Terra Rossa in the Mediterranean Region: Parent Materials, Composition and Origin

In the past, the term “terra rossa” became quite a common indication for all limestone derived red soils in the Mediterranean region. Today, in some classification systems based on the Mediterranean climate as the major soil differentiating criterion, the term terra rossa is used as a name for the soil subclass “Modal Fersiallitic Red soil” when situated on limestones (Duchaufour, 1982). However, several national soil classifications (e.g. Croatian, Italian, Israeli) retained the term “terra rossa” for the hard limestone derived red soils. The nature and relationship of terra rossa to underlying carbonates is a long-standing problem which has resulted in different opinions with respect to the parent material and origin of terra rossa. Terra rossa is a reddish clayey to silty-clay material, which covers limestone and dolomite in the form of a discontinuous layer ranging in thickness from a few centimetres to several metres. It is also found along cracks and between bedding surfaces of limestones and dolomites. Thick accumulations of terra rossa like material are situated in karst depressions in the form of pedo-sedimentary complexes. A bright red colour is a diagnostic feature of terra rossa and is a result of the preferential formation of haematite over goethite, i.e. rubification. Terra rossa can be considered as soil, vetusol, relict soil (non-buried-paleosol), paleosol or pedo-sedimentary complex (soil-sediments) among different authors. Most authors today believe that terra rossa is polygenetic relict soil formed during the Tertiary and/or hot and humid periods of the Quaternary. However, some recent investigation in the Atlantic coastal region of Morocco (Bronger & Sedov, 2002) show that at least some terra rossa previously referred to as polygenetic relict soils should be regarded as Vetusols. In some isolated karst terrain, terra rossa may have formed exclusively from the insoluble residue of limestone and dolomite but much more often it comprises a span of parent materials including, for example, aaeolian dust, volcanic material or sedimentary clastic rocks which were derived on carbonate terrain via different transport mechanisms. Boero & Schwertmann (1989) concluded that it is of little relevance for the process of rubification whether the primary Fe sources are autochthonous or allochthonous as long as the general pedoenvironment remains essentially suitable for the formation of terra rossa. This pedoenvironment is characterised by an association of Mediterranean climate, high internal drainage due to the karstic nature of a hard limestone and neutral pH conditions. Terra rossa is formed as a result of: (1) decalcification, (2) rubification and (3) bisiallitization and/or monosiallitization. Since Fed/clay ratios are relatively uniform in most terra rossa, translocation of clay particles is responsible for the distribution of the red colour throughout the whole profile. However, since terra rossa soils have been exposed to various climatic fluctuations they can be affected by eluviation, yellowing and secondary hydromorphy. Erosion and deposition processes which were superimposed on karst terrains and induced by climatic changes, tectonic movements and/or deforestation might be responsible for both the patchy distribution of terra rossa and thick colluvial or alluvial terra rossa accumulations in uvala and dolina type of karst depressions (pedo-sedimentary complexes, soil-sediments)

Terra Rossa in the Mediterranean Region: Parent Materials, Composition and Origin

In the past, the term “terra rossa” became quite a common indication for all limestone derived red soils in the Mediterranean region. Today, in some classification systems based on the Mediterranean climate as the major soil differentiating criterion, the term terra rossa is used as a name for the soil subclass “Modal Fersiallitic Red soil” when situated on limestones (Duchaufour, 1982). However, several national soil classifications (e.g. Croatian, Italian, Israeli) retained the term “terra rossa” for the hard limestone derived red soils. The nature and relationship of terra rossa to underlying carbonates is a long-standing problem which has resulted in different opinions with respect to the parent material and origin of terra rossa. Terra rossa is a reddish clayey to silty-clay material, which covers limestone and dolomite in the form of a discontinuous layer ranging in thickness from a few centimetres to several metres. It is also found along cracks and between bedding surfaces of limestones and dolomites. Thick accumulations of terra rossa like material are situated in karst depressions in the form of pedo-sedimentary complexes. A bright red colour is a diagnostic feature of terra rossa and is a result of the preferential formation of haematite over goethite, i.e. rubification. Terra rossa can be considered as soil, vetusol, relict soil (non-buried-paleosol), paleosol or pedo-sedimentary complex (soil-sediments) among different authors. Most authors today believe that terra rossa is polygenetic relict soil formed during the Tertiary and/or hot and humid periods of the Quaternary. However, some recent investigation in the Atlantic coastal region of Morocco (Bronger & Sedov, 2002) show that at least some terra rossa previously referred to as polygenetic relict soils should be regarded as Vetusols. In some isolated karst terrain, terra rossa may have formed exclusively from the insoluble residue of limestone and dolomite but much more often it comprises a span of parent materials including, for example, aaeolian dust, volcanic material or sedimentary clastic rocks which were derived on carbonate terrain via different transport mechanisms. Boero & Schwertmann (1989) concluded that it is of little relevance for the process of rubification whether the primary Fe sources are autochthonous or allochthonous as long as the general pedoenvironment remains essentially suitable for the formation of terra rossa. This pedoenvironment is characterised by an association of Mediterranean climate, high internal drainage due to the karstic nature of a hard limestone and neutral pH conditions. Terra rossa is formed as a result of: (1) decalcification, (2) rubification and (3) bisiallitization and/or monosiallitization. Since Fed/clay ratios are relatively uniform in most terra rossa, translocation of clay particles is responsible for the distribution of the red colour throughout the whole profile. However, since terra rossa soils have been exposed to various climatic fluctuations they can be affected by eluviation, yellowing and secondary hydromorphy. Erosion and deposition processes which were superimposed on karst terrains and induced by climatic changes, tectonic movements and/or deforestation might be responsible for both the patchy distribution of terra rossa and thick colluvial or alluvial terra rossa accumulations in uvala and dolina type of karst depressions (pedo-sedimentary complexes, soil-sediments)

Distribution of Iron and Manganese in Terra Rossa from Istria and its Genetic Implications

Haematite and goethite are the predominant pedogenic mineral phases in terra rossa from Istria. Limited variation of selected Fe oxide characteristics in analysed samples indicates the specific pedogenic environment in which terra rossa is formed. The mean value of the Fed/Fet ratio, taken as an index of weathering is 0.7 and reflects quite a high degree of weathering of Fe-containing primary silicates. Relatively uniform Fed/clay ratios clearly indicate a predominance of co-illuviation of clay and Fe oxides. Low values of Feo point to the low content of poorly crystalline Fe oxides in analysed terra rossa. Feo/Fed ratios in the analysed profiles vary. In the upper part of the Pomer, Porec and Novigrad profiles Feo/Fed ratios are higher than in the lower part of those profiles which may be explained as a result of different pedogenic environments and/or additions of external materials in the upper part of those profiles. The lack of positive correlation between Mnd and clay and Mnd and Fed is a consequence of remobilization of manganese due to hydromorphic processes which post-dated co-illuviation of clay and Fe oxides. During the Late Tertiary and Quaternary the pedogenic environment on hard carbonate rocks of the Jurassic-Cretaceous-Palaeogene carbonate plain of southern and western Istria generally remained suitable for rubification. However, (Neo)tectonic activity and the input of external material, as well as various climatic fluctuations might have significantly effected terra rossa through the processes of erosion, colluviation, yellowing and secondary hydromorphy

Distribution of Iron and Manganese in Terra Rossa from Istria and its Genetic Implications

Haematite and goethite are the predominant pedogenic mineral phases in terra rossa from Istria. Limited variation of selected Fe oxide characteristics in analysed samples indicates the specific pedogenic environment in which terra rossa is formed. The mean value of the Fed/Fet ratio, taken as an index of weathering is 0.7 and reflects quite a high degree of weathering of Fe-containing primary silicates. Relatively uniform Fed/clay ratios clearly indicate a predominance of co-illuviation of clay and Fe oxides. Low values of Feo point to the low content of poorly crystalline Fe oxides in analysed terra rossa. Feo/Fed ratios in the analysed profiles vary. In the upper part of the Pomer, Porec and Novigrad profiles Feo/Fed ratios are higher than in the lower part of those profiles which may be explained as a result of different pedogenic environments and/or additions of external materials in the upper part of those profiles. The lack of positive correlation between Mnd and clay and Mnd and Fed is a consequence of remobilization of manganese due to hydromorphic processes which post-dated co-illuviation of clay and Fe oxides. During the Late Tertiary and Quaternary the pedogenic environment on hard carbonate rocks of the Jurassic-Cretaceous-Palaeogene carbonate plain of southern and western Istria generally remained suitable for rubification. However, (Neo)tectonic activity and the input of external material, as well as various climatic fluctuations might have significantly effected terra rossa through the processes of erosion, colluviation, yellowing and secondary hydromorphy

Crvenica u području Kvarnera: geomorfološki uvjeti postanka

Red soil or terra rossa is the most common soil type developed on carbonate rocks in the Kvarner area. In most cases, terra rossa has polygenetic origin and was formed by mixing of insoluble residue of carbonate rocks with weathered and eroded loess and flysch sediments. Climatic and glacioeustatic changes and tectonic movements during Quaternary have influenced recent position of terra rossa and its mineralogical composition. The recent position of terra rossa is a consequence of erosion. In the areas where tectonic movements were more pronounced, because of slope erosion and resedimentation-colluviation processes terra rossa is found in isolated depressions in the form of thicker depostits. Examples are northern part of Cres island and southern slopes of the Učka mountain. In the areas where tectonic movements were less pronounced terra rossa covers larger areas in the form of thinner deposits. An example is the western part of the island Krk.Crvenica ili terra rossa je najzastupljeniji pedološki tip odnosno pokrivač na karbonatnim stijenama kvarnerskog područja. Crvenica je najčešće poligenetske prirode i tada je nastala miješanjem netopljivih ostataka karbonatnih stijena s trošnim i erodiranim naslagama lesa i fliša. Na minerološki sastav i današnji položaj crvenice utjecale su klimatske i glacioeustatičke promjene, kao i tektonski pokreti tijekom kvartara. Današnji raspored crvenice posljedica je erozije. Tamo gdje su tektonski pokreti bili izraženi, terra rossa se zbog erozije padina i resedimentiranja-koluvacije nalazi u izoliranim depresijama u obliku debljih nakupina. Primjeri su sjeverni dio otoka Cresa i padine južne Učke. Tamo gdje su tektonski pokreti bili slabo izraženi, terra rossa je male debljine, ali pokriva velike površine. Primjer je zapadni dio otoka Krka

Redoksimorfne značajke kao pokazatelji režima vlaženja tla

Soil water regime, as one of the key components of soil fertility, refers to the quantity, retention, and movement of soil water. Rather than through expensive and/or time-consuming measurements, it can be assessed from the fieldobservable morphological properties in the soil profile. Excessively wetted soils have a specific morphology, and are therefore often referred to as hydromorphic. Their morphology is caused by various soil redoximorphic features (RMFs), resulting from the reduction, translocation, and oxidation of iron and manganese oxides. Hydromorphic soils largely comprise Gleysols and Stagnosols (along with Gleyic Fluvisols) that are excessively wetted by groundwater, precipitation and/or flooded water. Their morphology is often described/analyzed with different terms/criteria in line with their global distribution. This complicates the comparison and classification of such soils and thus their use or reclamation. This review paper describes and compares common RMFs and explains their formation. It then proposes the revised Croatian terms for these features, which are in line with the terms used in the international soil classification systems of WRB and/or Soil Taxonomy. Furthermore, the criteria/rules used for diagnosing RMFs when classifying hydromorphic soils are critically reviewed. Finally, it is shown that a methodologically sound RMFs description can provide a quick insight into the crucial soil water regime parameters, such as location and duration of soil saturation, the origin of the excess soil water, recentness of excessive soil wetting, etc. However, depending on the research objectives and/or actual soil conditions, field soil description cannot always fully replace continuous field monitoring of the soil water regime and/or laboratory and micromorphological soil analyses.Režim vlaženja tla, kao jedna od ključnih komponenti njegove ukupne plodnosti, odnosi se na količinu, zadržavanje i kretanje vode u tlu. Umjesto skupim i/ili dugotrajnim mjerenjima, on se može procijeniti na terenu, i to putem opisa morfoloških svojstava tla. Prekomjerno vlažena tla imaju specifičnu morfologiju, zbog koje se nazivaju hidromorfnima. Takva njihova morfologija proizlazi iz redoksimorfnih značajki (RMZ), koje se stvaraju redukcijom, premještanjem i oksidacijom oksida željeza i mangana. Hidromorfna tla su uglavnom glejna i pseudoglejna tla (ali i oglejena fluvijalna tla), koja su prekomjerno vlažena podzemnim, oborinskim i/ili poplavnim vodama. U skladu s njihovom globalnom rasprostranjenošću, morfologija tih tala se često opisuje i analizira korištenjem različitih pojmova i kriterija. To otežava usporedbu i klasifikaciju hidromorfnih tala, kao i njihovu upotrebu ili popravak. Ovaj pregledni rad opisuje i uspoređuje uobičajene RMZ, objašnjavajući mehanizme njihova nastanka. Zatim predlaže revidirane hrvatske pojmove za ove značajke, skovane u skladu s onima koje koriste međunarodni sustavi WRB-FAO i/ili Soil Taxonomy. Nadalje, rad se kritički osvrće na kriterije i pravila, koja se koriste za dijagnosticiranje RMZ prilikom klasifikacije hidromorfnih tala. Konačno, ovaj rad pokazuje da metodološki ispravan opis RMZ može pružiti brz uvid u ključne parametre režima vlaženja tla, kao što su mjesto i trajanje zasićenja tla vodom, podrijetlo viška vode u tlu, recentnost prekomjernog vlaženja tla, itd. Međutim, ovisno o ciljevima istraživanja i/ili prisutnim uvjetima u tlu, terenski opis profila tla možda neće uvijek moći u potpunosti zamijeniti kontinuirano terensko praćenje režima vlaženja tla i/ili laboratorijske i mikromorfološke analize tla

The relationship between the geochemical and mineralogical characteristics of Calcocambisol, colluvium and recent marine lake sediment of the narrow seashore intertidal zone: a case study from the Veliko Jezero (Mljet Island, Croatia)

is study investigates the mineral composition, particle size distribution and geochemical characteristics of Calcocambisol, colluvium and recent marine lake sediment in a narrow intertidal seashore zone of the Veliko Jezero on the Island of Mljet (Croatia). The obtained results show that the fractions of Calcocambisol/colluvium less than 2 mm and 2 µm display similar particle size distribution (PSD) curves compared to marine lake sediments containing larger particles in these fractions. The smallest fractions of the investigated materials that are less than 1 µm show identical PSD curves. The bulk and clay mineral composition of the marine lake sediment show that the non-carbonate fraction is derived from weathering of the surrounding soils and colluvium containing quartz, feldspars and phyllosilicates (illitic material, kaolinites, chlorite, and a mixed layer clay mineral, MLCM), as well as the authigenic formation of early-diagenetic pyrite, while one part is related to the yield of material by aeolian deposition (amphibole). The observed difference between the phyllosilicate mineral phases in the clay fraction of the Calcocambisol/colluvium and the carbonate-free clay fraction of the marine lake sediment is related to 1) the presence of chlorite in the marine lake sediment and 2) the higher content of MLCM in the Calcocambisol/colluvium. The chlorite in the marine lake sediment was inherited from the Calcocambisol/colluvium as a result of soil erosion prior to its complete destabilization in the soil. High Chemical Index of Alteration (CIA) values in the Calcocambisol and colluvium clearly indicate their intense weathering. Based on the Sm/Nd and Ti/Al ratios, it can be concluded that the aluminosilicates in the Calcocambisol, colluvium and marine lake sediment are of the same provenance. The distribution of each analysed element among the sequential fractions is very similar in both the Calcocambisol and colluvium. The highest concentrations for most of trace elements in the Calcocambisol, colluvium and marine lake sediment was determined in their residual fraction. Mn, Co and Pb show a different partitioning between the Calcocambisol/colluvium and marine lake sediment, respectivel

Late Neogene, Seismic stratigraphy, Biostratigraphy, Mollusca, Evolution, Pannonian basin

The combined use of seismic stratigraphy and mollusc biostratigraphy in Late Neogene lacustrine deposits of the Pannonian basin offers three new approaches: First, the comparison of seismic facies and biofacies facilitates to make a distinction between biostratigraphic units and biofacies. Second, seismic datum levels permit crosschecking of discrete (magnetic, radiometric, and biostratigraphic) data, thus dating evolutionary events. Third, seismic monitoring of the sedimentary history of the basin helps in the understanding of the geographic distribution of molluscs (areals of younger forms are more and more restricted, due to progradation)