1、Sampling and Analysis of Sediments,1,Percussion Drilling a method to take undisturbed and stratified sediment / soil samples Gerd SchukraftLaboratory of Geomorphology and Geoecology,2,Field methods, sampling procedureLab methodsPossibilities of interpretation,3,Before sampling sediments you must loo
2、k for the representative location dependent on your question.Therefore non-destructive methods are suitable for:GeomagneticsGeoelectricsRefraction seismicsSurveying techniques (laserscanning, satellite image, ),4,4,GeomagneticsThe measurement shows variations and disturbances in the local line of th
3、e magnetic flux.The disturbances are caused by metals and/or fired materials.The example shows a geomagnetic map from a settlement with houses, storage pits and ditches from the Early Bronze Age.,5,5,GeoelectricsThe injection of electric current (until 200 mA and max. 50 V) into the soil shows the a
4、pproximate structure of the subsurface.The measurement of the resistance of the subsurface structure happens often with an array of 100 uncoated metal-electrodes with a distance of 1 to 4 m. The lower the distance the better the resolution limit.The example shows the structure of a cushian peatland
5、in the peruvian Andes with in-situ hard rock, fluvial deposits and nearly 10 m peat-sediments.,This example shows the presence of a subcutane wall of an ancient direction change of a river in Greece.,6,Refraction seismicsThis methode enables a sound logging of an impact-stimulus. With the observed t
6、ravel-times of the p-waves it is possible to model the structure of the subsurface.The example shows an array of 48 geophones with a spacing of 2 m in a valley in Santorin / Greece. The measured velocities produce the subcutaneous thickness.,7,Surveying techniquesIn addition to terrestrial Laser-sur
7、vey, LIDAR-survey, satellite images and aerial images belongs to the tools for the selection of the representative location.,8,After identification of the correct location the percussion drilling can take place,or /and digging,Percussion Drilling Equipment,9,Procedure of Percussion Drilling,10,Probl
8、ems with Percussion Drilling I,11,Problems with Percussion Drilling II,12,13,Problems with Percussion Drilling III,It does not make sense to load the vibration-hammer. It does not make sense to hit more than 10 minutes without progress of drilling,14,14,ProcessingAfter coring there is the posibility
9、 to measure non-destructive the magnetic susceptibility with the complete sediments in the linertube or you cut the liner in two halves.,15,Sampling in the field (e.g. percussion drilling, digging, ),Laboratory for Geomorphology and Geoecology,Non-destructive measurement of volume-susceptibility,Saw
10、ing, seperating in two halfes, preparing,Photo documentation, description, colour identification, .,Taking partial sample,Datinge.g. 14C, OSL, .,Further processing in the laboratory,Non-destructive exploration (e.g. geoelectrics, geomagnetics, ),16,16,Handling of sediment samples in the laboratory (
11、aerobic / anaerobic),pH, redox,Grain-sizeanalysis with destructionof organic matter and lime,ultrasound,Subsequentprocessinge.g. thin section, microscopy, X-ray, Fe- compounds,Dissolution e.g. aqua regia, Kaliumperoxodi-sulfat, liquefied material,CNSTC, TOC,CECcmoleq/kg,Milling of fine soil ( 2mm),H
12、eavy mineral-separation,Photo-metry,AAS(flame, GF),CNS-Isotope,Extraction(alkane, chlorophyll-derivatives, greenhouse-gases, pesticides),GC,17,Scientific use- Landscape development- Geomorphological questions- Geoecological questions- Geoarcheological questions- Paleo-environment questions- Pollution problems- Geochemical environment- Land use change,18,Land use change change of atmospheric CO2 concentration / soil carbon stock,19,Thank you,
