:U\A m:\v youk siatk ml;<i:um 



tlicckiiiir — Id-c.iUiiiLr up into small clicckorlikc stiuare frajrnu'uts i-liai'actor- 



istic »»f somo iiuuln)rUs 

 fluTt — the ainoriilious or irrcjjcular Idnii of silu-a (K-curiiiijj: in liiiicstoiios 



(flint) 

 rlasti<- rocks — ro<-ks coniitosctl of frairincuts of oldor rocks — o. u. sand- 

 stones, conjrlonio'Mtos etc 

 clcavaiL^o — (mineral I the property of splittini; along certain planes deter- 

 mined by the crystalline structure 



(ro<-k) si)littinjr into i)arallel sheets as in the case of roofing slates 

 coastal i>lain — the level jilain coniposcnl of horizontal or gently sloping 



strata of clastic material fronting tlu* coast and generally representing 



a strip of riM-ently emerged sea l»()ttom 

 eel — the low saddle conncH-ting two hills or peaks 

 conchoidal— with a curved surface marked by lines resembling the lines on 



a clam shell ; the type of fracture found in glassy rocks or shown in 



thick glass 

 concretion — a rock mass of varying form resulting from the segregation 



of mineral matter from all portions of the parent rock in favorable 



s])ots within this parent rock. The form, composition and mode of 



formation varies greatly 

 conformation — having a parallel position with reference to each other, as 



two strata or beds 

 conglomerate — a clastic rock comi)osed of water worn pebbles embedded in 



a matrix of varying composition 

 consequent stream — the type of stream resulting from the flow of water 



down a constructional slope or land surface 

 coralline limestone — limestone composed of or containing many corals or 



coral-like remains, specifically the Cobleskill limestone 

 corallite — one of the members or tubes of a compound head of coral, as in 



Favosites 

 correlation — determination of the equivalency or relative age of geologic 



formations in separated localities 

 costae — ribs on the surface of shells or other organisms 

 coquina — a rock composed entirely of shells, generally but little broken 

 crenulations — fine ridges or toothlike markings 

 crinoid>s — a class of marine invertebrates of the division Echinoilermata, 



consisting typically of a body or calyx composed of more or less regidar 



series of plates, set generally on a jointed stalk or stem, and IxNiring 



arms. A " sea lily " 

 cross-bedding — the variable angle of the layers or beds within a stratum 



of rock produced by strong currents, specially in rivers 

 cuesta — a toiwgraphic form resulting from the normal erosion of coastal 



plain strata of varying hardness, and comprising a steep escarpment 



or inface facing the old land and separated from it by a i)arallel valley 



and a gently sloping upper surface formed by a rc^sistant stratum. 



See illustration in body of text, figuie 210 

 cycle of erosion — the interval during which a land surface newly uplifted 



eitliei- as plain or mountain is worn down to tlu^ level of the sea (base 



level ) 

 cystoid — a class of organisms related to the crinoids, but with the calyx 



comf>osed of irregular plates 



