New Mexico Bureau of Geology Editorial Style Guide

The names of chemical elements and molecules are written out rather than abbreviated, with the following exceptions:

• When referring to geochronology methods (for example, ⁴⁰Ar/³⁹Ar, U-Pb).
• When listing more than five elements (for example, descriptions of samples accompany analytical data for Au, Ag, Cu, Pb, Zn, and As).
• In a complex term (for example, Ca-Mg-SO₃-NO solution).
• When describing ions (for example, Ca⁺ and Mg⁺).

Elements and molecules are abbreviated in figures.

Don’t abbreviate lithologic and time-stratigraphic terms in the text. Abbreviations are acceptable in figures and tables to save space.

Capitalize lithologic abbreviations when they follow a formal rock unit name (for example, Navajo Ss.). When used informally to refer to a general rock type, the lithologic abbreviation is lowercase (sandstone, ss.). Always capitalize time-stratigraphic abbreviations. Table 1 summarizes abbreviations used for lithologic and time-stratigraphic terms.

Time as a unit of measure – Use a numeral to express lengths of time (for example, 2 years, 4 months, 8 weeks, 13 days).

Calendar dates – Common Era (CE) and Before the Common Era (BCE) are the preferred notations for the Gregorian calendar; they are equivalent to Anno Domini (A.D.) and Before Christ (B.C.) but are religiously neutral. The abbreviations don’t take periods and are placed after the year. No abbreviations are needed if the time period is defined in the text (for example, a discussion of 20th century land-use policy would not need CE after dates). There is no year 0; the year 1 CE comes after the year 1 BCE. For ranges of years, start with the oldest year:

• 350–335 BCE
• 2000–2019

Use numerals for all dates (note comma usage in the examples below):

• January 1994
• May 18, 1980
• April 17, 1983, to August 26, 1995

January, February, August, September, October, November, and December may be abbreviated to save space in figures and captions:

• Oct. 13, 1956

Dates may be abbreviated with only numerals in tables to save space; use the format mm/dd/yyyy.

When naming computer files, the format yyyymmdd used at the beginning of the file name is preferred so the files will sort chronologically (for example, 20230711_file.docx).

Spell out months when used alone or with only a year:

• The convention is usually in September.
• She was born in October 1956.

Don’t use the ordinal form of the number (adding st, th, rd, etc.) with dates:

• The deadline for entries is May 31 (not May 31st)

Geologic time – ka for kilo-annum (thousand years), Ma for mega-annum (million years), and Ga for giga-annum (billion years) are reserved for reporting geologic ages. Time measured from the present is implicit in ka, Ma, and Ga, and neither before present nor ago is added to these abbreviations.

Durations and intervals of time (for example, for geologic processes) may be abbreviated as kyr (thousands of years), Myr (millions of years), and Gyr (billions of years).

Use ¹⁴C yr BP for uncalibrated radiocarbon ages (radiocarbon years before present, with present fixed as 1950 CE). Use cal yr BP (calendar years before present) for calendar-calibrated radiocarbon ages.

When listing ranges of geologic ages, list the oldest date first (for example, radiometric ages range between 24 and 22 Ma). Otherwise, time ranges are given with the youngest date first (as with ranges of other values; for example, 10–20 years ago, 22–25 Myr).

Examples

• An ⁴⁰Ar/³⁹Ar age of 986 ka and a K/Ar age of 1.22 Ma identify the age of the tuff as middle Pleistocene.
• The radiocarbon age of 3,650 ± 70 ¹⁴C yr BP (4,400–3,600 cal yr BP) obtained from the buried A horizon corresponds well with the thermoluminescence age of 4,200 ± 400 yr BP obtained from the loess unit.
• The beginning and the end of the Cretaceous Period are calibrated at 145.0 ± 4.0 Ma and 66.0  Ma, respectively; the interval of time represented by the Cretaceous is 79 Myr.

Capitalize the name of a biological phylum, class, order, family, or genus, but not species, subspecies, or variety (for example, Foraminifera, Arecaceae, Tyrannosaurus rex, Homo sapiens, Prunus virginiana var. demissa).

Capitalize the words figure, table, appendix, and chapter when they’re given in the text to refer readers to a subsequent item (for example, the features in Figure 1 illustrate, refer to Chapter 2).

When calling out to another chapter in the same publication, use the same numbering convention as the chapter itself; that is, if the chapters are numbered in Roman numerals, use Roman numerals in the callouts.

If another author’s figure, table, appendix, or chapter is being called out, use lowercase (for example, At its reference section in the Rio Salado Valley (Hook et al., 1983, table 3), the formation is divided into three members.).

See figure callouts.

The names of elements and molecules are not capitalized in text. When using chemical symbols (see abbreviations and acronyms), use the capitalization style in the periodic table.

Use lowercase for compass directions when written out (for example, north, south, northwest, north-northwest) and for descriptive terms that denote direction or position (for example, southeastern New Mexico). Abbreviations for compass directions should be capitalized (for example, N, S, E, W, NE, SW, NNE).

Capitalize directions only when they designate regions:

• Farmington is northwest of Albuquerque.
• Earthquakes are more common on the West Coast.
• Southerners eat more fried foods than Northerners.
• The climate is wet in the Northwest.

See directionals.

Proper geographic names are capitalized (for example, Monument Valley, Organ Mountains, El Vado Lake). Names that are not recognized as formal may be capitalized in some cases, for example, if they are the subject of a publication. This guide contains individual entries for some geographic names whose capitalizations differs from these rules due to common usage. For terms not listed here, authors should refer to the U.S. Geological Survey Geographic Names Information System (GNIS) to determine if a geographic name is formal and should be capitalized.

More specifics:

• Areas of indefinite extent are lowercase (for example, Albuquerque area, Bonneville basin).
• Mining districts, oil fields, gas fields, fields, mines, smelters, and other terms related to mineral or hydrocarbon extraction and processing are not capitalized when included as part of a proper name (for example, Luis Lopez mining district, Hobbs oil field, Raton coalfield, Kelley mine, Cuba smelter).
• Structural geologic terms are not capitalized when included as part of a geologic name (for example, San Ysidro anticline, Embudo fault zone). Even when used with a proper name, lowercase is preferred for anticline, arch, area, basalt flow, batholith, claim, coal bed, coalfield, coal seam, cone, cyclothem, deposit, dome, embayment, escarpment, facies, fault, fault zone, homocline, mill, mine, mining district, monocline, oil field, pluton, principal meridian, prospect, quadrangle, region, rift, sag, syncline, uplift, well, and zone.

See geographic names.

Capitalize the names of eons, eras, periods, epochs, ages, eonothems, erathems, systems, series, and stages.

The geochronologic terms early, middle, and late and the chronostratigraphic terms lower, middle, and upper are capitalized only as part of a formal geologic time or rock series name (for example, Early Jurassic, Upper Devonian). They are lowercase for informal designations (for example, early Holocene, middle Eocene). For geochronologic use, authors are encouraged to follow the Geological Society of America’s Geologic Time Scale. For chronostratigraphic use, authors are encouraged to follow the International Commission on Stratigraphy’s International Chronostratigraphic Chart.

Geochronologic (time)

• Capitalize the names of geologic eons, eras, periods, epochs, and ages.
• All subdivisions of ages are informal (for example, early Maastrichtian, late Albian).
• Capitalize early, middle, and late when used with Jurassic, Triassic, Pennsylvanian, Mississippian, Devonian, and Ordovician. Capitalize early and late with Cretaceous (no middle).
• Lowercase early, middle, and late when used with Quaternary, Neogene, Paleogene, Permian, and Silurian.

Chronostratigraphic (position)

• Capitalize the names of geologic eonothems, erathems, systems, series, and stages.
• All subdivisions of stages are informal (for example, lower Maastrichtian, upper Albian).
• Capitalize lower, middle, and upper when used with Jurassic, Triassic, Pennsylvanian, Mississippian, Devonian, and Ordovician. Capitalize lower and upper with Cretaceous (no middle).
• Lowercase lower, middle, and upper when used with Quaternary, Neogene, Paleogene, Permian, and Silurian.

The names of formal geologic units are proper nouns and are capitalized (for example, Chinle Formation, Navajo Draw Member of Arroyo Ojito Formation of Santa Fe Group). Authors should consult the U.S. Geological Society National Geologic Map Database (aka Geolex) to determine if a unit is formally recognized.

In the names of informal geologic units, don’t capitalize unit terms for lithology or formation (for example, Huckleberry Ridge ash bed, Left Creek quartzite, formation of Aurora).

See geologic names/geologic units.

Use title case capitalization for headings.

The full names of legislative, administrative, and judicial bodies, departments, bureaus, and offices are capitalized (for example, U.S. Department of Energy). Abbreviated names are not (for example, the energy department [in relation to the U.S. Department of Energy]).

Mineral names are not capitalized unless they begin a sentence; see minerals.

Capitalize professional titles only when they come before a person’s name (for example, Pat Jones is the state geologist, State Geologist Pat Jones).

Always capitalize proper nouns, including hyphenated words in titles and headings (for example, Pat Jones, Open-File Report 618).

Don’t capitalize conjunctions, short prepositions (for example, of, for, from), or articles (for example, the, a, an) in long proper names (for example, New Mexico Bureau of Geology and Mineral Resources).

In the report text, capitalize all important words in the titles of books, journal articles, and reports (for example, Geologic History of Utah by Lehi F. Hintze; see title case); for capitalization of reference entries, see references.

Singular nouns used to replace proper nouns are not capitalized (for example, Rio Grande del Norte National Monument, but the monument; White Sands National Park, but the park).

Don’t capitalize spring, summer, fall, autumn, or winter unless part of a formal name (for example, sampling was carried out in spring and winter, the program was held in the fall, the New Mexico Geological Society Fall Field Conference was in October).

Use title case capitalization for titles of works (books, journals, articles, etc.) in the main text of a publication.

If the unit description includes comments on the geologic history of the unit, or if it consists of two or more subunits described separately, write it as a complete sentence.

Even if the description consists of incomplete phrases, separating phrases that differ significantly in content with periods is preferred:

• Lower red member—Slope-forming, red siltstone, and fine-grained arkosic sandstone, commonly cross-bedded, coarsening upward; upper contact unconformable. About 50–75 m thick, thickening westward. Depositional environment: very shallow, low-energy marine to deltaic.

Conversely, don’t use less emphatic punctuation marks, such as commas and semicolons, to separate complete sentences:

• Conglomerate member—Gray, cobble to boulder conglomerate; lithic clasts dominantly Paleozoic carbonate; bedding chaotic to crudely stratified. The member is a basal rift-basin deposit unconformably overlying carbonate marine strata.

If a member has been formally named, capitalize the word “member” (for example, the Tshirege Member of the Bandelier Tuff). Use lowercase “member” for informal units. See capitalization.

Compound modifiers (adjectives) consist of two or more words or numbers that combine to describe a noun. The words forming the compound modifier are usually, but not always, connected by hyphens. General guidelines for hyphen use are given in the punctuation/hyphen section. Descriptions of map units, however, are often full of compound modifiers, and hyphenation rules can be a source of confusion and frustration for writers and editors. Generally, a hyphen is used to connect compound modifiers that come before the word being modified, and a hyphen is not used for compound modifiers that come after the word being modified. Consult the Glossary of Geology for examples of compound modifiers that are always hyphenated.

Exceptions: No hyphen if the first word in the compound modifier is very or an adverb ending in ly. Don’t use a hyphen if the first word in a three-word unit modifier is an adverb that describes the second word.

• Kirkman Limestone—Light-gray, thick- to medium-bedded, fine-grained dolomitic limestone; contains dark-gray, gray-weathering intraformational breccia.
• Olivine basalt—Dark-gray, dense to vesicular basalt; calcite-filled vesicles contain 1/2-inch crystals.
• Colluvium—Poorly to moderately sorted, clay- to boulder-sized, locally derived material on gently sloping surfaces.
• Ankareh Formation—Thinly laminated, moderately indurated, greenish-gray, poorly exposed sandstone.
• Kirkman Limestone—Light- to dark-gray dolomitic limestone.
• Straight Cliffs Formation—Dominantly cliff-forming, fine-grained, moderately indurated sandstone.

Formal geologic units are defined in accordance with the current or previously accepted versions of the North American Stratigraphic Code. Informal geologic units are sometimes useful locally, but, for whatever reasons, they don’t comply with the requirements of the current stratigraphic code. Use informal geologic units in Bureau of Geology reports with care, and always clearly identify them as informal units using lowercase words (for example, member, unit, sandstone).

Formal geologic unit names should always be written out to avoid confusion (for example, Chinle Formation versus Chinle, Arizona). Abbreviations may be used in figures and tables to save space.

There are no rules equivalent to the North American Stratigraphic Code for naming structural geologic features. Authors may choose names as they see fit, provided the feature has not been previously named in the literature. Common sense, good taste, and close adherence to the rule of precedence should guide authors who propose to name structural features in Bureau of Geology publications.

• If a list is short and simple, incorporate it directly into a sentence, separating each list item with a comma:
  • Descriptions of samples collected by the authors accompany analytical data for Au, Ag, Cu, Pb, Zn, and As.
• If the items themselves include commas, use semicolons to separate the items:
  • The board members present included J. Berry, chairman; R. Hughes, secretary-treasurer; L.E. Smith, chief financial officer; and R. Kinley, ex officio member.
• Numerals (preferred) or letters enclosed in double parentheses may be used to identify each item. Commas rather than semicolons separate numbered list items:
  • Much of the unit is (1) red, pink, or gray, (2) medium to coarse grained, and (3) equigranular or slightly porphyritic.
• Sentence lists are not preceded by a colon if the list follows a preposition or a verb:
  • The three types of rock are igneous, sedimentary, and metamorphic.
• Use a colon when the list follows a noun:
  • There are three types of rocks: igneous, sedimentary, and metamorphic.

A list that is long, contains complete sentences, or merits special emphasis should be indented and displayed vertically.

Numbers, letters, bullets, or dashes may be used to delineate list items. Numbers and letters may or may not imply an order or hierarchy among the items and are useful if items are referred to in the text. Bullets and dashes imply no particular order or hierarchy among items.

If the items in a vertical list complete their introductory sentence, a colon is used, the items are not capitalized, each item is followed by a comma (or semicolon when appropriate), and the last item in the list ends with a period:

• The investigation of the Red Rock fault zone proceeded by:
  1. mapping the surficial geology along the fault zone at 1:12,000 scale,
  2. excavating trenches across single- and multiple-event scarps identified during the mapping,
  3. logging the trench walls to determine the number and size of paleoearthquakes, and
  4. collecting samples of organic material for radiocarbon dating.

If a vertical list consists of a series of complete sentences, capitalize the first letter of each item and end each item with a period:

• Northwest-striking, extension-related faulting in the area largely preceded mineralization and alteration. Faults produced during this deformation host all known occurrences of mineralized veins.
• Eruption of rhyolitic flows and intrusion of possible subvolcanic rocks occurred 8.5 to 8.4 Ma.
• Heat derived from the emplacement of rhyolitic magmas induced a hydrothermal system in the surrounding host rocks. Extensional structures served as conduits for rising, dominantly meteoric, hydrothermal solutions.

Introductory sentences should end with a period only if the sentence is long and the anticipatory word or phrase occurs early in the sentence, or if another sentence comes between the introductory sentence and the list.

All lists must maintain parallel structure by beginning each item with the same part of speech (usually a noun, verb, or adjective).

An en dash may be used with ranges of numbers (for example, 24–14 Ma). However, don’t use an en dash to substitute for the words to, through, or until if the word from precedes the phrase (for example, from 10 to 15 m thick), or to substitute for the word and if the word between precedes the phrase (for example, between 24 and 14 Ma). With ranges of numbers, use only one unit symbol at the end. See dash.

• Always use numerals for people and animals, but spell out for inanimate objects (unless the age is 10 or greater):
  • Michael Phelps first swam in the Olympics when he was 15 years old.
  • The Kentucky Derby is a race for 3-year-olds.
  • The rule change is two years old.
  • The rule book is 16 years old.

• Use decimals rather than fractions wherever possible.
• If a decimal is not associated with a whole number, insert a zero before the decimal point (0.56, not .56).
• Zeros are retained after a decimal point only if they are significant figures (3.208 but not 3.200 unless both zeros are significant).

Sometimes established convention makes using fractions preferable to decimals. Rules for using fractions include the following.

• Use numerals when fractions express a measurement:
  • 1/2-inch pipe
  • 6-1/2-inch O.D. well casing
• Spell out and hyphenate fractions that stand alone in the text:
  • The project is two-thirds complete.

Use numerals with meters, centimeters, inches, feet, yards, grams, kilograms, etc., to indicate depth, height, length, width, and mass:

• The outcrop is 75 m long.
• The sample weighs 3 g.
• The 10-m-thick bed shows thin-bedding.
• The sampling site is 4 mi from Lexington.

Use common abbreviations for units in publications aimed at a scientific audience; spell out units for a general audience. Don’t use periods after ft, yd, m, etc. Exception: Use a period after in. to distinguish it from the preposition. See units of measurement.

Use a minus sign (Unicode 2212, Alt + 8722), not a hyphen:

• WRONG: -25
• RIGHT: −25

Apostrophes have two primary uses: to indicate possession and to make contractions.

To indicate possession:

• Add ’s to a singular noun to make it possessive (for example, the layer’s thickness).
• Add only an apostrophe to plural nouns ending in s (for example, the layers’ thicknesses).
• Add ’s to singular nouns ending in s (for example, Dr. Jones’s research). This is an exception to some style guides, but it indicates the correct pronunciation.
• Don’t use an apostrophe with possessive pronouns: ours, yours, his, hers, its, theirs, whose.
• Don’t use an apostrophe with a word ending in s when its use is descriptive rather than possessive (for example, Masters swimming, Beatles music, Titans game).
• Don’t use an apostrophe in place names unless it is part of the formal name (for example, Pikes Peak, Tates Creek, Martha’s Vineyard).

To make contractions:

• Use an apostrophe to form contractions and to indicate omitted letters or numerals (for example, don’t, won’t, can’t, rock ’n’ roll, class of ’74).
• Avoid contractions in technical writing, but use them sensibly for a general audience to prevent the prose from being overly formal.
• Don’t use ’s to pluralize numerals or multiple-letter combinations (for example, 1890s, not 1890’s; ABCs, not ABC’s).
• Don’t use an apostrophe as a substitute for the prime symbol.
• Don’t use an apostrophe as an abbreviation for feet (for example, 6 ft, not 6’).

Brackets serve the same function as parentheses—to enclose incidental information or explanatory material—but they’re restricted to situations where it’s necessary to enclose information within an existing set of parentheses:

• ...or thin dolomitic beds (note, however, that Bauch [1982, p. 42] included salt-cast-bearing gray siltstones in the upper Abo Formation).

Brackets are also used in equations and formulas, and to insert brief editorial comments or corrections into quoted material (see quotations).

Use a colon (not a semicolon) to introduce lists, long quotations, and for emphasis:

• These are the three classes of rocks: igneous, sedimentary, and metamorphic.
• Vanderbilt coach Bryce Drew said: “I’m really proud of our effort tonight. We could have ducked our heads when we got 10 points down, but we didn’t. We came back and became the aggressor late in the second half. That turned the game around for us.”
• Malik Monk: All he does is win.

Don’t capitalize the first word after a colon unless it’s a proper noun or the beginning of a complete sentence:

• The best songwriting team ever: Lennon and McCartney.
• The worst thing that can happen: defeat.
• You can count on one thing: The replay booth will rule against Vanderbilt.

Colons are also used after salutations in a formal letter (for example, Dear Dr. Jones:), to separate hours from minutes (for example, 3:45 p.m.), to separate the two halves of a ratio (for example, 4:1), and in reference entries to separate the title of a source from its publisher (see references).

For help with structuring lists with colons, see lists.

Commas have many uses.

To delineate items in a series:

• John, Paul, George, and Ringo are the Beatles.
• In lists of three items or more in technical publications, use a serial comma (also known as the Oxford comma) before the last item and its conjunction. In the above example, this is the comma after George.

Before and after a state name when a city is given:

• Nashville, Tennessee, is my hometown.

To separate adjectives that are equal in rank (adjectives that can switch locations in the sentence with one another such that the sentence will still make sense):

• tan, brown to reddish-brown, well-sorted silt and sand

No comma is needed before the last adjective if it’s critical to the meaning:

• a stretched-out, transparent team swimsuit (not just any suit, but the suit designated for team members)

To set off introductory phrases:

• When we arrived at the pool, we were overcome by chlorine fumes.

To set off two phrases joined by a conjunction when each phrase could stand alone as a sentence:

• She came to Savannah to score points, but the highest she placed was the dreaded 11th place.

To introduce short quotations:

• Phelps said, “I’m pleased with my time.”

In numbers greater than three digits (but not after a decimal):

• The attendance was 12,060
• The first 10 digits of pi are 3.141592653 (not 3.141,592,653)

To identify month, date, and year:

• On September 5, 1893, the New Mexico School of Mines opened.

Don’t use a comma to separate months and years:

• October 1956 (not October, 1956)

Don’t use a comma with Inc.:

• Pendant Publishing Inc. (not Pendant Publishing, Inc.)

Don’t use a comma with Jr. and Sr.:

• Garland Dever Jr. (not Garland Dever, Jr.)

There are two types of dashes: en dashes (–) and em dashes (—).

An en dash (so called because it’s the width of the letter n) is used to connect inclusive words and numbers such as dates, page ranges, and ranges of values when given as equivalent units of measure in parentheses:

• I usually swim 2,000–3,000 yards in a workout.
• 1945–1978
• p. 312–327
• 20 to 30 ft (6–9 m)
• cross section A–A’
• snowpack–runoff relationship
• north–south trajectory

As a test for when an en dash is appropriate over a hyphen, substitute the words to, through, or up to and including between the items.

An em dash (so called because it’s the width of the letter m) is used to set off extra information, such as examples, explanatory or descriptive phrases, or supplemental facts:

• One can piece together from different locales—particularly the Caballo Mountains and Sierra de las Uvas—a seemingly conformable sequence of these rock units.
• In central New Mexico, most now regard the Glorieta as a distinct formation—a practice followed in this study.

Don’t put spaces before or after either dash.

Don’t use a hyphen where a dash would be the correct choice and vice versa.

In reference list entries, use an em dash to replace a colon that appears within the document title to avoid possible confusion with the colon that is used to mark the end of the document title (see references):

• Basins of the Rio Grande Rift—Structure, Stratigraphy, and Tectonic Setting: Geological Society of America Special Paper 291

Don’t use en dashes to substitute for the words to or and when used with from or between, respectively, to indicate a range of values. Don’t use an en dash when the two items in the range are hyphenated:

• Nitrate concentration ranges from 2.6 to 9.3 mg/L. (not from 2.6–9.3 mg/L)
• Fine-grained sediments accumulated in a shallow lake between 45 and 40 Ma. (not between 45–40 Ma)
• We measured several 31- to 66-m-long profiles. (not 31–66-m-long)

PC/Mac controls for en dash:

• PC: Alt + 0150 (Note: This method works only for keyboards that include a 10-key numeric pad; use a double hyphen [--] if the alt code doesn’t work.)
• Mac: Option + Dash (-)

PC/Mac controls for em dash:

• PC: Alt + 0151 (Note: This method works only for keyboards that include a 10-key numeric pad; use a triple hyphen [---] if the alt code doesn’t work.)
• Mac: Shift + Option + Dash (-)

An ellipsis indicates that one or more words have been omitted from quoted material:

• A previous author wrote, “We will examine the development of Brough’s Tunnel … within Clifty Falls State Park.”

Ellipses are formed by typing three periods in a row. Include a space before the first period and after the last period.

Ellipses are not used before the first word of a quotation, even if the beginning of the original sentence is omitted, or after the last word of a quotation, even if the end of the original sentence is omitted.

Ellipses are not meant to indicate a break in thought; don’t use them instead of an em dash.

A hyphen joins two or more words that work together to modify a subsequent noun:

• a well-defined aquifer
• pale-green shale
• reddish-brown sandstone
• light-gray limestone
• 60-meter-wide graben
• fine-grained sandstone
• fine- to coarse-grained sandstone
• 1/2-inch crystals
• northwest-trending fault
• east-central New Mexico

Don’t use a hyphen when the noun comes first:

• an aquifer that is well defined
• shale of pale green color
• a graben that is 60 m wide
• the sandstone is fine grained
• sandstone that is fine to coarse grained
• crystals of 1/2 inch
• a fault trending northwest

Don’t use a hyphen with very or adverbs ending in ly:

• a very porous layer
• a finely crystalline rock

Don’t use a hyphen when the modifying words do not function as one unit and could be separated by a comma:

• a small, blue mineral
• a large, dry riverbed

Use a hyphen to prevent doubled vowels and tripled consonants:

• anti-intellectual
• well-liked

When describing rock units in stratigraphic sections, well logs, and other lists, compound modifiers following a rock name are traditionally hyphenated in the geologic literature:

• Sandstone: blue-gray, thinly bedded, coarse-grained
• Welded tuff: reddish-brown, flow-banded

A number of compound nouns exist in geological vocabulary. Some are hyphenated (acre-foot, cross-bed, cross-stratification, meta-arkose), and others are not (cross section, dip angle, dike swarm, solution banding). Consult the Glossary of Geology for the proper forms of compound nouns. (Note that the Glossary of Geology is an IP-based subscription and can only be accessed from on campus, or with a VPN connection if off campus).

Compound numbers between twenty-one and ninety-nine and fractions are hyphenated when written out:

• thirty-three
• four-fifths
• one-third

Use a hyphen to separate noninclusive numbers, such as telephone numbers and serial numbers:

• 801-537-3300
• no. 14558-789-D
• NMBGMR Miscellaneous Publication 03-7

Use a hyphen where numbers and units of measure form a compound modifier:

• A 4-foot-thick fossiliferous limestone bed is at the top of the interval.

See prefixes and suffixes for more on the use of hyphens.

Parentheses enclose incidental information or explanatory material and are the most common type of punctuation found in scientific reports after commas and periods. Parentheses are used in the following ways.

To enclose abbreviations the first time they appear:

• Differences in the timing of the most recent event (MRE) along a fault zone are used to define fault segments.

For in-text citations (see brackets):

• Wilpolt and Wanek (1951) were the first to map the geology of the Quebradas region.
• Terranes accreted to the southern margin of Laurentia during the Proterozoic (Karlstrom et al., 2004).

To provide alternative units of measurement:

• Deposition was rapid during the Pennsylvanian and Permian, resulting in a total accumulation of 25,000 to 30,000 ft (7,600–9,100 m) of marine sediments.

To call out figures, tables, chapters, and appendices:

• In the Blackington Hills, the tuff is 90–150 m thick (Fig. 63).

To provide additional information:

• The Emery high (or Piute platform as it is now called) and the Kaibab uplift (a poorly defined band of uplifts) have been identified by the thinning or absence of Pennsylvanian formations.

To enumerate points in a list:

• Much of the unit is (1) red, pink, or gray, (2) medium to coarse grained, and (3) equigranular or slightly porphyritic.

Don’t use back-to-back parentheses; use a semicolon to separate items, for example, (Fig. 2; Hook, 1983), or rewrite to avoid back-to-back parentheses or ambiguity.

A period is used to mark the end of a declarative sentence (a sentence that makes a statement) or an imperative sentence (a sentence that gives an instruction or command or makes a request). When used between sentences, a period is followed by a single space, not a double space:

• Sandstone is a type of sedimentary rock. Granite is a type of igneous rock.
  Give me the hand lens.

Periods are used with abbreviations that end in a lowercase letter:

• etc.
  i.e.
  e.g.
  Dr.
  Mrs.

Periods are also used for initials instead of full names, such as in a reference list:

• White, E.B.
  Du Bois, W.E.B.

If a full sentence is placed inside parentheses, the period goes inside the closing parenthesis; otherwise, it is placed outside:

• I will be there this week. (I was out sick last week.)
  Much of the variability in precipitation can be explained by natural fluctuations of Pacific Ocean temperatures (such as the El Niño cycle).

Periods and commas are always placed inside closing quotation marks:

• “If we get up early,” she said, “we’ll be sure to make it on time.”

Quotation marks set off direct speech and material quoted verbatim from other sources (see quotations):

• Hook and Cobban (2015, p. 27) defined it as “that portion of the Mancos Shale lying between the undifferentiated or main body of the Dakota Sandstone and the Tres Hermanos Formation.”

In text (but not reference entries), quotation marks enclose the titles of journal articles, book chapters, and newspaper articles and editorials. Italics are used for the names of the larger works these items are published in (see italics):

• “The House Range, Western Utah—Cambrian Mecca” by Hintze and Robison (1987) in Rocky Mountain Section of the Geological Society of America Centennial Field Guide, Volume 2 provides a succinct description of an important fossil locality in Utah.

Quotation marks also enclose words used in a special way:

• “Caliche” usually refers to an indurated layer of calcium carbonate accumulation in a soil; “hardpan” is a more general term that refers to any indurated soil layer resulting from the precipitation of soluble materials in the soil profile.

Commas and periods are always placed inside closing quotation marks; colons and semicolons are always placed outside closing quotation marks. All other punctuation marks are placed inside quotation marks only if they are part of the quoted material.

Don’t use a quotation mark as a substitute for the double-prime symbol (″; that is, seconds of angle; see prime symbol).

Don’t use a quotation mark as an abbreviation for inches (for example, 6 in., not 6”).

A semicolon indicates a pronounced separation between grammatical units. It’s stronger than a comma and almost as full as a period, but it implies a closer relationship between the thoughts than a period would. A semicolon separates two or more complete thoughts (independent clauses) within a single sentence:

• These bentonites range in thickness from 0.6 to 35.6 cm; most are white but weather orange.

When a semicolon is used to link complete thoughts, it doesn’t require a conjunction (and, but, or, if, so, etc.); however, a semicolon is necessary when an adverbial conjunction (accordingly, besides, consequently, furthermore, hence, however, instead, moreover, nevertheless, otherwise, still, therefore, thus) connects the thoughts:

• The full extent of the Escalante silver vein was known only after extensive exploration; consequently, a number of smaller ore deposits in the district were overlooked for many years.

Don’t use a semicolon with the simple coordinating conjunctions and, or, for, nor, yet, so, and but. Instead use a comma.

Semicolons are also used to separate items in a list when one or more of the items requires a comma (see lists).

Slashes are used to signify alternatives (for example, and/or, his/hers), in abbreviations (for example, m/s, acre-ft/yr), or in fractions (for example, 1/3, 1/4).

1. Author(s), last name first, followed by initials, followed by a comma. Specify editor(s) with ed. or eds.
2. Year of publication, followed by a comma.
3. Title (sentence case), followed by a colon.
4. New Mexico Bureau of Geology and Mineral Resources and series name and number, followed by a comma.
5. Total pagination (with p.), followed by a period.
6. DOI (if available).

Examples

1. Dunbar, N.W., Gutzler, D.S., Pearthree, K.S., Phillips, F.M., Bauer, P.W., Allen, C.D., DuBois, D., Harvey, M.D., King, J.P., McFadden, L.D., Thomson, B.M., and Tillery, A.C., 2022, Climate change in New Mexico over the next 50 years—Impacts on water resources: New Mexico Bureau of Geology and Mineral Resources Bulletin 164, 218 p. https://doi.org/10.58799/B-164
2. Rawling, G., 2021, Evaluation of water-level trends using spatiotemporal kriging in the Mimbres Basin, southwest New Mexico: New Mexico Bureau of Geology and Mineral Resources Open-File Report 616, 57 p.

1. Author(s), last name first, followed by initials (or organization if no author can be found), followed by a comma.
2. Year of publication, followed by a comma.
3. Title (sentence case), followed by a colon.
4. Name of journal (title case), followed by a comma.
5. Volume and number (use the abbreviations “v.” and “no.”), followed by a comma.
6. Pagination span (with p., en dash with no spaces), followed by a period.
7. DOI (if available).

Examples

1. Heller, P.L., and Liu, L., 2016, Dynamic topography and vertical motion of the U.S. Rocky Mountain region prior to and during the Laramide Orogeny: Geological Society of America Bulletin, v. 128, no. 5–6, p. 973–988. https://doi.org/10.1130/B31431.1
2. Amato, J.M., Mack, G.H., Jonell, T.N., Seager, W.R., and Upchurch, G.R., 2017, Onset of the Laramide Orogeny and associated magmatism in southern New Mexico based on U-Pb chronology: Geological Society of America Bulletin, v. 129, no. 9–10, p. 1209–1226. https://doi.org/10.1130/B31629.1

1. Author(s), last name first, followed by initials (or organization if no author can be found), followed by a comma.
2. Year of publication, followed by a comma.
3. Title (sentence case), followed by a comma and the word in (in italics).
4. Name(s) of editor(s), last name first, followed by initials, followed by ed. or eds., followed by a comma.
5. Name of edited volume (title case), followed by a colon.
6. Publisher and type of publication and number (if applicable, for example, Guide Book, Special Report), followed by a comma. For conference proceedings or abstracts, include the name, location, and date of the conference (if known).
7. Pagination span (with p., en dash with no spaces), followed by a period.
8. DOI (if available).

Examples

1. Seager, W.R., and Mack, G.H., 2018, Geology of the Doña Ana Mountains, south-central New Mexico—A summary, in Mack, G.H., Hampton, B.A., Ramos, F.C., Witcher, J.C., and Ulmer-Scholle, D.C., eds., Las Cruces Country III: New Mexico Geological Society Fall Field Conference Guidebook 69, p. 71–81. https://doi.org/10.56577/FFC-69.71
2. Dickinson, W.R., 2009, Anatomy and global context of the North American Cordillera, in Kay, S.M., Ramos, V.A., and Dickinson, W.R., eds., Backbone of the Americas—Shallow Subduction, Plateau Uplift, and Ridge and Terrane Collision: Geological Society of America Memoir 204, p. 1–29. https://doi.org/10.1130/2009.1204(01)
3. Humphreys, E., 2009, Relation of flat subduction to magmatism and deformation in the western United States, in Kay, S.M., Ramos, V.A., and Dickinson, W.R., eds., Backbone of the Americas—Shallow Subduction, Plateau Uplift, and Ridge and Terrane Collision: Geological Society of America Memoir 204, p. 85–98. https://doi.org/10.1130/2009.1204(04)

1. Author(s), last name first, followed by initials (or organization if no author can be found), followed by a comma.
2. Year of publication, followed by a comma.
3. Title (sentence case), followed by a colon.
4. Name of publisher and title of series (if applicable, for example, Open-File Geologic Map, Map and Chart Series, Scientific Investigation Map), followed by a comma.
5. Scale, followed by a comma, number of sheets (if more than one), followed by a period.

Examples

1. Rinehart, A.J., Love, D.W., and Miller, P.L., 2014, Geologic map of the Black Butte 7.5-minute quadrangle, Socorro and Valencia Counties, New Mexico: New Mexico Bureau of Geology and Mineral Resources Open-File Geologic Map 235, scale 1:24,000.
2. Aby, S., Timmons, J.M., and Miller, P.L., 2016, Geologic map of the El Vado 7.5-minute quadrangle, Rio Arriba County, New Mexico: New Mexico Bureau of Geology and Mineral Resources Open-File Geologic Map 257, scale 1:24,000.
3. Bauer, P.W., Kelson, K.I., Aby, S.B., Helper, M.A., and Mansell, M.M., 2021, Geologic map of the Picuris Mountains, Rio Arriba and Taos Counties, New Mexico: New Mexico Bureau of Geology and Mineral Resources Open-File Geologic Map 294, scale 1:24,000, 2 sheets.

1. Author(s), last name first, followed by initials (or organization if no author can be found), followed by a comma. Specify editor(s) with ed. or eds.
2. Year of publication, followed by a comma.
3. Title (title case), followed by a colon.
4. City and state or country of publication, followed by a comma. Don’t include state/country with major cities (for example, New York, Boston, London, Amsterdam).
5. Name of publisher, followed by a comma.
6. Total pagination (with p.), followed by a period.

Examples

1. Bates, R.L., and Jackson, J.A., eds., 1980, Glossary of Geology (second edition): Falls Church, VA, American Geological Institute, 749 p.
2. Allmendinger, R.W., Cardozo, N., and Fisher, D., 2011, Structural Geology Algorithms—Vectors and Tensors in Structural Geology: New York, Cambridge University Press, 304 p.

1. Author(s), last name first, followed by initials (or organization if no author can be found), followed by a comma.
2. Year of publication/presentation/etc., followed by a comma.
3. Title (sentence case), followed by a colon.
4. Name of conference, etc., followed by a comma.
5. Number of the conference, etc., followed by a comma.
6. Place of conference, etc., followed by a comma.
7. Year of conference, etc., followed by a comma.
8. Series, volume, part (if any), followed by a comma.
9. Full pagination (if entire publication is being cited) or pagination span (if only a section is being cited).

The degree mark (°) is used with numbers in statements of temperature, strike, dip, slope inclination, azimuth, latitude, and longitude. No space is used with the degree mark. Don’t use a degree mark when reporting Kelvin temperature. Don’t spell out degree.

• 32°F equates to 0°C and 273.15 K
• a bearing of S35W equates to an azimuth of 215°
• strike 66°, dip 46°; unless in a sentence, for example, striking 66° with a dip of 46° to the SE
• latitude 40°45′15″ N or 40°45.25′ N
• longitude 112°33′30″ W or 112°33.5′ W
• the ground surface slopes 33° to the north
• a right angle equates to 90°

PC/Mac controls for degree mark:

• PC: Alt + 0176 or Alt + 248
• Mac: Shift + Option + 8

Don’t use an apostrophe (') or quotation mark (”) as a substitute for the prime (′) or double prime symbol (″), for example, latitude 38°12′30″ N (not 38°12'30” N).

Prime: PC: Alt + 8242, Mac: Option + 2032
Double prime: PC: Alt + 8243, Mac: Option + 2033