Soil evolution over the Quaternary period in a semiarid climate (Segre river terraces,northeast Spain)

A macro- and micromorphologic study was done on the soils from a stepped sequence of seven dated fluvial terraces in the lower Segre river valley (Lleida, northeast Spain) under a present-day semiarid Mediterranean climate. The soils have evolved from the Holocene through the early Pleistocene, providing an excellent morphostratigraphic framework for evaluating time-dependent factors influencing soil formation in a dry and calcareous environment. Throughout the chronosequence, some properties are regularly age-related specially carbonatation in subsurface horizons. The carbonates occur mainly as micrite, and although microsparite and sparite also appear in the oldest soils, they are replaced by fine-grained calcite by dissolution–reprecipitation processes (micritization process), which is active at present. Some pedological paleofeatures as the presence of sparite and recarbonated argillans in oldest terrace can be interpreted as the reflex of climatic changes during the Quaternary. In spite of this climate variability, the soils display progressive and systematic patterns of carbonate accumulation: on the lowest terraces, the soils do not yet have secondary carbonates but in the beginning Late Pleistocene calcic horizons, with carbonate pendents, are developed; these pendents increase its thickness with age although pendent growth rates decreases from Late Pleistocene to Middle Pleistocene. In the middle of the Late Pleistocene, calcic horizons evolved to petrocalcic horizons, which increase its thickness in the Middle and specially in Early Pleistocene. The presence of calcic and petrocalcic horizons is the primary basis for soil classification. This criterion is applicable not only to the soils of the lower Segre river basin, but also to many soils throughout the semiarid Mediterranean region.     

Pedogenic characteristics of soils distributed under Warm-temperate forest climate in Nyu mountains,Fukui Prefecture,Central Japan

The bioclimatic conditions, profile morphology and physico-chemical properties of five different soils under the Warm-temperate deciduous broad-leaved forest climate, Warm-temperate lucidophyllous forest climate, and Cool-temperate deciduous broad-leaved forest climate in the northern part of the Nyu mountains in Fukui Pref., Central Japan were examined. The outline of the results is as follows: 1) The Dark red soil, Kunimidake series, derived from pyroxene andesite may have been formed by the hydrothermal action of volcanism. 2) The Dry brown forest soil, Takasu-1 series, showed a brighter colour in the Bw horizon and a sudden decrease in the humus content below the AB horizon, suggesting that this soil was similar to Yellow-Brown Forest soils rather than to Brown Forest soils. 3) The Dry brown forest soil (reddish), Tega series, is likely to be a Yellow-Brown Forest soil derived from the loess which covered the underlying paleo-red soil. 4) The Red soil, Oshibayama series, was a paleo-red soil in which the upper part had been lost by erosion. 5) The Yellow soil, Yada series, on the Takasu coastal terrace was also considered to be a Yellow-Brown Forest soil affected by the seawater components from the neighboring coast. 6) It was suggested that zonal soils formed under the Warm-temperate deciduous broad-leaved forest climate in the northern part of the Nyu mountains, in the northwestern region of Fukui Pref. were Yellow-Brown Forest soils like those under the Warm-temperate lucidophyllous forest climate.     

Characteristics of free sesquioxides and humic acids in soil distributed under Warm-temperate forest climate in Nyu mountains,Fukui Prefecture,Central Japan

The activity and crystallinity ratios of free iron oxides, and the ΔlogK and RF values of humic acids were analyzed in five soil types in the Nyu mountains, Fukui Prefecture, to examine the relation between the zonality of soils and the bioclimatic conditions under the Warm-temperate deciduous broad-leaved forest climate. The characteristics of free iron oxides and humic acids were as follows: The Dark red soil, Kunimidake series was a Dark Red soil under the Cool-temperate deciduous broad-leaved forest climate; the Dry brown forest soil (reddish), Tega series was a Yellow-Brown Forest soil under the Warm-temperate deciduous broad-leaved forest climate; the Dry brown forest soil, Takasu-1 series and the Yellow soil, Yada series were Yellow-Brown Forest soils under the Warm-temperate lucidophyllous forest climate; and the Red soil, Oshibayama series and the lower parts of the Tega series were paleo-red soils. These results indicated that zonal soils under the Warm-temperate deciduous broad-leaved forest climate were Yellow-Brown Forest soils in the Nyu mountains, Fukui Prefecture. The Dark red soil, Kunimidake series corresponded to a Hyperdystri-Rhodic Cambisol of World Reference Base for Soil Resources, WRB (FAO, ISRIC, and ISSS: World Soil Resources Reports 84, 1998). The Dry brown forest soil (reddish), Tega series, the Dry brown forest soil, Takasu-1 series, and the Red soil, Oshibayama series were compared with the Hyperdystri-Chromic Cambisol (WRB). The Yellow soil, Yada series was a Hypereutri-Chromic Cambisol (WRB).     

Studies on genesis and classification of soils in warm-temperate region of southwest Japan

In the previous paper (1), it was shown that the soil distribution pattern on Pleistocene terraces and hilly areas in the vicinity of Lake Ramana in Tokai region along the Pacific Coast of Southwest Japan has a close correlation to the cyclic development of topography caused by glacio-eustatic movement of sea level during Pleistocene. And it was inferred that in the area Red-Yellow soils occur as relict or buried soils on the older ground surfaces of the higher terraces and foothills which are considered to have been formed before Shimosueyoshi transgression (Riss-Würm interglacial), whereas YellowBrown (Forest) soils develop on the younger ground surfaces of the middle and the lower terraces or upper hillslopes which are considered to have begun to develop after the transgression.     

Indian land use in the Raposa–Serra do Sol Reserve,Roraima, Amazonia,Brazil: Physical and chemical attributes of a soil catena developed from mafic rocks under shifting cultivation

Native Indians (Macuxi, Ingarikó and Uapishana) in the Raposa–Serra do Sol Indian Reserve have been cultivating forest soils since the early XIX century, especially those derived from dolerite sills, scattered within the quartzitic dominated landscape. Representative soils developed from mafic rocks under Indian shifting cultivation in northeastern Roraima, were submitted to physical, chemical and mineralogical analyses to characterize their pedogenetic characteristics and infer on their status under native Indian shifting cultivation. The soil profiles were classified as: Orthic Ebanic Chernosol (USDA Mollisol), vertic Orthic Ebanic Chernosol (USDA Mollisol), Eutrophic Haplic Cambisol (USDA mollic Inceptisol) and Eutrophic Red Nitosol (USDA Red Alfisol), which occupy, respectively, lower slopes and less dissected terrains (Mollisols) and steeper slopes (Alfisols). The first two are eutrophic, and not typical of the Amazon region. Their mineralogies range from kaolinite/goethite rich upland, deeply weathered Nitosol, to 2:1 clay rich downslope Chernosols. The latter has primary minerals in the silt fraction and high CEC resulting in high fertility. The Nitosols reveal a process of severe topsoil loss, due to widespread sheet erosion from deforestation and shifting cultivation. Chemical analyses showed varied soil fertility, ranging from high levels in the Chernosols to a low level in the non-cultivated Nitosol. Phosphorus levels are limited in all soils, despite the high fertility. The Chernosols located in lowland, flat areas close to the valley floor are more suitable environments for the slash-and-burn native farming system. In the Chernosols and Cambisols, the clay activity below the value limit for this class indicates a current natural process of increasing leaching. The more weathered and eroded Nitosol showed low Fe-oxalate and Si-oxalate levels. Micronutrients such as total zinc and copper, decreased with depth and weathering. The Nitosols showed the highest phosphate adsorption levels (1.574 mg g^− 1 of soil) which can be attributed to its clayey texture. Chernosols showed overall lower P adsorption values, increasing with depth. All soils under native Indian cultivation display signs of physical and chemical degradation due to shortened fallow under intense land use pressure in the Raposa–Serra do Sol Reserve.     

Distribution and development of sclerotium grains as influenced by aluminum status in volcanic ash soils

Granulometric and clay mineralogical analyses were performed on soil types differing in their genesis which had been formed on the raised coral limestone terraces and plateaux under the perhumid subtropical maritime climate of the Ryukyu Islands. The amount of clay fraction in Rendzina-like soil on the lower terrace was relatively small (8-34%) and decreased with depth, while those in Terra fusca-like soils on the middle terraces and in Terra rossa-like soil on the plateau were very large (45–78%) suggesting the occurrence of clay migration.

Rendzina-like soil mainly contained illite and metahalloysite with a moderate amount of mixed layered mineral consisting of illite and vermiculite, and a small amount of vermiculite, Al-vermiculite, goethite, and quartz. Clay mineral composition of Terra fusca-like and Mottled Terra fusca-like soils was similar to that of Rendzina-like soil except that the content of illite was lower in these soils. Terra rossa-like soil, on the other hand, mainly contained Al-vermiculite, metahalloysite, and gibbsite, indicating a highly advanced stage of hydroxyaluminium interlayering. Differences in clay mineral composition from that of Rendzina, Terra fusca, and Terra rossa soils in the European countries were recognized, in that mont-morillonite was absent and hydroxyaluminium interlayering actively proceeded in the soils studied here. This finding is considered to reflect the rapid alteration and intense hydroxyaluminium interlayering of clay minerals under the perhumid subtropical conditions.     

The study on method to draw large-scale soil map in diluvial soil area in Hokkaido, using digital elevation data for a 10 m grid

(pp. 59–66)
In order to understand the detailed soil distribution of a terrace with a diluvial deposit, the method to draw a large-scale soil map was studied in Urausu Town of Sorachi district by combinig soil survey and digital elevation data for a 10 m grid.
The results are summarized as follows:

• 1) 

  From a soil survey, soils in the research area were classified into 3 soil series groups according to Classification of Cultivated Soils in Japan, Third Approximation, which were Skeletal Terrace Brown Forest Soils, Fine-textured Aquic Brown Forest Soils and Fine-textured Haplic Gray Upland Soils. In addition, Fine-textured Haplic Gray Upland Soils · were classified into 2 categories based on the abundance of gravel in the subsoil.

       
  
  

Mineralogical composition of iron oxides in red- and yellow-colored soils from Southern Japan and Yunnan,China

Six soil samples from the Bt2 horizon of red- and yellow-colored soils collected in Southern Japan and Yunnan, China, were used in this study. Detailed mineralogical studies by differential X-ray diffraction analysis showed the presence of hematite in association with goethite in the red-colored soils, whereas no hematite was detected in the yellow-colored soils. Among the samples studied, the increase in the hematite contents was as follows: Terra rossa-like/Red-Yellow soil in Kikai Island, Red soil in Toyota City, Lateritic Red soil in Minami-Daito Island and Lateritic Red soil in Yunnan, China. Since Lateritic Red soil and Lateritic Yellow soil are distributed adjacently on the Pleistocene raised coral reef terrace in Minami-Daito Island, having a fairly similar soil temperature regime, soil pH, soil organic matter and iron oxide contents, the difference in the soil color between the two soils may be caused by the difference in the hydrologic conditions.     

A quaternary soil sequence in the Kennet Valley,central southern England

The field characteristics, texture, mineralogy and micromorphology of the soils of four chronologically separate river terraces of the River Kennet are described. The soils on the three uppermost terraces have illuvial (palaeoargillic) horizons, which have been intensely disturbed by periglacial activity. These horizons are overlain by similarly disrupted eluvial horizons mixed with aeolian silts derived from outside the Kennet catchment. The illuvial horizons most probably result from interglacial pedogenesis under climatic conditions warmer and wetter than at present, whilst the aeolian material was probably added to the soils during the last glacial period (Devensian). The lowest and youngest terrace is characterised by an undisturbed (normal argillic) soil developed in loams derived predominantly from the aeolian silts. Consequently, it is postulated that the soils of the lowest terrace owe their characteristics to a phase of postglacial pedogenesis.The results illustrate that several phases of pedogenesis can be recognised, which provide important information on the Quaternary development of the area. This is especially significant where floral, faunal, or archaeological evidence of environmental changes is unavailable.     

Adsorption of phthalic acid and salicylic acid by two variable charge soils as influenced by sulphate and phosphate

Low‐molecular‐weight (LMW) organic acids exist widely in soils, especially in the rhizosphere, and the adsorption of these acids may affect their reactions in soils. The adsorption behaviour of phthalic acid and salicylic acid by two variable charge soils (a Rhodic Ferralsol and a Haplic Acrisol) was investigated. Both soils exhibited great adsorption capacity for these organic acids, with a greater affinity for phthalic acid. The Rhodic Ferralsol adsorbed more organic acids of both kinds than the Haplic Acrisol, which was consistent with the content of iron and aluminum oxides in the two soils. The iron oxides in these soils played a significant role in adsorption of the organic acids, whilst the soil aluminosilicate minerals, such as kaolinite, showed a small adsorption capacity. The presence of phosphate and sulphate caused a decrease in the adsorption of both organic acids because of their competition with them for sorption sites. The phosphate showed a bigger inhibition on the adsorption than sulphate as a result of a greater amount of phosphate adsorbed by the soils. The adsorption of both organic acids was affected by pH only slightly at pH < 4.5. However, the adsorption decreased with the increase in pH at pH > 4.5. A similar trend was observed for the phosphate system, but the opposite was seen for the sulphate system. This suggests that the inhibition of sulphate on the adsorption of the organic acids decreased with the increase in pH, because the adsorption of sulphate decreased strongly with increasing pH.     

Zur Genese von Schwarzerden auf der Sontheimer Hochterrasse in der Donauniederung bei Ulm

Pedogenesis of chernozems in the upper river terrace of the Danubian river near Ulm (South West Germany) The “chernozem-like” soils in the upper river terrace of the Danubian river near Ulm (FRG) were examinated. Field analyses as well as soil physical and chemical, clay mineralogical and pollen analyses were carried out. The parent material of the soils was identified as loess, on the basis of its texture, clay mineral composition, structure, carbonate content, the presence of loess molluscs, and the location on an upper river terrace with loess findings in the surrounding. Characteristic pedogenetic processes, such as deliming, silicate weathering, formation of oxides and hydroxides, neoformation of clay minerals and clay translocation prove a non-groundwater-influenced development of the soils within at least the last 8000 years. Therefore an accumulation of organic matter under anaerobic conditions during the peat formation in the lower river terrace nearby was not possible. According to this finding, it can be deducted that the humus accumulation may be due to influences of continental climate and forest steppe during the preboreal period, whereby the humus horizons were formed at deeper horizons through bioturbation. After the groundwater level was raised in boreal age, the steppe stage of the soils had ended and the fluctuating levels of groundwater, rich in carbonates, stabilized humic substances. Thus strong degradation of the soils to date was prevented. Therefore the soils under study could be classified as gleyic Chernozems or luvic Phaeozems.     

Priming effects in different soil types induced by fructose, alanine, oxalic acid and catechol additions

It is well established that certain substrate additions to soils may accelerate or retard the mineralisation of soil organic matter. But up to now, research on these so called ‘priming effects’ was almost exclusively conducted with arable soils and with plant residues or glucose as additives. In this study, the effects of the uniformly ¹⁴C-labelled substrates fructose, alanine, oxalic acid and catechol on the mineralisation of soil organic carbon (SOC) from different horizons of two forest soils (Haplic Podzol and Dystric Cambisol) and one arable soil (Haplic Phaeozem) under maize and rye cultivation were investigated in incubation experiments for 26 days. Apart from the controls, all samples received substrate additions of 13.3 μg substrate-C mg⁻¹ C_org. During the incubation, CO₂-evolution was measured hourly and the amount of ¹⁴CO₂ was determined at various time intervals. In almost all soils, priming effects were induced by one or several of the added substrates. The strongest positive priming effects were induced by fructose and alanine and occurred in the Bs horizon of the Haplic Podzol, where SOC mineralisation was nearly doubled. In the other soil samples, these substrates enhanced SOC mineralisation by +10 to +63%. Catechol additions generally reduced SOC mineralisation by −12 to −43% except in the EA horizon of the Haplic Podzol where SOC-borne CO₂-evolution increased by +46%. Oxalic acid also induced negative as well as positive priming effects ranging from −24 to +82%. The data indicate that priming effects are ubiquitously occurring in surface and subsoil horizons of forest soils as well as in arable soils. Although a broad variety of soils was used within this study, relationships between soil properties and priming effects could not be ascertained. Therefore, a prediction on occurrence and magnitude of priming effects based on relatively easily measurable chemical and physical soil properties was not possible. Nevertheless, the data suggest that positive priming effects are most pronounced in forest soils that contain SOC of low biodegradability, where the added substrates may act as an important energy source for microbial metabolism.     

Structure and function of bacterial communities in ageing soils: Insights from the Mendocino ecological staircase

The ecological staircase of Mendocino (California, USA) is characterized by a succession of uplifted marine terraces that are derived from the same mineralogical parent material but have different ages, levels of fertility, and types of vegetation, from grassland in the youngest and most fertile terrace to a pygmy forest in the older terraces. Such conditions present a unique opportunity to determine how the structure, abundance, and function of bacterial communities vary with soil fertility along this natural chronosequence. Pyrosequencing analysis of 16S rRNA gene amplicons revealed that Acidobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundantly represented phyla. Bacteroidetes, Firmicutes, Verrucomicrobia were significantly enriched in the grasslands, while the less fertile forested terraces showed higher abundance of Acidobacteria Gp2 and Alphaproteobacteria. The pygmy forest soil harboured significantly more Actinobacteria and OP10 than the non-pygmy forest. Between samples from different terraces, the structure of the bacterial community clearly correlated with soil characteristics. Notably, the number of operational taxonomic units was greater in the fertile terrace, as was the density of culturable bacterial populations. Functional characterization of the soil culturable bacteria from the pygmy and non-pygmy forest terraces revealed that the soil bacteria from the non-pygmy terrace were significantly more effective in solubilizing minerals and more abundant than in the pygmy terrace. Our results provide new information on bacterial community structure as a function of soil age, land cover and fertility, which improve our understanding of soil evolution.     

Evolution of soil properties and plant communities along an extreme edaphic gradient

Plant-litter-soil interactions were investigated along a soil chronosequence occurring on five coastal terraces in northern California that range in age from about 100 000 to 500 000 YBP. Soil and plant communities vary dramatically and consist of slightly acidic, fertile soils supporting highly productive mixed-conifer forests on the youngest terrace to highly acidic, infertile soils supporting pygmy forests of dwarf (< 3 m) conifers and Ericaceae species on the older terraces. Soil genesis, soil nutrient status, soil acidity and plant community structure reach a steady-state after approximately 250 000 years. All major species of the pygmy forest are polyphenol-rich, and those species that also grow elsewhere on the gradient have their highest concentrations of extractable polyphenols when growing on the most highly acidic, infertile sites. Polyphenols provide several beneficial effects on highly acidic and infertile soils, such as nutrient conservation, detoxification of soluble aluminum and enhanced phosphorus availability. Polyphenols may also provide some plant species with a competitive advantage by altering nitrogen cycling, allowing these plants to alter forest succession. The convergent evolution of polyphenol-rich plant communities on highly infertile soils throughout the world may be due to the ability of polyphenols to ameliorate acid soil infertility factors and regulate the nitrogen cycle.     

极端暴雨条件下黄土高原水平梯田损毁情况调查分析——以岔巴沟流域“7·26”特大暴雨为例

2017年7月25日20时至26日8时,陕西榆林市11个县区遭遇特大暴雨侵袭,我们于当年10月对位于暴雨中心的岔巴沟流域的梯田损毁情况进行了专项调查。首先通过室内Google Earth近实时影像结合GIS绘图在流域内确定梯田位置和数量,根据修建时间、利用和植被类型将这些梯田分类。在流域内空间分布均匀地选择不同类型典型梯田并进行野外实地测量,统计各类型梯田的损毁情况、损毁形式并估算各类型梯田的土壤侵蚀模数及其流域平均侵蚀模数。结果表明:岔巴沟流域梯田以≤ 4 hm²规模为主,梯田数量上占91.4%,面积上占了50.7%。暴雨造成梯田的损毁形式以田埂表层结皮脱落、田埂滑塌崩塌、田埂冲毁、田面陷穴穿洞为主,有人为干扰时会产生更加剧烈的后果。暴雨造成的梯田损毁侵蚀坑大部分为深度0~0.5 m的侵蚀。老梯田农地、老梯田乔木和老梯田草地侵蚀坑发生频率远远多于新机修梯田,保持在20~36处/100 m。新机修梯田的侵蚀测坑发生频次少,为5处/100 m,但深度可达4.8 m,后果严重。不同类型梯田损毁产生侵蚀模数差异较大,老梯田农地、老梯田草地和老梯田乔木的侵蚀模数为34 000~37 000 t/km²,新机修梯田为19 404.3 t/km²,老梯田灌木侵蚀模数最低,为5 958.4 t/km²。流域内梯田平均侵蚀模数为30 733.4 t/km²。通过本次调查,掌握不同类型梯田在极端暴雨条件下的损毁情况,为黄土高原梯田保护及修复提供数据支持。     

Soil development on Late Quaternary river terraces in a high montane valley in Bhutan,Eastern Himalayas

We examined the geochemistry and micromorphology of the soils on a suite of morphologically well-defined and visually distinct fluvial terraces, up to 40 m elevation above the current riverbed, at Thangbi in the upper Bumthang Valley, Bhutan. The alluvia forming each of the terraces are lithologically and structurally similar, with shallow or moderately deep, clast-free sandy loam overbank deposits capping deep clast-supported beds of rounded boulders and interstitial sand. The topsoils on the 40 m terrace have more silt than those on the lower terraces. The soils are interpreted mainly as a monoclinal post-incisive chronosequence. Features that indicate progressive pedogenesis with increasing elevation include subsoil rubefaction, crystallinity of free Fe sesquioxides, and weathering of susceptible primary minerals, such as biotite and hornblende. However other soil attributes show no systematic trends and the overall impression is of limited pedogenesis, even in the soils on the higher terraces. We examine possibilities that the immaturity of the soils is due to pedogenic rejuvenation by post-incision additions to the soil parent materials.     

Genesis of red and dark brown soils on basaltic parent materials near Armidale,N.S.W., Australia

Morphological, physical, chemical and mineralogical data are presented for contiguous euchrozem (nitosols) and chocolate soils (cambisols) developed on basaltic parent materials in the Armidale district of northern New South Wales. The genesis and distribution of the different soils classified at great soil group and series level are related to parent material and topography. The dark brown chocolate soils associated with the modern surface overlie a uniform parent material of partly weathered alkali-olivine basalt. The red euchrozem soils, although having morphological and mineralogical properties associated with intensive weathering and long term soil genesis, have also developed on the modern surface under a moderate leaching regime. They are derived from re-exposed, highly weathered, sesquioxidic, interbasaltic lapilli tuffs and underlying basalt which were probably transformed under a different climate in Pliocene—Pleistocene times. The study showed further that reddish chocolate soils are not necessarily the uppermost member of a sequence of soils developed on partly weathered basalt.     

Chrono-toposequences of soils on the river terraces in Transylvania (Romania)

A sequence of surface soil profiles and buried soils described on the 4th, 3rd, 2nd and 1st terraces of different rivers in Transylvania is presented as part of an attempt to perform a paleopedologic interpretation of the dominant soil types of this area. Excepting the first terrace, the described soils were formed from Pleistocene slopewash deposits of Würm, or possibly of Riss age, which overlay alluvial terrace deposits. On the basis of fossil animal remains, periglacial cryostructures, prehistoric artifacts (Coţofeni culture of the transition period from the Neolithic to the Bronze Age) and Scythian graves an approximate age of different soil horizons, as well as the polycyclic nature of soils was established. There is no essential difference between a Würmian buried soil horizon and the argic Bt horizon of the surface soils; moreover, in some cases, the buried paleosols become the Bt horizon itself of the surface soils, through the thinning of the overlying deposits. Even if the possibility of formation of the argic Bt horizons during the postglacial until the end of Neolithic, cannot be excluded, from the presented situations it seems that these horizons in the Transylvanian Basin are Würmian relics, formed in the periglacial interstadials. In most of the cases Bt horizon has nothing in common genetically with the topsoil.     

Phosphorus removal from secondary-treated wastewater using overland flow

The removal of total phosphorus from secondary effluent by overland flow was studied using five terraces constructed 91 m in length and 140 or 70 m in width. Three methods of wastewater application were tested on the terraces including sprinkler, fan nozzle, and gated pipe. In addition, three different application rates were used. Samples of applied wastewater, runoff collected at points along the terraces, effluent from each terrace, and soils were analyzed for total phosphorus over a ten-month period. Hydraulic application rate had a significant effect on the removal of total phosphorus; the removal efficiency was inversely proportional to the hydraulic application rate. However, the method of application did not have an effect on phosphorus removal. An increase in phosphorus was observed in terrace soil samples; the increase was attributed to adsorption and precipitation.     

A sequence of marine terraces near Latina (Agro Pontino, central Italy)

A detailed physiographic soil survey has been carried out in the NW part of the Agro Pontino, near Latina. Four marine terraces and extensive eolian sand covers were found. The oldest marine terrace, the Latina complex, largely consists of augitic fine sands of marine-lagoonal origin. Towards the end of the transgression (of uncertain age) some minor sea level fluctuations occurred. The next marine terrace, the Minturno complex, is thought to date from the Tyrrhenian II transgression and was preceded by a major regression. This has the characteristics of a normal transgressive system, including late minor sea level fluctuations. The beachridge and lagoonal deposits are slightly tilted to the SW and are underlain by littoral gravels, most probably derived from the adjacent Latina complex through strong abrasion. Following a minor regression another marine terrace was formed (the Borgo Ermada complex). This terrace is considered to date from the Tyrrhenian III transgression, but has a regressive character, a phenomenon which can be explained by assuming a synformational tectonic tilting, some evidence for which is found. During a subsequent major regression (Würmian) eolian sands were repeatedly deposited, particularly on the Borgo Ermada complex. This was followed by the formation of a simple beachridge-lagoon system during the Holocene (the Terracina complex). The datings are based on correlation with sequences elsewhere, the two marine faunas studied give no clue as to their ages.Soil formation depends strongly on the texture of the parent materials and these relationships are indicated schematically. Soils in sands form a clear chronosequence, exhibiting an increased rubefaction and illuvial concentration of clay with age (Regosols - Arenosols - Luvisols). The distinction between the Borgo Ermada and Minturno complex is partly based on this chronosequence. Soils with a sandy albic E horizon, more or less abruptly overlying a stagnative clayey B horizon (Planosols and related soils) abound in intermediate materials of the Pleistocene terraces. The characteristically abrupt textural change was found to be due to the heterogenity of the parent material (eolian sand over loam to clay) rather than to soil formation.Some attention is paid to prehistoric artefacts, in particular Pontinian type tools and observations of BLANC on the famous site of Gniff-Gnaff are reinterpreted.