Uniform Legend

Uniform geological legend

The uniform legend of geological maps and borehole databases is published in a table. The legend was elaborated by the Mapping Database Department (responsible: László Gyalog) with the effective contribution of the Geocartography Department (responsible: Ferenc Síkhegyi) and the GIS Department (responsible: Gábor Turczi).

The processing of the harmonised Hungarian legend table started in 2000 on the basis of the English legend of the MÁFI-MOL (Hungarian Oil and Gas Company) geological database building with some thematic additions. Since then it has continuously been developed and complemented.
The uniform legend is aimed at compiling all maps and processing the borehole database according to a legend set up by uniform concepts.
The basis of the uniform legend is

The legend of geological maps and brief description of stratigraphic units

(editor: L. Gyalog 1996) as well as the work reflecting the changes in subsequent years

Proposals for the introduction (or modification) of stratigraphic units to the Hungarian Stratigraphic Committee

(editor: L. Gyalog 2000) and

Proposals for the introduction (or modification) of stratigraphic units on the basis of the results of the 1998-2002 MÁFI-MOL co-operation project

(editor: L. Gyalog 2002) continuously supplemented by new suggestions for amendments. Some other elements of the legend are different combinations, integrations, indexes complemented by lithological types and signs of units that could not yet be adjusted in the formation system.

The modifications applied so far reflect new knowledge acquired in several maps, map series and borehole log reinterpretations as follows:

-borehole log reinterpretations and maps compiled in the framework of the MÁFI-MOL co-operation project between 1998- and 2002

-proposals for modification during the compilation of the hilly sheets of the 1:100 000 geological map series of Hungary

-digital processing of detailed mapping data of hilly regions (mainly the Vértes and Gerecse regions)

-suggestions based upon the printed regional geological maps (Velence Hills, Börzsöny, Eastern Mecsek, Western Mecsek)

-amendments arisen in other research projects

Figure 1

Data table of the uniform legend (on the basis of the PhD dissertation of L. Gyalog)

The basis of the database is the uniform legend. It functions through a continuously extended legend table structured by uniform principles. This is the so-called master table (MSTR_GEOLOGY) or the derived Magyar_jelkulcs (Hungarian_legend). The key of the table is the GEO_ID, the identifier of geological units (geological index). By default it is equal to the so-called unfolded index of the unit (GEO_NDX). It is different if an already introduced and extensively applied index is amended for some reason (e. g. re-interpretation of geological age). In this case the old index is preserved as identifier. The real, cartographic form of the symbol is indicated in the NDX_GRAFIKUS (NDX_GRAPHIC) field.
As of April 2004 the harmonised legend table consisted of 42 fields and included some 3693 indexes (signs, symbols, in other terms identifiers). Symbols are ordered from younger to older formations. Within the age main symbols appear first followed by their lithological versions and their occasional subdivisions. Integrated or mixed versions resulting of the combination of already existing units, as well as symbols bearing only geological age are represented separately. The main fields of the legend table and their explanation are presented in Table 1. Of the 3693 indexes 1530 and 2063 are Quaternary and pre-Quaternary, respectively.

The main fields of the legend table can be described as follows:

SORREND (ORDER)

: it is an identity-type running number facilitating to line up the sum of the indexes of a map or map series (a symbol set) according to the conception adopted in the legend table, excluding thus the indexes that are not contained there. Inserting a new index in the table increases automatically the reference number of the following indexes.

Figure 2

TYPE [Index type]

: it indicates the type of the symbol. Typical types are as follows:

-part (r) - part of a base type, e. g. if the age of the unit can be specified with more precision in a region than the base index (e. g. parts of haMb-Pa1: haMb, haMs, haMs-Pa1);
-partly formation-based (f) some formation-based unit including some non-formation-based part (e. g. mb2K1s[a]K1-2);

-non-formation-based (n) non-formation- or non-genetics- but age-based units, essentially the signs of geochronological ages (e. g. Qp3, Ms-Pa1, K);

-lithological (k) the most frequent category. If the lithological type of any unit is specified its sign is invariably displayed in the upper-right index (e. g. fQph, tPa2h, Mbk);

-combined (o) combined representation of two or more linked units in the same or subsequent ages (e. g. f-rT3, dT3-krJ1);

-mixed (x) combined representation of two or more separate (unlinked) units (e. g. dT3+oE2).

The field

HOL1 (WHERE1)

[where did it occur first] reports on the site of the first occurrence of the units introduced recently in the table. In the field VULKANI (VOLCANIC) the lithological types of volcanic formations are presented. These two fields furnish solely auxiliary information they are irrelevant concerning the legend table and merely show a possibility as to for what purposes and how the legend table can be used

The field

GEO_ID [index identifier (initially used unfolded index)]

is the key field in database links. It is the basis for the linkage of the symbol to the borehole and map databases. The modification of this field should be avoided by all possible means. If it is all the same necessary it can only be done by reconsidering appropriately its effect on the whole database. It is displayed as the so-called unfolded index when the sub-indexes in upper and lower positions are represented in one line with the main index.

The field

GEO_NDX [unfolded index (utilisable, currently approved]

includes the actually valid symbols. They are usually the same as in GEO_ID but there are three main exceptions. Firstly if the form of the already used symbol is amended for some reason (e. g. its age was revised) the initial form is preserved as identifier. The second case is the application of accents in vowels. Letters with accents cannot yet consistently be converted between different database systems (particularly the long ő and ű), hence they are stored without accent in the identifier. Greek letters marking magmatic rocks are put in phonetically in both fields (e. g. Mmk-alpha,alphat Mátra Formation Group, andesite, andesitic tuff; h_vMb2-Mb2rot Hidas Formation, Várpalota Member and Upper Badenian rhyolite tuff combined; vC2qgamma,ibgamma Velence Formation, silicified granite, intrusive breccia). Finally, this field has still another function (the most important): if, for some reason, a sign already used in map production or database reinterpretation was eliminated of the system (e. g. its age or form was revised) it is done so that its cell in this field becomes empty.

The field

NDX_NEM (NDX_NOT) [unfolded index (non utilisable)]

includes the symbols that should not be used currently. Of the fields GEO_NDX and NDX_NEM each symbol can be featured only in one of them but each symbol in the table should be present in one of them

The fields

NDX_JAV [suggested now in its replacement] and NDX_REGI (NDX_OLD)

[old index] assist in tracing changes done in the legend table. If an index is present in the field NDX_NEM, the field NDX_JAV contains the symbol currently suggested for its substitution if it can be done unambiguously. Simultaneously the old, yet unused form of a current symbol is featured in the field NDX_REGI for retrieval.

In the field

NDX_GRAFIKUS (NDX_GRAPHIC)

sub-indexes of the symbols are presented in their appropriate upper and lower position. This form is the closest one to map representation. The only difference is that Microsoft Word and Excel do not support the superimposition of lower and upper indexes. Therefore the upper-left index is followed by lower-left one (if present) and the lower right one by the upper right one though they are presented below or above each other on map.

The following four fields

NDX_BAL_F [index/upper left], NDX_BAL_A [index/lower left], NDX_KOR [index/age], and NDX_JOBB_F [index/lithology]

represent the four parts of the index individually, in order to facilitate querying different aspects of the database (e. g. age, lithology).

The fields

CEL [is there a cell?] and CEL_ROVID (CEL_SHORT) [is there a cell of the short index?]

inform on the availability of the cell of the complete and the short index. One cell was generated for the symbols in the MicroStation MGE environment currently used in MÁFI that can directly and automatically be placed on the map.

The

ROVID_NDX_GRAFIKUS (SHORT_INDEX_GRAPHIC) [short graphic index]

is very important concerning map display since if the map content is dense there is not enough room for the placement of complete symbols.

According to the main principles for Quaternary deposits: in case of the formations of the most common age only their genetic type (and lithology if exists) are presented, for the others age also is marked but without the letter Q (e. g. gpQp3-h > gp Upper Pleistocene Holocene slope- and proluvial deposit; gQh > gh Holocene slope deposit, Qp3-h > p3-h Upper Pleistocene Holocene deposit undifferentiated; fQp-hh > fp-hh Pleistocene Holocene fluvial sand). For pre-Quaternary deposits: if lithology is absent the short index is made up of the sign of the formation (and member or bed if present) and the ages upper case letter without further classification (e. g. eMk > eM Egyházasgerge F.; cOl1-2 > cOl Csatka F.) If the age is complex only the older one is marked (e. g. bOl2-Mer > bOl Becske F.). If the complex index combines several ages or the lithological type is defined the symbol of the age can also be omitted (e. g. mvJ3-K1 > mvJ Márévár Limestone F.). Considering the combined display of two-three formations of different ages or with long indexes the age can altogether be omitted in due case (e. g. böT2-3svT3 > bösv Budaörs and Sédvölgy F. combined).
The use of short indexes is naturally not binding. If the whole symbol is short or the map content is not dense (e. g. in lowland areas), it is not advisable to apply short indexes. In case of some sheets featuring lowland margins the idea was brought up to use mixed indexes i. e. short indexes and complete ones in the dense and the more uniform parts, respectively. But it is better to be avoided for it deteriorates the understanding of the map. To reduce the size of complete symbols it is advisable to use narrower fonts (without sole) (e. g. Arial, Sans Serif, etc.).

The fields

PANTON_SZIN (PANTONE_COLOUR)

{the number of the pantone colour scale] and SAJAT_SZIN (SELF_COLOUR) store the colour of the unit for the 1:100.000-scale map series. It is advisable to use the same colours for other maps and map series as well but it is only a suggestion, colours have to accommodate to the features of the particular map or map series.

The field

LITO_EGYSEG (LITO_UNIT)

[name of the stratigraphic unit] stores the name of the stratigraphic unit. Each type has its own specific characteristics.

-In case of base types the name of the unit is described (formation, member, etc.) but not the unit of which it can be part (e. g. Póckő Chert Member [lpJ2-3], Hajósárok Bed [p(h)J3], Lókút Radiolarite Formation [lJ2-3], Ipoly Crystalline Schist Formation Group [IPz], Körös complex [KPz]).

-For genetic base types in Quaternary it merely summarises the genetic type (e. g. fluvial sediment).

-In case of a part type the main unit is described specifying which part of it the part type is (generally the part separated by age) (e. g. Karpatian and Badenian parts of the Mátra Formation Group [MMk-b], Upper Jurassic part of the Lókút Radiolarite Formation [lJ3], Upper Eocene part of the Baláta Member [pbE3]).

-In case of partly formation-based symbols the facies of volcanic formations (e. g. Nagyhársas Formation, dike [nh[t]Mb]), facies of sedimentary formations (e. g. Ajka Coal Formation, "storm breccia" [a[v]K3]), temporary beds (marked with numbers) within members (e. g. Balázsorma Member, third bed [mb3K1]), or horizons marked with numbers (e. g. Boda Aleurolite Formation, lower horizon [bo1P2]) are represented.

-At non-formation-based units the formations of a certain age are combined together, most frequently with epithet (e. g. Upper Triassic formations undifferentiated [T3], Upper and Middle Devonian formations undifferentiated [D1-2]).

-In the lithological type are the most signs. By default the precise description of the lithological composition is provided following the name of the specific unit.

-The integrated and combined categories (2 or more formations, one or more members of a formation, one formation and a member of another, and a number of other variants can occur) include the most units. The variants represented under this type were used at some borehole log reinterpretation or map compilation.

The field

LITO_EGYSEG_2 (LITO_UNIT_2)

[the part of which formation] and if necessary

LITO_EGYSEG_3 (LITO_UNIT_3)

[the part of which formation group (complex)] specifies the higher ranked groups of LITO_EGYSEG

(formation for members and beds, formation group for formations) (e. g. Köszörűkőbánya Conglomerate Member Lábatlan Sandstone Formation Gerecse Formation Group).

As its name shows the field

SZINONIMA (SYNONYM)

[old names, synonyms] specifies the formerly used names of the given unit occurring in literature, naturally without the need for completeness (e. g. for the Budafa Sandstone Member of the Budafa Formation (Budafa sandstone, upper conglomerate).

The field

FACIES [facies]

is filled in for each base unit and genetics-based unit (and their lithological versions). For Quaternary deposits they are the genetic descriptions put in the LITO_EGYSEG field (e. g. fluvial-lacustrine, aeolian, proluvial-deluvial). This information is also presented for pre-Quaternary formations though it is not marked in their symbol. It is evident that marine facies predominate among sedimentary formations (e. g. shallow-marine bar Lajta Limestone Formation; platform, sublitoral Szépvölgy Limestone Formation) though terrestrial ones are not rare either (e. g. terrestrial, lacustrine, fluvial Hernádvölgy Clay Formation; fluvial, subordinately brackish Ligeterdő Gravel Formation). Facies types of magmatic rocks exhibit large variety as well (e. g. pyroclastics, rarely lava flow or dome Szerencs Rhyolite Tuff Formation; submarine pyroclastics, subordinately lava Hasznos Andesite Formation). Metamorphic facies are specified only roughly e. g. metamorphite of chlorite-sillimanite facies Óbrennberg Mica-schist Formation; upper part of the anchizone and lower part of the greenschist facies Litér Basalt Formation).

The field

LITOLOGIA [lithology]

specifies the lithological composition of the units. In case of the symbols with lithological signs it provides their occasionally more detailed explanation, whereas for formation- and genetics-based units it gives their detailed lithological specification as far as the width of the field (120) allows. For combined and mixed signs the field remains empty, they are described at their single versions.

The field

MEGJEGYZES [comment]

provides some additional information. It can specify e. g. at which section of the higher ranked unit a member is located, how widely it is extended, how much it is exposed (whether it is recovered only in drilling), and describe its characteristic lithological (the composition of gravels), palaentological features and its metamorphic grade.

Figure 3 The field

TELJES_LITO (COMPLETE_LITO)

[complete name of the stratigraphic unit] completes the content of the LITO_EGYSEG field with information if necessary (the complete name of each unit is specified, the part of which higher ranked unit is it?, etc.), in other cases it is the same as LITO_EGSEG. Some examples of the differences between the two fields are exhibited in

Table 3.

The online

Uniform Legend

Table prepared on the basis of the Harmonised Legend System