Quaternary River Terraces Research Articles

Palaeolithic and Quaternary research in the Trent Valley (UK): contributions by early collectors

A brief history is presented here of the activities of the three most notable collectors of Lower and Middle Palaeolithic artefacts from Quaternary river terrace deposits in the Trent Valley, derived from archival material that has been largely ignored by previous research. Two, Mr. Fred W.G. Davey and Mr. George F. Turton, were local amateur collectors who did not publish the results of their work themselves and were reliant on collaboration with established archaeologists. The third, Mr. A. Leslie Armstrong, was an archaeologist best known for his work at Creswell Crags and Grimes Graves. Armstrong also made many Palaeolithic discoveries in the Trent Valley but published few details of his own material. Although such details of early Palaeolithic research in the Midlands and North of Britain are predominantly of historical interest only, they nonetheless provide a number of insights into the apparent lack of interest shown in areas north of the ‘Severn–Wash Line’ by collectors of Palaeolithic artefacts. Importantly, the dataset assembled by the Trent Valley Palaeolithic Project (TVPP) and summarized here is the only complete record of the known artefacts and archival material from the Trent, a proportion of which is now unavailable to the research community, having entered unknown private ownership since being studied. The second part of the paper relates this early research to current knowledge of the British Palaeolithic at its most northern fringes and to recent developments in reconstructing the Quaternary evolution of the River Trent.

Late Quaternary river terrace sequences in the eastern Kunlun Range, northern Tibet: A combined record of climatic change and surface uplift

The Kunlun Range, a reactivated orogenic belt, constitutes the northern margin of the Tibetan Plateau. The extreme relief and major landforms of the Kunlun Range are a product of late Cenozoic tectonics and erosion. However, well-developed late Quaternary terraces that occur along the northern slope of the Kunlun Range probably resulted from climatic change rather than surface uplift. The terrace sequences formed in thick Quaternary valley fills and have total incision depths of 50–60 m. Optically stimulated luminescence dating was employed to place time controls on the valley fills and associated terraces. Dating results suggest that periods of significant aggradation were synchronous between different rivers and correspond to the last glacial stage. The abrupt change from aggradation to incision occurred between 21.9 ± 2.7 and 16 ± 2.2 ka, coincident with the last glacial–interglacial transition. Additional terraces developed during the late glacial period and early to middle Holocene. Based on a broader set of chronological data in northern Tibet, at least four regional incision periods can be recognized. Chronological data, terrace elevation profiles, and climate proxy records suggest that these terracing periods were triggered by cool and/or wet climatic conditions. A geometric survey of the riverbed longitudinal profile suggests that surface uplift serves as a potential dynamic forcing for long-term incision. A model is proposed for terrace formation as a response to climatic perturbation in an uplifted mountain range.

Characterisation and evolution of the River Rhine system

AbstractThe River Rhine and its tributaries represent one of the largest drainage systems in Europe. Its prominence among other fluvial systems is due to the location of its headwaters within the central Swiss Alps, which were repeatedly glaciated during the Quaternary, and the concurrence of major parts of the River Rhine course with the European Cenozoic Rift System. Sediments of the Rhine have thus recorded both changes in climate and tectonic activity as well as sea level change in the lower part of the river course.The River Rhine is composed of different subdivisions characterised by distinct geographical and geological settings. Vorder-and Hinterrhein in the headwaters are inner-alpine rivers frequently influenced in their course by tectonic lines and the blockage of valley floors by the deposits of mass movements. The Alpenrhein is located in a main Alpine valley that drains into a large foreland basin, the Bodensee (Lake Constance). The Hochrhein flows out of the lake following the Jura Mountains in a western direction. All these areas display a series of geological features such as moraine ridges and outwash plains, which directly reflect Quaternary glaciations of the Alps. The Oberrhein (Upper Rhine) Valley, as a graben structure, is part of the rifting system that started to develop during the middle Tertiary. The northern end of the graben is represented by the triple junction of the Mainz Basin, which is mainly characterised by the remains of marine transgressions that occurred during the initial rifting phase. The Rhine continues following the western branch of the tectonic system by passing through the Rhenish Massif. Uplift in this so-called Mittelrhein (Middle Rhine) area is well documented by a flight of late Tertiary to Quaternary river terraces. This region is also characterised by young volcanic activity as found, for example, in the Eifel volcanic field. The Niederheinische Bucht (Lower Rhine Embayment), especially the Roer Valley Rift System, represents the northern continuation of the rifting system. This area is characterised by differential uplift in the southern and subsidence in the northern part of the basin, which continues into the Netherlands. Here, the main stream of the River Rhine is separated into different branches developing an active delta at the coast of the North Sea. When the North Sea Basin was covered by ice during the Elsterian, Saalian and probably also the Weichselian glaciation and global sea level was low, the Rhine continued its course through the English Channel and flowed into the North Atlantic off Brittany.

Evolution of Quaternary river terraces related to the uplift of the central part of the Bohemian Massif

Fluvial sediments in the Vltava, Berounka, Sázava and Labe valleys are preserved as extensive river terrace sequences. These accumulation terraces originated from an interaction of climate-morphogenetic and neotectonic processes in the late Cenozoic. The palaeogeographical history of the central part of the Bohemian Massif is described. Geomorphological analysis of late Cenozoic fluvial sediments preserved in the Bohemian Massif confirm that in total 7 main terrace accumulations with several secondary levels can be differentiated. A chronostratigraphical scheme of erosion and accumulation periods and their relations to variable uplift rates in the late Cenozoic is suggested. The relative height of the oldest fluvial terraces above the present-day bottoms of river valleys is more than 100 m which indicates the approximate depth of erosion in the Quaternary.

Late Cenozoic development of the Strouma and Mesta fluviolacustrine systems, SW Bulgaria and northern Greece

The Strouma and Mesta are two of the largest rivers that drain across SW Bulgaria and northern Greece into the northern Aegean Sea. Their modern valleys, flanked by Quaternary river terraces, are incised into a diverse landscape, which records the region's complex tectonic history. A network of lacustrine basins existed in the region in the Late Oligocene to earliest Miocene, but was disrupted by thrusting and folding related to Early Miocene transpression. This deformation was followed by a period of erosion, covering most of the Early and Middle Miocene, which probably marked the initiation of the Strouma and Mesta fluviolacustrine system, with geometries unrelated to the older systems. The first clear evidence of these river systems dates from the Middle Miocene (late Badenian to Sarmatian). The systems evolved in the Late Miocene (Maeotian to early Pontian), when lakes existed, characterized by diatomaceous algae and by occasional burial of abundant plant fragments and coal formation. Areas in the south, south of the Kerkini fault, were intermittently submerged beneath the Aegean Sea at this time. Intense localized uplift of horst blocks in late Pontian and Pliocene, associated with crustal extension, resulted in deposition of thick alluvial fans, with tilting of sedimentary successions in adjacent grabens evident by the end of the Pliocene. The highest horsts (Osogovo, Rila, Pirin, and Belasitsa) experienced additional uplift in the Pleistocene, in part as a result of regional uplift and in part through continued normal faulting. Pleistocene climate change also resulted in influxes of glacial and fluvioglacial systems. The present form of the Strouma and Mesta fluviolacustrine systems is thus the result of interplay between crustal extension, regional uplift, and global climate change.

Morphologic expression of Quaternary deformation in the northwestern foothills of the Ysyk-Köl basin, Tien Shan

The Tien Shan is one of the most active intracontinental mountain belts exhibiting numerous examples of Quaternary fault-related folding. To provide insight into the deformation of the Quaternary intermontane basins, the territory of the northwestern Ysyk-Kol region, where the growing Ak-Teke Anticline divided the piedmont apron of alluvial fans, is studied. It is shown that the Ak-Teke Hills are a sharply asymmetric anticline, which formed as a result of tectonic uplift and erosion related to motions along the South Ak-Teke Thrust Fault. The tectonic uplift gave rise to the local deviation of the drainage network in front of the northern limb of the fold. Optical (luminescent) dating suggests that the tectonic uplifting of the young anticline and the antecedent downcutting started 157 ka ago. The last upthrow of the high floodplain of the Toru-Aygyr River took place 1300 years ago. The structure of the South Ak-Teke Fault is examined by means of seismologic trenching and shallow seismic profiling across the fault. A laser tachymeter is applied to determine the vertical deformation of alluvial terraces in the Toru-Aygyr River valley at its intersection with the South Ak-Teke Fault. The rates of vertical deformation and an inferred number of strong earthquakes, which resulted in the upthrow of Quaternary river terraces of different ages, are calculated. The study territory is an example of changes in fluvial systems on growing folds in piedmont regions. As a result of shortening of the Earth’s crust in the mountainous belt owing to thrusting, new territories of previous sedimentation are involved in emergence. The tectonic activity migrates with time from the framing ridges toward the axial parts of intramontane basins.

Paragenesia of Quaternary pediments and river terraces on the north piedmont of Wutai Mountains

A study has been made of the paragenetic relations of the pediments and river terraces on the northern piedmont of Wutai Mountains via geomorphologic mapping of 1:10000 scale, and an analysis on the role of tectonic, climatic, and drainage factors in the parageneses. The Quaternary pediments and river terraces on the north piedmont of Wutai Mountains united to constitute six steps of geomorphic surfaces. The episodic uplifting of fault blocks was the dominant factor in the formation of the unified surfaces, however, climatic change and drainage diversities led to undulation of the surfaces. The second terrace of Yangyan River (T2) was formed in the last glacial maximum, when the river was in aggradational state. The third to fifth terraces were formed in interglacial stages, when the river was in equilibrium or degradational state. It is inferred that climate had no insignificant effect on the river incision caused by tectonic uplifting. In light of terraces dating, since the Quaternary the Wutai fault-block mountains experienced six rapid uplifting events, and the starting time of the last four events was respectively 1.2, 0.6, 0.13, and 0.02 Ma B.P.

Strike-slip faulting, rotation, and along-strike elongation in the Kopeh Dagh mountains, NE Iran

SUMMARY The Kopeh Dagh is a linear mountain range separating the shortening in Iran from the stable, flat Turkmenistan platform. In its central part is an array of active right-lateral strike-slip faults that obliquely cut the range and produce offsets of several kilometres in the geomorphology and geological structure. They are responsible for major destructive earthquakes in the 19th and 20th centuries and represent an important seismic hazard for this now-populous region of NE Iran. These strike-slip faults all end in thrusts, revealed by the uplift and incision of Late Quaternary river terraces, and do not continue beyond the Atrak river valley, which forms the southern margin of the Kopeh Dagh. The cumulative offset on these strike-slip faults, and their associated rotation about vertical axes, can account for ∼60 km of N‐S shortening. This value is similar to estimates of the Late Quaternary N‐S right-lateral shear between central Iran and Afghanistan, which must be accommodated in NE Iran. The strike-slip faults also require ∼30 km of along-strike extension of the Kopeh Dagh, which is taken up by the westward component of motion between the South Caspian Basin and both Eurasia and Central Iran. It is probable that these motions occurred over the last ∼10 Ma.

3-D mapping of segmented active faults in the southern Vienna Basin

In this paper we present novel data on the location and kinematics of seismically active fault segments of the Vienna Basin Transfer Fault System in the southern Vienna Basin. Spatial mapping of active faults and kinematical analyses are based on commercial 3-D reflection seismic data, geomorphological features such as tilted Quaternary river terraces and fault scarps, the geometry of subsided Quaternary basins, and published geodetic data. Accordingly, active faulting in the southern Vienna Basin occurs partly by reactivation of the Miocene fault system related to the formation of the Vienna pull-apart basin between c. 17 and 8 Ma. Two domains of Quaternary and active faults can be distinguished with, (1) predominantly strike-slip and (2) mainly normal faulting. (1) A seismically active NE-striking sinistral strike-slip fault zone with large negative flower structures is mapped at the south-eastern margin of the basin. Subsidence within the reflection seismically imaged flower structure is documented by up to 1000 m of throw since Pannonian times and the accumulation of up to 150 m thick Quaternary gravels. At the surface the fault zone is characterized by en-echelon faults with some prominent scarps. (2) Major E-dipping normal faults branch off from the transfer strike-slip fault system. The normal faults extend into the central and western part of the basin as well as into the urban area of Vienna. Close to Vienna, the normal offset along such a normal fault is at minimum 300 m since Pannonian times. Surface expressions of active normal faulting are tilted Quaternary terraces of the Danube river and tilted ancient land surfaces in the hanging wall of the normal faults. The mapped active normal faults are kinematically linked by a common detachment horizon, which is in contact with the seismically active strike-slip zone along the south-eastern border of the basin. Northeast of the Vienna Basin the seismically active zone continues as a straight line indicating a rather linear transfer fault zone than a pull-apart step over geometry.

Late Quaternary river terrace development in the Macgillycuddy's Reeks, southwest Ireland

Geomorphological, sedimentological, pedostratigraphical and palaeoecological analyses of fluvial and glacigenic deposits infilling the Gaddagh valley, Macgillycuddy's Reeks, southwest Ireland, are used to elucidate the patterns and controls of Late Quaternary valley floor development in a 3 km reach of the catchment lying immediately downvalley of two mid-basin lakes, Lough Gouragh and Lough Callee. A total of four Holocene alluvial terraces (Terrace Level, TL 2–5) and a modern floodplain (TL 6) have been identified and lie inset within a strath terrace comprising Late Quaternary (Midlandian) till (TL 1). The combination of mid-basin lakes and flanking strath terraces acted to decouple the Gaddagh channel from upper catchment and valley-side debris sources shortly after regional deglaciation. Postglacial fluvial terrace development in the study reach has therefore occurred primarily in response to hydrological changes and reworking of local valley floor deposits rather than catchment-wide debris supply changes. Pollen analyses of valley floor peat deposits interbedded with minerogenic alluvium indicate that anthropogenic disturbance of catchment tree cover had commenced by c.a 1690–1450 cal BC and that the catchment was largely cleared of woodland by later prehistoric times. Major phases of incision and alluviation represented by terraces TL 3–5, however, have been radiocarbon dated to the period after 250–530 cal AD and broadly correspond with Holocene fluvial records elsewhere in the region, upland Britain and northwest Europe. Although fluvial system responses to hydrological changes will have been promoted by anthropogenic disturbances of catchment vegetation cover, the timing of late Holocene incision and alluviation episodes are interpreted as reflecting enhanced flood frequencies and (or) magnitudes associated with late Holocene climatic shifts. In the Gaddagh Valley, however, we hypothesise that the headwater lakes Lough Gouragh and Lough Callee may also have exerted a critical control on the postglacial evolution of the valley floor. In particular, high-magnitude flooding is likely to have been instrumental in valley floor entrenchment and formation of TL 3, TL 4 and TL 5 terraces.

A Fluvial Record of Long-term Steady-state Uplift and Erosion Across the Cascadia Forearc High, Western Washington State

Six late Quaternary river terraces, preserved along the Clearwater River in northwestern Washington State, provide a ∼140 ka record of long-term incision and uplift across the western side of the Cascadia forearc high. Terrace ages are constrained by weathering rind and radiocarbon dating and by correlation to dated coastal glacio-fluvial deposits and the global eustatic curve. The terraces overlie flat bedrock surfaces, called straths, which represent uplifted segments of the river channel. Bedrock incision is measured by the height of a strath relative to the adjacent modern river channel. The straths along the Clearwater show an upstream increase in bedrock incision, ranging from ∼0 at the coast to a maximum of 110 m in the headwaters. The incision at any point along the profile increases systematically with strath age. The calculated incision rates range from ∼10 ky) the Clearwater River valley has maintained a steady-state profile defined by a long-term balance in the rates of incision and rock uplift. Upstream divergence of terraces is best explained by an increase in the rate of rock uplift from the coast toward the central part of the range. These results are consistent with other evidence indicating a long-term steady-state balance between the accretionary influx and the erosional outflux for this part of the Cascadia subduction wedge since ∼14 Ma. These results help show how terrace deposits form in tectonically active landscapes. The dominantly fluvial Clearwater drainage was forming straths while alpine glaciers were advancing in adjacent drainages. In turn, the straths were buried during the transition to interglacial times because of increased sediment supply due to local deglaciation and because of eustatic highstands that forced aggradation in the lower reach of the drainage and across the continental shelf as well. The fluvial system shows strong forcing by the glacial climate cycle. Even so, the river appears to have returned to the same valley profile during each cycle of strath cutting. Thus, bedrock incision is clearly unsteady at time scales shorter than the glacial climate cycle (∼100 Ky) but appears to be relatively steady when averaged over longer time scales. A simple kinematic model is used to examine how uplift of the Cl. Our analysis indicates that the accretionary flux into the wedge occurs mainly by frontal accretion and not by underplating. If accretion occurred entirely at the front of the wedge, the present west coast should be moving to the northeast at ∼3 m/ky, relative to a fixed Puget Sound. This prediction is in good agreement with offset of a ∼122 ka sea cliff preserved at the southwest side of the Clearwater valley profile. In this case, the long-term margin-perpendicular shortening would account for 20 to 35 percent of the geodetically-measured northeast-southwest shortening across the Olympic Mountains.

Tectonic and paleoclimatic significance of Quaternary river terraces of the Waipaoa river, east coast, North Island, New Zealand

Remnants of four aggradational terraces in the lower 45 km of the main branch of the Waipaoa River have been correlated with cold/cool climate episodes of the Otiran glaciation. The youngest of the aggradation levels—the Waipaoa‐1 terrace—has the c. 14.7 kaRerewhakaaituTephra as the oldest part of the coverbed sequence, indicating cessation of aggradation about 16 ka BP. This terrace is broadly correlated with Ohakean‐aged terraces in other parts of the North Island. The second most recent episode of aggradation—the Waipaoa‐2 terrace—is slightly older than the c. 28 ka Mangaone Tephra, and is broadly correlated with the Rata terrace. The third most recent aggradation episode— the Waipaoa‐3 terrace—is slightly older than the c. 55–57 ka Rotoehu Tephra (age estimate based on stratigraphic relationships in this study), indicating cessation of aggradation at c. 65 ka BP, and correlative with the Porewa terrace. The fourth, and oldest, aggradation episode we identify in the present landscape—the Waipaoa‐4 terrace—has poor age constraints, but is probably related to the cool period of late oxygen isotope stage 5 at c. 90 ka BP or the glacial period of oxygen isotope stage 6 at c. 140 ka BP. Tectonic deformation in the middle reaches of the Waipaoa catchment is deduced from the elevation difference of pairs of aggradation terraces, and takes the form of broad regional uplift in the range of 0.5–1.1 mm/yr. Uplift is probably driven by subduction processes in the middle part of the catchment and by a combination of deep‐seated subduction processes and local deformation associated with active faults and folds in the lower valley area. Downcutting rates of up to 7 mm/yr occur in upper reaches of the river. In the middle reaches of the valley, where there are both uplift and downcutting data, we find that downcutting is about four times faster than tectonic uplift. Thus, climate fluctuations are interpreted to be the primary control on formation of fluvial terrace landscapes in the region.

Development of ‘rockhead’ computer-generated geological models to assist geohazard prediction in London

Abstract Much of London is founded on Quaternary river terrace deposits, consisting mainly of sand and gravel associated with the course of the River Thames. The base of these Quaternary river terrace deposits, the ‘rockhead’ surface, is generally planar and rests on London Clay. Locally, however, the terraces may include steep-sided, gravel-filled hollows, some of which penetrate other solid formations below the London Clay, such as the Lambeth Group (formerly known as the Woolwich and Reading Beds). Unforeseen engineering problems involving deep foundation construction or tunnelling beneath London have resulted from failure to predict irregularities in the base of Quaternary deposits. Detailed knowledge of the three-dimensional shape of the Quaternary deposits can assist in predicting ground conditions. In order to provide such a model more than 22 000 borehole records from London have been encoded into a digital, relational database. Contour plots of specific geological surfaces, including the top of the Chalk, the base of the London Clay and the base of the Quaternary deposits have been generated from the database using computer-modelling software. Quality assurance is an important part of the databasing procedure and suspect borehole information is discarded at an early stage. As computer modelling proceeds, further data may be eliminated if considered anomalous. The computing infrastructure provides graphical presentations of borehole logs, contour plots, isopachyte (thickness) plots of the major geological units together with cross-sections, fence diagrams, block diagrams and perspective views, giving an enhanced, three-dimensional understanding of the geology of London.

Alluvial Soil Chronosequence in the Inner Coastal Plain, Central Virginia

A chronological sequence of soils formed on a series of alluvial depositional surfaces ranging in age from late-middle Miocene to late Pleistocene was characterized to clarify soil-geomorphic relations and provide a basis for allostratigraphic subdivision of the inner Coastal Plain. On Quaternary river terraces, Ultic Hapludalfs containing abundant weatherable mineral species and clast types are estimated to have formed in 60,000-120,000 yr, whereas Typic Hapludults greatly depleted in weatherable minerals and showing strong weathering of clast types are estimated to be 700,000-1,600,000 yr old. Typic Paleudults with incipient plinthite, duripan, and ferricrete development characterize interfluves that have been little eroded since early Pliocene time (3.4-5.3 myr ago). Typic-Plinthic Paleudults with intense weathering of siliceous clasts and moderate to strong duripan and ferricrete development are found on surfaces that formed near the beginning of late Miocene time (10.8-13.0 myr ago). Chemical weathering in the chronosequence may be classified into three progressive stages: (1) decomposition of unstable sand- and silt-sized minerals into a mixed (stable + unstable) clay-mineral suite (stable Fe + Al/Si bulk chemical composition, < 10 6 yr); (2) transformation of mixed clay-mineral suite into a stable suite (increasing Fe + Al/Si bulk chemical composition, 10 6 - 10 7 yr); and (3) transformation of stable suite into ultrastable clay-mineral suite (increasing Fe/Si bulk composition, > 10 7 yr). Not all soil properties show unidirectional development, nor is a steady state of pedon development observed even after approximately 10 7 yr of chemical weathering. Soil development in the chronosequence is episodic. The transition from one phase to the next is marked by a change in rate, and sometimes a reversal in the direction, of development of one or more soil properties.

The micromorphology of quaternary river terrace deposits in the Kennet Valley, Berkshire, England

AbstractThree groups of micromorphological features are recognized in the river terrace deposits of the Kennet Valley. These are orthic pedological features, orthic pedological features disrupted by cryoturbation, and transport‐inherited features. Fluvial and solifluction processes account for the presence of the transport‐inherited features. Used in conjunction with sedimentological and geomorphological investigations the distribution, composition, size, shape, and relative proportions of micromorphological features are helpful in separating pedogenically‐altered materials from undisturbed sediments, and in recognizing the occurrence of more than one phase of soil development.

The mineralogy of Quaternary deposits in the Kennet Valley, Berkshire

The sedimentary characteristics, composition and mineralogy of a sequence of Quaternary river terraces is described. An exotic suite of heavy minerals is found in the silt fraction of topsoil deposits on the higher terraces and throughout the lowest terrace and floodplain. Mineralogical analyses of local Tertiary deposits indicate that this heavy mineral suite was derived from outside the catchment. The most probable source of the exotic silts was the North Sea Basin during the Late Devensian period. The gravels, coarser sand fractions and majority of the clay minerals in the terrace deposits indicate derivation from Cretaceous, Tertiary and early Pleistocene deposits within the Kennet Catchment.

Attention to topography of terraces in geological mapping

This article relates examples of topographic expression of geological structure and composition of some Quaternary river terraces in Siberia. --A. G. I. Staff.

Relation between Chelles-Acheul Implements and Quaternary River-Terraces of the Coega and Sundays Rivers

Relation between Chelles-Acheul Implements and Quaternary River-Terraces of the Coega and Sundays Rivers