ISSN 1026-8774 printed version
ISSN 2007-2902 versión on-line

GUIDELINES FOR CONTRIBUTORS

• General instructions
• Manuscript preparation

1. The RMCG accept contributions in the form of Original research papers, Review papers, Short notes, Comments and Replies, written in Spanish or English.

2. In a cover letter, the corresponding author must clearly states that the submitted manuscript has not been published, submitted or accepted elsewhere, and that all authors agree with the content and the submission of the manuscript.

3. Manuscripts should be submitted electronically by sending to the Chief Editor (rmcg@geociencias.unam.mx) a single file in PDF or MS Word format (maximum 15 megabytes) containing (1) cover letter; (2) manuscript; (3) figure captions; (4) figures; (5) tables. Manuscript, figures and tables must fulfill the requirements specified under "Manuscript Preparation ".

4. The manuscript must be in double-spaced form with a 3 cm wide margin, written in font Times New Roman and font size 12. They should not exceed 12 pages in the final printed version (a printed page correspond to about three double-spaced pages in font 12). All pages in excess of 12 pages will incur a charge per page of MN$500.00 pesos for
payments in Mexico or US$50.00 dollar for payments from aboard. Color figures can be included at no additional
charge.

5. The entire manuscript should be paginated, starting by the title page. Manuscripts must contain an abstract in English and its translation into Spanish. By request, a member of the editorial board can translate the abstract into Spanish.

6. Every manuscript is reviewed by two independent referees selected by the editors. Authors can submit the names and addresses of appropriate reviewers. The decision concerning acceptance or rejection of a manuscript will be made by the editors, and will depend on the evaluation by the referees.

7. After the evaluation of the manuscript, it will be returned to the author with the suggestions of the referees. The revised manuscript must be returned to the editor with an accompanying letter specifying the changes made in response to those suggestions; changes to the manuscript must be marked with a different text color. This revised manuscript must fulfill the format specifications detailed below in the sections "Revised Version " and "Manuscript Preparation ".

8. Page proofs in PDF format will be sent to the corresponding author to be checked for typesetting/editing. A query form from the technical editor can be sent with the proofs. Carefully check the proof, answer all queries, and indicate any modification, as no later changes are allowed. After this stage, content and edition of the final article are solely responsibility of the author.

Revised version

Besides the requirements specified under "Manuscript Preparation ", for the revised version returned to the editors:

1. Send the main text in a file in MS Word format; figure captions should be included at the end of the text.
2. Do not import figures or tables into the text file.
3. Send each figure in a separate electronic file, clearly identified with the first author name and figure number. Following formats are preferred for line drawings: Corel-Draw, Canvas, Adobe Illustrator, Freehand or Encapsulated Postscript; alternatively they can be sent in PDF format with a resolution of at least 300 dpi in the final size. Figures in Excell, Power Point o Word format are not acceptable. Photographs must be sent in TIFF format (at least 300 dpi); if elements are added to the photos (text, lines), send also the original, unmodified version.
4. Send each table in a separate electronic file in MS Word format, clearly identified with the first author name and table number. Tables must include table number and table title in the upper part.

Consult a recent issue of the RMCG or the web site <http://www.rmcg.unam.mx> for style.
The submitted manuscripts should be arranged as follows: (1) title, (2) authors' names, (3) authors' affiliations, (4) abstract in English, (5) keywords in English, (6) Abstract in Spanish, (7) Keywords in Spanish, (8) Manuscript, (9) References (10) Figure captions, (11) figures, (12) tables.

Title : Title should be short, specific and informative, and be written in capital and lower case.

Authors : Write the full name(s) of author(s), followed by affiliation(s) and complete postal address. The e-mail address of the corresponding author must also be included.

Abstract : The abstract should be presented in English and its translation into Spanish, must not exceed 500 words, and should not contain abbreviations or reference citations. The abstract should be brief and objective, and represent a summary of the paper that includes the methods used, the main results and conclusions.

Keywords : Five to six keywords in both languages used in the abstracts should be given below the abstract.

Main text:

1. Follow the structure shown bellow for the headings:

FIRST LEVEL (Bold capitals, left)
Second level (Bold, capital and lower case, left)
Third level (Bold, italic, capital and lower case, left)
Fourth level. (indented 0.75 cm, italic, capital and lower case, text continue on the same line).

2. Italics should be used for terms or abbreviations in other languages (et al., ca., etc.)

3. Chemical and isotopic analyses, as well as radiometric or paleontological datings must be referred to sampling locality and include coordinates.

4. Measure units must be represented by their symbol in the International System of Units (BIPM, 2006).

5. If the manuscript contains a Systematic Palaeontology section, please refer to the appended document.

6. Equations must be numbered consecutively and all parameters must be explained immediately after the equation.
References to equations in the text should appear as Equation 1 or (Equation 1)

7. Acronyms and abbreviations should be clearly defined on their first occurrence in the text

8. For proper usage and capitalization of stratigraphic terminology and concepts follow the North American Stratigraphic Code (NACSN, 2005), the International Stratigraphic Guide (ISSC, 1994), The International Stratigraphic Chart (ICS, 2010), and the GSA Geologic Time Scale (Walker et al., 2012).

9. References cited

a. All references cited in the text, figures, captions, and tables must be presented in a list of references following the
main text.
b. References are cited in the text by the last name of the author (exactly as it appears in the original work) and the year (Aguillón-Robles, 1994). If the authors' name is part of the sentence, only the year is bracketed: "Aguillón-Robles (1994) determined……". For references with two authors use the last names of both (Hoffman and Feigerson, 1983), and for those with three or more authors, use the last name of first author followed by "et al." (Carmichael et al., 1974).
c. References cited should be arranged chronologically; use a, b, c, etc. for references to one author in the same year. Separate with comma the references to same author, and with semicolon the references to different authors: (Persson, 1960a, 1960b; Keller, 1977).
d. Do not include cites or references to papers in preparation, in review or in revision.

References

1. Include only references cited in the text, figures, captions, and tables.

2. Arrange the references alphabetically by first author and then alphabetically by second author. If more than one reference of the same author(s) is included, arrange them chronologically.

3. For references with more than two authors, list alphabetically by the first author and then chronologically.

4. Corporative authors (Universities, companies, government departments, etc.) should be included with full name, followed by initials in parenthesis, year, etc.: "United States Environmental Protection Agency (US-EPA), 1996,……..".

5. Do not abbreviate journal titles or publisher names.

6. For the most common cases, follow the examples:

1. Papers in periodical journals
   [Last name(s)], [Initial(s)], [year], [article title]: [Journal title], [volume (issue number)], [pages].
   Peslier, A.H., Francis, D., Ludden, J., 2002, The lithospheric mantle beneath continental margins; melting and melt-rock reaction in Canadian Cordillera xenoliths: Journal of Petrology, 43(11), 2013-2047
   
2. Books
   [Last name(s)], [Initial(s)], [year], [Book title]: [city of publication], [publisher], [no. of pages] p.
   Faure, G., 1986, Principles of Isotope Geology: New York, John Wiley, 587 p.
   
3. Chapters in edited volumes
   [Last name(s)], [Initial(s)], [year], [Chapter title], in [Last name(s)], [Initial(s)] (ed(s).), [book title]: [city of publication], [publisher], [pages].
   Leeder, M.R., 1995, Continental rifts and proto-oceanic rift troughs, in Busby, C.J., Ingersoll, R.V. (eds.), Tectonics of sedimentary basins: Cambridge, Blackwell Science, 119-148.
   
4. Proceedings from symposia and conferences
   [Last name(s)], [Initial(s)], [year], [Title], in [symposia/conference name(s)], [city of meeting], [year if it differs from publication year]: [city of publication], [publisher], [pages].
   Bear, C., 1972, Creep measured in deep potash mines vs. theoretical predictions, in Proceedings of the 7th Canadian Rock Mechanics Symposium, Edmonton: Ottawa, Canada, Department of Energy, Mines and Resources, 23-77.
   
5. Unpublished thesis, reports, etc.
   [Last name(s)], [Initial(s)], [year], [Title]: [City], [University, government department, company, etc.], [type of work (Ph. D. thesis, M.S. thesis, technical report, etc.)], [pages]:
   Cameron, C.S., 1981, Geology of the Sugarloaf and Delamar Mountain areas, San Bernardino Mountains, California: Cambridge, U.S.A., Massachusetts Institute of Technology, Ph. D. Thesis, 180 p.
   
6. Maps
   [Autor(s)], [Initial(s)], [year], [Type, title, and map number], scale [scale]: [City of publication], [Publisher], [Map series], [number of sheets] with text (if that is the case).
   Alvarado-Méndez, H., Sánchez-Garrido, E., Pérez-Vargas, M.A., Caballero-Martínez, J.A., 1997, Carta geológico-minera Guanajuato F14-7, escala 1:250,000: Pachuca, Hidalgo, México, Consejo de Recursos Minerales, 1 map.
   Cserna, Z. de y Fries, C., 1981, Hoja Taxco 14Q-h (7), Geología de los Estados de Guerrero, México y Morelos: México, D.F., Universidad Nacional Autónoma de México, Instituto de Geología, Cartas Geológicas de México serie 1:100,000, 1 map with text.
   
7. Corporative authors
   [Full name of corporative author (Initials)], [year], [report publication according to the type following the previous examples]
   United States Environmental Protection Agency (US-EPA), 1984, Methods for the chemical analysis of water and waste water: Washington, D.C., Environmental Protection Agency, Technical Document, 16 74000.
   Instituto Nacional de Estadística, Geografía e Informática (INEGI), 1979, Carta topográfica Ciudad Sahagún E14-B12, escala 1:50,000: México. D.F., Secretaría de Programación y Presupuesto, Instituto Nacional de Estadística, Geografía e Informática, 1 map.

Figure captions

A list of all figure captions should be supplied on a separate sheet(s), numbered consecutively, and printed with double space. In the electronic file with the main text, the captions can be included after the list of references.
The captions should include the figure number and a figure description. The description should be precise and contain the explanation of all symbols and abbreviations used.

Figures

1. Each figure (maps, graphs, line drawings, photographs) must be submitted on a separate sheet, be clearly identified with figure number and first author name.
2. Submit figures as close to final size as possible. Maximal allowed sizes for figures are:
   One-column width 8.2 cm (3.2 in)
   Page width 17.0 cm (6.7 in)
   Page depth 22.0 cm (8.7 in)
3. Use font Times New Roman between 7-12 point type size for letterings and line weight between 0.5 and 2 points. Use
   graphic scala instead of magnification factors; include units of measure.
4. Include general titles of illustrations in the figure caption, not in the figure itself.
5. Maps must indicate the North, have at leats two coordinate data en each axis, and have a graphic scala. Localities mentioned in text, should be included in maps.
6. Good, clear contrast, black and white photographs are acceptable. They should show the object of interest in an adecuate size.
7. References to figures in the text should appear as Figure 1 or (Figure 1). References to figures in cited works should be written in lower case and abbreviated (Smith, 1990, fig. 2).
8. Figures in color are acceptable if the author covers the printing costs.

Tables

1. Tables should be submitted on separate sheets, numbered consecutively, and be identified by authors' names.
2. Size of the tables should be in proportion of type area (17 x 22 cm). Tables can be separated in two or more pages.
3. Include table number and title in the upper part. All columns must have headings; the units of measure should be written in parenthesis. Do no use division lines between columns or files. Footnotes can be included below the table, and should be referred to by superscript lower case letters.
4. References to tables in the text should appear as Table 1 or (Table 1). References to tables in cited works should be written in lower case and abbreviated (Smith, 1990, tab. 2)

REFERENCES

Bureau International des Poids et Mesures (BIPM), 2006, The International System of Units (SI) (en línea): Sèvres Cedex, Francia, Bureau International des Poids et Mesures, SI brochure (8th edition), <http://www.bipm.org/en/si/si_brochure/>

Estivill A., Urbano C., 1997, Como citar recursos electrónicos (en línea), ver. 1.0: <http://members.tripod.com/hipocrates/artigos/citas_elt.htm>, 30 Mayo 1997, consulta: 15 Noviembre 2002.

International Commision on Stratigraphy (ICS), 2010, International Stratigraphic Chart (en línea): International Union of Geological Sciences, International Commision on Stratigraphy <http://www.stratigraphy.org/>

International Subcommission on Stratigraphic Classification (ISSC), 1994. International Stratigraphic Guide –An abridged version (Amos S., Murphy, M.A. eds.), (en línea): International Subcommission on Stratigraphic Classification of the International Union of Geological Sciences, International Commission on Stratigraphy, <http://www.stratigraphy.org/>

North American Commission on Stratigraphic Nomenclature (NACSN), 2005, North American Stratigraphic Code (en línea): The North American Commission on Stratigraphic Nomenclature, <http://www.agiweb.org/nacsn/code2.html/>, actualización april 7, 2006.

Walker, J.D., Geissman, J.W., Bowring, S.A., Babcock, L.E. (compilators), 2012, Geologic Time Scale v. 4.0: Geological Society of America, doi: 10.1130/2012.CTS004R3C http://www.geosociety.org/science/timescale/.