A

a, an The indefinite article. See 'The indefinite articles 'a' and 'an' in 'Grammar'.

a axis, a horizon

abandon, abandoned

about, approximately Usually about can take the place of approximately. If there is a difference it is that approximately suggests a more careful calculation. Around should not be used to mean about.

abridgment

absorption, adsorption Absorption means 'assimilation' (e.g. of liquids in solids, or gases in liquids). Adsorption means 'the adherence of gas molecules etc. to the surface of solids'.

abstract, concrete Try to use the concrete rather than the abstract in writing. Terms implying geological processes, such as mineralization, chloritization, granitization, shearing, faulting, etc., are abstract. Faulting cannot 'strike northeasterly', though the fault, or faults, or fault zone may. Another abstract term commonly misused in a concrete sense is values. Value is an attribute, not a substance. An ore does not 'carry high gold values', though it may contain much of that valuable metal. Nor does a miner 'encounter good values' in an ore, but may encounter valuable minerals, or minerals that carry valuable metals. Also, values are not lost in sinking, but the orebody may be lost.

abyssal

accede

accessories See INTRUSIVES.

accessory As in 'an accessory mineral'.

accommodate, accommodation

accumulate, accumulation

accuracy, precision Accuracy is 'a measure of how closely a fact or value approaches the absolute or true value'. Precision is 'a measure of the fineness of a value'. Thus, 1.0103 is more precise than 1.01 but it may not be more accurate.

achieve Achieve implies 'successful effort and not the mere completion of something'. You may achieve a merit increase but you get a statutory raise.

acknowledgment (not acknowledgement)

active layer

active voice See 'Active and passive voice' in'Grammar'.

addendum (pl. addenda)

adsorption See ABSORPTION.

advice (n.), advise (vb.)

aegirine

aeolian (not GSC spelling, see EOLIAN).

aerial, areal Aerial means 'from the air (e.g. aerial photograph, airphoto)', whereas areal relates to 'area'.

aerobic, anaerobic Aerobic (oxidizing) means 'living, active, or occurring only in the presence of oxygen'. Anaerobic (reducing) means 'living, active, or occurring in the absence of free oxygen'.

affect, effect In the noun forms, affect signifies 'an emotion or feeling', whereas effect denotes 'a result or consequence'. In scientific papers, the noun form is almost always effect. As verbs, affect means 'to act upon or to have an influence', whereas effect means 'to cause, produce, accomplish, or to bring about a change': The granite affected the position of the fault, and the fault effected a detour around the granite.

AFM diagram A triangular diagram used to indicate the composition of peliticschist and gneiss by plotting the molecular quantities of three components: A(Al₂O₃), F(FeO), andM(MgO).

after See 'Italics' in 'Grammar'

aftershock, foreshock Major earthquakes are commonly preceded and followed by many less intense earthquakes (foreshocks and aftershocks). These foreshocks and aftershocks decrease in frequency and magnitude with time, and whereas foreshocks may precede a main shock by an interval ranging from seconds to weeks, aftershocks can occur many days or months after the main shock. See also FORECAST, PREDICTION; INTENSITY, MAGNITUDE.

age, aging

agendum (pl. agenda)

aggravate Aggravate means 'to increase or intensify, or make worse' (not to annoy).

airborne (not airborn) Airborne magnetometer.

aircraft

air-fall (n. and adj.) (deposition)

airphoto, aerial photograph See AERIAL.

alga (pl. algae)

alignment

alkali feldspar (no hyphen)

alkalis (not alkalies)

all (not all of)

all-inclusive

allochthonous

all ready, already All ready is an adjectival phrase, as in: When the whistle blew they were all ready. Already is an adverb, meaning 'by this time'.

all-terrain vehicle (ATV)

all together, altogether Use all together when referring to 'several people, things, or ideas that have been brought together': the caribou herded all together. The ore-bearing veins are all together in the northern part of the intrusion. Altogether means 'on the whole, entirely, in all': not altogether pleased with the assistant.

allude, elude Allude means 'to refer indirectly (to)'; elude means 'to escape from'.

allusion, illusion An allusion is 'an indirect reference'; an illusion is 'an unreal image or false impression'.

alluvial fan

alternate(ly), alternative(ly) Alternate means 'by turns'; alternative means 'in a way that offers a choice (between two things)': The stratigraphic sequence consists of alternating mafic and felsic layers. Alternatively, the pluton could be synorogenic.

although See THOUGH.

altitude, elevation The terms altitude and elevation are essentially synonymous, and mean 'height above sea level'; however, specifically, altitudes are 'the approximate heights of geographic features (or aircraft)', whereas elevations denote 'exact heights, as indicated by bench marks'.

aluminosilicate

amid, amidst Although both forms are correct, the shorter is commonly preferred.

among, amongst Although both forms are correct, the shorter is commonly preferred.

among, between Among is generally used when more than two persons or things are involved: between is normally used for two: between five and nine (not between five to nine). See 'Prepositions' in 'Grammar'.

amount, number Amount means 'total (masses or bulks)'. Number (noun) refers to 'collective units (things that can be counted one by one)': the amount of faulting; the number of specimens.

ampersand (&) The ampersand should be used when it forms part of an official corporate name. In paleontological papers governed by the International Code of Botanical Nomenclature, the names of two joint authors of a taxon should be joined by an ampersand. The ampersand should never be used in any other connection in text.

amygdale not amygdule

anaerobic See AEROBIC.

analogous (not analagous), analogue

analysis (pl. analyses)

analyze (not analyse) See -ISE,-IZE.

anastomosing

and/or This complex construction is acceptable in scientific texts. Its use indicates that all of the three possibilities linked by and/or may be applicable: The pelite contains kyanite and/or sillimanite.

ångstrom (Å) 1Å= 0.1 nm. The GSC uses the SI unit 0.1 nm in the place of 'ångstrom'.

anomalous

antecede

anthropomorphism Anthropomorphism, personification, or pathetic fallacy, 'the ascription of human attributes or personality to inanimate objects', should be avoided in scientific writing. Rocks do not 'suffer deformation or metamorphism', regions do not 'experience glaciation or uplift', minerals do not 'call for or argue for an explanation', and special sessions do not 'invite papers'.

anticipate Anticipate means 'to forestall by prior action, to foresee, to expect'.

anticlimax

anticusp

anyone, any one and everyone, every one Anyone (everyone, no one, someone) is the correct form when the meaning is 'anybody, everybody', etc. Any one (every one, no one, some one) is the correct form when 'things and not persons' are meant.

apex (pl. apices)

apparent, evident, obvious Obvious means 'easily seen, in the sense of discovered'. Evident denotes 'the existence of visible signs, all pointing to one conclusion'. Apparent goes one step beyond evident and implies 'visible signs and some reasoning', as in: Although faulting was evident from the aerial photographs, its true extent was not apparent until the outcrops had been studied.

appear Appear suggests 'that which is visible'. A person appears to be young, but seems to be intelligent.

appendix (pl. appendices) Capitalized as in Appendix A.

appreciate Appreciate means 'to place value on', and ought to be used with a noun as object: I appreciate your kindness.

apprise

approximately See ABOUT.

apt, liable, likely Apt means 'having a tendency to do or feel something, because of the subject's character': apt to take offence. Liable expresses 'probabilities that the subject will suffer something undesirable'; likely expresses 'probability'.

aquifer

arabic numerals (not Arabic numerals)

arc Capitalized as in Great Bear Arc.

arch Capitalized as in Boothia Arch.

Archean (not Archaean)

archeology (not archaeology)

Arctic Canadian Arctic, Arctic Islands, Arctic Archipelago, the Arctic; but arctic Canada and an arctic environment. Compare BOREAL.

area The Rouyn-Bell River area.

areal See AERIAL.

areally

arguable, argument

armour

around Around means 'on every side, enveloping' (not about). Around should not be used to mean 'about'.

artifact (not artefact)

as See LIKE.

as far as Distinguish between: 'as far as Vancouver', which implies 'a fact', and so far as is known', which implies 'doubt'.

ascendant (n.), ascendent (adj.)

ash flow (n.), but ash-flow (adj.)

assume, presume Problems occur where both verbs are used to mean 'to suppose or to take for granted'. When you assume, you are expressing 'a theory, or even a hypothesis'. When you presume, you are expressing 'your belief or opinion'.

asymmetry, asymmetrical

Atlantic provinces

atmospheric

aulacogen

aurora borealis

autochthonous

auxiliary

avenue Capitalized as in Carling Avenue, 14^th Avenue, but 'avenue of exploration'.

avoid, avoidable

avulsion

axial plane (n.), but axial-plane cleavage (adj.)

azimuth Azimuth is 'the horizontal angle, measured clockwise, from due north', and is recorded numerically as three digits with a degree symbol (i.e. the point of the compass): 145° the fault trends 015°; (not the fault trends N15°E); with a 328° trend (not N32°W, S32°E trend). See also DIRECTION; STRIKE AND DIP.