Japan Oceanographic Data Center Marine Geological Data File: README file NGDC Data Set # 1079 obtained from: U.S. Department of Commerce National Environmental Satellite, Data, and Information Service National Oceanic and Atmospheric Administration U.S. National Geophysical Data Center (NGDC) (http://www.ngdc.noaa.gov/mgg/mggd.html) & collocated World Data Center for Marine Geology & Geophysics (http://www.ngdc.noaa.gov/mgg/wdcmgg) _______________________________________________________________________ NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THESE DATA _______________________________________________________________________ CONTRIBUTOR: Dr. Hideo Natani, Japan Oceanographic Data Center NAME OF DATASET: JODC Seafloor Sediment Descriptions LAST UPDATE: December, 1977 (original receipt date by MGG) GEOGRAPHIC REGION: Global DATA VOLUME: approximately .2 mbytes MGG IDENTIFIER: MGG56995001 LIST OF FILES jodc.txt and README (this file) SUMMARY This file was compiled by the Japan Oceanographic Data Center using the IOC Marine Geological Data Format. It includes 748 master records and 1740 data records. It contains information on unconsolidated sediments and hard rocks from the seafloor, including station location, collecting institution and ship, date of collection, type of collecting device, analysis method(s), grain size information, biogenous components, structure, non-biogenous components, age, sediment color, and remarks. Igneous, sedimentary, and metamorphic rocks are also noted including encrustations, and erratics. AVAILABILITY Data are available for free download from NGDC's Web site. NGDC/WDC for MGG, Boulder Technical Contact: Carla Moore NOAA/NGDC E/GC3 325 Broadway Boulder, CO 80305 USA phone: 303-497-6339 fax: 303-497-6513 email: Carla.J.Moore@noaa.gov JODC SEDIMENT FILE DOCUMENTATION Extraction of JODC ship code and institution code JODC Ship Code ship ship name institution code code 09S Yorii 09 E1 Tanakai Maru No. 1 00 GH Hakurei Maru GS HK Hakuho Maru 35 K4 Kaiyo No. 4 00 ME Meiyo 00 SI Seifu Maru 15 TA Takuyo (after 1965) 00 TK Takuyo (before 1964) 00 UM Umitaka Maru 36 YY Shoyo 00 JODC Institution Code institution institution name code 00 Hydrographic Department, Maritime Safety Agency 09 9th Regional Maritime Safety Headquarters, MSA 15 Maizuru Marine Observatory, JMA 35 Ocean Research Institute, University of Tokyo 36 Tokyo University of Fisheries GS Geological Survey of Japan VK Faculty of Science, Kanazawa University _______________________________________________________________________________ IOC DATA FORMAT DESCRIPTION _______________________________________________________________________________ IOC/IODE-VIII/INF.1 Paris, 14 February 1975 INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION Data Format for International Exchange of Marine Geological Data This data format was prepared by the IODE Ad Hoc Group for the Development of Marine Geological/ Geophysical Data Management and prsented to the 7th Session of the Working Group on International Oceanographic Data Exchange (9-13 July 1973). The Working Group recommended (Recommendation 2) Member States as a standard international exchange format for the next two to three years with a view to testing its effectiveness and usefulness and that Member States inform the IOC Secretariat of their experience and findings. This recommendation was approved by the 8th Session of IOC (November 1973) in its Resolution VIII-21. SC-75/WS.6 Introduction Many organizations around the world collect marine geological samples which are expensive to obtain and are useful for a variety of research purposes additional to those for which they were originally collected. Realizing this, the organizations collecting such materials generally conserve them as well as possible with the limited resources available for this purpose and make subsamples available to researchers requesting them. The most serious impediment to the wider and more economical utilization of these sediment cores and dredges rocks is the lack of an effective means of informing researchers of the nature of the samples in collections. To fill this need, IOC's ad hoc Group for the Development of Marine Geological/ Geophysical Data Management has attempted to determine which items of information on such samples are most useful to a wide spectrum of researchers, and to devise a format for recording and trasmitting this information. In devising this scheme we have had to strike a balance by excluding some items considered to be important by specialized, small communities of users, while including items needed by larger communities of users. We have had also to compromise between outlining on the one hand a set of descriptors too brief to accomplish the desired goal, or on the other hand a set of parameters so comprehensive that it could not reasonably be expected to become available relatively soon after the collection of the materials. The format outlined in the following pages is not so much meant to serve for the recording and transmission of large volumes of quantitative data suitable for synthesizing for special research purposes, but rather is designed to inform marine geologists of the nature of materials available in collections. On the basis of this information, the investigator would be able to request samples from specific intervals in sediment cores, or from specific dredge hauls, suitable for his research purposes. GENERAL DESCRIPTION OF THE DATA FORMAT The entire data system is divided into three separate parts: (only two are described here; mass physical properties are not included in this data file) A. the data format for unconsolidated sediments; B. the data format for hard rocks; Each data format (part of the entire system) consists of one Station Master Card and the pertaining Data Cards. The Station Master Cards of the three partial systems are identifcal except for columns 65-69. The following card types belong to the individual partial systems: A. Unconsolidated sediments 1. Station Master Card (Card Type 1); 2. (a) Sediment Data Card I (Card Type 3); (b) Sediment Data Card II (Card Type 4); this card is the continuation of card type 3. 3. Plain Language Card(s) (Card Type 5): This card will be produced by the data centre, if necessary. Any additional remarks that cannot be stored in card types 3 or 4 may be entered in plain language on this card. Retrieval of specific information from this card type is of course not possible. B. Hard rocks 1. Station Master Card (Card Type 1); 2. (a) Rock Data Card I (Card Type 6); (b) Rock Data Card II(Card Type 7); this card is the continuation of card type 6; 3. Plain Language Card(s) (Card Type 8): As under A.3 it is possible to store additional plain language information concerning hard rocks. As each partial format is independent, the individual experts would be in a position to deliver the results of analyses separately on the partial formats to the storage centre. On account of the information igiven in each of the Station Master Cards, the partial results of one sample (sediment, hard rocks, etc.) can be reassembled in the data centres. Subsequent delivery of more recent results of one partial format will in principle, also be possible. The information would, however, have to be repeated in the Station Master Card, in order to enable a clear co-ordination of the data delivered subsequently to those already available in the data centre. A. CODING THE DATA OF UNCONSOLIDATED SEDIMENTS A.1 The Station Master Card (Card Type 1) Columns 1-2 COUNTRY The code designation for the country of the agency sponsoring or operating the vessel (Table I). Columns 3-5 SHIP Code number of the vessel. Each measuring platform (research vessel, group of vessels, ships of opportunity, rigs, etc.) must be given a national code number. This number can be obtained from the national oceanographic data centre (NODC). Columns 6-8 NODC REFERENCE NO. These columns provide a cumulative identification reference number which is assigned by the NODC prior to processing. Columns 9-11 CONSECUTIVE STATION NUMBER Consecutive numbers are assigned and coded by the NODC. Stations or samples included within a single NODC reference number are consecutively numbered, starting with 001 regardless of the originator's sample numbers. One consecutive number includes two samples only, if both are taken during one lowering. Additional samples from the same position but from another lowering are assigned a new consecutive number. Columns 12-14 MARSDEN SQUARE Code number identifying the Marsden Square containing this station. A Marsden Square chart (Figure 1) is provided to show how this number is related to the geographic co-ordinates entered in columns 18 through 31. Columns 15-16 1 DEGREE SQUARE Code number identifying the degree square of the Marsden Square within which the station is located. A chart (Figure 2) showing the position of one-degree divisions within a Marsden Square is provided. Note: The degree square is obtained by comgining the unit numbers of the degrees of latitude and longitude (example: 63 deg 15' N and 02 deg 56' E is coded 32). Column 17 POSITIONAL ACCURACY Enter the estimated accuracy of the position reported according to the following code: Code Less than 0.2 nautical miles 1 Between 0.2 and less than 1 nautical mi. 2 Between 1 and less than 3 nautical miles 3 Between 3 and less than 10 " " 4 Greater than or equal to 10 " " 5 Columns 18-23 LATITUDE Enter the latitude in degrees, minutes, and hundredths of a minute where the sampler touched the bottom, a photo was taken, etc. For dredge operations, the position given should be the midpoint of the dredge run. Columns 24-30 LONGITUDE Enter the longitude in degrees, minutes, and hundredths of a minute where the sample touched the bottom, a photo was takne, etc. For dredge operations, the position given should be the midpoint of the dredge run. Column 31 QUADRANT Code number identifying the quadrant containing the position reported according to the following code: Code 0 - N and E 1 - N and W 2 - S and E 3 - S and W In this connexion the following rules are to be followed: 0 deg latitude is taken N 0 deg longitude is taken E 180 deg longitude is taken W Columns 32-35 DEPTH TO BOTTOM Enter the sounding depth in meters m of the geographic position reported in columns 18 through 31. Columns 36-38 YEAR Enter the last three figures of the year. Columns 39-40 MONTH Enter the month using Arabic numerals 01 through 12 Columns 41-42 DAY Enter the day of the month Columns 43-46 CRUISE NUMBER Enter the cruise number of the ship. Columns 47-51 ORIGINATOR'S STATION NUMBER Enter the originator's station number or sample number placing the last character in column 51. Columns 52-53 DRAGGING SPEED Use these columns only, if the instrument was towed. Enter the speed in tenths of knots at which the sampler was dragged. Columns 54-55 DRAGGING DIRECTION Use these columns only, if the instrument was towed. Enter the direction in 10 -degree units (187 deg coded as 19) in which the sampler was dragged. Columns 56-57 DRAGGING TIME Use these columns only, if the instrument was towed. Enter time interval in tenths of an hour in which the sampler was dragged, while touching the bottom. Columns 58-59 REPOSITORY The code designation for the repository where the sample is stored will be entered at the NODC. Columns 60-64 ARCHIVE NUMBER(S) Enter the archive number under which the sediment sample is stored in the repository. Columns 65-69 These columns are used only, if the card functions as a Master Card (ct 1) for hard rocks. In connexion with columns 60-64 these columns can be used for indicating the range of archive numbers for the complete rock collection of that sample stored in the repository. Columns 70-75 No entry Columns 76-80 CARD IDENTIFICATION Consecutive card numbering within a card type and identification of the marine geological card deck. The code numbers are preprinted in the coding forms. A.2 Sediment Data Card I (Card Type 3) Columns 1-16 Identical to the Master Card (ct 1). These columns do not appear in the coding forms; the information will be reproduced automatically. Column 17 SAMPLING DEVICE Enter the type of device used to obtain the sample according to the following code: Code Corer ......................... 1 Grab ......................... 2 Dredge ........................ 3 Secondary Core Sampler ........ 4 " Grab " ........ 5 " Dredge " ........ 6 Other instruments and devices.. 9 Column 18 PARTICULAR TYPE Indicate the particular type of the respective sampling device in column 17 (see Table II). Columns 19-22 CORE LENGTH or VOLUME OF DREDGE/GRAB if core sampler: Enter the total length of the core obtained, including the disturbed portion in centimeters [cm.]. If total length is unknown, enter disturbed length. if dredge or grab sampler: Enter the volume of the sample in [dm3]. Columns 23-30 CORE INTERVAL Enter the upper and lower boundary in centimeters [cm.] (from the sea floor) of the core segment described. Columns 31-34 PRECISE LEVEL Enter the precise level in centimeters [cm.] (from the sea floor), from where the analysed sample was taken. Column 35 OUTCROP Indicate whether an outcrop could be observed or not; enter Y - Yes N - No The following items of Sections A and B should be given for each lithological unit in the core. The fineness of the lithological units into which a core-describer divides his cores will depend to some extent on the time available to him, and on the personal judgement, and thus no guidelines are given. Clear distinction has to be made between "not present" (N = None) and "not looked for" (no entry; blank). Columns 36-39 GRAIN SIZE Enter the amount (according to Table IV) of grain of each in the total sediment (biogenous and non-biogenous components combined) in the appropriate column: 36 - Coarser than sand 37 - Sand-size 38 - Silt-size 39 - Clay-size (The "Standard Size Table" (Table III) is recommended for use in determining the classification.) Column 40 GRAIN SIZE ANALYSIS Are the indications given in columns 36-39 the results of a complete grain size analysis, which would be available on request? Y - Yes N - No Columns 41-49 ANALYSING METHOD Indicate the method(s) used for the grain size analysis by entering a cross in the appropriate column(s); 41 - megascopic examination 42 - sieving 43 - pipette 44 - hydrometer 45 - microscopic slides 46 - heavy liquid separation 47 - settling velocity 48 - photoelectric techniques 49 - caliper (coarse particles) Columns 50-68 BIOGENOUS COMPONENTS Indicate the appearance of the biogenous components by entering the appropriate code (see Table IV) in columns: 50 - calcareous nannofossils 51 - foraminiferae 52 - pteropods and/or heteropods 53 - scaphopods 54 - gastropods 55 - pelecypods 56 - ostracods 57 - corals 58 - bryozoa 59 - algae 60 - echinoids 61 - shell fragments 62 - fish teeth or skeletal debris 63 - silicoflagellates 64 - diatoms 65 - radiolarians 66 - sponge spicules 67 - plant fragments (including spores, pollen, etc.) 68 - worms Columns (69-75) No entry Columns 76-80 CARD IDENTIFICATION Code numbers for the identification of the card deck and the card type. The figures are preprinted in the coding forms. A.3 Sediment Data Card III (Card Type 4) [Continuation of Card Type 3] Columns 1-16 Identical to the Station Master Card (ct 1) and the Sediment Data Card I (ct 3). These columns do not appear in the coding forms; the information will be reporduced automatically. Columns 17-25 STRUCTURE Indicate the structure of the core segment by entering the appropriate code (or number) in columns: 17-19 - finely bedded; enter thickness of the beds in millimeters [mm] 20 - cross-bedded (Y = Yes, N = No) 21 - convolute bedding ( " , " ) 22 - graded bedding ( " , " ) 23 - burrow-mottling (use Table IV) 24 - bioturbation (Y = Yes, N = No) 25 - flow-in [indicate as N = None S = Slight (beds disturbed, but some useful stratigraphy sequences retained) G = Great (vertically streaked, not useful stratigraphically)] Column 26 LITHIFICATION Indicate whether lithification of the sediment could be observed: N = None L = Low M = Middle H = High Column 27 NATURE OF LOWER BOUNDARY Indicate the nature of the lower boundary of the lithologic unit (core segment): S = Sharp G = Gradational Columns 28-50 NON-BIOGENOUS COMPONENTS Indicate the appearance of non-biogenous components by entering the appropriate codes in columns: 28 - pyroclastic shards (volcanic ash)(1) 29 - sulphides (1) 30 - glauconite (1) 31 - manganese micronodules (1) 32 - macro-tektites (1) 33 - zeolites (1) 34 - method used for determination of zeolites (code see below) 35 - light minerals (1) 36 - method used for determination of light minerals (code see below) 37 - dark minerals (1) 38 - method used for determination of dark minerals (1) Use Table IV. [Code for determination methods of zeolites and minerals: Code 1 - visual inspection 2 - microscope 3 - x-ray 4 - spectroscope . . 9 - others] 39-41 - number of larger manganese nodules 42-44 - mean size of larger manganese nodules [mm] 45-47 - number of phosphatic nodules 48-50 - mean size of phosphatic nodules [mm] Columns 51-59 COLOUR Enter the Munsell colour code (**) number for the colour of the wet sample beginning in column 51. Do not suffix zeros to fill the field. (**) Not included with this draft. Columns 60-61 GEOLOGICAL AGE Enter the geological age of the core segment according to the following code: 01 - Quaternary 02 - Pliocene 03 - Miocene 04 - Oligocene 05 - Eocene 06 - Paleocene 07 - Late Cretaceous 08 - Early Cretaceous 09 - Jurassic 10 - pre-Jurassic Columns 62-63 DETERMINATION OF GEOLOGICAL AGE Enter the method(s) used for determining the geological age according to the following code: 01 - calcareous nannofossils 02 - foraminiferae 03 - gastropods 04 - pelecypods 05 - ostracods 06 - bryozoa 07 - algae 08 - fish teeth 09 - silicoflagellates 10 - diatoms 11 - radiolarians 12 - plant fragments 13 - carbon 14 14 - potassium-argon 15 - paleomagnetism If more than one determination method was applied write this in plain language in the remark columns. Columns 64-65 OLDER MICROFOSSILS Age of older microfossils reworked into the sediment. Use the same set of ages as listed above. Column 66 Abundance of older microfossils reworked into the sediment. Use Table IV. Columns 67-65 Available for comments. Columns 76-80 CARD IDENTIFICATION Code numbers for the identification of the card deck and the card type. The figures are prepreinted in the coding forms. B. CODING THE DATA OF HARD ROCKS B.1 Station Master Card (Card Type 1) Use the same card type as for the unconsolidated sediments. There is only one difference in the column field 65 through 69. A detailed description of the Master Card is given under paragraph A.1. B.2 Rock Data Card I (Card Type 6) Columns 1-16 Identical to Station Master Card (ct 1). These columns do not appear in the coding forms; the information will be reproduced automatically. Column 17 SAMPLING DEVICE For explanation see paragraph A.2. Column 18 PARTICULAR TYPE For explanation see paragraph A.2. Columns 19-22 CORE LENGTH or VOLUME OF DREDGE/GRAB For explanation see paragraph A.2. Columns 23-26 PRECISE LEVEL Precise level in centimeters [cm] (from the top of the core) from where the rock(s) was (were) taken. Columns 27-30 WEIGHT OF ROCKS If the rock(s) was (were) taken from a distinct level in the core, enter the weight in kilogrammes [kg.]. Use the next line in the data sheet for rocks from another core level. If the rocks were gathered with a grab or dredge give the total weight for the complete rock collection in kilogrammes [kg.] in one line of the form. Columns 31-33 NUMBER OF ROCKS Enter the total number of rocks from either a core segment, dredge or grab sample. Columns 34-42 IGNEOUS ROCKS Give a megascopic classification of igneous rocks by entering in columns: 34-36 - number of volcanic rocks 37-39 - number of plutonic rocks 40-42 - number of pyroclastic rocks Columns 43-69 SEDIMENTARY ROCKS Give a megascopic classification of the sedimentary rocks by entering in columns: 43-45 - number of breccias 46-48 - number of conglomerates 49-51 - number of sandstones 52-54 - number of mudstones 55-57 - number of limestones 58-60 - number of recent biogenous rocks 61-63 - number of cherts 64-66 - number of concretions 67-69 - number of other specified sedimentary rocks Columns 70-72 METAMORPHIC ROCKS Indicate the number of metamorphic rocks found in the sample. Columns 73-75 FABRIC Indicate the fabric terms of the metamorphic rocks by entering Y for yes; N for no; or no entry, when "not looked for" in columns: 73 - relict texture 74 - schistosity 75 - porphyroblastic Columns 76-80 CARD IDENTIFICATION Code numbers for the identification of the card deck and the card type. The figures are preprinted in the coding forms. B.3 Rock Data Card II (Card Type 7) [Continuation of Card Type 6] Columns 1-16 Identical to the Station Master Card (ct 1) and the Rock Data Card (ct 6). These columns do not appear in the coding form; the information will be reproduced automatically. Columns 17-22 ULTRAMAFIC ROCKS Give a megascopic classification by entering in columns: 17-19 - number of periodotides 20-22 - number of serpentinites Columns 23-28 ENCRUSTATIONS Indicate by entering in columns: 23-25 - mean thickness in millimeters [mm] of manganese encrustations 26-28 - mean thickness in millimeters [mm] of other encrustations specified in the remark columns. Columns 29-30 ERRATIC ROCKS Give the number of rocks which may be erratic in your opinion. Columns 31-37 ARGUMENT Indicate the basis for your opinion on erratic rocks by entering a cross in the appropriate column(s): 31 - dredging history 32 - roundness 33 - sorting 34 - absence of fresh fractures 35 - surface markings 36 - heterogeneity of collection 37 - others (specify under remarks) Columns 38-47 GEOLOGICAL AGE Indicate the geological ages from where rocks have been collected by entering a cross in the appropriate columns: 38 - Quaternary 39 - Pliocene 40 - Miocene 41 - Oligocene 42 - Eocene 43 - Paleocene 44 - Late Cretaceous 45 - Early Cretaceous 46 - Jurassic 47 - pre-Jurassic Columns 48-59 AGE DETERMINATION Indicate the method(s) used for determining the geological age(s) by entering a cross in the appropriate columns: 48 - paleontol 49 - optical 50 - chemical 51 - spectrographic 52 - neutron-activ. 53 - radiogenic isot. 54 - non-rad. isot. 55 - electr. microscop. 56 - electr. microprob. 57 - x-ray diffract. 58 - diff. thermal 59 - others (specify) Columns 60-75 Space for plain language comments. Columns 76-80 CARD IDENTIFICATION Code numbers for the identification of the card deck and the card type. The figures are preprinted in the coding forms. TABLE I IOC country code for oceanographic data processing purposes The following Country Code was recommended by the seventh session of the Intergovernmental Oceanographic Commission Working Group on International Oceanographic Data Exchange for incorporation in the Manual on International Oceanographic Data Exchange. Its maintenance and updating will be provided by the Intergovernmental Oceanographic Commission Working Group on International Oceanographic Data Exchange on a continuing basis. Code Country Code Country 72 Albania 42 Indonesia AL Algeria IN Intergovernmental/International 08 Argentina 45 Ireland 09 Australia 47 Israel 10 Austria 48 Italy 11 Belgium IC Ivory Coast 13 Bolivia JA Jamaica 14 Brazil 49 Japan 15 Bulgaria 24 Korea, Republic of 12 Burma 52 Lebanon 18 Canada 55 Madagascar 19 Ceylon (Sri Lanka) MS Malaysia 20 Chile 57 Mexico 21 China MO Monaco 22 Colombia 56 Morocco RC Congo MZ Mozambique CR Costa Rica 64 Netherlands CU Cuba 59 New Caledonia DA Dahomey 61 New Zealand 26 Denmark NI Nigeria 70 Dominican Republic 58 Norway 28 Ecuador 62 Pakistan 27 Egypt PA Panama 75 El Salvador 65 Peru 34 Finland 66 Philippines 35 France 67 Poland 96 German Democratic Republic 68 Portugal 06 Germany, Federal Republic of 73 Romania GH Ghana SE Sengal 36 Greece SL Sierra Leone 37 Guatemala 91 South Africa GU Guinea 29 Spain 38 Haiti 19 Sri Lanka HO Honduras SU Sudan 46 Iceland 77 Sweden 47 India ZA Tanzania, United Republic of 86 Thailand 31 United States of America 88 Tunisia 99 Unknown 89 Turkey 92 Uruguay 90 USSR 93 Venezuela TABLE II Code Numbers for Particular Types of Devices Corer Grab Dredge Others Code Unknown Unknown Unknown Unknown 0 Gravity Orange Peel Pipe Photography 1 Piston Hand/scuba diver Chain bag Film 2 Suction Ekman, van Veen Metal box TV 3 Pettersen Vibrating Lead line or anchor Trawl Sparker 4 Impact Submersible vehicle Bucket Air-gun 5 Metal box Suspended sediment Scoop Boomer 6 Expendable Push box Barge (shovel) - 7 Rotary Shipek Suction - 8 Other (specify) Other (specify) Other (specify) Other (specify) 9 TABLE III Standard Size Table * US Standard Millimeters Microns Phi (0) Wentworth Size Class Sieve Mesh _____________________________________________________________________________ 4096 -12 1024 -10 Boulder (-8 to -12 phi) ---------------- 256 ---------------------- - 8 ------------------------------- Cobble (-6 to -8 phi) Use wire ------- 64 ---------------------- - 6 ------------------------------- squares 16 - 4 Pebble (-2 to -6 phi) -----5 --------- 4 ---------------------- - 2 ------------------------------- 6 3.36 - 1.75 7 2.83 - 1.5 Granule 8 2.38 - 1.25 === 10 ========== 2.00 =================== - 1.0 ============================= 12 1.68 - 0.75 14 1.41 - 0.5 Very coarse sand 16 1.19 - 0.25 --- 18 ---------- 1.00 ------------------- 0.0 ----------------------------- 20 0.84 0.25 25 0.71 0.5 Coarse sand 30 0.59 0.75 --- 35 ---1/2---- 0.50 ----- 500 --------- 1.0 ----------------------------- 40 0.42 420 1.25 45 0.35 350 1.5 Medium sand 50 0.30 300 1.75 --- 60 ---1/4---- 0.25 ----- 250 --------- 2.0 ----------------------------- 70 0.210 210 2.25 80 0.177 177 2.5 Fine sand 100 0.149 149 2.75 ---120 ---1/8---- 0.125 ---- 125 --------- 3.0 ----------------------------- 140 0.105 105 3.25 170 0.088 88 3.5 Very fine sand 200 0.074 74 3.75 ===230 ===1/16=== 0.0625 === 62.5 ======= 4.0 ============================= 270 0.053 53 4.25 325 0.044 44 4.5 Coarse silt 0.037 37 4.75 ----------1/32--- 0.031 ---- 31 ---------- 5.0 ----------------------------- 1/64 0.0156 15.6 6.0 Medium silt 1/128 0.0078 7.8 7.0 Fine silt ========= 1/256 == 0.0039 ==== 3.9 ======== 8.0 ===== Very fine silt ======== 0.0020 2.0 9.0 0.00098 0.98 10.0 Clay 0.00049 0.49 11.0 0.00024 0.24 12.0 0.00012 0.12 13.0 0.00006 0.06 14.0 * from Folk (1968) TABLE IV Since it does not seem realistic to expect good numerical values routinely, those items marked with an asterisk (*) should be indicated as either N = None F = Few C = Common A = Abundant E = Exclusive Note: the remaining figures in this document consisted of a Marsden square chart, a sheet explaining one degree divisions of Marsden squares, and four sheets showing visually the layout of the card formats described above.