R

RADARSAT

radio As a prefix, radio is rarely followed by a hyphen: radioactive, radiocarbon, radioecology, radioisotope.

radiocarbon dates Because of the need to distinguish between uncalibrated (14C) and calibrated (cal.) radiocarbon dates, and in the absence of a standard convention, the following formats should be used for expressing these dates:

Uncalibrated:

18 000 ± 600 ¹⁴C years BP
18 ka ¹⁴C BP

Calibrated:

18 000 ± 600 cal. years BP
18 ka cal. BP

rainfall, rainwater, but rain gauge

range The word range implies a minimum as well as a maximum limit. It is imprecise to say that 'the beds range up to 3 m thick', although a minimum thickness close to zero would be understood, perhaps wrongly. It is more accurate to state that the beds range from 50 cm to 3 m in thickness. Do not say that 'the beds are between 50 cm and 3 m in thickness', as this could mean that all the beds are of one thickness and the reader must guess exactly how thick, within the minimum and maximum values given.

Also, do not say that 'the beds range between 50 cm and 3 m in thickness'; the word between constitutes a repetition of range and should be omitted. Bedding thickness ranges from 50 cm to 3 m, is the correct entry.

rare earth, but rare-earth element (REE), rare-earth elements (REEs).

rarefy

ratio in written text use slash or colon (e.g. Pb/Zn, water:gas ratio; water-to-gas ratio also accepted).

rationale, rationalize

re Many compound words with the prefix re are written as one word. A hyphen is used when two similar vowels occur together, when the appearance of the word is confusing without the hyphen, or when the word written without a hyphen has another meaning. Several words occur both with and without a hyphen, and have different meanings and pronunciations. Examples are listed below in alphabetical order.

reaction This word implies an automatic rather than an intellectual response. Reserve its use for chemical, biological, and mechanical processes, and do not use it in place of opinion or impression.

readvance, reappraise, reassess, reassign

recede

recognize

recollect, re-collect Recollect means 'to remember'; re-collect means 'to collect again'.

reconcilable

recount, re-count Recount means 'to narrate'; re-count means 'to count again'.

recover, re-cover Recover means 'to get (a thing) back'; re-cover means 'to cover again'.

recreation, re-creation Recreation is 'a pleasant pastime'; re-creation means 'creation anew'.

recurrence

redbeds

reducible

redundant words See 'Jargon and contrived or redundant words' section in 'Grammar'

REE See RARE EARTH.

re-educate

reef core, reef edge, reef front, reef rock, reef wall

re-entrant

re-establish

refer, referable, reference, but referred

reform, re-form To reform is 'to improve, to correct'; re-form is 'to form anew'.

re-fused rocks

regardless, not irregardless

reinterpret

relatively See COMPARATIVELY.

relay, re-lay Relay means 'to relieve, to replace'; re-lay means 'to lay again'.

relic, relict Relic and relict have come to be used differently from everyday English, where both tend to be used as nouns, and where relict is obsolete except in legal sense. Premetamorphic minerals or textural features are said to be relics (noun) or relict (adjective) textures.

In paleontology, relict serves as both adjective and noun.

replace See SUBSTITUTE.

reproduction, reproducible

requisition (vb.) One requisitions makes a requisition for it, but does not 'requisition for it'.

reserve, resource In simple terms reserves (of coal, oil, gas, etc.) are proven quantities, whereas resources are estimated quantities.

resign, re-sign Resign means 'to relinquish'; re-sign means 'to sign again'.

resistance, resistant

resort, resource Resort means 'that to which one has recourse for aid': as a last resort. Resource is 'a reserve upon which one can draw when necessary'.

resource See RESERVE; RESORT.

respective, respectively

responsible Do not confuse responsible with cause. People are responsible for events, but things cause them.

résumé

retrothrust Retrothrust means 'a fault on which reverse or thrust movement has been followed by normal displacement'.

reversible

revise

rhythm, rhythmite

right angle (n.), right-angled (adj.)

right-hand rule See STRIKE AND DIP.

right-lateral fault

rigour, rigorous

ripple bedding, ripple crosslamination

ripple mark Use this for the structure in sediments or rocks ('ripple' is unacceptable: use ripple mark).

rip-up clasts

river Capitalized as in Fraser River, but Fraser River valley.

river bed, river bottom, river valley, but riverbank

road not capitalized unless official name

roadbed, roadcut, roadside, roadway

roches moutonnées

Rock-Eval

rockburst

rock names When applying 'unit modifiers' to the names of rocks, remember that like names (i.e. names of rocks, minerals, textures, and clastic aggregates) are connected by hyphens, whereas unlike names are not:

See also MAP LEGEND.

rock names used in the plural form To write: The gneisses, schists and iron-formations of the area is geological jargon comparable to mineralization, clastics, accessories, etc. and should be avoided. Gneiss, schist, iron-formation, shale, sandstone, and limestone are collective nouns that need not be pluralized. 'The iron-formations of the area' can be rewritten: The iron-formation units. See also INTRUSIVES.

rocks, magmas, melts, liquids In igneous petrology, the names of rocks (particularly of the volcanic types) are commonly also applied to the magmas from which they solidified, and confusion commonly results. For example, authors write about basalt the rock in one sentence, and basalt the magma in the next, without specifically identifying them or explaining that they have switched. Try, therefore, always to make the distinction by identifying the magma, as in andesitic magma or kimberlite magma.

Other ever-recurring problems concern the distinctions between magma, melt, and liquid. By its traditional definition, magma is molten rock material, but it can also embody crystals, rock fragments, and gas bubbles. Thus, if the liquid is the part of interest, it should be specifically identified. It is properly called melt if the topic concerns the formation of the magma by melting processes, but if the topic pertains to crystallization, assimilation, or related processes occurring under cooling conditions, then magmatic liquid (or just liquid) is more appropriate.

rocks, rock bodies Geologists frequently speak (for example) of kimberlites when they mean 'kimberlite dykes, pipes, or diapirs'; of basalts when they mean 'basaltic lavas or flows'; and of peridotites when they mean 'peridotite lenses or bodies'.

The plural form of a rock name should probably be reserved for reference to its variants, e.g. basalts might refer to an association of alkaline and subalkaline basalts in one situation, or to an affiliation of tholeiitic and high-alumina basalts in another.

See also INTRUSIVES; MINERALS, MINERAL CRYSTALS, MINERAL GRAINS.

rock type, rock unit, but rockslide

Rocky Mountains Capitalized as in the Canadian Rockies, the Rockies (colloquial), Rocky Mountain Foothills, Rocky Mountain Trench.

roman numerals (not Roman numerals)

runoff

R-wave