with slices of serpentinite and granitoids). LA-ICP-MS and ID-TIMS 206Pb/238U zircon ages of granodiorite from the Chalepa Group reveal several similar zircon populations suggesting continuous emplacement of granitoids inside a magmatic arc from ca. 72.5 to 79 Ma. The minimum emplacement age of granodioritic magma, deduced from the 206Pb/238U median age of the youngest zircon population, is 72.6 +0.1/−0.2 Ma. Deformation (micro)fabrics of granodiorite result from low strain obtained at T > 600 °C. This along with the U–Pb ages and published K–Ar ages indicates intrusion of the plutonic rocks at deep structural levels followed by very slow cooling. Monzogranitic dykes cutting through granodiorite in north-eastern Anafi are undeformed and yielded a 206Pb/238U median age of 69.9 +0.7/−0.7 Ma. Based on the new and published data, the following implications for the tectonometamorphic evolution on Anafi can be made: (1) obduction and accretion of mantle slices (serpentinite) to the Asterousia-type rocks were prior to amphibolite facies metamorphism; (2) intrusion of granitoids during the middle to late Campanian within a magmatic-arc setting and coeval shift of the magmatic arc towards the south; (3) Maastrichtian intrusion of dykes; (4) Palaeocene greenschist facies metamorphism and coeval ductile top-to-the SE thrusting of the Anafi Amphibolite Group on top of the Anafi Greenschist; (5) post-Eocene brittle top-to-the SE thrusting of the Anafi Greenschist and the Anafi Amphibolite Group on top of flysch sediments; (6) clockwise rotation of the system and (Early) Oligocene brittle top-to-the SE thrusting of the Chalepa Group on top of all units mentioned above; and (7) ongoing clockwise rotation of the Aegean block during the Oligocene to Early Miocene and change in stress field (NE–SW compression).

This project focuses on the western branch of the East African Rift System (EARS) and its related climatic changes. The study area lies in the western part of Uganda, north of the over 5000 m high Rwenzori Mountains situated along the eastern coast of Lake Albert. The aim of this sedimentological study was, to close existing terrestrial gaps in the paleoenvironmental and paleoclimatic record as well as the lack of a multi proxy approach to make conclusions more robust and meaningful. Therefore, a further focus was not only the sedimentology itself but also clay mineralogy, gamma-ray, petrographical as well as magnetic susceptibility and palynology. We logged 230m in the Kaiso-Tonya area at a centimeter to decimeter scale with sedimentological and geophysical methods. First results show an interfering system of near shore, lacustrine, deltaic towards a finally fully fluvial environment in the Pleistocene. The Rwenzori Mountains and an accelerated up-lift of the rift-flank combined with a subsidence of the rift floor most likely led to a general aridisation trend. That trend is supported by a gradual increase of smectite from 55% up to 80% towards the Pliocene and a decrease of kaolinite from around 35% to 5%. We found a two-fold hierarchy of stratigraphic baselevel cycles at macro- and mesoscale. Wavelet analyses of lithofacies and magnetic susceptibility (MS) indicate a significant cyclicity at 7m that is caused by lake level changes and related intermittently fluctuating sediment supply. Surprisingly the MS readings remain constant in the negative range despite abundant ironcrusts and impregnations. Heavy mineral studies of intercalated sand layers show a significant increased zircon content up to 70% in the Pliocene and support changed trans- port pathways and/or changed provenance caused by increased tectonism towards the Pliocene. Pa- lynological data will be available at the conference.

The present study is dealing with the emplacement and deformation of diorite and quartz diorite exposed along new road cuts between Agios Nikolaos and Sitia (Uppermost Unit, eastern Crete). Mingling of both melt types is indicated by enclaves of diorite inside quartz diorite and vice versa. The diorite and quartz diorite intruded into coarse-grained white marble, which is in lateral contact to, but also forms the roof of, the intrusive body. Evidence for contact metamorphism is indicated by increasing grain size of calcite in the marble with decreasing distance from the diorite. U–Pb (TIMS) dating of zircons, separated from quartz diorite, yielded a concordant age at 74.0 ± 0.25 Ma, which is interpreted as emplacement age. As this age is close to published K–Ar cooling ages of hornblende and biotite, the melt should have intruded and cooled down rapidly at upper structural levels, which is not common for granitoids of the Uppermost Unit of Crete. Upper crustal melt emplacement is also documented by stoped blocks and by the lack of any ductile (viscous) deformation. The diorite and quartz diorite, however, are affected by strong post-Oligocene brittle faulting. Paleostress analysis, based on these faults, revealed a change in stress field from N–S and NNW–SSE shortening by thrusting (convergence between African and European plates) to NNE–SSW and NE–SW shortening accommodated by strike-slip (SW-ward extrusion of the Anatolian microplate). Calcite-twin density indicates high differential stress (260 ± 20 MPa) related to these phases of crustal shortening.

The present study is focusing on Variscan basement xenoliths, which are present inside pyroclastic rocks of the Miocene Vogelsberg volcanic field (VVF). The investigated samples have been collected from quarries situated at the SW margin of the Vogelsberg (Nickel quarry, Nidda Ober-Widdersheim) and at the NE margin of the Vogelsberg (Rauher Berg quarry, Alsfeld-Brauerschwend). Moreover, we investigated different types of trachyte, which are present (1) as xenoliths inside an alkali basaltic tuff breccia of the Nickel quarry, (2) as trachytic lava from an outcrop at the Hauserhof (Nidda Ober-Widdersheim), and (3) as part of a trachytic/phonolitic lava dome drilled in the central VVF near Schoften-Sichenhausen.Apart from one garnet-bearing sample, the investigated basement xenoliths consist of phyllite and basic to felsic metavolcanics. Both the metamorphic index minerals and the quartz deformation microfabrics suggest that these rocks underwent greenschist facies metamorphism, and thus can be attributed to the Northern Phyllite Zone of the Variscan chain. These findings allow tracing the Northern Phyllite Zone from the Rhenish Massif via the VVF to the Harz Mountains. Variscan basement underneath the VVF is also documented by inherited U-Pb zircon ages obtained from the Hauserhof trachyte (366 +/- 8.5 Ma and 294 +/- 3 Ma) and from the trachyte of the Sichenhausen-Eschwald drilling (323 +/- 12 Ma to 344 +/- 6 Ma and ages ranging from the Middle Proterozoic to Cambrian/Ordovician boundary). The Permian and Carboniferous ages correlate with widespread late-Variscan volcanic activity in Central Europe at similar to 290 Ma, and with granitoid intrusions along the Rheic suture during the main phase of the collision of the Rhenohercynian and Saxothuringian domains at similar to 340 Ma, respectively. For the Latest Devonian ages (366 +/- 8.5 Ma) several scenarios are possible. Middle Proterozoic to Cambrian/Ordovician ages are regarded as reworking of pre-Variscan sedimentary and magmatic material. The new ages and the garnet-bearing xenolith, the metamorphic grade of which does not fit with the greenschist facies rocks of the Northern Phyllite Zone, suggest that rocks of both the Northern Phyllite Zone and the Mid-German Crystalline Zone are present underneath the volcanic rocks of the VVF.The U-Pb zircon ages of trachytic xenoliths of the Nickel quarry suggest the emplacement of a trachytic lava dome at 66.7 +/- 0.4 Ma. Similar ages have been obtained from camptonitic dykes and trachyte intrusions within Permian and Triassic sediments exposed at the southwestern margin of the VVF. The large amount of trachyte together with a significant positive magnetic anomaly in the southwestern VVF might indicate a magma chamber that developed at shallow crustal levels below the southwestern part of the present Vogelsberg during the Upper Cretaceous. The new results have been used to develop a model for the early evolution of the southwestern Vogelsberg.

We investigated volcanic and sedimentary rocks of the Toplou Beds, which constitute the uppermost part of the Tyros Unit of eastern Crete. U-Pb TIMS analyses of zircons, separated from a metarhyolite of the lower Toplou Beds, yielded concordant ages at 361.2 +/- 1.2, 307.4 +/- 1.2 and 228 +/- 1.7 Ma. The youngest age is interpreted to reflect the timing of melt emplacement in Carnian times. The older ages are inherited from zircons, which belong to the crystalline basement through which the rhyolite melt was ascending. At higher stratigraphic levels we found fern fragments inside black slates, which are intercalated with Carnian metasandstones and metaconglomerates. The fern fragments resemble most closely the genus Phlebopteris, which is typical for the Triassic to Early Jurassic of Europe. Findings of the foraminifera Gandinella falsofriedli inside dolomite of the uppermost part of the Toplou Beds suggest a Norian/Rhaetian age. As the basal parts of the Tripolitza Nappe yielded Ladinian and Carnian ages, the Tyros Unit cannot continue upwards into the Tripolitza Platform. The misfit in ages and the inversion in metamorphic grade of Tyros and Tripolitza rocks suggest a thrust contact between both units.The Triassic records inside the Tyros Unit can be explained by subduction and collision following the closure of the Palaeotethys. Subduction underneath the Cimmerian ribbon continent is documented by metaandesite in the basal parts of the Tyros Unit (Chamezi Beds), which rest unconformably on top of Carboniferous/Permian crystalline basement. The andesites and shallow marine clastics are interpreted to have been deposited in a fore-arc position. Redeposited neritic carbonates in the form of pebbles in Lower Triassic and Anisian conglomerates of the Chamezi and Tripokefala beds, respectively, suggest uplift and erosion of pre-existing carbonate platforms. This phase of uplift and erosion is attributed to collision of Pelagonia with the Cimmerian ribbon continent following the closure of the Palaeotethys. Uplift and erosion were still active in Ladinian times explaining the lack of Ladinian fossils inside the Tyros Unit. The shallow-marine and terrestrial conditions during Carnian sedimentation of the Toplou Beds can be well correlated with the conditions during deposition of the Cassianer/Raibler Beds of the Southern Alps.