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Indian summer monsoon (ISM) rainfall is contributed by two moisture sources; Arabian Sea (AS) and Bay of Bengal (BoB). While monsoonal rainfall in eastern and central India is dominantly contributed by the vapor derived from BoB, the source of rainfall in western India is mostly from AS vapor. Meteorological conditions in these regions also differ. In contrast to the BoB component of monsoon in central India, temporal variations in the AS sourced rainfall from western India are poorly constrained due to lack of paleohydrological records. Towards this, pedogenic carbonates were collected from two chronologically constrained cliff sections in the Gujarat alluvial plain, western India. Oxygen isotopic ratio of carbonate (δ18Ocarbonate) was used to reconstruct variation in AS derived rainfall and its influence on vegetation and fluvial systems in western India for the last 75 ka. A negative correlation between the δ18O value of modern rainwater and its amount (known as amount-effect) in the study site is used as a framework for interpreting variations in δ18Ocarbonate values. The amount-effect based monsoon reconstruction showed that two distinct dry phases at 75 ka to 60 ka and 30 ka to 10 ka were punctuated by a wet phase from 60 ka to 30 ka. These hydroclimatic variations in western India during the late Quaternary were responsible for the changes in regional fluvial architecture. Comparison with published records showed that fluctuations in the AS sourced rainfall were more pronounced compared to BoB component. Carbon isotopic ratio (δ13C) of carbonate and co-existing organic matter were used to reconstruct vegetation composition. Significant and strong positive correlation between δ18Ocarbonate and δ13Ccarbonate values indicated that rainfall amount controlled the relative abundance of C3-C4 plants in western India during the late Quaternary period. Furthermore, C3 plants were more abundant in western India for the last 75 ka relative to central India.

The early Permian Chemnitz Fossil Lagerstatte (Leukersdorf Formation, Chemnitz Basin, SE Germany) represents a diverse T 0 assemblage of a fossil forest ecosystem around the Sakmarian-Artinskian transition (290.6 ± 1.8 Ma), which was preserved by pyroclastic deposits of a multi-phased volcanic eruption. The multi-aged plant community consists of predominantly hygrophilous elements, which grew on an alluvial plain mineral substrate under sub-humid conditions, representing a wet spot environment. Strong seasonality triggered the formation of annual tree rings in arborescent woody plants, such as pycnoxylic gymnosperms, medullosan seed ferns and calamitaleans. From several hundred fossil trees, the 53 best-preserved specimens were selected and investigated in detail by measuring 2,081 tree rings in individual sequences of up to 77 rings. Ring sequences were analysed by standard dendrochronological methods to determine both annual growth rates and mean sensitivity. Morphological and statistical analyses on single tree rings reveal different tree-ring types according to the different plant groups. Pycnoxylic gymnosperms have distinct and regular tree rings, whereas medullosan seed ferns and calamitaleans show indistinct and regular tree rings as well as so called event rings. Results reveal differences between plant groups regarding their physiological reactions or adaptations to seasonal fluctuations. In comparison to pycnoxylic gymnosperms, both medullosan seed ferns and calamitaleans exhibit reduced growth rates and more sensitive reaction to environmental perturbances as water deficiency pointing to comparably lower adaptation to seasonally dry palaeoclimate. In this context, event rings are in many cases traced back to plant physiological stress during particularly severe drought periods. Altogether, these fossil trees serve as sensitive environmental archives, which shed light on growth conditions several decades back in time from the entombing eruption.

To study the stratal stacking patterns and controls on coal accumulation in a lowland alluvial plain, coastal plain, and shallow-marine setting, the depositional facies, sequence stratigraphy, and paleogeography of the Carboniferous–Permian strata in the Anyang-Hebi (Anhe) coalfield, Henan Province, northern China were analyzed based on borehole cores. Ten facies were grouped into four facies associations, which represent alluvial plain, delta plain, delta front and prodelta, and offshore marine depositional environments. Ten sequences (S1 to S10, in ascending order) were defined on the basis of vertical facies stacking patterns. Sequences S1–S3, of Moscovian to early Asselian age, are composed mainly of offshore marine carbonate and mudstone, prodelta and delta front mudstone and sandstone, and delta plain sandstone, mudstone and coal. Sequences S4–S9, late Asselian to Wuchiapingian in age, consist of delta plain sandstone, mudstone and coal. Sequence S10, corresponding to the Changhsingian stage, is composed mainly of alluvial plain sandstone and mudstone. From S1 to S10, the Anhe coalfield experienced an environmental evolution from offshore marine, prodelta and delta front through delta plain to alluvial plain environments, an evolution from a low-accommodation to a high-accommodation setting, and a paleoclimatic change from humid to semi-arid conditions. Coal accumulation was controlled by a combination of relative sea-level fluctuation, paleoclimate and paleogeography. The cyclothemic nature of S2, including presence of parasequences, and the significant sea-level fall interpreted at the base of S4 may be related to Gondwanan ice dynamics in the late Carboniferous–early Permian. The thick coals are concentrated in the transgressive systems tracts of S2 and S4. The results of this study provide new insights into the environmental evolution of Carboniferous–Permian lowland alluvial plain, coastal plain and shallow-marine successions of the northern subtropical paleolatitudes and the controls on coal deposits in North China.

An integrated palaeoecological study was performed regarding the Early Jurassic coal bearing succession (Mecsek Coal Formation) of the Mecsek Basin (S Hungary) focusing on boreholes from Maza-South and Rucker areas representing the periphery and the central part of the coastal plain of a delta respectively. Comparative investigations were based on a previous palaeobotanical ecogroup model and on the integrated interpretation of sedimentological and palaeobotanical data from Maza-South. Sedimentary isopach and coal seam ash content data were applied to reconstruct palaeotopography and coal seam thickness data to detect plant growing intensity at Maza-South (10 km2). Plant fossils identified from the corresponding strata were used as sources for the identification of four topography-related plant succession stages determined by sequential facies changes. Channel banks and small islands are characterised by underdeveloped associations composed of colonist elements. Exposed slopes or levees, or local elevations in overbank conditions are covered with assemblages of small herbaceous plants. Crevasse splay complexes are characterised by more developed plant cover and swamps in floodplain depressions are characterised by typical swampy successions. Based on these succession stages, plant remains from Rucker were also interpreted, however, mainly swampy and elevated overbank habitats alternated at Rucker reflecting continuous floods. According to the results, Maza-South was a small area located very close to the bayline between the alluvial plain and the coastal plain of a delta, less favourable for intensive plant growing where dry land was restricted to levees and crevasse splays. This resulted in more dynamic plant changes, typical for deltaic peripheral territories. In contrast, Rucker represents the central part of the delta plain environment dominated by woody forms of large growth. In the uppermost sequence plant composition at Maza-South became similar to that of Rucker indicating that, with transgression, the central delta plain environment, permanent at Rucker, advanced towards the peripheral zone represented by Maza-South.

Long-term data on flooding events are necessary for understanding the flood frequency and magnitude variations, but the available instrumental records span only a few decades. Recently, lake sediment sequences have emerged as a relatively untapped archive for high-magnitude floods over longer timescales. In the present study, multi-proxy data from a lacustrine sequence at Timbi in the Dhadhar river basin were analysed to determine high magnitude floods in this semi-arid region of western India in response to southwest monsoon variability. The results indicate the occurrence of discreet high magnitude flood events and depositional phases corresponding to different climatic conditions during the mid to late Holocene. Three large flash floods between 4830 and 2730 cal yr B.P. (Phase-I) have been identified as coeval with flood events from fluvial archives and correlated to the widespread period of aridity and weak monsoon recorded in the lakes of north western India. A shift in the depositional environment from fluvial to lacustrine occurred around 2730 cal yr B.P. as inferred from an abrupt change in the sediment character and palynofacies caused by high intensity flash floods and high sediment influx. Phase II (2730–1730 cal yr B.P.) was marked by periodic erosion and deposition in the catchment and sediment influx during pulses of higher precipitation as evident in the dominance of Glomus sp. and Alternaria sp., and relatively low values in concentration-related magnetic parameters and S-Ratio. A high magnitude flood event occurred at 1770 cal yr B.P. towards the end of phase II. During phase III (1730–880 cal yr B.P.) the monsoon was enhanced and climate was warmer as suggested by low χfd%, SIRM/χ, S-Ratio, higher Ba/Sr ratio and presence of aquatic palynomorphs. A high percentage of structured Organic Matter (OM), low fungal remains and increased Ba/Sr ratios between 880 and 360 cal yr B.P. indicate higher lake waters and better monsoon condition during phase IV. The phase V (360–0 cal yr B.P.) corresponds to lake level lowering, soil formation and eutrophication. The Timbi lake sediments demonstrate the potential for lakes in semi-arid alluvial plains of western India to preserve proxy flood records providing additional archives for generating long-term datasets. The flood record generated substantiates palaeoflood data from the fluvial archive suggestive of regional-scale southwest monsoon variability. Low frequency-high magnitude floods occurred during arid periods and low magnitude-high frequency events during relatively strengthened monsoon and thus have implication for linking the palaeoflood events to the southwest monsoon intensity in the semi-arid continental regions.

A sediment core from Pariyaj Lake, from the Vatrak River basin, located at the desert margin in the Gujarat Alluvial Plains of western India, was investigated in a multidisciplinary aspect. The goal was to reconstruct the palaeoclimate, palaeoenvironment and tectonic history and to understand the role these factors played in the geomorphological evolution of the area during the Holocene. Palaeoclimatic interpretations also shed light on the factors responsible for the rise and fall of the Harappan civilisation. The results obtained based on multiproxy studies show five climatic phases during the last 11,000 yr BP. Phase 1 (~ 11,000 cal yr BP) represents a very humid climate and high precipitation/discharge leading to high lake stand as attested by the high pollen concentration of semi-evergreen tree taxa, phytoliths belonging to cool and moist grasses, and large proportion of algae, marking the onset of Holocene. In phase 2 (~ 8000 to 9000 cal yr BP) a significantly reduced yield of pollen, phytoliths and aquatic algae indicates shrinkage of the lake. Phase 3 (~ 7630 cal yr BP) shows moderate yield of pollen and phytolith pointing towards fluctuating precipitation conditions. Phase 4 (~ 5864 to 4680 cal yr BP) shows very low pollen and phytolith counts, indicating a very dry spell. Finally, phase 5 (~ 4680 to 3500 cal yr BP) shows a good density and diversity of flora. The wet climate and high lake stand ~ 11,000 cal yr BP, 7630 cal yr BP and after ~ 4680 cal yr BP are synchronous with the lacustrine, marine and aeolian records of western India. The contribution of winter precipitation at 7630 cal yr BP and after ~ 4680 cal yr BP can be correlated with similar records from Rajasthan Lake. Decrease in the precipitation activity, the low lake stand and the onset of dry climatic condition between 8000 and 9000 cal yr BP corresponds to a near global anomaly of this period. Another dry event between ~ 5864 and 4680 cal yr BP documented in Pariyaj Lake record is synchronous with various proxy records of the mid–late Holocene Afro-Asiatic monsoonal belt.

Paleozoic tetrapod footprints are a common and well-known phenomenon in almost all large European countries except for Spain. Here we report on hitherto unpublished vertebrate tracks from Permian red-beds of the south-central Pyrenees that with regard to their relative abundance, diversity and quality of preservation are suitable to fill this gap of knowledge. The described tracks come from two localities in muddy to fine-grained, sandy, alluvial plain deposits in the lower third of the Peranera Formation of the Erill-Castell Basin near Les Iglesies, northern Catalonia. The tracks can be assigned to five ichnogenera, i.e., Batrachichnus Woodworth, 1900, Limnopus Marsh, 1894, Varanopus Moodie, 1929, Hyloidichnus Gilmore, 1927, and Dromopus Marsh, 1894, that we interpret as footprints of temnospondyls, captorhinomorphs, and araeoscelids or similarly sized sauropsids with a lacertoid foot pattern. This ichnofossil assemblage is most similar to ichnofaunas from the Hermit Formation of the Grand Canyon, Arizona, the upper Abo and Robledo Mountains formations of New Mexico, and the main trace fossil site of the Tiddas Basin, Morocco, suggesting a late Early Permian (Artinskian) age for this stratigraphic level of the Peranera Formation. Considering the relative abundance and diversity of captorhinomorph footprints, the new Spanish tracefossil localities may cover the onset of the Early Permian radiation of non-diapsid eureptiles. The thick Late Paleozoic red-bed successions of the south-central Pyrenees have the potential to also bear footprints of otherwise unknown early therapsids, so systematic fossil prospecting of this area is strongly recommended.

The issue of whether major and rapid global sea-level changes existed on a preglacial Earth can be resolved by the detailed study of the Paleocene-Eocene (P-E) interval, where a large and rapid carbon isotope excursion linked to an important global warming event, the Paleocene Eocene Thermal Maximum, allows for high-resolution correlation between terrestrial, coastal and marine settings. Based primarily on outcrop and borehole information from the Tremp-Graus Basin in the southern Spanish Pyrenees, it is shown that a sea-level fall of at least 20 m occurred less than 75 kyr prior to the PETM. This forced a seaward displacement of the shoreline of ca. 20 km, a widespread incision of valleys in the alluvial plains and the subaerial exposure and excavation of the adjacent marine carbonate platform. The subsequent sea-level rise caused the infilling of the incised valleys, a process completed before the onset of the PETM, and continued rising during and after the event, leading to the aggradation of the alluvial plain and eventually to the transgression of the whole Tremp-Graus Basin. However, the sea level did not regain its pre-fall position until near the end of the PETM. Therefore, although rising, the sea level was comparatively low in the southern Pyrenean area during most of the PETM. The pre-PETM sea-level fall has been reported in other basins of the southern Pyrenees, in the North Sea area, the Austrian Alps and in Egypt, and the subsequent sea-level rise has been documented in widely separated sites around the Earth, an evidence of their global (eustatic) scope. The causal mechanism(s) of the pre-PETM sea-level fall is (are) unresolved, although glacioeustasy may have played a role. The subsequent sea-level rise was most likely caused by tectonomagmatic activity in the North Atlantic. (C) 2013 Elsevier B.V. All rights reserved. (Less)

The Cameros Basin sedimentary infill comprises a large, essentially continental, megasequence ranging from the Tithonian (Upper Jurassic) to the Albian (Lower Cretaceous). It occupies an area of some 5500 km2, and is home to around 300 dinosaur tracksites. Most of these tracksites are found in either the Huerteles Formation, which is part of the Oncala Group (Berriasian), or the Enciso Group (Lower Aptian), both of which represent early Cretaceous lacustrine episodes. Dinosaur trackways (n = 1170) from both episodes were analysed in order to establish the preferred direction of dinosaur movement, and to determine whether these movements were influenced by the palaeogeographic and palaeoenvironmental conditions of the area. The Huerteles Formation is interpreted as a complex record of alluvial plain systems distally connected with a playa-lake. Its dinosaur tracksites are distributed throughout its alluvial plain facies and trackways show two preferential unidirectional orientations: 1) NW, more or less parallel to the distribution of the facies belt and 2) NNE. The Enciso Group is represented by a wide and shallow lacustrine system connected with marine environments towards the SE (Iberian Basin realm) and in close proximity to marine settings to the NW (Basque–Cantabrian Basin realm), rendering the Cameros Basin as the only continental connection between the Ebro and Iberian Massifs. The fluctuating (but always shallow) water level of the system with frequent desiccations probably allowed dinosaurs to pass through the lake basin. As a consequence of these paleogeographic restrictions, the dinosaur trackways generally show a bidirectional NE–SW orientation. Despite the temporal and geographical differences between the Huerteles Formation and Enciso Group, the ichnocenoses of both are dominated by theropod dinosaur trackways (85% as a mean value). This is probably explained by these dinosaurs being more active than others, a consequence of their searching/hunting behaviour.

The Early Cretaceous (Barremian) Wessex Formation of the Isle of Wight primarily represents high sinuosity fluvial, but also lacustrine and terrestrial deposition on a low relief floodplain occupying half grabens, with active normal faults immediately to the north. Plant debris beds form a very small proportion of the succession but are the main source of vertebrate fossils, including dinosaurs. These conspicuous, but thin, grey units are distributed randomly throughout the Wessex Formation and are of limited lateral extent. The lower part of most plant debris beds comprises a poorly sorted, matrix-supported conglomerate. The upper part of most consists of structureless mudstone, which usually grades up into colour-mottled but predominantly red and purple floodplain mudstones. The plant debris beds contain an unusual mixture of freshwater molluscs, diverse aquatic and terrestrial vertebrates, and mainly terrestrial plants with a variable quality of preservation. We conclude that each plant debris bed represents a locally generated sheetflood, which was then transformed on the floodplain into a debris flow by the acquisition of surface material. The debris flows surged into, and were deposited in depressions on the alluvial plain, including abandoned chute and cut-off channels, oxbows and ponds. These units are therefore intrabasinal and interfluvial, and the fossils that they contain are locally derived. Similar deposits of palaeontological significance have not been reported elsewhere in the literature. In view of this, their origin and sedimentology, their palaeontological significance, and the taphonomy of the flora and fauna they contain are discussed.

Pedogenic nodules, calcitic shells, dispersed organic carbon and bulk rocks affected by low diagenesis are judged to be reliable tools for carbon-isotope chemostratigraphy. Up to now no systematic study has been carried out to check the reliability of fossil wood material for carbon-isotope chemostratigraphy in terrestrial settings. The 235-m thick Wealden facies sediments of the Danube-Bouchon quarry at Hautrage (Hautrage Clays Formation, Mons Basin, Belgium) encompass dark to grey clays and sands, rich in organic matter and coalified-charcoalified fragments of fossil wood, deposited in an alluvial plain during middle Barremian to earliest Aptian. We measured and compared the carbon-isotope ratios of 110 levels of the stratigraphic succession for dispersed organic carbon (δ13CDOC), and fossil wood (δ13CWOOD) collected in the same geological level. In the whole succession, the averages of δ13CDOC and δ13CWOOD have a significant difference of about 0.9‰. The δ13CWOOD is usually heavier than the δ13CDOC, which is consistent with measurements on different constituents of modern trees (branches versus leaves and tissues). In one single stratigraphic level, the variability of δ13CWOOD is much higher (up to 7.3‰) than that of δ13CDOC (0.4‰). Four main causes may explain these results. Firstly, the δ13CDOC averages the isotopic signal of different compounds and tissues (such as leaves, seeds, cuticles) as they become mixed and dispersed. The δ13CWOOD reflects the carbon-isotope ratio of a small part only of one single tree, which is a complex system with δ13C variations over a range of 4‰. Secondly, there is strong δ13C variability between different species of plants. In Hautrage, several gymnosperm genera were collected (including Podocarpoxylon, Taxodioxylon, Brachyoxylon, and Thujoxylon) and numerous fern taxa. Thirdly, coalification and charcoalification can affect the δ13C of the DOC and the various kinds of woods in a different way. Fourthly, the wood fragments may be reworked several times from more ancient geological levels, especially in the alluvial plain environment of Hautrage where thick levels of fluviatile coarse sand deposits are observed. However, in the whole succession, both δ13CWOOD and δ13CDOC curves show similar trends. This suggests that carbon-isotope curves on fossil wood can be matched to carbon-isotope curves on DOC. For the whole trend fossil wood is a relatively good chemostratigraphic tool when sufficient samples are measured in the succession. Whenever possible both control of the wood taxa, and estimation of degree of (char)coalification are however recommended. In one single level, charcoal has more stable δ13CWOOD values than δ13CWOOD of coalified fragments. The δ13C positive trend can be due to several causes, including global pCO2 variations and/or regional changes and/or local environmental conditions in the alluvial plain. If global, the dating of the Hautrage succession may be refined to the late Early Barremian-early Late Barremian by matching palynological and carbon-isotope chemostratigraphical data. © 2010 Elsevier B.V. All rights reserved.

Paleosols of the Late Cretaceous Sânpetru Formation (Haţeg Basin, Romania) are the subject of macroscopic, microscopic, and geochemical investigation in order to reconstruct the palaeoenvironmental and palaeoclimatic conditions in which dinosaurs lived. Study of overbank deposits present in an 860-m-thick stratigraphic interval of the Sânpetru Formation exposed along the Sibisel Valley reveals the presence of one facies and five different pedotypes: 1) finely laminated gray-green mudstones and siltstones interpreted as pond deposits; 2) bioturbated gray-green mudstones lacking macroscopic pedogenic features, interpreted as very poorly-developed hydromorphic paleosols; 3) bioturbated gray-green mudstones containing carbonate concretions, interpreted as poorly-developed hydromorphic paleosols; 4) mottled gray-green mudstones containing carbonate concretions and limited illuvial clay accumulation, interpreted as moderately-developed paleosols characterized by a high but fluctuating watertable; 5) bioturbated brown-red mudstones lacking macroscopic pedogenic features other than the occasional mottles, interpreted as poorly-developed paleosols that formed on the higher and better-drained floodplains; and 6) bioturbated brown-red mudstones containing carbonate nodules, interpreted as moderately-developed calcareous paleosols that formed on distal floodplain settings. Although limited exposure prevents the documentation of lateral relationships of pedotypes, the presence of paleosol profiles that display characteristics of two different pedotypes suggests that they represent a lateral continuum on the landscape related to local differences in hydrology and relief (i.e., catena). The pedotype assemblage reveals that the Sânpetru landscape was a mosaic of wetlands, seasonal wetlands, and better-drained floodplain habitats, similar to the present-day Indogangetic Plains. Pedogenic features and paleosol geochemistry indicate that the Maastrichtian climate of Romania was subhumid ( The distribution of pedotypes through the Sânpetru Formation reveals small- and large-scale palaeoenvironmental changes associated with the shifting of a complex mosaic of wet and dry habitats in response to shifts in river position on the alluvial plain. However, a major palaeoenvironmental change occurs in the upper Sânpetru Formation, where the region was transformed into extensive wetlands. Such dramatic changes coincide with river competence increase, change in palaeocurrent directions, and dearth of macrovertebrate remains, which had been previously misinterpreted as evidence for the disappearance of dinosaurs at the Cretaceous-Tertiary boundary. These palaeoenvironmental changes, induced by tectonism, are responsible for the shift from preservation of macrofossils concentrated by hydraulic processes into conspicuous lenticular bonebeds in the lower Sânpetru Formation to preservation of microfossil, and more rarely macrofossil, remains in hydromorphic calcareous paleosols in the upper Sânpetru Formation. The consequences of palaeoenvironmental changes on vertebrate preservation mode must be considered in the search for fossils and interpretation of the fossil record.

The Danube Basin situated at the Alpine–Carpathian–Pannonian junction represents a region of the Central Paratethys strongly influenced by orogen building processes and climatic changes. The geodynamic development mirrors gentle docking of the Carpathians into the European platform margin, associated with synrift and later postrift subsidence of the back-arc area. Onset of the basin inversion characterized the Pliocene evolution. The aquatic environments gradually changed from marine, brackish to caspibrackish and to freshwater within the “Lake Pannon” due to isolation, followed by development of ephemeral lakes and alluvial plains. The terrestrial record documents the extinction of the Middle Miocene fauna and the retreat of vegetation with subtropical floral elements at the beginning of the Late Miocene, due to changes in paleogeography and climate between 11.5 and 7.1 Ma. The immigration of a new “hipparion fauna”, as well as the replacement of swamp vegetation by “coniferous forest” of the temperate zone can be interpreted as the first appearance of seasonality, with lowered humidity at the Pannonian/Pontian boundary. The Late Pontian to Early Pliocene fauna and flora, as well as sedimentary environments support the increase of humidity in warm temperate climate between 7.1 and 5.4 Ma.

The vegetation ecology of Pennsylvanian upland/dryland regions is poorly known, despite its evolutionary significance. Here, fossil plant assemblages are described from well-drained alluvial fan/piedmont deposits in the uppermost Boss Point and Tynemouth Creek formations (late Yeadonian–Langsettian), southern New Brunswick. Beds record the northward building of a large alluvial fan complex over alluvial plain deposits in response to near-continuous sourceland uplift. Proximal alluvial fan environments, characterized by sheetfloods and braided streams, were dominated by large cordaitalean trees, medullosan pteridosperms, ferns, and calamiteans. Distal alluvial fan environments, where braided stream and levee/splay sedimentation predominated, were covered by similar vegetation, together with lycopsids in localized poorly drained depressions. Calamitean thickets were particularly widespread in rapidly aggrading settings on the distal fan. Well-drained alluvial plains beyond the fan toe were characterized by axial braided rivers containing cordaitalean trunks transported from proximal settings. Piedmont vegetation is otherwise poorly resolved. All studied plant assemblages are of low- to medium-diversity, and dominated by the remains of a single group, cordaitalean seed plants. Such dominance-diversity characteristics, together with the presence of charcoal, the product of wildfire, imply that Pennsylvanian upland/dryland vegetation experienced water-stress and that the seed habit was integral to successful colonization.

Fossil charcoal (fusain), indicating the occurrence of wildfire, is common in the Carboniferous rocks of North America and Europe. During the Carboniferous these regions lay on the southern margins of the Laurasian continent and within the tropical zone. This study examines the facies distribution and botanical identity of charcoal in order to investigate the influence of fire on Carboniferous tropical ecology. New data from charcoal-bearing units in eastern Canada, Poland and the British Isles are presented and synthesised with previously published data of charcoal occurrence. Tournaisian–Visean charcoal-bearing strata were deposited in volcanic, lacustrine, alluvial plain and coastal marine environments. In these deposits, charred floras are dominated by (pro?)gymnospermous plants, whilst uncharred (compressed or permineralised) floras are dominated by lycopsids. Uncharred lycopsid remains were probably derived from wetland communities growing close to the depocentres, whilst charred gymnospermous remains may have been sourced from well-drained extrabasinal settings. Based on the vertical distribution of charcoal layers in annually(?) laminated lacustrine deposits, it is estimated that fires occurred with high frequency, approximately every 3–35 years. Palaeoclimatic analysis indicates that southern Laurasia at this time was subject to a seasonal (monsoonal) tropical climate. Such environments today are characterised by tropical savannas with high fire frequencies, and Early Carboniferous fire-prone gymnospermous plant communities may have represented a comparable vegetation biome. Namurian–Stephanian charcoal-bearing strata were deposited in alluvial plain, coastal plain and coastal marine environments. Channelised sandstone units, interpreted as river channel deposits, contain charcoal derived from cordaitaleans and conifers. This assemblage records fires in extrabasinal coniferopsid forests. Mudstone units containing coals are interpreted as the deposits of floodbasins and peat mires. Hollow uncharred lepidodendrid stumps occur in this facies and contain lepidodendrid charcoal in the stump bases and lepidodendrid, pteridosperm, coniferopsid and sphenopsid charcoal outside the stumps. This assemblage records fires in wetland lepidodendrid-dominated forests. Lepidodendrid trunks, comprising of a spongy parenchymatous core surrounded by dense periderm, became hollowed out during fire events. An estimate of fire frequency based on the vertical spacing of charcoal layers in coals implies that fires occurred every 105–1085 years in the peat mires. Palaeoclimatic analysis indicates that southern Laurasia was subject to a humid tropical climate during the Late Carboniferous. Such environments today are characterised by tropical rainforests where fires occur rarely, and Late Carboniferous communities may have represented a comparable biome.

The Lano quarry, located in the northern part of the Iberian Peninsula (Basque–Cantabrian Region), has yielded a diverse continental vertebrate assemblage from the Late Cretaceous (late Campanian to early Maastrichtian). The fossil assemblage consists of almost 40 species, including bony fish, amphibians, lizards, snakes, turtles, crocodilians, dinosaurs, pterosaurs and mammals. Lano is the most productive European vertebrate locality hitherto known from the Late Cretaceous. The sedimentology of the Lano section shows that the three associated fossiliferous beds (known as L1A, L1B and L2) were deposited in an alluvial system composed primarily of fluvial sands and silts. The sedimentary structures are consistent with channel areas within an extensive braided river. The L1A level was excavated in detail and mapped following a square-metre grid system. The main features of the multispecies vertebrate assemblage are as follows: wide range of body size (including microfossils); large proportion of adult individuals; rare articulated skeletal parts; size-sorting and dominance of small elements; high spatial density; long bones showing some preferential orientation; variable dip; variable degree of breakage and large proportion of splintering; wide range of weathering and abrasion; no evidence of predatory activity or chemical alteration. On the basis of these features, we suggest that the Lano association lies between the taphonomic modes for attritional vertebrate assemblages in fluvial channels, though it tends more toward the channel-fill than the channel lag mode. The L1A sample of Lano is a heterogeneous assemblage of elements ranging from isolated bones and teeth to articulated skeletons with allochthonous and para-autochthonous characteristics. It consists of a mixture of vertebrates from different palaeocommunities, and includes aquatic (or semi-aquatic) elements and remains transported from a variety of habitats on the alluvial plain. The dinosaur bones are commonly broken and show a greater degree of abrasion than those of freshwater vertebrates, indicating that they may be allochthonous. However, actinopterygians, amphibians, pleurodiran turtles and eusuchian crocodilians are interpreted as being para-autochthonous. Palaeobatrachid frogs, bothremydid turtles and alligatoroid crocodilians are the most relatively abundant vertebrates of the Lano fossil assemblage. The occurrence of pelomedusid turtles and crocodilians is indicative of an intertropical, warm climate.

Field observations are often not sufficient for process-based interpretations of palaeosols, particularly where they form parts of thick aggradational pedocomplexes within alluvial successions. Under such conditions micromorphology provides genetic, temporal and spatial information on soil-forming processes that is critical to an understanding of past environmental conditions. Thick alluvial successions of the Albian Mill Creek Formation contain abundant evidence of pedogenesis, but few well-developed palaeosol profiles, and therefore, provide an ideal case study in which to demonstrate the usefulness of micromorphological data for palaeoenvironmental interpretation. The micromorphological features of greatest interpretive value are types of clay coatings and ferruginous segregations, structure and fabric. Papules, evidence of bioactivity and ferruginous concretions provide information on geomorphic surface stability and assist in reconstructing temporal changes in drainage conditions. While individual features can provide some palaeoenvironmental information, the relationships of features to one another and assemblages of features provides additional information when analysed hierarchically to establish a sequence of sedimentologic and pedogenic events. A common, recurring sequence of palaeoenvironmental events, subject to local variations, can be recognized throughout the Mill Creek Formation. The presence of illuvial clay requires that water percolated through the soil and that the soil periodically dried out so that the translocated clay was retained. Dark reddish clay coatings indicate clay illuviation under freely drained conditions, while pale-yellow and silty clay coatings suggest that phases of free drainage alternated with phases of poorly drained or saturated soil conditions. The presence of iron-depletion coatings, iron nodules and quasiferrans indicates that these units were at least periodically saturated, and the occurrence of multiple, overlapping phases within single thin sections demonstrates that redox conditions fluctuated, strongly suggesting development in the vadose zone. Recent soils containing similar assemblages of features develop under warm temperate seasonal climates. Alternating phases of well-drained and saturated conditions on the Mill Creek floodplains are attributed to changing sediment supply and local palaeogeomorphology rather than to any major regional climate change. This type of process-based, micromorphological analysis should have broad application in other complex, pedogenically modified alluvial successions and similar studies would lead to a more detailed understanding of ancient palaeoenvironments.

The Gujarat alluvial plain in the semi-arid desert margin of the Thar desert contains a record of continental Quaternary sequences. These sequences were built by drainages originating in the Aravalli Hills and flowing westward into the Indian Ocean. Stratigraphic studies of a part of the Late Quaternary succession in the Sabarmati basin have resulted in a fourfold lithostratigraphic scheme—the Waghpur Formation (Conglomeratic Member; Sand Member); the Mahesana Formation (Lower Heterolithic Member; Upper Sand Member); the Akhaj Formation, and the Sabarmati Formation. Facies analysis, distribution of conglomerates and cross-bed azimuths of the clastic facies of the Waghpur Formation were used to infer NE-SW trending semi-arid alluvial fans. The deposition of the overlying Heterolithic Member took place in ephemeral streams influenced by episodic flows and aeolian reworking. The upper member of the Mahesana Formation represents aeolian and older levee deposits. Feasibility studies of Thermoluminescence (TL) and Infra-red Stimulated Luminescence (IRSL) dating on the Sabarmati succession yielded stratigraphically consistent ages ranging from ∼ 5 ka to ≥ 300 ka. For two samples, TL ages on quartz and IRSL ages on feldspar separates, were consistent. These results, together with the stratigraphic and petrographic data reveal the following events in the accumulation history of the Sabarmati sequence: 1. (1) Significant aggradation at ≥ 300 ka (gravel-sand) and at 58 ka (sand), and 2. (2) Pedogenesis bracketed to 58-39 ka The Sabarmati river in its middle stretches follows a regional slope-deviatory course interpreted previously to be a neotectonic adjustment within the Cambay graben. Our chronological data suggest that this adjustment occurred, possibly, within the past 39 ka.

Late Carboniferous (mid to late Westphalian D) to Early Permian strata of south Staffordshire, English Midlands were deposited on the margins of a foreland basin (Pennine Basin) during a period of increasing climatic aridity. Approximately 300–500 m of grey and red-bed alluvial sediments contain five vertically stacked facies associations, each with characteristic stratal architecture and palaeosols. The succession exhibits three orders of cyclicity. First order cycles (100–150 m thick) resulted from tectonic activity in the hinterland. Second order cyclicity, reflected in three regionally extensive, dekametre-scale, upward-fining packages resulted from isostatic readjustment of the source area. Third order, autocyclic responses caused metre- to dekametre-scale, upward-fining and upward-coarsening trends. Tectonics and climate were interdependent and their combined effects led to deposition of first order cycles or sequences. Cycle 1 was deposited largely upon a poorly drained alluvial plain; caliches within the interfluves indicate relatively high evapotranspiration rates. Heavy mineral data suggest a distant source. Cycles 2 and 3 reflect a switch to a local source. This was probably due to the combined effects of hinterland tectonism and increasing aridity. The latter led to fluvial inefficiency and increasing input from local drainage basins. The change in climate and source area resulted in variable sand/mud ratios and depositional styles for each cycle. Recognition of the influence of tectonics and climate in fluvial sedimentation means that the resultant genetic alluvial sequence architecture has a predictive function. In the absence of good biostratigraphical markers, this can be used in correlation and predicting sequence architecture in adjacent areas.

The Maastrichtian Lameta Beds of central India are intimately associated with the Deccan lavas and are critical to determining Upper Cretaceous palaeoenvironments and palaeogeography of the area. In the type Jabalpur sub-region, four mappable units of the Lameta Beds are recognised. The basal Green Sandstone is interpreted as a braided stream deposit. The Lower Limestone, characterised by brecciation and shrinkage cracks, is interpreted as a sub-aerially exposed palustrine flat with calcrete formation occurring on topographic highs of low relief plains. The overlying Mottled Nodular Beds exhibit a variable range of calcrete fabrics and morphologies including circum-granular and linear cracks, root casts and nodules. These are interpreted as pedogenically modified sheet wash deposits of a semiarid alluvial plain. The Upper Sandstone is a sheet flood deposit, again pedogenically modified before arrival of the basal lava flows. Overall the Lameta beds are considered to represent a regionally extensive Maastrichtian regolith. Carbon and oxygen isotope analyses of calcareous components are entirely consistent with soil-zone environments. The δ13C values are low, typically −8 to −9‰ PDB, demonstrating a strong input of carbon from the decay of terrestrial land plants. Calcrete δ18O values are variable, −5 to −10‰ PDB consistent with precipitation from meteoric water, some of which was evaporatively modified in pools on the alluvial/palustrine flat. The Lameta Beds are well known for sauropod nesting sites and sedimentological analyses of these sites suggest that the animals selected topographic highs, usually in marly or sandy, soft sediment. Multiple nests with similar egg types probably indicate colonial nesting. Isotopic analyses of eggshell carbonate agree with earlier work suggesting that the sauropods ate a “C3” plant food.

The ichnofossil assemblage of the lower Eocene Willwood Formation consists of at least nine distinct endichnia that are preserved in full relief. Four forms (three ichnogenera and four ichnospecies) are new and represent fodinichnia and domichnia of oligochaete worms, an insect or spider, an unknown vertebrate (probably a mammal), and domichnia of an unidentified organism. Other potential trace makers of the ichnofauna include insects, mollusks, and decapods. In contrast to an Egyptian Oligocene fluvial ichnofauna produced largely by animals that burrowed in stream channel deposits, the Willwood assemblage is principally of flood-plain origin. Though the ichnofauna occurs in a variety of paleosol types, most of the fossils are restricted in distribution to specific sediment and soil types and, within paleosols, to specific identifiable horizons. This attribute will make them valuable indiced of paleoenvironment once they are better known in other ancient alluvial sequences. The environment suggested by the Willwood trace fossils (damp, but not wet soils with fluctuating water tables) is consistent with the warm temperate to subtropical (possibly monsoonal) conditions that are interpreted for the Willwood Formation by independent evidence of body fossils and paleopedology.

The lower Eocene Willwood Formation of northwest Wyoming is a 700 m thick accumulation of alluvial floodplain and channel mudstones and sandstones, nearly all of which show paleopedogenic modifications. Pedogenesis of Willwood sandstones is indicated by taproot and vertebrate and invertebrate bioturbation, early local cementation by calcium carbonate, and thin illuviation cutans on clastic grains. Pedogenesis in Willwood mudstones is indicated by plant bioturbation, insect and other invertebrate burrow casts and lebensspuren; free iron, aluminum, and manganese mobilization, including hydromorphic gleying; sesquioxide and calcareous glaebule formation in lower parts of the solum; presence of clay-rich and organic carbon-rich zones; and well differentiated epipedons and albic and spodic horizons. Probable A horizons are also locally well developed. Occurrence of variegated paleosol units in thick floodplain mudstone deposits and their association with thin, lenticular, and unconnected fluvial sandstones in the Willwood Formation of the central and southeast Bighorn Basin suggest that these soils formed during times of rapid sediment accumulation. The tabular geometry and lateral persistence of soil units as well as the absence of catenization indicate that Willwood floodplains were broad and essentially featureless. All Willwood paleosols were developed on alluvial parent materials and are complex in that B horizons of younger paleosols were commonly superimposed upon and mask properties of suspected A and B horizons of the next older paleosols. The soils appear to be wet varieties of the Spodosol and Entisol groups (aquods and ferrods, and aquents, respectively), though thick, superposed and less mottled red, purple, and yellow paleosols resemble some ultisols. Most Willwood paleosols resemble warm temperate to subtropical alluvial soils that form today under alternating wet and dry conditions and (or) fluctuating water tables. The up-section decrease in frequency of gley mottles, increase in numerical proportion and thickness of red versus orange coloration, and increase in abundance of calcrete glaebules indicate better drained soils and probably drier climate in late Willwood time. This drying is believed to be related to creation of rain shadows and spacing of rainfall (but not necessarily decrease in absolute rainfall) due to progressive tectonic structural elevation of the mountainous margins of the Bighorn Basin.

The Daban Basin is filled with 2700 m of Middle Eocene to Oligocene clastic deposits. From the bottom of the sequence upward six sedimentary environments are distinguished: restricted lagoon, delta, lagoon, alluvial plain, ephemeral and perennial lakes. The latter show a lateral transition into thick fan-delta sequence (Kalajab fan-delta). A general vertical trend from an ephemeral, saline lake to perennial fresh-water lake has been recognized. The lower portion of the lacustrine sediments, which is 1100 m thick, consists of red and green siltstones, interbedded with cross-laminated sandstones representing dry mudflat (playa) deposits. An interval of saline playa sedimentation, interbedded in the playa mudflat sequence, includes red siltstones, green siltstones and laminated gypsum arranged in cycles; these were deposited in dry mudflats and in a chemically stratified lake. The upper portion of the lacustrine deposits, which is 900 m thick, is composed of green siltstones, cross-lamimated sandstones, chalky laminated limestones and some tuff layers. Fresh-water fishes, ostracods, gastropods and tree trunk remains are locally present. These sediments were laid down in a fresh-water perennial lake. The Daban Basin was a rapidly subsiding depression during the period that rifting was taking place in the adjacent Gulf of Aden. Lacustrine deposition was controlled by the paleogeographic and paleoclimatic changes induced by this event.

During the Holocene period, lake basins existed in some parts of the Danakil Desert. These basins were supplied either by the Awash River or by ground waters flowing through highly fissured basaltic flows. It is possible to reconstruct the areas and fluctuations of lake levels because of the preservation of old shore lines. Calcareous and diatomaceous bottom deposits give information about lacustrine paleo-environments (isotopic analyses, diatoms). It is suggested that the Holocene period started with an extensive lacustrine episode between 11,000 and 7,000 years B.P. At least one other transgressive stage, of lesser importance, took place between about 2,000 and 1,000 years B.P. The lakes mainly supplied with ground waters (Afrera) exhibit evidence of chemical and biochemical sedimentation. The depostion continued after 7,000 years B.P., and indicates a buffering effect owing to the aquifers. Hence, these basins do not have the simple behaviour of a rain gauge recording the local climate fluctuations of the Danakil Desert. The Dobi Graben can be partly related to this kind of basin. Because of the strong turbidity of the flood waters, the lakes with both shallow and underground supplies are quickly filled up in the head of the alluvial plain of the Awash River. The lakes at the downward part of the plain (Gamari and terminal Lake Abhe) have been preserved from the solid supply during the two humid episodes. During the intermediate stage, the lacustrine regression allowed the transport of silts and muds as far as Lake Abhe. The Awash River has not ceased flowing and the progression of the alluvial deposits isolates some area of retention on the margins of the plain (lacustrine relicts at about 4,000 and 5,000 years B.P.). After subtracting the local hydrological influences, by means of comparison with the recent phenomena, this succession fits into the general pattern of the Holocene climatic events of the southern margin of the Sahara.

From Kimmeridgian to Valanginian, the northern part of the Iberian plate broke up into several graben systems, one of which is the Cameros basin in the northwestern part of the Iberian Range. The infill consists of fluvial-clastic and lacustrine or evaporitic carbonate rocks. During the Berriasian, a lacustrine complex developed. Detailed study of these deposits traces the limits of three typical zones: Zone (1), a periodically emergent lake (palustrine facies, extending over a large area), Zone (2), lakes in an alluvial plain, and Zone (3), a permanent lake (a) with a palustrine fringe (b). The corresponding zones are bounded by prominent, long-lasting and tectonically active structures.