tbl_methods

Contains definitions and details of various analysis methods.

The full list of methods

(Sorted by tbl_method_groups, as of 2026-04-20, copied from https://browser.sead.se/postgrest/tbl_methods)

1. Palaeobiological

method_id	method_name	description	method_abbrev_or_alt_name
3	Palaeoentomology	Primarily fossil insect analyses, although other similar groups are usually included.\nThe method is commonly used for the reconstruction of natural and human environments in archaeological and palaeoecological contexts as well as climate change studies through the Mutual Climatic Range (MCR) method. \nStandard method: \n- samples disaggregated in warm water over a 300µm sieve; \n- excess water removed from sieved residue, then residue mixed with small amount of liquid paraffin (kerosene); \n- cold water added and left to stand for 15 minutes after which the floating (paraffin captured) fraction is pored into a 300µm sieve; \n- latter stage (fill, float, pour) repeated three times; paraffin washed out with detergent and warm water; \n- float is then stored and examined under a binocular microscope usually under 96% alcohol;\n- insect remains and other interesting finds are picked out and identified through the use of reference collections and identification keys.\nNOTE: storage in alcohol most likely has a detrimental effect on the possibility for using insect remains for C14 dating! Any samples where insect remains are to be dated should therefore be only stored in distilled water.	Fossil insects
6	Chironomid analyses	Non-biting midge (Chironomid) analyses, most commonly performed on lake sediments.	Chirono
8	Plant macrofossil analyses	The analysis of macro- or microscopic plant remains from either archaeological (archaeobotany) or ‘natural’ contexts.\nStandard method and variations:\n- samples are disaggregated in warm water and washed through a sieve (mesh size varies with application, most commonly 250 or 500µm);\n- material caught in the sieve is then either dried or stored in water/alcohol before sorting under a binocular microscope;\n- specimens are identified with the help of reference collections and identification keys.	Plant macros
14	Palynology	Pollen analysis.	Pollen
15	Charcoal analysis	The analysis of burnt/carbonised particles or fragments.	Charcoal
40	Mollusc analyses	Analysis of either land, fresh water or marine molluscs.	Molluscs
111	Plant macros (volume)	Plant macrofossil amount quantified by absolute volume	null
175	Ancient DNA analysis (Sample Extraction/Analysis)	Extraction and analysis of ancient DNA recovered from biological material (human, animal, plants, etc.)	aDNA-Sample
176	Ancient DNA analysis (Library Preparation)	Library preparation of ancient DNA recovered from biological material (human, animal, plants, etc.)	aDNA-Library

2. Palaeo chemical/physical

method_id	method_name	description	method_abbrev_or_alt_name
32	Loss on ignition	An evaluation of the proportion of organic matter present in a sample, measured by comparing pre-burnt and post-burnt sample weights.\nStandard method:	LOI
33	Magnetic susceptibility	A measurement of the ability of a sample to retain an induced magnetic field.	MS
35	Magnetic susceptibility (Low frequency)	A measurement of the ability of a sample to retain a low frequency induced magnetic field.	MS-lo
36	Magnetic susceptibility (High frequency)	A measurement of the ability of a sample to retain a high frequency induced magnetic field.	MS-hi
37	Phosphate degrees	Amount of phosphates. Standard method: Inorganic phosphate content. Extraction by citric acid (2%). Based on Arrhenius and further developed by EAL. The amount of phosphate is specified as mg P2O5/100g dry soil.	P°
74	Total phosphates citric acid	Measurement of total phosphate content through citric acid extraction and photospectrometer	citPtot
94	Phosphate degrees HCL	Amount of phosphates. Standard method using HCL instead of citric acid.	P°HCL
106	MS loop	Bartington MS2 & MS2D	null
107	Conductivity µS (H2O)	Conductivity in µS (H2O)	null
109	pH (H2O)	Acidity (pH)	null
110	pH (KCl 0,1M)	Acidity (pH) (KCl 0,1M)	null
118	0,6mm (%)	0,6mm. Extracted through sieving.	Grain size 0,6-2mm (%)
119	0,6mm (%)	0,6mm. Extracted through sieving.	0,6 mm (%)

3. Dating by radiometric methods

method_id	method_name	description	method_abbrev_or_alt_name
38	C14 Accelerator dating	Accelerator Mass Spectrometer Carbon-14 dating.	C14 AMS
39	C14 Conventional	Conventional Carbon-14 dating.	C14
146	U-Series U234/U238		U234/U238
147	Uranium-Series (general)		U-Series
148	Radiocarbon (14C Unspecified)	Dating by a radiocarbon method, the details of which are not provided in the publication or supporting material.	C14 Unspec.
149	Radiometric date by unknown method	Dating by an unspecified radiometric method (information missing in publication).	UnknownRadio
151	C14 Conventional	Conventional Carbon-14 dating. Uncalibrated dates.	C14 Std
152	Amino Acid Racemization	Age determination based on the post-mortem decay (or racemization/epimerization) of amino acids in fossils. The method has primarily been used to date shells, and less sucessfully on bone, teeth and wood under some conditions.	AAR
153	C14 dating of humic substances in sediment	Age determination by radiocarbon on humic substances extracted by pretreatment of sediments (e.g. peat, colluvium). A number of method variations are applied, aimed at dating different fractions of the sample (as opposed to the bulk dating of organic matter), including: humic acid fraction (alkali soluble) and humin fraction (alkali insoluble). Modern dates are generally determined through AMS, but older dates may have been aquired through standard counting.	C14 Humous
154	Argon39-Argon40	Argon39-Argon 40 radiometric dating	Ar39-Ar40
159	Interpolated C14	Dating using the interpolation of 14C dates from other samples (give details in dating notes)	Interp 14C
161	Helium-Uranium	Dating based on the production of helium during the radioactive decay of uranium and thorium.	He-U
162	Chlorine 36	Dating based on the radioactive decay of chlorine 36	Cl36
163	Uranium trend	Dating utilizing disequilibrium in the decay of Uranium-238, Uranium-234 and Thorium 230.	U-Trend
164	Berylium 10	Dating based on the radioactive decay of berylium 10.	Be10
165	Potassium-Argon	Dating based on the radioactive decay of potassium into argon.	K-Ar
167	U-Series Pa231/U235	Dating based on the radioactive decay of uranium-series isotopes protactinium-231 and uranium-235.	Pa231/U235
168	Lead 210	Dating based on the measurement of radioactive isotope lead-210, which is a product of uranium decay.	Pb210
169	U-Series Th230/U234	Dating based on the radioactive decay of uranium-234 to thorium-230, and the degree to which secular equilibrium has been restored between these	Th230/U234
170	Fission-Track	Dating based on the trails left in some glassy minerals as a result of the radioactive decay of uranium.	Fis-Track

4. Modern biological

method_id	method_name	description	method_abbrev_or_alt_name
16	Vegetation survey	Survey of modern (living) vegetation	Veg survey

9. Biological/Chemical/Physical

method_id	method_name	description	method_abbrev_or_alt_name
21	Non-pollen palynomorphs	Specimens commonly found in association with pollen analyses, and/or incorporated into pollen diagrams.	NPP
117	2mm (%)	2mm. Extracted through sieving.	2mm (%)
171	Petrographic microscopy	A piece of the ceramic sherd is cut off, fastened to a microscope slide, ground down to 0,03 mm, and polished. The tempering grains and clay is then studied under a microscope to determine clay content, fraction size, sorting and tempering content. These are all determined ocularly. The max grain size and total percent tempering is determined by marking the tempering grains in a photograph projected from the camera connected to the microscope and calculating in the program.	Petrographic
172	Thermal analysis	A raw clay sample and a sample of the ceramic sherd, or archaeological sample, is heated in a lab oven in 100 °C intervals, for a total of 30 minutes, up to 1000 °C. The colour change during and after heating is noted and compared to the Munsell Colour Chart to determine the firing temperature and firing atmosphere of the archaeological sample. The samples are then once more heated above 1000 °C, in 50 °C intervals, until they reach their melting point. The assumption for the thermal analysis is that the colour change of the ceramic sample doesn’t occur until after the original firing temperature has been reached.	Thermal

13. Sampling

method_id	method_name	description	method_abbrev_or_alt_name
53	Core by Russian	Core taken using a Russian Auger	Russian core
56	Core by freeze corer	Core taken using a freeze corer	Freeze core
57	Kubiena sample	Samples taken using kubiena boxes	Kubiena
58	Monolith	Monolith samples from exposed section or excavated pit	Monolith
60	Grab samples	Samples taken in unspecified, non-rigourous method (e.g. excavator, spade, hands etc.)	Grab samples
61	Temporary record	Temporary record used for testing data entry where a field is manditory but no data exists as yet…	Temp record
81	Soil auger or probe	Soil extraction by auger or probe	Auger sample
91	Dendrochronology Cross-section	A cross section perpendicular to the grain is cut with a saw.	Dendro cross-section
92	Dendrochronology coring	Dendrochronological information extracted from a piece of wood by coring.	Dendro coring
173	Ceramics collection	Collection of ceramic samples by unspecified means	Ceramics

14. Size measurement

method_id	method_name	description	method_abbrev_or_alt_name
46	Volume estimate	Subjective estimation of (sample) volume - usually from bag size or bucket	Volume est.
47	Distance etc measurement	Distance measures: Height, length, depth or width measured by device	Length measured
48	Distance etc estimate	Distance measures: Height, length, depth or width estimated	Length est.
51	Volume measurement	Volume measured accuarately	Volume measured

15. Colour

method_id	method_name	description	method_abbrev_or_alt_name
42	Munsell Colour\n	Soil colour based on Munsell system.\n	Munsell
44	Subjective colour (trained)	Subjective colour description by a person qualified in sediment description, or with other experience of judging colour (e.g. artist, paint mixer).\n	Colour trained
45	Subjective colour (amateur)	Subjective colour description by untrained individual.\n	Colour untrained

16. Preparation method

method_id	method_name	description	method_abbrev_or_alt_name
62	Paraffin floatation	Reduction of sediment by floatation using paraffin (=kerosine, lysfotogen…). Commonly used for extracting insect remains, especially Coleaoptera…	Paraffin float
65	Hydroflouric acid treatment	Treatment with hydroflouric acid, generally to remove mineral (silicate) particles from pollen samples prior to slide preparation.	HF-treatment
66	Centrifugation	High velocity rotation of sample to separate contents by density.	Centrifuge
82	Heating at 550°C	Sample is heated in an over at 550°C. Generally used to burn off organic matter.	Heating 550
83	Water floatation	Reduction of sediment by water floatation. Sample is washed through a seive to remove fine material and retrieve lighter organic matter.	Water floatation
84	Sieving >300µ retained	Separation through 300 micron sieve. Large fraction saved.	Sieving 300µ
85	Sieving >250µ retained	Separation through 250 micron sieve. Large fraction saved.	Sieving 250µ
86	Sieving >500µ retained	Separation through 500 micron sieve. Large fraction retained.	Sieving 500µ
87	Sieving >2mm retained	Separation through 2 mm sieve. Large fraction saved.	Sieving 2mm
88	Weak hydroxide solution added	Sample mixed with dilute hydroxide solution to spead up dissaggregation of sample.	Weak OH solution
112	Sieving 600µ	Preparation method: Sieving through 600µ seive (retaining seive contents)	null
124	Sieving 1.25mm	Preparation method: Sieving through 1.25mm seive (retaining seive contents)	null

17. Coordinate and altitude systems

method_id	method_name	description	method_abbrev_or_alt_name
67	UK Ordnance Survey National Grid	The United Kingdom National Grid system, established by the Ordnance Survey under the name OSGB36.	OSGB36
68	Irish Grid Reference System	The Irish National Grid System, established by the Ordnance Survey of Ireland.	Irish National Grid
69	Swedish RT90[2.5 gon V]	Swedish Rikets Nät (National Grid) system. Full name “RT 90 2.5 gon V 0:-15”. X = south-north, Y = west-east. Essentially superceded by SWEREF 99 although still in extensive use.\nSee http://www.lantmateriet.se/templates/LMV_Page.aspx?id=4766&lang=EN (NOTE: include URL as biblio link)	RT90[2.5 gon V]
70	SWEREF 99 TM (Swedish)	Swedish geodetic reference system, based on UTM zone 33N bit extended to include the whole of Sweden.\nCoordinates are generally with decimeters of WGS 84 coordinates for the same place.\nSee http://www.lantmateriet.se/templates/LMV_Page.aspx?id=4219	SWEREF 99 TM
71	SWEREF 99 dd mm	Swedish geodetic reference system for local coordinates (where dd mm are replaced by the appropriate zone meridian.\nNOTE: exactly how we handle the specific zones yet to be discussed - maybe one method entry per zone?	SWEREF 99 dd mm
72	WGS84	World Geodetic System.\nSystem is used by the Global Positioning System.	WGS84
73	Local project grid	Any coordinate or grid system established for local recording of objects. Includes abstract archaeological site grids with origin (0,0) at any location.\nI available, conversion factors for alignment wiwth standard reference systesm should be given in site notes.	Local grid
76	Altitude above sea level	Height above sea level. Negative values are under standard sea level.	Alt
77	Depth from reference level	Depth from reference level. Negative values are above reference level.	Depth from datum
78	Height from datum	Height from reference level/datum. Negative values are below datum.	Height from datum
79	Depth from surface	Depth from ground or lake/river surface. Neqative values are above ground. Note: use altitude for relative to standard sea level.	Depth from surface
80	Height from surface	Height from ground or lake/river surface. Negative values below surface. Note: for heights above standard sea level use altitude.	Height from surface
102	Rikets höjdsystem 1970	Rikets höjdsystem 1970. Swedish national altitude system 1970.	null
103	RT90 5 gon V	Rikets koordinatsystem RT90 5 gon V	null
105	Local or unknown grid	Site-specific grid or unknown site or sampling grid or coordinate system.	null
108	Göteborgs kommuns koordinatsystem	Göteborgs kommuns koordinatsystem. Gothenburg municipality coordinate system.	null
113	Malmö stads koordinatnät	Malmö stads koordinatnät. Malmä city coordinate system. In use until 2008-01-01	null
114	WGS84 UTM zone 32	Global coordinate system zone UTM 32 in WGS84 system. Last Revised: June 2, 1995 Area: World - N hemisphere - 6°E to 12°E - by country	null
115	Depth from surface lower sample boundary	Depth from surface lower sample boundary (depth is positive)	null
116	Depth surface to upper sample boundary	Depth from ground surface to upper sample boundary (depth is positive)	null
120	WGS84 UTM zone 33N	WGS84 UTM zone 33N	null
121	Rikets höjdsystem 1900	\nKorrektioner: Ingen landhöjnings- eller tidjordskorrektion	RH 00
122	Depth surface to lower sample boundary	Depth from ground surface to lower sample boundary (depth is positive)	null
123	EUREF89 UTM U32	Official geodetic datum (reference system/projection) of Norway. UTM zone U32. EUREF89. https://www.kartverket.no/Posisjonstjenester/Kartprojeksjoner/	null
125	Upper sample boundary (positive depth)	Upper sample boundary positive	null
126	Lower sample boundary (positive depth)	Lower sample boundary depth positive	null

18. Soil horizons

method_id	method_name	description	method_abbrev_or_alt_name
97	ISRIC soil horizons	Soil horizon classification according to strict International Soil Reference and Information Center (ISRIC) guidelines. http://www.isric.org/isric/webdocs/docs/ISRIC_TechPap19.pdf	ISRIC horizons
98	FAO soil horizons	Soil horizon classification according to strict Food and Argriculture Organization of the United Nations (FAO) guidelines. ftp://ftp.fao.org/agl/agll/docs/guidel_soil_descr.pdf and http://www.fao.org/docrep/W8594E/w8594e0g.htm for more detailed descriptions.	FAO horizons
100	Goldberg & Macphail soil horizons	Soil horizon calssification according to Goldberg & Macphail (2006) Practical and theoretical geoarchaeology. Variation and simplification of ISRIC system.	Goldberg & Macphail horizons
101	Soil horizons by undefined system	Soil horizons given without any specified classification system.	Undefined system horizons
104	MAL soil horizon classifications	Qualitative soil horizon classifications used by MAL. Derived from: Troedsson, Tryggve & Nykvist, Nils (1973). Marklära och markvård. Stockholm: Almqvist & Wiksell	null

19. Dating to period

method_id	method_name	description	method_abbrev_or_alt_name
127	Pollen Zonation	Age determined by comparison of pollen flora with reference data. A number of standard regional pollen zones have been determined through the compilation and zonation of multiple pollen profiles. Zonation is general achieved through the identification of significant changes in fauna (e.g. from birch to pine dominated), either manually or through cluster analysis.	PollenZone
128	Archaeological period calendar years	Age determined by comparison of pollen flora with reference data. A number of standard regional pollen zones have been determined through the compilation and zonation of multiple pollen profiles. Zonation is general achieved through the identification of significant changes in fauna (e.g. from birch to pine dominated), either manually or through cluster analysis.	ArchPerCal
129	Archaeological period C14 years	Age determined to an archaeological period defined in 14C years. This is a bulk method for numerous techniques for assigning a deposit to a particular cultural period, where the period boundaries have been defined by radiocarbon dating. More specific method details should preferably be given as to how the date has been derived, but may not be available.	ArchPerC14
130	Historical Period	Age determined to historical period. More specific method details should preferably be given as to how the date has been derived, but may not be available.	HistPer
131	Geological calendar period	Age determined to geological period defined in calendar years. More specific method details should preferably be given as to how the date has been derived, but may not be available.	GeolPerCal
132	Geological C14 period	Age determined to geological period defined in C14 years. More specific method details should preferably be given as to how the date has been derived, but may not be available.	GeolPerC14
133	Geological radiometric period	Age determined to geological period defined by radiometric methods but not necessarily radiocarbon (e.g. U-series). More specific method details should preferably be given as to how the date has been derived, but may not be available.	GeolPerRadio
134	Stratigraphic (Geological)	Dating through strategraphic association, placing the sediment (and enclosed artefacts) in the context of geological layers of known or unknown age.	Strat(Geol)
137	Artefact typology (calendar years)	Dating by artefact typology with calendar date. The form, design and material of an artefact may allow it to be placed in the context of a known sequence of artefact characteristics (a typological sequence). This allows it to be dated through the assumption that the typologies are correctly and independently dated. There is a slight danger or circular reasoning is the constraints of independent dating are not rigourously enforced, and a tendency for typologies to persist even if evidence suggests that there may be problems.	TypoCal
138	Artefact typology (radiometric years)	Dating by artefact typology with radiometric date. The form, design and material of an artefact may allow it to be placed in the context of a known sequence of artefact characteristics (a typological sequence). This allows it to be dated through the assumption that the typologies are correctly and independently dated. There is a slight danger or circular reasoning is the constraints of independent dating are not rigourously enforced, and a tendency for typologies to persist even if evidence suggests that there may be problems.	TypoRadio
158	Geological period (unspecified years)	Age determined to geological period using undefined (or possibly multiple) method(s).	GeolPer

20. Dating to calendar year(s)

method_id	method_name	description	method_abbrev_or_alt_name
10	Dendrochronology	Dating by comparison of tree-ring sequences.	Dendro
135	Tephrochronology Calendar	Dating by relation to volcanic ash layer of a known calendar age.	TephraCal
136	Tephrochronology C14	Dating by relation to volcanic ash layer dated by radiocarbon.	TephraC14
139	Other archaeological dating	Unspecified dating method leading to an archaeological date in calendar years.	ArchCal
140	Wiggle matching of 14C dates	A sequence of radiocarbon dates may be compared with variation in the C14 calibration curve, and dates nudged so that they align with the curve. The method requires a sequence to be tightly dated and may be especially useful around flatter parts of the calibration curve. User discretion is required.	Wiggle
141	Lichenometry	Dating method which relies on the predictable growth pattern of some lichen species. Some lichens (e.g. Rhizocarpon geographicum) exhibit colonisation, linear growth and non-linear phases of growth. By calibrating sizes against surfaces of known age (e.g. buildings, grave stones) it is possible to guage the age of exposure of a surface through the sizes of the lichens growing on it. A number of variations exist in terms of how to measure. The method has been applied to historical and archaeological remains as well as to geological features such as erosion surfaces and raised beaches.	Lichen
142	Calendar date by unknown method	Calendar years derived by unknown or unspecified method.	UnknownCal
143	Geologically derived calendar date	Derivation of calendar date by reference to  geological processes, features or events (e.g. volcanic eruption, earthquake).	GeolCal
144	Historical Records	Dating based on historical documentation.	HistCal
155	Archaeological period (unspecified)	Period based dating method leading to a range of potential archaeological dates in unspecified years.	ArchPer
156	Calibrated radiocarbon date (method unspecified)	Calendar years date provided by the calibration of a radiocarbon age. Exact dating method unspecified.	Cal
157	Calibrated AMS radiocarbon date	Calendar years date provided by calibration of an AMS radiocarbon age.	CalAMS

21. Dating by other method

method_id	method_name	description	method_abbrev_or_alt_name
145	Other date by unknown method	Unspecified dating method.	UnknownOther
160	Electron Spin Resonance	Dating based on the trapped charges of electrons, electron spin resonance dating.	ESR
166	Orbital Tuning	Dating through the synchronization of events according to Milankovitch cycles, casused by changes in the Earth’s orbit, and their expected effects on climate.	Orb-Tuning
174	Composite chronology	Chronology derived from a combination of dates using various methods.	Composite chronology

22. Dating by radiation exposure methods

method_id	method_name	description	method_abbrev_or_alt_name
150	Thermoluminescence	Dating using the release of stored energy properties of (mainly sonte) material previously exposed to the sun.	TL