High Terrace Research Articles

Riverscape-level patterns of riparian plant diversity along a successional gradient, Willamette river, Oregon

Riparian forest communities dominated by Populus balsamifera ssp. trichocarpa L. (Torr. and Gray ex Hook.) Brayshaw are important contributors to biodiversity in terrestrial and aquatic ecosystems of the Western United States. Species composition along a successional gradient from stand initiation to late-succession of P. balsamifera-dominated riparian forests was investigated along 145 km of the Willamette River, Oregon. There were 151 total species encountered across 28 stands and a mean species richness of 33.3 species per stand. Young stands were dominated by P. balsamifera and Salix tree spp. and opportunistic herbaceous species. Understory trees, shrubs, and herbaceous species as well as late-successional tree species established 12–15 years after stand initiation. Fraxinus latifolia Benth. was the dominant late-successional tree species. Vertical structural diversity, P. balsamifera mean diameter at breast height, large tree biomass, and stand age were strongly correlated with understory species presence and abundance based on non-metric multidimensional scaling (NMS) ordination. There were no young stands on mid and high terraces and this was reflected in geomorphic position being strongly correlated with the stand age gradient. Abundance of Phalaris arundinacea L. an invasive grass species, was also significantly correlated with plant species composition and abundance. This study indicates that Willamette River riparian forests are diverse and therefore important to the biodiversity of the Willamette River valley and that their presence as a mosaic of communities of different successional stages may be threatened by human interventions, including influences exerted by introduced plant species.

Uranium-series Age of the Highest Marine Terrace of the Upper Pleistocene on Kikai Island, Central Ryukyus, Japan

The uplifted Pleistocene marine terraces in Kikai Island have been investigated using radiometric dating since the 1960s. The highest terrace was called the Hyakunodai Terrace, which is divided into three blocks by faults, assigned in this study as Block C, Block B and Block A in ascending order of height. Previous studies indicate that Block A was formed during Marine Isotope Stage (MIS) 5e and that MIS 5c corals were distributed on the cliff between Blocks A and B based on Uranium-series dating. We carried out careful fieldwork and report more precise α-spectrometric U-series ages of Blocks A and B. Fossil corals showed eight Mid- to Late Pleistocene dates ranging from 154.8±6.4 to 97.7±3.0 ky (2σ) and three Middle Pleistocene ages (>450 ky). Mid- to Late Pleistocene dates are divided into three age groups, 154.8±6.4-142.7±5.8 ky, 122.1±3.8 ky and 108.2±3.2-97.7±3.0 ky, corresponding to MIS 6, 5e and 5c, respectively. While all age groups were obtained from Block A, Block B only contains MIS 5c and Middle Pleistocene corals. The MIS 5c outcrop at Block A contains clear reef structure (bindstone) and the coral assemblages indicate depositional depth ranging from 5 to 15 m. These facts suggest that the highest terrace was formed during MIS 5c. Exposure of MIS 5e or 6 corals is possibly due to erosional effect during MIS 5c transgression.

Eolian origin of the Miocene loess-soil sequence at Qin’an, China: Evidence of quartz morphology and quartz grain-size

Recent study revealed that the so-called Neogene Gansu System in the western Loess Plateau contains loess-soil sequences of Miocene age. A most complete sequence (QA-I) covers a time interval from ~22 to ~6.2 Ma BP, consisting of more than 230 visually definable paleosols interbedded with loess layers. A loess-soil sequence of late Miocene-Pliocene age, synchronous with the Hipparian Red Clay in the eastern Loess Plateau, was also recognized, and extends the Miocene sequences into the Pliocene, ~3.5 Ma BP. Recently, Miocene eolian deposits were also reported from the high terraces near Xining. Eolian origin of the Miocene sequences near Qin’an is supported by several lines of evidence, including micromorphological, sedimentological and geochemical data. Here, we further examine the morphology and sedimentological characteristics of more samples covering the entire QA-I sequence, to provide additional evidence of the eolian origin. Quartz is a dominant mineral component of eolian dust deposits . Because of its stable physical and chemical properties under surface conditions, grain morphology of the quartz is usually used to determine the sources, transportation dynamics and postdepositional modifications of the sediments . Grain-size of the quartz fraction is also better reflective to that of the original eolian dust as quartz is resistant to postdepositional chemical weathering in the semi-arid/ semi-humid loess regions. In this study, grainmorphology and grain-size distributions of the quartz fraction from the QA-I sequence are examined, and compared with those of the typical eolian deposits of Quaternary age from the Xifeng site.

Predictive modelling of multiperiod geoarchaeological resources at a river confluence: a case study from the Trent–Soar, UK

This research project developed a terrace sequence model of alluvial landscape development to aid the management of the geoarchaeological resource within a temperate valley floor threatened by aggregate extraction. The model was created using the remote sensing techniques of light detection and ranging (lidar) and ground-penetrating radar (GPR), dovetailed with other archaeological and geological data sets within a geographical information system (GIS). Lidar first pulse (FP), last pulse (LP) and intensity models were used in a combination of ways to characterize the landscape. The topographic LP model was particularly effective at defining the major alluvial landforms, such as the higher terraces and palaeochannels. Lidar intensity data defined the palaeochannels, in response to the surface sediments' ability to absorb/reflect the lidar laser pulse. The three-dimensional architecture of the sediments infilling the valley floor was elucidated and modelled by GPR survey along geospatially referenced transect lines. These surveys had their time-slices calibrated through gouge coring along the transect lines, allowing depth slicing of the sediment stratigraphy. The GPR surveys accurately defined the depth of silty clay alluvium overlying the sands and gravels. Internal structure was revealed within the terrace gravels and at the margins of palaeochannels, allowing identification of bounding surfaces and construction of relative landform chronologies. However, GPR penetration into fine-grained palaeochannel fills was generally shallow, with little internal channel stratigraphy revealed. The lidar data sets and the GPR depth slices were integrated within ArcGIS and ArcScene. The distribution of the known and sometimes visible archaeological remains is considered in context of the geomorphology. It is demonstrated that erosion and sedimentation have geologically filtered the archaeological resource and that some areas that have previously been considered archaeologically barren have high potential for both cultural and environmental archaeological remains.

平成16年 (2004年) 新潟県中越地震震源域の地表部における地形と地質構造

The Mid Niigata prefecture Earthquake occurred on October 23, 2004. Suzuki et al. (2004) and Maruyama et al. (2005a, 2005b) found small surface ruptures at Obirou and Aoshima areas. Suzuki et al. (2004) also argued that the earthquake was caused by movements of the Obirou Fault and the northern part of the Muikamachi-Bonchi-Seien fault. The aim of this report is to examine active geological structures and landforms in epicentral region of the earthquake. We carried out aerialphoto interpretation, geological survey, and geomorphometry by airborne laser scanning. As a result of our survey, the Suwatoge Flexure was found to be an active structure in the region, together with Obirou Fault and the Muikamachi-Bonchi-Seien fault. The Suwatoge Flexure is recognized as the fold on Uonuma formation (Plio-Pleistocene) and uplifts terraces in west/northwest direction; this is generally correspond with the earthquake source direction. The amount of vertical displacement in each terrace is as follows; more than 70m on Higher terrace (H2 surface), about 40m on Middle terrace (M1 surface) and about 10m on Lower terrace (L1 surface). The mean rate of vertical displacement is estimated 0.3m/103 year based on M1 Terrace surface covered by In-Kt Tephra [≥130, 000 year: Machida and Arai (2003)]. The Suwatoge Flexure is located at the eastern margin of the distributed area of aftershock epicenters, and its south end corresponds with that of the distribution of aftershock epicenters. The largest vertical movement of 71.5cm uplifts (GSI, 2004) as the co-seismic crustal deformation is located on the west side of the Suwatoge Flexure. Therefore, the formation of the Suwatoge Flexure were probably caused by activities of earthquake source faults.

Растительность южной части острова Большевик (архипелаг Северная Земля)

Bolshevik Isl. is the one of the largest islands within the Severnaya Zemlya archipelago. It is situated in the southern part of the polar desert zone. In the course of three field work trips in 1997, 1998 and 2000 years 252 relevees were made in its southern part on three geomorphologic surfaces: coastal plain, inner upland close to glacier and ancient high river terraces. As the result 27 syntaxonomical units of different rank (15 associations, 2 subassociations, 2 variants, and 8 community types) were described using Braun-Blanquet approach. All syntaxa, except one, are new and mostly similar to communities described on Franz Josef Land. The problems were to put new syntaxa into the higher level units (including class) within the syntaxonomical hierarchy. The main bulk of syntaxa, both zonal and intrazonal ones, has to be preliminary placed into Salicetea herbaceae class although there is a lot of reasons to consider zonal syntaxa as a new class that is specific for the polar desert zone. In any case, there are no one syntaxon that can be referred to Loiseleurio-Vaccinietea class that combines zonal vegetation in the tundra zone. The wide ecological range of great majority of species as well as the changes of their intralandscape distribution compare to the tundra zone made additional difficulties in finding character and differential species. 340 species (vascular plants — 52, mosses — 97, liverworts — 41, lichens — 150), that compiles 73 % of the whole island flora and 84 % of its southern part, were recorded within the all relevees. Almost half of these (182) are very rare on the island and 127 species were met 1—2 times. There are 70 species with wide ecological range throughout all landscape types with such commonly distributed herbs as Saxifraga cernua, S. hyperborea and Stellaria ed­ward­sii, mosses Polytrichastrum alpinum and Sanionia uncinata and lichen Stereocaulon rivulorum among these. Phippsia algida, the character species for snow bed communities, occurs in about 70 % of syntaxa. Useful for differentiation of syntaxa have been appeared 87 species. Few species with wide distribution within a landscape demonstrate their preference to a certain syntaxon by higher abundance (preferential character species). These are mostly bryophytes: mosses Bryum cryophilum and Grimmia torquata, and liver­worts Gymnomitrion corallioides, Marsupella arctica and Scapania crassiretis. Cryptogam species predo­minate in the whole flora as well as in each syntaxon. The number of species varies from 12 to 70 per sample plots 5÷5 m and from 20 to 195 in different syntaxa. The richest in species (70 per community and about 190 for association) are zonal plant communities on the accumulative coastal plain in the region of Sol­nechnaya Bay, the poorest one, with 10 and 20 species consequently, is ass. Hygrohypno polari—Saxifragetosum hyperboreae that was described on the upland, close to glacier in the inner part of island.

Mineral Composition of Clay Fractions and Oxygen Vacancies in Silt-Sized Quartz in Soils on the Ka-Etsu Plateau, Fukui, Central Japan—Possibility of Eolian Dust Brought from Northern Asia as Parent Material of Soils

Fine- to medium-textured soils are distributed on the Early Pliocene rocks and Pleistocene sandy sediments in the Ka-Etsu plateau. The Jingaoka (JIN) soil was classified into Aluandic Andosols by WRB, and Low-humic Non-allophanic Kuroboku soils by the Fourth Committee for Soil Classification and Nomenclature of the Japanese Society of Pedology, although it was similar morphologically to Yellow-Brown Forest soils. On the other hand, the Tomitsu (TMI) and Yamamuro (YAM) soils were classified into Hyperdystri-Chromic Cambisols by WRB, and Typic Yellow-Brown Forest soils by the Fourth Committee for Soil Classification and Nomenclature based on the morphological, physical and chemical properties. These soils were influenced considerably by the Akahoya tephra, especially the JIN soil. Based on the results of clay-mineralogical analysis and the measurement of the ESR-signal intensity associated with the oxygen vacancies in fine quartz, a large part of parent materials in the soils distributed on the Ka-Etsu plateau was derived from the eolian dust which was brought with the NW winter monsoon from the Precambrian sediments in the northern part of the Asian continent during MIS 2 (24–11 thousand years ago) at the Last Glacial Maximum. The parent materials of the fine-textured JIN soil located on the highest terrace near the rocky coastline were mostly composed of eolian dust, although the influenced of the Akahoya tephra was recognized. The parent materials of the TMI soil were admixed with a small amount of autochthonous materials from the sandy coast located windward. In the YAM soil which was located on the side of a hilly area distant from the coastline, the ESR-signal intensity in fine quartz was considerably low, and the admixture of autochthonous materials was also considered since the texture of this soil was coarser than that of the JIN and TMI soils.

Influence of Aluminum Hydroxide on Potassium Release from Two Colombian Soils

The effect of sesquioxides on the mechanisms of chemical reactions that govern the transformation between exchangeable potassium (Kex) and non‐exchangeable K (Knex) was studied on acid tropical soils from Colombia: Caribia with predominantly 2∶1 clay minerals and High Terrace with predominantly 1∶1 clay minerals and sesquioxides. Illite and vermiculite are the main clay minerals in Caribia followed by kaolinite, gibbsite, and plagioclase, and kaolinite is the major clay mineral in High Terrace followed by hydroxyl‐Al interlayered vermiculite, quartz, and pyrophyllite. The soils have 1.8 and 0.5% of K2O, respectively. They were used either untreated or prepared by adding AlCl3 and NaOH, which produced aluminum hydroxide. The soils were percolated continuously with 10 mM NH4OAc at pH 7.0 and 10 mM CaCl2 at pH 5.8 for 120 h at 6 mL h−1 to examine the release of Kex and Knex. In the untreated soils, NH4 + and Ca2+ released the same amounts of Kex from Caribia, whereas NH4 + released about twice as much Kex as Ca2+ from High Terrace. This study proposes that the small ionic size of NH4 + (0.54 nm) enables it to enter more easily into the K sites at the broken edges of the kaolinite where Ca2+ (0.96 nm) cannot have access. As expected for a soil dominated by 2∶1 clay minerals, Ca2+ caused Knex to be released from Caribia with no release by NH4 +. No Knex was released by either ion from High Terrace. After treatment with aluminum hydroxide, K release from the exchangeable fraction was reduced in Caribia due to the blocking of the exchange sites but release of Knex was not affected. The treatment increased the amount of Kex released from the High Terrace soil and the release of Knex remained negligible although with Ca2+ the distinction between Kex and Knex was unclear. The increase in Kex was attributed to the initially acidic conditions produced by adding AlCl3 which may have dissolved interlayered aluminum hydroxide from the vermiculite present, thus exposing trapped K as exchangeable K. The subsequent precipitation of aluminum hydroxide when NaOH was added did not interfere with the release of this K, and so was probably formed mostly on the surface of the dominant kaolinite. Measurement of availability of K by standard methods using NH4 salts could result in overestimates in High Terrace and this may be a more general shortcoming of the methods in kaolinitic soils.

An Early Miocene Dome-Skulled Chalicothere from the “Arikaree” Conglomerates of Darton: Calibrating the Ages of High Plains Paleovalleys Against Rocky Mountain Tectonism

Fragmentary skeletal remains discovered in 1979 in southeastern Wyoming, associated with a mammalian fauna of early Hemingfordian age (∼18.2 to 18.8 Ma), represent the oldest known occurrence of dome-skulled chalicotheres in North America. The chalicothere and accompanying fauna were found in silica-cemented fluvial sandstones and conglomerate capping a series of west-to-east trending buttes in Goshen County, Wyoming, extending eastward into Sioux County, Nebraska. These butte caprocks, herein named the Carpenter Ranch Formation, are the reversed topographic remnants of a major paleovalley incised in the early Miocene and filled with coarse granitic/mafic gravels and sands derived from Precambrian-cored upifts to the west. The Carpenter Ranch Formation is identified as a coarser-grained, westward extension of the early Hemingfordian Runningwater paleovalley of Skinner, Skinner, and Gooris (1977) situated in northwest Nebraska. The age-diagnostic mammal faunas and coarse crystalline gravels of the Carpenter Ranch Formation of Wyoming and the coeval Martin Canyon beds of northern Colorado document the timing of tectonic rejuvenation of Rocky Mountain uplifts to the west in the early Hemingfordian.A second line of buttes situated 3 miles (∼ 4.8 km) north of the Carpenter Ranch paleovalley includes the regional landmark recorded as “Spoon Butte” in 19th century military and topographic surveys of the region. Spoon Butte, its caprock in northwest-southeast alignment with adjacent satellite buttes, represents a second and younger mid-Miocene paleovalley trend, characterized by silica-cemented sandstones and basal granitic/chert gravel with Barstovian mammals.N.H. Darton and G.I. Adams of the U.S. Geological Survey first described these caprocks as Arikaree conglomerates and mistakenly assumed they were of the same age as the caprock at Spoon Butte and its accompanying buttes to the north. However, this investigation shows that (a) mammal faunas from the two caprock trends are of markedly different ages; (b) the clast composition of the gravels is distinct; and (c) the paleovalleys align along two entirely different geographic trends.Furthermore, a loose gravel found on top of Spoon Butte, previously believed to date the caprock, is identified as a lag deposit sharing the same distinctive clast composition as high Quaternary terrace gravels in the vicinity. These terrace gravels include acid volcanics (not present in the Carpenter Ranch and Spoon Butte basal gravels) and a composite assemblage of water-worn mammal bones of Barstovian, Clarendonian, and Pleistocene ages. Thus they demonstrate that late Cenozoic deposits once occupied the extensive tableland east of the Hartville Uplift, but were later removed by erosion and reworked into Pleistocene and Holocene drainages.

Distribution of Soil Microbial Biomass and Free-living Nematode Population in Terrace Chronosequences of Makhtesh-Ramon Crater

ABSTRACT In this study, we examined the effects of the age of erosional fluvial terraces of Makhtesh Ramon (Ramon crater) in the central Negev Desert on soil chemical and biological properties. There were significant effects of erosion age of these terraces on soil moisture, organic carbon, soil salinity, and electrical conductivity. It is known that soil biological activity in arid ecosystems is determined by well-known limiting factors such as soil moisture and organic matter. Significant (P < 0.002) differences in total nematode population and microbial biomass [(22.0–3.4 Cmic (µg C g−1 soil)] were observed between terraces. Biological activity of soils in lower and younger terraces was greater than in older and higher terraces. The ecophysiological status (qCO2) of the soil microbial community was found to decrease from a maximal value of 1.3 to 0.32 mg CO2‒C (gCmich)−1 along the terraces (from younger to older ones). This study illustrates the integrated effect of age, altitude, and the morphostratigraphic position of terraces on the biological activity of soils.

What is the amount of mercury accumulated in the Idrijca River overbank sediments?

Part of mine tailings and roasted ore remains of the Idrija mercury mine was deposited in the bed of the Idrijca River that transported the load downstream at high waters. It was deposited in alluvial sediments of the Idrijca and Soča Rivers, and in the Trieste Bay, essentially contributing to mercury pollution of environment. The goal of the reported research was to estimate the mercury amount accumulated in the Idrijca alluvial deposits. This was attained by multiplying the mercury contents in sediments by their weight. For calculation of this amount the Idrijca Holocene sediments in the terrace systems from Idrija to confluence of Bača river into it were mapped. For assessing the spatial distribution of mercury contents in sediments the alluvial floodplains were sampled according to an analysis-of-variance sampling design. This was important for establishing the amounts of mercury also in alluvial deposits that were not sampled. The analysis of variance indicated the mercury contents in alluvium to be the most dependent upon the position of the material within the alluvial plain, i.e. either on the most polluted floodplain, on the first or on some higher terrace. By considering this indication and the mapping results we estimated the amount of mercury accumulated in the Idrijca river alluvial sediments from Idrija to the confluence of Bača at 2029 tons.

Cavanaugh: A Late Prehistoric Platform Mound in Western Arkansas

Cavanaugh Mound (3SB3, also known as Etter's Mound, Jones Mound, Site Zeta, and occasionally misspelled Cavenaugh) is a largely intact Late Prehistoric platform mound on the Arkansas River just east of the Oklahoma border, about 14 km from the Spiro Mounds complex. The site is situated on a high terrace above the Arkansas River as it runs between the Ouachita Mountains to the south and the Ozarks to the north. The Poteau River enters the Arkansas River floodplain just west of Cavanaugh, creating one of the widest stretches of bottomland in the region. The area immediately around Cavanaugh Mound is now a residential neighborhood in the city of Fort Smith, and the mound itself is in a tiny lot with a church to the south, a trailer park to the east (named Indian Mounds Trailer Park), and a row of houses to the west. At about 60 m across and 9 m high, Cavanaugh Mound is one of the largest, if not the largest, prehistoric mound in the region. Very little has been published concerning this site, however, and very little formal archeological work has been done there. This article is partly intended to call attention to Cavanaugh Mound, and to compile all reports and descriptions of the mound in one publication. The first part of the article is therefore mostly descriptive. I also offer some tentative interpretations of the site and its possible relationship to the nearby Spiro and Skidgel sites. The size , shape, and stratigraphy of the mound all indicate that it was constructed and used in a manner similar to other Caddoan era platform mounds in the Arkansas River valley. The mound appears to be alone on the landscape, not connected to a group of surrounding mounds and not located within or near a contemporaneous settlement. It overlooks the Poteau/ Arkansas River bottoms to the west and was probably visible from both the Spiro and Skidgel sites in prehistoric times.

Climatic Influence on Sedimentology and Geomorphology of the Rio Ramis Valley, Peru

Abstract Fluctuations in regional precipitation and in base-level (the level of Lake Titicaca) trigger changes in fluvial erosion and deposition in the largest tributary valley of Lake Titicaca, the Rio Ramis, Peru. Relationships between fluvial sedimentation and terrace formation demonstrate that large-scale aggradational and downcutting events are associated with specific regional climatic events that have been previously documented in the Lake Titicaca basin and elsewhere on the Altiplano. Five laterally extensive terrace tracts (A through E) are present within the valley. Downcutting of the Ramis valley is correlative with base-level (Lake Titicaca level) fall caused by a decrease in precipitation. Aggradation is correlative with base-level rise during increasing precipitation. Sedimentary facies underlying the terraces record deposition in a large paleolake followed by deposition of both meandering and braided fluvial sediments. The highest terrace in the valley—E—is underlain by a thick sequence of lacustrine strata that was deposited during an extremely wet period in the Lake Titicaca region that terminated at about 40,000 cal yr BP. These lacustrine strata were subsequently downcut, likely at a time of large drop in lake-level, resulting in a deeply incised valley. The main phase of fluvial aggradation in the valley (sediments underlying the D through B terraces) was slow, spanning about 25,000 years. It occurred before, during, and after the Last Glacial Maximum (from before 35,140 ± 790 cal yr BP until about 10,421 ± 181 cal yr BP), a time period that was mostly characterized in the Lake Titicaca basin by high precipitation rates and high base-levels. The aggradation resulted in almost 40 m of sediment accumulation in the valley and was followed by rapid (about 2,000 years), but episodic, incision into the underlying fluvial sediments to form the C and B terraces, as well as the erosional surface beneath the modern fill terrace (A). This erosional phase corresponded to several periods of local base-level (Lake Titicaca) lowering between 10,241 ± 181 and 1,668 ± 76 cal yr BP. The modern fill terrace has aggraded about 2 m above modern river level, likely within the last 1,500 years.

The Indian Springs #2 Site(41BW512): A Late 18th Century Kadahadacho Settlement in Northeast Texas

The Indian Springs #2 site (41BW512) is on a high alluvial terrace or bluff edge (330 ft. amsl), overlooking the Red River floodplain and Hubbard Slough, an old channel of the river. The current channel of the river is ca. 1.6 km north of the site. The site appears to be a late 18th century Kadohadacho settlement with a small cemetery, although there is evidence in the collections known to have come from it that it was also occupied in Archaic and Early Caddo times (ca. A.D. 900-1200) as well as in the early to mid-19'h century. The site was discovered by the landowner, Mr. Julian Cranfill during earth-moving activities associated with construction of a pond. When European glass beads were noted by Mr. Cranfill on the disturbed ground surface, he began a limited excavation of the area where the beads were found, attempting to ascertain their context and what other kinds of artifacts may be associated with them. He excavated a circular area about 3-4 m in diameter along the eastern side of the bluff, on a small knoll. During this work, he documented three obvious cultural features and a dark charcoal-stained patch of burned soil that may represent remnants of a shallowly-buried burned structure. Feature I and II are burials of Caddo people, and both had European glass beads and pottery vessels placed in the grave as funerary objects. Feature III is a pit that contained butchered hog jaws; it may be associated with the later 19tb century Anglo-American farm occupation also present at the site. The Feature I burial pit was oriented east-west, and was the size of a child or subadult burial. The burial pit extended to ca. 66 em bs, and the bottom 2-5 em of the pit fill was a very dark soil. This soil is probably the product of firing episodes associated with Caddo burial ceremonies. There was a large concentration of glass beads at the eastern end of the burial, probably from necklaces of beads that were worn by the deceased. More than 3000 beads came from this area, along with a few preserved teeth, and three ceramic vessels. Feature II was a larger burial pit, probably that of an adult Caddo, oriented almost north-south. According to Mr. Cranfill, there were four ceramic vessels, more than 430 glass beads, and five triangular Fresno arrow points accompanying this individual.

Landforms, sediments, soil development, and prehistoric site settings on the Madaba‐Dhiban Plateau, Jordan

AbstractThis paper examines recurrent spatial patterns of prehistoric sites in relation to landforms, alluvial fills, and soil development in the uplands and valleys of the Madaba and Dhiban Plateaus of Jordan. Mousterian lithics (Middle Paleolithic) are largely found on high strath terraces plateaus, where they are associated with red Mediterranean soils. In valleys, Upper Paleolithic sites are often associated with reworked loess deposits of the Dalala allostratigraphic unit. Epipaleolithic occupations are found stratified in deposits of the Thamad Terrace, and Pre‐Pottery Neolithic and Pottery Neolithic occupations are associated with colluvium mantling the Thamad Terrace. The Tur al‐Abyad Terrace and the Iskanderite alluvial inset are the remnants of middle Holocene floodplains, which were attractive areas for Chalcolithic and Early Bronze Age settlements. Sometime around 4000 B.C., stream incision and further lateral erosion destroyed these floodplains. These historic terraces are underlain by alluvial deposits ranging in age from Roman to Early Islamic periods. The sequence of allostratigraphic units, paleosols, and terraces are the basis for reconstructing phases of fluvial aggradation and stream incision during the past 20,000 years. © 2005 Wiley Periodicals, Inc.

Arundo (Gramineae) in the Mediterranean reconsidered

Danin, A.: Arundo (Gramineae) in the Mediterranean reconsidered. — Willdenowia 34: 361–369. — ISSN 0511-9618; © 2004 BGBM Berlin-Dahlem.Finding the recently described Arundo hellenica in Italy initiated a study on the identity of taxa related to A. plinii, in the field, in the literature and in several herbaria. According to the somewhat preliminary results, besides A. donax with nodding leaves, three species with upright leaves are proposed for recognition in the Mediterranean. Their distribution and ecology are still incompletely known. A. plinii in its original sense is shown to be a 1–2 m high riparian plant, so far confirmed to occur in N Italy, S France and, perhaps, NE Spain. A. mediterranea is described as a new species for the illegitimately named A. mauritanica of Desfontaines, which has hitherto been erroneously recorded as “A. plinii” and is a caespitose reed with 1–5 m long obliquely erect culms that branch already in the first year; it grows on alluvial clayey soils or high river terraces along temporary water courses of N Africa, Israel, Cyprus, Greece, Crete, Lebanon and possibly other East Mediterranean countries. A. collina, including the recently described A. hellenica, is the lowest (0.5-2 [-3] m) and most drought resistant Arundo of the Mediterranean and forms monotypic grasslands on clay in badlands, on hill slopes up to 300 m, on sides of newly constructed roads, etc. and is currently known to occur in S Italy, mainland Greece and Crete.

Pattern formation in para-quaterphenyl film growth on gold substrates

Polycrystalline films of conjugated organic semiconductors offer attractive potential for optoelectronic applications. Controlling the film morphology is essential for preparing thin films tailored for optimized devices. Here, we use atomic-force microscopy (AFM) to investigate the morphology of para-quaterphenyl (4P) films deposited under UHV conditions onto Au(1 1 1) gold surfaces and polycrystalline gold films. Films of 4P with and without additional carbon pre-coverage have been investigated on an Au(1 1 1) single crystal surface. Individual rod like 4P crystallites as well as chains of rod like and tetragonal crystallites were observed for thick films. For thin films, depending on the carbon pre-coverage either fan like arrangements of linear 4P chains, bent 4P crystallites with a distinct height distribution, or growth hillocks of upright standing molecules were found. In order to study the effect of different surface orientations on shape and arrangement of the crystallites, 4P has been deposited onto a polycrystalline Au foil. On individual gold grains, preferential orientations of the 4P crystallite chains can be found. The orientation of the chains is linked to the crystallographic orientation of the underlying Au grain. In addition, growth hillocks with 1.8 nm high terraces of upright standing 4P molecules are observed.

Raised Pleistocene marine terraces of the Crotone peninsula (Calabria, southern Italy): facies analysis and organization of their deposits

Wide marine terraces well known in the Italian literature are present in the Crotone peninsula, Ionian Calabria. They are related to the interplay between Pleistocene sea-level changes and the progressive uplift of the Calabrian Arc from the middle Pleistocene onwards. We present a description of facies organization and stratigraphical characteristics of the terrace deposits, along with a new geological map of the area. All the marine terraces unconformably overlie a Plio-Pleistocene slope succession known as Cutro Clay. The oldest and highest terrace, named Cutro terrace, is placed between 90 and 200 m of elevation and is gently inclined south-eastwards. Four younger terraces placed at progressively lower elevations and dipping seawards at low angles have been recognized. The sedimentary deposits of the terraces are represented by mixed carbonate and siliciclastic bodies, up to 10 m thick. Algal reefs and grainstone to rudstone deposits are common in the south-eastern part of the study area, whereas mostly siliciclastic sandstone units of shoreface environments are more abundant northwards and westwards. The deposits of some terraces are made up of minor cycles, bounded by subaerial, transgressive, and flooding surfaces referred to minor sea-level fluctuations. NNE-, ENE-, E-, and WNW-trending normal fault systems are present within the study area and dissect the marine terraces. Specifically, the activation of ENE-trending faults took place after the formation of the oldest terrace but prior to the formation of the younger terraces.

Solute fluxes in throughfall and stemflow in four forest ecosystems in northwest Amazonia

The contribution of throughfall and stemflow as pathways for solute inputs into the forest floor in four mature forests in northwest Amazonia was investigated. Total solute inputs, resulting from the changes of atmospheric deposition after rainfall passes through the forest canopy, are presented in the form of throughfall and stemflow nutrient inputs and their possible sources are discussed. Throughfall is by far the most important solute input into the forest floor of the forests studied. On average, it represents about 98% of the total solute inputs. Although trends in solute enrichment varied among the forests, there is a general tendency in all ecosystems towards a distinct enrichment of SO4, K, Cl, NO3 and NH4 in throughfall and stemflow and a small increase of protons, Mn, orthoP and Fe. When comparing the net enrichment between the forests, the relative increase of solutes in throughfall and stemflow was higher in the flood plain and low terrace than in the high terrace and sedimentary plain forests. While highest values for total cation inputs were observed in the flood plain, the low terrace showed the highest value for total inorganic anions. The length of the antecedent dry period was the main factor affecting throughfall and stemflow composition, concentrations increasing with increasing length. A second, less important factor was the amount of throughfall and stemflow, which showed a poor and negative correlation with solute concentrations. The increased activity of frugivores in the canopy during fruiting periods seemed to lead to temporary increased solute concentrations in throughfall and stemflow as a result of the wash off of deposited faecal materials and detritus in the canopy. Leaching from leaves and wash off of exudes, of solutes deposited on the foliage after evaporation of intercepted rainfall and of dry deposited materials were all found to contribute to the concentration of solutes in the throughfall and stemflow. Gross rainfall enrichment after passing the forest canopy, mainly by nutrient leaching, is considerably lower than the amounts of nutrients released in litterfall implying a tight nutrient cycling and nutrient conserving mechanisms by forests studied.

Pedodiversity analysis at large scales: an example of three fluvial terraces of the Henares River (central Spain)

This paper presents the results of the application of richness and diversity indices and the fitting of four probabilistic distribution models to a soil chronosequence developed on the fluvial terraces of the Henares River (NE Madrid) as a means to analyse the soil mantle evolution of the valley during the Quaternary. Richness–area relationships were also investigated. Calculations were performed considering individuals (i.e., pedons) and the area covered by a given soil type, at different hierarchy levels of the USDA taxonomic classification (Great Group, Subgroup and family) as well as for diagnostic horizons. Abundance of Great Groups and Subgroups (richness or pedorichness) increases from low (young) to high (old) terraces. It has also been found that the higher the detail in the classification, the higher the pedodiversity values. Diagnostic horizons accounted for the genetic pedodiversity; its value decreases with soil development in the first meter of the solum; this trend changes with increasing observation depth. Therefore, genetic pedorichness and pedodiversity increase in this example with the age of geomorphologic surfaces. However, an appropriate quantification of the genetic diversity should consider the entire solum depth. It is also shown that pedodiversity increases with the area considered. On the other hand, the fit of sampled areas to the probabilistic distribution models used by ecologists is less conclusive. Regarding richness–area relationships, the low and middle terraces fitted a logarithmic function, while the high terrace fitted a power model, in agreement with the ecological literature on biotaxa–area relationships.