See also:

• CONGLOMERATE (from the Lat. conglomerare, to form into a ball, glomus, glomeris; so also the general term " conglomeration " for a miscellaneous collection of things, gathered together in a mass)

CONGLOMERATE (from the See also:

• LAT

Lat. conglomerare, to See also:

• FORM (Lat. forma)

form into a See also:

• BALL (in Mid. Eng. bal; the word is probably cognate with " bale," Teutonic in origin, cf. also Lat. falls, and Gr. 7raXXa)
• BALL, JOHN (1585-1640)
• BALL, JOHN (1818-1889)
• BALL, JOHN (d. 1381)
• BALL, SIR ALEXANDER JOHN, BART
• BALL, THOMAS (1819- )

ball, glomus, glomeris; so also the See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general See also:

• TERM

term " conglomeration " for a See also:

• MISCELLANEOUS

miscellaneous collection of things, gathered together in a See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass)  , in See also:

• PETROLOGY

petrology, the See also:

• TERM

term used for a coarsely fragmental See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock consisting of rounded pebbles set in a finer grained See also:

• MATRIX

matrix . The pebbles must be rounded, otherwise the rocks are breccias, and these have a distinctly different See also:

• GEOLOGICAL

geological significance . They have attained their See also:

• PRESENT

present shapes by weathering and by See also:

• ATTRITION (Lat. attritio, formed from atterere, to rub away)

attrition during transport by streams and the waves and currents of the See also:

• SEA (in O. Eng. sae, a common Teutonic word; cf. Ger. See, Dutch Zee, &c.; the ultimate source is uncertain)
• SEA, COMMAND OF THE

sea . The pebbles consist mainly of hard rocks, such as See also:

• GRANITE (adapted from the Ital. granite, grained; Lat. granum, grain)

granite, See also:

• GNEISS

gneiss, See also:

• SANDSTONE

sandstone, See also:

• GREYWACKE, or GRAUWACKE (a German word signifying a grey earthy rock)

greywacke, or sometimes See also:

• LIMESTONE

limestone . Quartzites, cherts and flints, and vein-See also:

• QUARTZ

quartz are among the hardest and most durable of all rocks, and hence are specially abundant in conglomerates . Fragments of vein-quartz See also:

• FORM (Lat. forma)

form a large See also:

• PART

part of the "See also:

• BANKET

banket-rock" of the auriferous See also:

• TRANSVAAL

Transvaal reefs, one of the most important conglomerates economically . In this See also:

• CASE
• CASE, JOHN (d. 1600)

case the matrix consists mainly of quartz and See also:

• CHLORITE

chlorite, and See also:

• GOLD
• GOLD [symbol Au, atomic weight 195.7(H = 1),197.2(0 =16)]

gold occurs both in the matrix and in the pebbles . Igneous rocks on See also:

• ACCOUNT
• ACCOUNT (through O. Fr. acont, Late Lat. comptum, cornputare, to calculate)

account of their toughness are also very abundant in many conglomerates; those at the See also:

• BASE

base of the Old Red Sandstone of See also:

• SCOTLAND
• SCOTLAND, CHURCH OF
• SCOTLAND, EPISCOPAL CHURCH OF

Scotland, which are thousands of feet in thickness, consist largely of See also:

• ANDESITE

andesite, porphyrite, granite, See also:

• DIORITE (from the Gr. S&oi4eiv to distinguish, from hA through, Epos, a boundary)

diorite and See also:

• PORPHYRY (IlopcPisptos) (A.D. 233-c. 304)

porphyry, along with vein-quartz, See also:

• QUARTZITE

quartzite and various kinds of gneiss . Soft and friable rocks, on the other See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand, such as shale, See also:

• MICA

mica-schist and See also:

• COAL

coal, are rarely found in any quantity as pebbles in See also:

• CONGLOMERATE (from the Lat. conglomerare, to form into a ball, glomus, glomeris; so also the general term " conglomeration " for a miscellaneous collection of things, gathered together in a mass)

conglomerate-beds . They are ground to pieces by See also:

• FRICTION (from Lat. fricare, to rub)

friction against harder masses and help to form the matrix . The See also:

• SIZE

size of the pebbles varies greatly; occasionally they are to or 20 ft. in See also:

• DIAMETER (from the Cr. &a, through, µErpov, measure)

diameter, more frequently they are a See also:

• FOOT

foot or less . The cementing matrix in which the pebbles are embedded usually bears some resemblance in See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition to the nature of the pebbles, but contains a larger proportion of the softer ingredients, such as See also:

• CLAY (from O. Eng. claeg, a word common in various forms to Teutonic languages, cf. Ger. Klei)
• CLAY, CASSIUS MARCELLUS (1810-1903)
• CLAY, CHARLES (1801–1893)
• CLAY, FREDERIC (1838–1889)
• CLAY, HENRY (1777–1852)

clay, mica, weathered See also:

• FELSPAR, or FELDSPAR

felspar, See also:

• CALCITE

calcite and See also:

• DOLOMITE

dolomite .

Often it resembles a felspathic or calcareous sandstone; if limestone fragments are See also:

• COMMON

common it may be highly calcareous, or may be in large measure dolomitic . Often the matrix is stained red by compounds of See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron . The " brockram " of the See also:

• NORTH
• NORTH, BARONS
• NORTH, MARIANNE (1830—1890)
• NORTH, ROGER (1653-1734)
• NORTH, SIR THOMAS (1535?-16o1?)

north of See also:

• ENGLAND
• ENGLAND, THE CHURCH OF

England is a well-known See also:

• PERMIAN

Permian limestone-conglomerate . The Dolomitic Conglomerate is a similar rock, but of Triassic See also:

• AGE (Fr. age, through late Lat. aetaticum, from aetas)

age . Both of these are often extensively dolomitized and pass into breccias, where their fragments are angular and unworn . The pebble beds of the See also:

• BUNTER

Bunter (Triassic See also:

• PERIOD
• PERIOD (Gr. irepioSos, a going or way round, circuit, aepi, round, and &Sis, way, road)

period) are also See also:

• FAMILIAR (through the Fr. familier, from Lat. familiaris, of or belonging to the familia, family)

familiar to geologists . They See also:

• COVER (from the Fr. convert, from couvrir, to cover, Lat. cooperire)

cover extensive areas in the See also:

• MID

mid-lands of England, and are well seen at Budleigh Salterton on the See also:

• SOUTH
• SOUTH, ROBERT (1634–1716)

south See also:

• COAST (from Lat. costa, a rib, side)

coast . The pebbles are mostly quartzite with granite, chert, sandstone and igneous rocks . Conglomerates are rarely well bedded, showing at most a See also:

• RUDE, FRANCOIS (1784–1855)

rude stratification, but they may contain intercalations of finer materials such as sandstone and shale, which indicate the bedding clearly . In these fossils may be found, but they do not often occur in the conglomerates themselves, as the conditions are generally unsuitable for the preservation of organic remains . The pebbles, however, may be highly fossiliferous, and sometimes important See also:

• EVIDENCE (Lat. evidentia, evideri, to appear clearly)

evidence is provided by this means as to the age of the'eonglomerate . On account of the imperfect stratification it is often very hard to estimate the thickness of conglomerates, and this difficulty is increased by the fact that many of them must have been laid down as sloping See also:

• BANKS, GEORGE LINNAEUS (1821-1881)
• BANKS, NATHANIEL PRENTISS (1816–1894)
• BANKS, SIR JOSEPH
• BANKS, THOMAS (1735-1805)

banks of pebbles and not as See also:

• FLAT (a modification of O. Eng. flet, an obsolete word of Teutonic origin, meaning the ground beneath the feet)

flat layers of See also:

• DEPOSIT (Lat. depositurn, from deponere, to lay down, to put in the care of)

deposit .

Conglomerates are merely consolidated gravels, and have originated mostly on seashores or in shallow See also:

• WATERS, TERRITORIAL

waters near See also:

• LAND

land . They are typical See also:

• SHORE

shore formations, and are especially frequent where one See also:

• SERIES (a Latin word from serere, to join)

series of stratified rocks See also:

• REST (O. Eng. rest, reste, bed, cognate with other Teutonic forms, e.g. Ger. Rast, Riiste, rest, and probably Gothic Rasta, league, i.e. resting or stopping place)

rest upon an older See also:

• GROUP

group unconformably . Other conglomerates occur along with See also:

• FINE

fine-grained red sandstones, See also:

• SALT (a common Teutonic word, cf. Dutch zout, Ger. Salz, Scand. salt; cognate with Gr. &Xs, Lat. sal)
• SALT, SIR TITUS, BART

salt beds and such rocks as accompany See also:

• DESERT

desert deposits . We may compare them with the accumulations of pebbles which cover extensive areas of existing deserts . A quite distinct group of conglomerates characterizes regions where the rocks are much broken and sheared; these may very closely resemble true conglomerates, but have really been produced by the mashing together of rock masses along zones of fracture and See also:

• MOVEMENT

movement . They are known as " crush-conglomerates " or " auto-clastic rocks." Conglomerates may undergo See also:

• METAMORPHISM (Gr. ise-rci, change of, and liop¢i, shape)

metamorphism, and are then converted into " conglomerate-gneiss " or " conglomerate-schist." Their pebbles are flattened and dragged out of shape by interstitial movement, while the matrix becomes highly crystalline . One of the best-known examples of this is the Obermittweida gneiss (See also:

• SAXONY
• SAXONY (Ger. Provinz Sachsen)

Saxony) . (J . S .