S2 Fig: Predicted SD nitrogen and phosphorus content and ratios. S1 File: Soil nitrogen and phosphorus at soil sampling sites. S2 File: Environmental predictors for digital soil mapping. Abstract Nitrogen N and phosphorus P in topsoils are critical for plant nutrition. Introduction Nitrogen N and phosphorus P are the most important nutrients for primary productivity in terrestrial ecosystems [ 1 , 2 ].
Materials and methods Research area The study area has a size of 9. Open in a separate window. Fig 1.
Research area. Soil sampling and chemical analyses Soil samples were collected from the organic layer and the A horizon at 91 sampling sites in Environmental predictors LiDAR is a remote sensing technology, which provides structural information on the illuminated surface, including the 3D terrain, vegetation canopy information, and object heights [ 43 ]. Table 1 Environmental predictors for digital soil mapping. Note: NIR, near-infrared. Random forest Random forest RF is an ensemble learning method that operates by building a set of regression trees and averaging the results [ 57 ].
Results Descriptive statistics of soil nutrients Summary statistics for the N and P data are shown in Table 2. Table 2 Statistical summary of N and P content mg kg -1 and ratios. Fig 2. Model validation based on R-square with cross validation methods.https://myasimonrerou.tk
Fig 3. Boxplots showing standard deviations of predicted values for each raster cell with cross validation methods. Fig 4. Maps of mean and coefficient of variation CoV of models of phosphorus in the organic layer P o with cross validation methods.
Environmental drivers of spatial nutrient patterns To analyze the influence of topography and vegetation on soil nutrients, the results from repeated fold CV are displayed. Table 3 Selected predictors using recursive feature elimination RFE based on repeated fold cross validation. Fig 5. N, nitrogen; P, phosphorus; o, organic layer; and a, A horizon. Fig 6. Predicted mean soil N and P content and ratios. Model performance based on different cross validation schemes We observed the typical bias-variance tradeoff when comparing the various CV schemes as was discussed at length in Hastie et al.
TIFF Click here for additional data file. S2 Fig Predicted SD nitrogen and phosphorus content and ratios. S1 File Soil nitrogen and phosphorus at soil sampling sites. XLS Click here for additional data file. S2 File Environmental predictors for digital soil mapping. ZIP Click here for additional data file. Data Availability All soil and environmental data used in this study are available in the supporting information file S1 and S2 File.
References 1. Nitrogen and nature. Ambio A J Hum Environ. Terrestrial phosphorus limitation: mechanisms, implications, and nitrogen—phosphorus interactions. Ecol Appl. How does pedogenesis drive plant diversity? Trends Ecol Evol. Does nitrogen deposition increase forest production? The role of phosphorus Environ Pollut. Manning P. The impact of nitrogen enrichment on ecosystems and their services In: Wall DH, editor.
Soil Ecology and Ecosystem Services. Oxford University Press; J Korea Soc Environ Adm. Increasing anthropogenic nitrogen in the North Pacific Ocean. Turner BL. Resource partitioning for soil phosphorus: A hypothesis. J Ecol. Osman KT. Soils: Principles, Properties and Management. Huang W, Spohn M. Effects of long-term litter manipulation on soil carbon, nitrogen, and phosphorus in a temperate deciduous forest. Soil Biol Biochem. Elsevier Ltd; ; 83 : 12— Cleveland CC, Liptzin D.
Spatial distribution of soil organic carbon and total nitrogen based on GIS and geostatistics in a small watershed in a hilly area of northern China. Spatial patterns of soil total nitrogen and soil total phosphorus across the entire Loess Plateau region of China. A simplified approach for estimating soil carbon and nitrogen stocks in semi-arid complex terrain. Elsevier B. Soil phosphorus and nitrogen predictions across spatial escalating scales in an aquatic ecosystem using remote sensing images.
Spatial variability of soil phosphorus in the Fribourg canton, Switzerland. Spatial prediction of soil properties using environmental correlation. Soil Sci Soc Am J. Topographical influences on soil properties in boreal forests. Soil properties and tree growth along an altitudinal transect in Ecuadorian tropical montane forest. J Plant Nutr Soil Sci. Nutrient availability at different altitudes in a tropical montane forest in Ecuador.
J Trop Ecol. On digital soil mapping. Grunwald S. Ballabio C. Spatial prediction of soil properties in temperate mountain regions using support vector regression. Binkley D, Fisher R.
- The More I See You (De Piaget series).
- Geology and Sedimentology of the Korean Peninsula - 1st Edition.
- Going Fishing;
Ecology and Management of Forest Soils. Fusion of soil and remote sensing data to model soil properties. Adv Agron. The use of remote sensing in soil and terrain mapping—A review. Oxford: Oxford University Press; Disentangling the effects of climate, topography, soil and vegetation on stand-scale species richness in temperate forests. For Ecol Manage.
Classifying species of individual trees by intensity and structure features derived from airborne laser scanner data. Remote Sens Environ. The fate of phosphorus during pedogenesis. Smeck NE. Phosphorus dynamics in soils and landscapes. Korea meteorological administration. Korea weather survice. Korea Institute of Geology Mining and Material. Chough SK.
Geology and Sedimentology of the Korean Peninsula. London: Elsevier; Lee G. Characteristics of geomorphological surface and analysis of deposits in fluvial terraces at upper reach of Soyang river. J Korean Geogr Soc. Wohl E. Mountain Rivers. National Academy of Agricultural Science. Korean Soil Information System. A conditioned Latin hypercube method for sampling in the presence of ancillary information.
Comput Geosci. Digital Soil Assessments and Beyond. Franklin SE. New York: McGrawHill; Int J Remote Sens. National Geographic Information Institute. National Spatial Information Clearinghouse. Isenburg M. Jensen JR. Hyperspectral Remote Sensing of Vegetation. Geosci Model Dev. Identification of the spatial distribution of soils using a process-based terrain characterization. Quantitative analysis of land surface topography.
Earth Surf Process Landforms. Freeman TG. These results are in accordance with the grouping based on the IRM acquisition behaviour Fig. Most samples of greenish siltstone belong to the PSD region, while dark grey sandstone samples are plotted in the MD region Fig. Although the Day plot is used to determine the domain state of magnetite-bearing samples, the results from red beds and black shales are also shown in Fig.
Hysteresis properties and domain state for selected samples from the study area after Day et. Because both ARM and IRM imparted in haematite or other minerals of high H cr are rarely removed by AF demagnetization, this test is inadequate for red beds and black shales. Electron microscope observations were carried out for representative samples of greenish siltstone and red siltstone from the study area.
To identify the magnetic carriers and their relation with the adjacent grains or matrix, compositional analyses using energy dispersive spectroscopic EDS system for X-ray analysis were performed. In order to distinguish the magnetic phase between magnetite and haematite, the morphological characteristics and the iron—oxygen ratio determined by optical and electron microscopic observations, the results of the rock magnetic experiments, and thermal demagnetization behaviour of samples were collectively used.
Detrital iron oxide grains were known to show eroded features and some relic phases such as titanomagnetite, titanohaematite or rutile Suk et. In a greenish siltstone sample, a non-spherical pure magnetite, filling the pore space between quartz and clay minerals, does not show any detrital characteristics Fig. This feature implies that magnetite in greenish siltstone might be formed authigenically after deposition.
Scanning electron microscopy photographs of samples from greenish siltstone a and red siltstone b — e. Mgt, magnetite; Qtz, quartz; Spn, sphene; Cal, calcite. Hem, haematite; Chl, chlorite; Fds, feldspar. Haematite grains are the most frequently observed iron oxides in samples of red siltstone and are commonly accompanied by quartz, feldspar and clay minerals.
Although rarely encountered, detrital Fe-Ti oxide grains showing severe corrosion features of an originally large elongated grain are observed in the centre of Fig. Pure iron oxide grains, presumably authigenic haematite, are also observed next to the Fe-Ti oxides. Euhedral haematite and small pigmentary haematite grains distributed along grain boundaries are observed in a red siltstone sample Fig.
In Fig. These features imply that most haematite grains in red siltstone generally have authigenic characteristics. XRD patterns show the distinct peaks of illite, chlorite and quartz Fig. This result implies that rocks in the study area were altered significantly through illitization and chloritization. It was reported that conversion of smectitic minerals to illite could result from burial diagenesis at depths of 2—3. Iron ions, which are major ingredients for magnetite authigenesis, can be released during illitization Hirt et.
Therefore, it can be assumed that the magnetite authigenesis is related to the burial diagenesis in the study area. The alteration of the rocks, however, can be caused by not only burial, but also interactions between fluids and rocks. Potassium can be supplied from the decomposition of K-feldspars associated with the illitization Chamley or orogenic-type fluids McCabe et.
The results of the electron microscope observations and the XRD analyses suggest that the major magnetic carriers e. Magnetite authigenesis can occur in relation to burial diagenesis or fluid-mediated alteration under reduced conditions, whereas secondary haematite may form under oxidized conditions. Hence, both haematite and magnetite hardly ever form simultaneously.
- Geology and Sedimentology of the Korean Peninsula;
- The Supremes at Earls All-You-Can-Eat.
- Introduction | SpringerLink.
The existence of both haematite and magnetite will be discussed in Section 7. C, chlorite; I, illite; Q, quartz. In this study we show that the Pyeongan Supergroup in the Jeongseon area has been undoubtedly remagnetized. In the study by Uno , the primary component was isolated from four sites that are within the same region as sites J8, J20 and J23 of this study. The tilt-corrected directions of Uno and this study do not seem to be different and the directions before tilt correction are also similar except for one site NF1 of Uno The mean direction in geographic coordinates calculated from three sites excluding the site NF1 of Uno is not statistically different at the 5 per cent significance level from the Late Cretaceous and Tertiary palaeomagnetic directions in Korea.
Although the directions in geographic coordinates are more dispersed than those in stratigraphic coordinates, it is interpreted that the Pyeongan Supergroup in the study area has been remagnetized, because we cannot find any differences to distinguish the directions of these three sites from those of the other sites in this study Fig. The site-mean direction showing shallow inclination in geographic coordinates e.
NF1 of Uno does not appear in this study. Additional arguments contrary to the result of Uno can be raised. In contrast, all the samples of greenish siltstone in our study show magnetite behaviour during thermal and AF demagnetizations Figs 2d and f and in the rock magnetic studies Figs 5 and 6. In contrast to these areas, the Yeongwol area was remagnetized by the acquisition of a CRM during the Tertiary Doh et.
Comparison of the results of this study with those of the previous palaeomagnetic studies for the adjacent regions suggests that the complete remagnetization occurred in the northwestern part e. This result implies that each part of the basin has experienced different geological events since the deposition of the strata.
- The Birthday Present (BDSM).
- Peter the Great Tsar of Russia: Early Modern History (Early Modern History Series Book 12);
- The Road to Weird [Carlys Ghost and Harpo Marx is Seeing Things].
- The Creative Business Guide to Marketing: Selling and Branding Design, Advertising, Interactive, and Editorial Services!
- Dance As the Spirit Moves: A Practical to Worship and Dance.
- Geology and sedimentology of the Korean Peninsula (eBook, ) [uhemowikel.cf];
Cheong reported the significant difference of palaeontologic facies in the Pyeongan Supergroup between the southeastern and northwestern parts of the Taebaeksan Basin. The Sakmarian fusulinids occurred only in the northwestern part, indicating a hiatus in the southeastern part during the Sakmarian. Choi et. These reported palaeontologic data and structural characteristics of the Taebaeksan Basin are consistent with the results of this study in the sense that the pervasive remagnetization in the northwestern region was apparently connected to the severe structural deformations.
Several possible mechanisms can cause remagnetization. More importantly, magnetic grains found by electron microscope observations cannot be produced by weathering processes. Secondly, a thermoviscous remanent magnetization TVRM origin for the remagnetization can be proposed. Based on rock magnetic studies and electron microscope observations, the major magnetic carriers are SD—PSD haematite and magnetite of secondary authigenic origin. Hence, the CRM is most likely to be the major mechanism of remagnetization in the study area. Traditionally, many have reported CRM to be connected to the tectonically driven external fluid migration over long distances Oliver or the in situ pore waters related to tectonic pressure Elmore et.
Recently, Katz et. On the other hand, Henry et.
It is known that intense hot fluid circulations, associated with modifications of porosity and permeability of sediments, induced large authigenesis of illite and reworking of pre-existing clay minerals in eastern France Tournier et. Although the results of our XRD study, revealing abundant secondary illite and chlorite without any smectite, agree with those of Katz et.
Therefore, it is interpreted that a fluid-mediated process is most likely to be responsible for acquisition of the CRM. The nature of fluid related to the acquisition of the CRM is still problematic. There are many skarn and hydrothermal vein deposits, especially the meso-epithermal-type deposits, near the study area. Most meso-epithermal-type deposits in the Taebaeksan Basin are genetically associated with Late Cretaceous granitic activity Park et. Shelton et. Although it has not been proved that these mineralizing fluids circulated the host rocks pervasively, we speculate that the CRMs in the study area are related to the mixed magmatic—meteoric fluids.
The regional distribution of remagnetized and unremagnetized areas within the Taebaeksan Basin, as stated in the previous section, can be explained by the connection of the CRMs with the extent of structural deformation. There are many thrusts in the more intensively deformed northwestern region, while there are a limited number of thrusts in the southeastern region Ree et al. It can be interpreted that the remagnetizing fluids penetrated more easily and pervasively into the northwestern region by utilizing the already well-developed thrust system.
It can be interpreted that the authigenesis of these magnetic phases were mainly controlled by the lithology and the oxidation state of the host rocks rather than the chemical composition of fluids because all CRMs in each magnetic phase were acquired at almost the same time. The mixed magmatic—meteoric fluid propagated in the graphite-containing black shales formed goethite and pyrrhotite under reduced conditions, while the fluid in red beds under oxidized conditions caused haematite precipitation.
The fluid in greenish siltstones of less oxidizing condition relative to the red beds might form magnetite. The palaeomagnetic pole calculated from the remagnetized component of this study is at This palaeomagnetic pole position is close to those of the Late Cretaceous, Tertiary and Quaternary poles in Korea Fig.
Thus, it can be interpreted that the remagnetization occurred during the Late Cretaceous—Quaternary. Because any remarkable geological events, such as orogeny or igneous activity that might cause the remagnetization, are not recognized during the Quaternary, the remagnetization in the study area could have occurred during the Late Cretaceous—Tertiary.
Geology and Sedimentology of the Korean Peninsula (Elsevier Insights) | KSA | Souq
A number of hydrothermal vein deposits in the northeastern subzone of the Ogcheon Fold Belt formed between 94 and 73 Ma Park et. Some K-Ar age dating data Hence, the CRM of the study area is interpreted as having been acquired due to the formation of the authigenic minerals during the Late Cretaceous—Early Tertiary under the influence of the hydrothermal fluids that might be triggered by the Late Cretaceous Bulguksa igneous activity.
Similar aspects of the chemical remagnetization are also observed in several areas such as the Yeongwol area Doh et. The palaeomagnetic pole position calculated from the remagnetized component of the Yeongdong Basin is distinguishable from the Late Cretaceous and Tertiary pole positions and those of the other areas Fig. This difference implies that fluid-mediated chemical remagnetization in the Yeongdong Basin and the other areas occurred at significantly different times.
Palaeomagnetic pole calculated from the remagnetized component of the Pyeongan Supergroup in the Jeongseon area compared with a middle Early Cretaceous to Quaternary poles obtained in Korea and b those from remagnetized sedimentary rocks in the Yeongwol, Eumseong and Yeongdong basins. It is also reported that the basinal fluid events were triggered by the Kula—Eurasia convergence and migrated through the fault system within the Ogcheon Fold Belt during the Cretaceous period Sillitoe ; Kong et.
Ichnos —49 CrossRef Google Scholar.
Abstract of the spring meeting of the goegraphical of society of Korea no paginated, in Korean Google Scholar. Kim HM Cretaceous dinosaurs excavated from two dinosaur sites of Korea. Kim HM Cretaceous dinosaur fossils discovered from Korea and their stratigraphy. In: Gillette DD ed First international symposium on dinosaur tracks and traces. This journal has not been continued after publication of the first volume Google Scholar. In: Proceeding of the spring meeting of the Korean earth science society, p in Korean Google Scholar.
Ichnos —92 CrossRef Google Scholar. Ichnos — CrossRef Google Scholar. Jindong Formation, Lower Cretaceous : implications for polarities in ornithopod foot morphology. In: The 11th symposium on Mesozoic terrestrial ecosystems, pp — Google Scholar. Ichnos —65 CrossRef Google Scholar. Ichnos —42 CrossRef Google Scholar. Ichnos —83 CrossRef Google Scholar. Ichnos —74 CrossRef Google Scholar.
Ichnos —80 CrossRef Google Scholar.
Related Geology and Sedimentology of the Korean Peninsula (Elsevier Insights)
Copyright 2019 - All Right Reserved