Items listed in order of radiometric age Radiometric ages in this list have been arranged in order of increasing magnitude. If every age were exact, the list would correspond to the stratigraphical order of the Items, but since some determinations are imprecise or anomalous the list is only a first approximation to a true chronological order. Its purpose is to provide a summary of data, including that basic for the construction of a time-scale, and to assist in finding data in the Items when the approximate stratigraphical or radiometric age is known. Each entry gives the Item number, stratigraphical range (with the youngest rocks first), age (in millions of years), method used, and mineral (or rock) on which the determination was made. The abbreviations used are listed overleaf. Determinations on metamorphic or intrusive igneous rocks are indicated by an oblique stroke that separates the stratigraphical range of the metamorphosed and igneous rocks from that of any overlying rocks; e.g., Pliocene/Jurassic. This con- vention has not been adopted in the Items themselves. The values used have been standardized wherever possible (see the introduc- tion to the Items for details), and the Rb-Sr age listed is that determined from the A = I "47 × I0--11 Year-1 decay constant. In a given entry, ages determined by different methods have not been combined into a single average or mean age (as they may have in some parts of Part 4) but have been given separately. If, however, several approximately concordant ages have been found by the same method, the figure given for the age under that entry is the mean of these values. When ages are widely scattered, their range is generally listed, with the youngest age first. A few very anomalous ages have been omitted. In the latest stages of preparation, improvements in presentation of data sug- gested themselves, and it was decided that it would be helpful to adopt them, even though consistency between different parts of the volume would be reduced. Thus the presentation of the following data, although based on the Items, differ in several respects from them.

The Geological Society Phanerozoic time-scale 1964 is summarized on pp. 260-3.

443 Items listed in order of increasing age ABBREVIATIONS USED FOR MINERALS AND ROCKS ab, albite hb, hornblende or, orthoclase ur, uraninite an, anorthoclase il, illite pl, plagioclase vat., various minerals, ad, adularia km, kolm pt, pitchblende rocks bi, biotite lp, lepidolite py, pyroxene xn, xenotime br, brannerite mb, molydenite sd, sanidine zr, zircon fi, feldspar mu, muscovite sy, sylvine ?, not stated gl, glauconite mz, monazite TR, total rock

Note: Although/.7, M, and L generally correspond to the formally recognized stratigraphical sub- divisions Upper, Middle, and Lower respectively, they may also stand for the following: U, upper, late, top; M, mid-; L, lower, early, basal.

Age Item Stratigraphical range (m.y.) Method Mineral lO 7 Plio-Pleistocene o" 95 K-Ar sat 243 Pleistocene (Irvingtonian) i- 36 K-Ar TR i o8 --/Plio-Plelstocene (?U. Blancan) i. 53 K-Ar bi 244 L. Pleistocene (Villafranchian)-Pliocene (Astian) 1.6i K-Ar TR 245 L. Pleistocene (Villafranchian) I75 K-Ar an 246 --/Plio--Pleistocene (?U. Blancan) I9 K-Ar bi 247 Plio-Pleistocene (?U. Blancan) 2 05 K-Ar bi 248 Plio-Pleistocene (U. Blancan) 225 K-Ar bi 3o9 Plio- Pleistocene (Blancan) 32 K-Ar TR 3o8 Plio-Pleistocene (Blancan) 33 K-Ar TR 249 Plio--Pleistocene (?U. Blancan) 33 K-Ar pl 250 Plio-Pleistocene (Blancan) 3"48 K-At pt, py 251 Pliocene (L. Blancan-U. Hemphillian) 4. I K-Ar TR 25 U. Pliocene 5.2 K-At gl 252 Pliocene (U. Hemphillian) 5.2 K-Ar fi 318 U. Miocene (~ Pontian) 6.1-7.6 K-Ar ? 253 Mio-Pliocene (Hemphillian) 6"4 K-Ar sd Io9 L. Pliocene (Tabanian)/U. Eocene 7.0 K-At ? Io9 L. Pliocene (Tabanian)/U. Eocene 7-o Rb---Sr var. 317 U. Miocene (L. Hemphillian-U. Clarendonian) 7'7 K-Ar ? 36 Pliocene (Scaldisian) 8"o5 K-At gl 254 Mio-Pliocene (Hemphillian) 8-i K-Ar pl 27 ° ~/U. Miocene (Clarendonian) 8- 9 K-Ar sd 255 Mio-Pliocene (Hemphillian) 8"9 K-At sd 256 Mio--Pliocene (Hemphillian) 9"2 K-Ar TR 28 U. Miocene (L. Hemphillian) 9.2 K-Ar bi 1 Io U. Miocene 9-6 K-Ar gl 271 U. Miocene (Clarendonian) 9"8 K-Ar TR 272 U. Miocene (Clarendonian) 9"8 K-Ar TR 258 U. Miocene (U. Clarendonian) 9"89 K-Ar pl 259 U. Miocene (Clarendonian) 9"9 K-Ar bi 257 U. Miocene (L. Hemphillian) 10"0 K-Ar TR 264 U. Miocene (L. Clarendonian) IO.6 K-Ar TR 26 U. Miocene (U. Clarendonian) lO- 7 K-Ar bi 26o U. Miocene (Clarendonian) lO- 7 K-Ar sd 266 U. Miocene (L. Clarendonian) lO. 7 K-Ar bi

AAA Items in order of increasing age Age Item Stratigraphical range (m.y.) Method Mineral 265 U. Miocene (L. Clarendonian) xo.8 K-Ar bi 262 U. Miocene (L. Clarendonian) IO'85 K-Ar bi 261 U. Miocene (Clarendonian) I I "o K-Ar sd 263 U. Miocene (L. Clarendonian) I I "o K-Ar bi 268 U. Miocene (L. Clarendonian) x I. I K-Ar bi 27 U. Miocene (L. Clarendonian) I I. 1-I2 K-Ar bi 274 U. Miocene (Clarendonian) I x '4 K-Ar TR 269 U. Miocene (L. Clarendonian) x I "4 K-Ar bi 267 U. Miocene (L. Clarendonian) ix. 5 K-Ar sd 273 U. Miocene (Clarendonian) x x. 7 K-Ar TR 275 U.-M. Miocene (L. Clarendonian-U. Barstovian) i x .8 K-Ar bi, pl 314 - 'U. Tertiary' x3"4 K-Ar 313 'L. Pliocene' 14" o K-Ar 276 M. Miocene (Barstovian) x4" 6 K-At TR, pl 277 ) 312 L. Pliocene-L. Miocene x4" 6-15" 9 K-At ? 278 M. Miocene (U. Barstovian) x4. 7 K-Ar TR 279 M. Miocene ( ?L. Barstovian) x5" o5 K-At sd 38 M. Miocene (Barstovian) x5" 2 K-Ar bi 39 M. Miocene (Barstovian) 15" 2 K-Ar bi i28 L. Miocene (Hutchinsonian) 15" 4 K-Ar gl 28o M.-L. Miocene (Barstovian-Hemingfordian) 15" 4 K-Ar TR 28[ M. Miocene (Barstovian) x5" 4 K-Ar sd 282 M. Miocene ( ?L. Barstovian) x5" 6 K-Ar sd I3I 'U. Miocene' I6 Pb-a zr, mz, xn 40 ~/U. Oligocene x7" o K-Ar bi 79 M.-L. Miocene (U. Hemingfordian) 17 • 2 K-Ar bi 15o U.-M. Eocene 18 K-Ar gl I27 L. Miocene (Waitakian) x9" 4 K-Ar gl I29 M. Miocene (Waiauan) x9" 9 K-Ar gl i26 Oligocene (Duntroonian-Whaingaroan) 2o'8 K-Ar gl 8o L. Miocene (U. Arikareean) 2 I- 45 K-Ar bi I97 Oligocene (Whitneyan-Orellan) 2 I. 6 K-Ar ad 3IO L. Miocene (Santacrucian) 2 I- 7 K-Ar pl 8i L. Miocene-U. Oligocene (L. Zemorrian) 22"5 K-At gl 315 L. Miocene (L. Arikareean) 23"3 K-Ar 82 L Miocene (Burdigalian) 24"8 K-Ar gl 283 L. Miocene (L. Arikareean) 24"9 K-Ar ab I48 U.-M. Eocene 25 K-At gl 284 L. Miocene (Arikareean) 25"3 K-Ar TR 285 L. Miocene (L. Arikareean) 25"6 K-Ar TR 83 U. Oligocene (Whitneyan) 25"7 K-Ar sd I34 'U. Miocene' 26-24 ° Pb-a zr x49 U.-M. Eocene 27 K-At gl 286 L. Miocene (L. Arikareean) 29"5 K-At TR 287 Recent-L. Oligocene (U. Chadronian) 29"7 K-At I35 U. Miocene (Tongaporutuan) 3 °. 2-35" 8 K-Ar gl I46 U.-M. Eocene 31 K-Ar gl 23I L. Cretaceous (Upper Hauterivian) 31 K-Ar gl 288 U.-L. Oligocene (Whitneyan-Chadronian) 3 x. [ K-Ar sd III U. Eocene 3 i. 4 K-Ar gl 289 U.-L. Oligocene (Whitneyan-Chadronian) 3 I" 5 K-At sd 445 Items in order of increasing age Age Item Stratigraphical range (m.y.) Method Mineral 296 L. Oligocene (Chadronian) 3 I. 6 K-Ar bi 3xI L. Oligocene 3 I. 6 K-Ar TR I55 Oligocene 32 K-Ar bi 295 L. Oligocene (M. Chadronian) 32" 6 K-Ar bi 297 Oligocene 32" 8 K-Ar bi I5I U.-M. Eocene 33 K-Ar gl 84 L. Oligocene (Chadronian) 33" x K-Ar sd 292 L. Oligocene (L. Chadronian) 33"3 K-Ar bi 293 L. Oligocene (M. Chadronian) 33"7 K-Ar bi 85 L. Oligocene/M. Eocene 35 K-Ar bi I3O L. Oligocene 35 K-Ar sy 29 x L. Oligocene (L. Chadronian) 35"2 K-Ar sd, pl 23 U. Eocene (Kiev stage) 35" 6 K-Ar gl 294 L. Oligocene (M. Chadronian) 35"7 K-Ar sd, pl x47 U.-M. Eocene 36 K-Ar gl 299 L. Oligocene-U. Eocene (L. Chadronian- U. Duchesnean) 36" 5 K-Ar sd 125 U. Eocene (Kaiatan) 36" 6 K-Ar gl 29° L. Oligocene (L. Chadronian) 36"8 K-Ar fs 3oo L. Oligocene-U. Eocene (Duchesnean) 37' o K-Ar sd, bi, TR 298 L. Oligocene-U. Eocene (L. Chadronian- U. Duchesnean) 37" 5 K-Ar TR I32 'Oligocene-U. Eocene' 38 Pb--a zr, mz, xn I52 L. Eocene-Palaeocene 38 K-Ar gl I23 M. Eocene (Claibornian) 39 K-Ar gl I I 4 U. Eocene (Jacksonian) 39"4 K-Ar gl xx 5 M. Eocene (~ Lutetian) 4 x "8 K-Ar gl 2 i8 L. Cretaceous (U. Albian) 42-82 K-Ar gl 124 M. Eocene 42" 4 K-Ar gl 3oi U. Eocene (Uintan) 42 "7 K-Ar pl 86 U.-M. Eocene (Kreyenhagen) 43" 2 K-Ar gl i8 L. Eocene-M. Palaeocene (Waipawan-Teurian) 43"6 K-Ar gl 22 U. Eocene (Kiev stage) 44 K-Ar gl 3o2 U. Eocene (Uintan) 45"o K-At bi 3o 3 U.-M. Eocene (L. Uintan-U. Bridgerian) 45"4 K-Ar bi 153 Palaeocene 46 K-Ar gl 3x6 L. Miocene (L. Arikareean) 46 K-At 112 Palaeocene 46. 2 K-Ar gl i o4 Palaeocene 46. 4 K-Ar gl 17 L. Eocene-M. Palaeocene (Waipawan) 46. 6 K-Ar gl 87 M. Eocene (Lutetian) 47 K-Ar gl xo 4 Palaeocene 47" 7 K-At gl I33 'U. Eocene' 48 Pb-a zr, mz, xn 21 M. Eocene 49 K-Ar gl io2 M. Eocene (Claibornian) 49 K-Ar gl 3o4 M.-L. Eocene (L. Bridgerian-U. Wasatchian) 49 K-Ar bi 3o 5 L. Eocene (U. Wastachian) 49"2 K-Ar bi x5 L. Eocene-Palaeocene (Sparnacian-Danian) 5o K-Ar gl 2o U. Palaeocene 5o" 5-59 K-At gl 88 L. Eocene 5 x K-Ar gl 37 U./L. Eocene 52 K-Ar bi I o I L. Eocene-U. Palaeocene (Sabinlan) 52" 5 K-Ar gl 446 Items in order of increasing age Age I tem Stratigraphical range (m.y.) Method Mineral I98 M. Eocene/U. Cretaceous (Maestrichtian) 54-73 K-Ar fs, bi IO3 Eocene-U. Cretaceous (post-Turonian) 54"5 K-Ar bi 136 'Eocene' 55 K-Ar bi ]39 'Eocene' 55 K-Ar TR IO5 U. Palaeocene (Thanetian) 57"5 K-Ar gl 14 L. Eocene-Palaeocene (~-~ Sparnacian-Danlan) 58 Rb-Sr gl x38 Eocene 58 K-Ar gl I4 L. Eocene-Palaeocene (~ Spamacian-Danian) 58'5 K-Ar gl II 3 U. Palaeocene (~ Thanetian) 58"5 K-Ar gl 306 L. Palaeocene (Puercan) 58"7 K-Ar TR 24 ?Eocene]Palaeocene 59 U-Pb pt x98 M. Eocene/U. Cretaceous (Maestrichtian) 59 Rb-Sr bi io6 Palaeocene 59"5 K-Ar gl I4I Palaeogene 6o K-Ar TR ]54 L. Palaeocene-U. Cretaceous 6o K-Ar gl ~98 M. Eocene/U. Cretaceous (Maestrichtlan) 64 U-Pb sp 206 Palaeocene (Danian) 64 K-Ar gl 321 U. Palaeocene/U. Jurassic 64-I 6o K-Ar VaT. 199 Palaeocene-U. Cretaceous (U. Maestrichtian) 64 K-Ar bi, sd 307 L. Palaeocene (Puercan) 64"8 K-Ar pl ~37 'Eocene' 65 K-Ar bi I42 Palaeogene 65 K-Ar TR I44 'L. Eocene-U. Cretaceous' 65 K-Ar TR 13 U. Cretaceous (~ Maestrichtian) 65"5 Rb-Sr gl 329 Palaeocene (Danian) 65 "5 K-Ar TR 200 U. Cretaceous (U. Maestrichtian) 66 K-Ar bi, sd 332 Palaeocene-U. Cretaceous (~--~ Danian- Senonian) 66"5 K-Ar TR 333 Palaeocene (Danian) 67" 5 K-Ar TR i8x Cretaceous (Senonian) 68"5 K-Ar gl I2 U. Cretaceous (Campanian) 69 K-Ar gl 54 U. Cretaceous (Maestrichtian) 69 K-Ar gl I95 U. Cretaceous (Cenomanian) 69- x 2 x K-Ar gl I4o Eocene 7° K-Ar TR 238 U. Cretaceous (Cenomanian) 7° K-Ar gl 334 U. Cretaceous (Senonian) 7o'5 K-Ar TR 328 'Cretaceous' 7 i-136 K-Ar raY. 2OI U. Cretaceous (U. Campanian) 74 K-Ar bi, sd 208 U. Cretaceous (Coniacian) 74 K-Ar gl 207 U. Cretaceous (Senonian) 75 K-Ar gl 2IO U. Cretaceous (Cenomanian) 75 K-Ar gl 233 L. Cretaceous (M. Albian) 75-115 K-Ar gl 239 U. Cretaceous (Senonian) 75"5 K-Ar gl 334 U. Cretaceous (Turonian-L. Senonian) 76"5 K-Ar TR x43 L. Eocene-U. Cretaceous 77 K-Ar TR 320 Cretaceous] ?Triassic 77 K-Ar bi I8T L. Cretaceous (L. Albian) 77"5 K-Ar gl 59 U. Cretaceous (U. Turonian) 79 K-Ar gl 62 U. Cretaceous (L. Campanian) 8I'5 K-Ar gl 229 U. Cretaceous (L. Santonian) 83 K-Ar gl 58 U. Cretaceous (M. Turonian) 83'5 K-Ar gl 6I U. Cretaceous (L. Turonian) 85"5 K-Ar gl 447 Items in order of increasing age

Age Item Stratigraphical range (m.y.) Meth~ Mineral 57 U. Cretaceous (Coniacian) 86. 5 K-Ar gt 22I U. Cretaceous (L. Cenomanian-U. Aptian) 87 K-Ar gl 209 U. Cretaceous (Cenomanian) 89 K-Ar gl 2~4 L. Cretaceous (Barremian) 89 K-Ar gl 319 U./L. Cretaceous 89 K-Ar lt, 335 'U. Cretaceous (Cenomanian)' 9 ° K-Ar TR 330 Miocene/?Jurassic 9 °- x35 Pb-a vaT. 227 U. Cretaceous (L. Cenomanian) 9 x K-Ar gl 224 U. Cretaceous (Maestrichtian) 92 K-Ar gl 225 U. Cretaceous 92 K-Ar gt 204 L. Cretaceous (U. Albian) 93"5 K-Ar 9 213 L. Cretaceous (Aptian) 93"5 K-Ar gt 5 I L. Cretaceous (M. Albian) 94 K-Ar gl 230 L. Cretaceous (L. Albian) 94 K-Ar gl 240 L. Cretaceous (U. Aptian) 94 K-Ar gl x94 U. Cretaceous (Turonian) 95 K-Ar TR 202 U.-L. Cretaceous (Cenomanian-Albian) 95 K-Ar bi, sd, fs 2II U. Cretaceous (Cenomanian) 95 K-Ar gl 56 L. Cretaceous (U. Albian) 96 K-Ar gl 226 U. Cretaceous (?U. Cenomanian) 96 K-At bi 228 L. Cretaceous (Albian) 97 K-Ar gt lp 3~9 U./L. Cretaceous 97 "5 Rb-Sr ~45 L. Eocene-U. Cretaceous 98 K-Ar TR i8x L. Cretaceous (L. Aptian) 98 K-At gl 212 L. Cretaceous (Albian) 98 K-Ar gt 220 L. Cretaceous (Albian) 98 K-Ar gt 222 ) L. Cretaceous (Valanginian-Hauterivian) 98 K-Ar gl 223 242 L. Cretaceous (M. Albian) 98 K-Ar gl 217 U./L. Cretaceous (Maestrichtian/Albian) 99 Pb-a mz 327 'g. Cretaceous' 99-134 K-Ar TR 336 U.-L. Cretaceous IOO K-Ar TR 240 L. Cretaceous (L. Aptian) IoI K-Ar gl 60 L. Cretaceous (Aptian-Albian) IO2 K-Ar gl 326 ' ?U. Cretaceous-U. Jurassic' Io5 K-Ar TR 219 L. Cretaceous (M. Albian) io8 K-Ar gl 236 L. Cretaceous (M. Hauterivian) 1o8 K-Ar gl 236 L. Cretaceous (L. Barremian) IO9 K-At gl 49 L. Cretaceous (U. Aptian) IIO K-Ar gl 232 U. Jurassic (L. Volgian) III K-Ar gl 33x U./L. Cretaceous (Maestrichtian]Albian) II2 Pb-a zr 337 L. Cretaceous (?Neocomian)-M. Jurassic II2 K-Ar TR 236 L. Cretaceous (L. Hauterivlan) xi4 K-Ar gt 50 L. Cretaceous (L. Aptian) IX5 K-Ar gl 917 U./L. Cretaceous (Maestrichtian/Albian) i15 U-Pb mz 203 L. Cretaceous (Albian) ix7 K-Ar bi 235 L. Cretaceous (Ryazanian) ~x7 K-Ar gl 234 U. Jurassic (U. Volgian) ii9 K-Ar gl 237 L. Cretaceous (U. Albian) xx9 K-Ar gl 322 L. Cretaceous (Ryazanian) 119 K-Ar gl 24I L. Cretaceous (L. Albian) x24 K-Ar gl 52 U. Jurassic (L. Portlandian) i25 K-Ar gl 448 Items in order of increasing age

Age Item Stratigraphical range (m.y.) Method Mineral 72 U. Jurassic (U. Volgian) 127 K-Ar gl 75 L. Cretaceous (Barremian)/M. Jurassic (Bajocian) I27 K-Ar bi 323 U. Cretaceous (Cenomanian)]Jurassic I27 K-Ar bi x79 U. Jurassic (L. Volgian) I29 K-Ar gl i8o U. Jurassic (L. Volgian) I29 K-Ar gl 2I 5 L. Cretaceous (Neocomian)-U. Jurassic (Volgian) x3 x K-At gl 322 U. Jurassic (Volgian) x31 K-At gl 178 U. Jurassic (L. Volgian) x32 K-At gl x77 L. Cretaceous (Ryazanian) I33 K-Ar gl 324 ~[L. Jurassic x34 K-Ar bi, mu 78 U. Jurassic (Callovian) 135 K-Ar gl 76 L. Cretaceous (?Barremian)/M. Jurassic ( ? Bajocian) 136 K-Ar bi 77 U. Jurassic (U. Oxfordian) I36 K-Ar gl 216 L. Cretaceous (Albian) x36 K-Ar gl 73 U. Jurassic (U. Purbeckian-L. Portlandian) x39 K-At gl 325 ~/L. Jurassic (Toarcian) x4o K-At bi, mu x9 U. Permian (Kazanian) x65 K-Ar gl 9o U./M. Jurassic (Kimmeridgian/U. Bajocian) I66 K-Ar bi, hb, TR 19° L. Tertiary/M. Triassic 167 K-Ar var. 89 M./L. Jurassic (Bathonian/Pliensbaehian) 169 K-At bi 2o5 U.-L. Cretaceous (L. Cenomanian-U. Albian) I74 K-Ar il x I M. Jurassic (M. Bajocian)/U. Triassic (Norian) 178 K-Ar bi 7 x Jurassic/U. Triassic 180 K-Ar bi xo M. Jurassic (Bajocian)/U. Triassic (?Norian) 186 K-At bi 9 ~]U. Triassic x93 K-Ar bi, TR 35 L. Jurassic/U. Triassic (Norian) I93 K-Ar 46 ~/L. Permian (Autunian) > 2 x6 Th-Pb zr 160 -]U. Triassic > 2 x8 U-Pb pt 175 L. Triassic/L. Palaeozoic 219 K-Ar bi 53 L. Permian (Kungurian) 221 K-At sy 33 U. Triassic/L. Carboniferous 222 K-Ar 69 U. Triassic/L. Permian (Artinskian-L. Kun- gurian) 223 K-At bi, hb xo M. Jurassic (Bajocian)lU. Triassic (?Norian) 224-245 K-Ar bi 121 L. Jurassic-L. Permian (Artinskian--Sakma- rian) 225 Re-Os mb x62 Triassic/Carboniferous 225-3o6 K-At TR 53 L. Permian (Kungurian) 238 K-Ca sy 67 L. Jurassic/L. Permian (?Artinskian-L. Kun- gurian) 238 K-At bi i6 Carboniferous (L. Moskovian) 24I K-At gl 32 Carboniferous (~ L. Stephanian) 246 K-Ar il 159 L. Devonian-U. Silurian 247 K-Ar gl 43 --/Carboniferous (Pennsylvanian) 25I Rb-Sr bi 68 L. Permian (M. Kungurian) 252 K-At fs 43 ~/Carboniferous (Permsylvanian) 255 K-Ar bi, TR 45 ~/L. Permian (M. Autunian) 259 K-At bi 46 ~/L. Permian (Autunian) >259 U-Pb zr 8 Permian/Carboniferous (L. Stephanian-L. Westphalian) 262 K-Ar bi

449 Items in order of increasing age Age Item Stratigraphical range (m.y.) Method Mineral I20 L. Permian (Sakmarian) 262 K-Ar gl 8 Permian/Carboniferous (L. Stephanian- L. Westphalian) 270 K-Ar bi 8 Permian/U. Carboniferous (L. Stephanian-L. Westphalian) 275 Rb-Sr bi 3° U. Carboniferous (post-?Stephanian) 278 K-Ar bi 193 Triassic-Carboniferous (Namurian) 279 K-Ar bi 44 Carboniferous (Pennsylvanian)/Devonian 28o K-Ar TR 122 L. Permian (?Autunian)-Carboniferous (U. Stephanian) 282 Rb-Sr bi 192 ?L. Permian 284 K-Ar bi 63 Carboniferous (U. Stephanian) 288 Rb--Sr bi 66 Carboniferous (Namurian-Visfan) 288-328 K-Ar bi, hb 64 Carboniferous (L. Moskovian) 294 K-Ar gl 8 Permian-U. Carboniferous (L. Stephanian- L. Westphalian) 295 K-Ar TR 29 Carboniferous (~ L. Westphalian) 295 K-Ar il 176 Permian/Carboniferous (Westphalian) 295 K-Ar TR x71 U./L. Carboniferous (Stephanian/L. Vis6an) 297-328 Rb-Sr bi, mu 65 Carboniferous (U. Stephanian) 298 K-Ar bi I 19 U./L. Carboniferous (Stephanian]Vis6an) 3oo Rb--Sr bi I7i U./L. Carboniferous (Stephanian/L. Visfan) 3oo-324 K-Ar bi i9i -/Carboniferous (L. Namurian) 322 K-At TR I64 U. Silurian (L. Ludlovian) 326 K-Ar il 3I U./L. Carboniferous (Stephanian/Visfan) 327 K-Ar bi I72 L. Carboniferous (U. Vis6an) 328 Rb-Sr bi I74 L. Permian/L. Carboniferous 328 K-Ar ? x65 U. Silurian (L. Ludlovian) 332 K-Ar il 173 L. Carboniferous (Vis6an) 334 Rb-Sr bi 94 U. Devonian (U. Frasnian) 34° K-Ar bi 99 L. Carboniferous (Vis6an)/L. Devonian 343 K-Ar bi I89 Ordovician (L. Trentonian) 343 Pb-a zr 2 U. Devonian (L. Famennian) >35o U-Pb 7J 92 Devonian/Silurian 35 ° Rb-Sr or 95 L. Carboniferous-? U. Devonian (Fammenian) 35 ° K-Ar bi 96 M.-L. Devonian (Siegenian-Eifelian) 35 ° Rb-Sr TR, hb 98 L. Carboniferous (Vis6an)/L. Devonian 35 ° Rb-Sr bi I89 U. Ordovician (L. Trentonian) 353 Pb--a zr I67 M. Silurian (U. Llandovery) 357 K-Ar il 9I L. Carboniferous (Visfan)/U. Silurian 362 Rb-Sr 7~ 91 L. Carboniferous (Visfan)/U. Silurian 363 K-Ar 7J i66 M. Silurian (U. Llandovery) 363 K-Ar il 7 ~/L. Devonian (Oriskany) 364 K-Ar bi, TR 99 L. Carboniferous (Vis6an)/L. Devonian 364 Rb-Sr bi 7 ~/L. Devonian (Oriskany) 365 Rb-Sr bi I68 M. Silurian (U. Llandovery) 367 K-Ar il I69 L. Ordovician 369 Rb--Sr gl 98 L. Carboniferous (Vis6an)/L. Devonian 37 ° K-Ar bi 4 Devonian (U. L. Gedinnian)/Ordovician (Canadian) 379 Rb-Sr bi 3 Devonian (L. Coblenzian) 385 K-Ar bi, sd 93 ?M. Devonian/U. Silurian (Wenlockian) 39 ° K-Ar bi 450 Items in order of increasing age Age Item Stratigraphical range (m.y.) Method Mineral 6 Carboniferous (Tournasian)/U. Silurian (Lud- lovlan) 39 I K-Ar i Devonian (L. Givetian-U. Eifelian)/Devonian (Givetian) 393 K-Ar bi, mu 97 L. Devonian/U. Silurian 394 K-Ar bi 6 Carboniferous (Tournasian)/U. Silurian (Lud- lovian) 397 Rb-Sr 4 Devonian (U. L. Gedinnian)/Ordovician (Canadian) 399 K-Ar bi 93 ?M. Devonian/U. Silurian (Wenloekian) 399 Rb-Sr bi I87 U. Ordovician (L. Edenian-U. Trentonian) 4o2 K-Ar bi 5 U. Devonian/L. Devonian (L. Gedinnian) 4o4 K-Ar bi x96 M. Devonian/Pre-Cambrian 4I o K-Ar TR i58 L. Silurian (U.-M. Llandovery) 416 K-Ar gl I56 M. Ordovician (L. Caradocian) 42o K-At bi 188 ?Ordovician/Cambrian 425-5oo K-Ar bi x57 M. Ordovician (Caradocian) 444 K-Ar bi, sd x56 M. Ordovician (L. Caradocian) 447 U-Pb zr 156 M. Ordovician (L. Caradocian) 447 Rb-Sr bi 7o M. Cambrian/Pre-Cambrian 453 Rb-Sr bi, fs 163 Ordovician 453 K-Ar gl 47 L. Ordovician (Beekmantown)-U. Cambrian (Trempealeauian) 457 K-Ar il I86 U. Cambrian/Pre-Cambrian 46o K-Ar bi 42 M.L. Cambrian/U. Pre-Cambrian 479 Rb-Sr TR 170 ?M. Silurian/M. Ordovician (Trenton-Wilderness) 479 K-At x86 U. Cambrian/Pre-Cambrian 48 I Rb-Sr bi 41 M.L. Cambrian]U. Pre-Cambrian 495 Rb-Sr bi, mu 41 M.L. Cambrian/U. Pre-Cambrian 497 K-Ar bi, mu 34 U. Cambrian >5oo U-Pb km 186 U. Cambrian/Pre-Cambrian 5oo Th-Pb zr I oo L. Cambrian 517 K-At gl x86 U. Cambrian/Pre-Cambrian 517 U-Pb zr 7o M. Cambrian]Pre-Cambrian 5 x8 K-Ar bi 184 U. Precambrian]Pre-Cambrian 52o U-Pb br I86 U. Cambrian/Pre-Cambrian 524 U-Pb zr x85 L. Cambrian 527 K-Ar gl 48 M. Cambrian 53o K-Ar il I83 L. Cambrian 546 Rb-Sr gl I I6 U. Precambrian 549 K-Ar gl x86 U. Cambrian/Pre-Cambrian 55 ° Pb-Pb zr I87 U. Ordovician (L. Edenlan-U. Trentonian) 55 ° Rb-Sr bi 42 M.L. Cambrian/U. Pre-Cambrian 553 K-Ar bi i I7 U. Pre-Cambrian 572 K-At gl i84 U. Pre-Cambrian/Pre-Cambrian 585 Th-Pb br x 18 U. Pre-Cambrian 59 I K-Ar gl I84 U. Pre-Cambrian/Pre-Cambrian 6oo U-Pb br 55 ~]U. Pre-Cambrian 62o U-Pb ur x82 L. Cambrian 644 K-Ca sy

451 Alphabetical index to Items The following index lists those geographical and formational names that appear prominently in the Items. In each case the reference is to the Item number, not the page. No systematic indexing has been attempted, the object being to give a con- venient entry to the Items from key names. The geographical distribution of items can be discovered by following through the entries given under Africa, Americas, Antarctica, Asia, Australasia, and Europe as well as under individual countries, states, and counties where conveniently abstracted. General names of rocks (e.g., glauconitic sands) as well as stratigraphical names or stages have been omitted, since they involve varying degrees of interpretation, but if the approximate age of a rock is known the chronological list of Items should be useful.

Aberdeenshire, 92 Bald Peak basalts, 3 x7 Abkhaziya, 20 Baltic Series, ioo Adams County, I58 Bargate Beds, 49 Africa, see Congo Republic, Kenya, Tangan- Barstow Formation, 38 yika Basses-Alpes, 22 i Alabama, i56 Bays Formation, I56 Alaska, 89 Bazovsk volcanic suite, 334 Alberta, i99-2o2 , 2x8, 2x9, 233 Bear River granite, 98 Aldrich Station Formation, 262-3, 264 Bearpaw Mrs, 37 Allier, i72 Shale, 2oi Alpes-Maritimes, a22 BeIaya River, 213 Alturas Formation, 254 Belgium, 36 Americas, see Argentina, Canada, Greenland, Berkeley Hills, 258, 27o-4, 317 Jamaica, Mexico, U.S.A. latite, 68 Anglesey, t96 Bertie Formation, I64 Antarctica, i88 Bidahochi Formation, 25 I Aral Sea, north of, 2 I Big Bend National Park, 3o I Ardoisi~re basin, 172 Billiton granite, 7 I Argentina, 3 ,o Binnewater Sandstone, 159 Arizona, x6o, 25x Bishop tuff, IO7 Arkansas, 224 Bi Uingen region, 34 Armenia, 323 Blount County, I83 Ashcroft area, IO Blue clay (Baltic Series), IOO Ashinsk series, L., , ,6 Bochumer Greensand, 58 Asia, see Indonesia, Mongolia, New Guinea, Boisdale Hills granite, 7° U.S.S.R. Bracks Formation, 29° Athis granite, 4' Brassfield Limestone, I58 Australasia, see Australia, New Guinea, New Bressac, tufs de, 63 Zealand Brisbane, x75 Australia, 3o, 65-9, 95, 97, ,2,, I75, I84, I9O Britain, see Great Britain Austria, 82 British Columbia, I o, t I, 35, 203 Avawatz Formation, 26% 26, Bruneau basalts, 243 Bad Hall, 82 Bukamkoye deposit, 2 xI Badzhal River, 336 Bureinsk region, 336, 337 Baja California, 217, 33' Burlington County, 12, 15 Baksan River, 2,3 Butterly dolomite, 47 453 Alphabetical index to Items

Cache Creek, 226 Denton Formation, 2o 5 Calais granite, 5 Denver Formation, 3o6, 3o7 Caliente Formation, 39 Derbyshire, I62 California, 25, 26, 38, 39, 75, 76, 79, 8i, 86, IO4, Dergunovka, 64 IO6--8, II2, II3, II5, I46--5I , I53 , I54 , 226, Devon, 8, I93, 227 246-9, 252, 254, 258--6I, 27O-5, 317, 319 Domengine Formation, i 15 Calvados, 42 Dommartin, I x9 Cameron, I6o Dorset, 56 Camillus Formation, x65 Dortmund, 59, 6I Canada, 3, io, 11, 35, 7o, 98, 99, 17o, 187, Drammen granite, 45 x99-2o3, 216, 218, 219, 233; see also separate Drewsey Formation, 255 provinces Duntroonian sediments, I26 Cape Breton Island, 7o Durham, 9I, 176 Cape Gasp6, 3 Durulguev granitoid, 325 Carters Limestone, I56 Cascades, North, 4 ° Egan Range, 155 Cassiar Mts, 35 Eggleston Limestone, x56 Castro Daire grznite, I22 Egorevskoe deposit, 72, 322 Catskill Mts, i59 Elba, Io9 Caucasus, I38 , I8I, 206, 212, 213, 220 Elmore County, 243, 25 ° Cedar Mountain area, 266, 267 Ely, 297 Cerrillos Hills, 132 Emscher, 57 Chasmops Limestone, 157 England, see Great Britain Ch~,teau-Chinon granite, i x9 Enogerra granite, 175 Chattanooga Shale, 2, 94 Ermolino, 234 Chevkino, 235 Erzgebirge Mts, x74 Chinle Formation, 16o EscragnoUes, 223 Chisos Volcanic Formation, 3o1 Esmeralda Formation, 266- 9 Churt, 49 Essener Greensand, 6x Ciscaucasia, 23 Essex porphyrite, I92 Clarke Bluff, 32o Esthonia, 163 Clarno Formation, 298 Europe, see Austria, Belgium, Czechoslovakia, Clayton, I3, 14 France, Germany, Great Britain, Italy, Clearwater Formation, 233 Norway, Portugal, Spitsbergen, Sweden, Coal Valley (Nevada), 27, 262-65 U.S.S.R. Formation, 27, 265 Exeter Volcanic Series, I93 Coleman, 202 Colorado, 24, 13 I, 134, 3o6, 307 Fakhralo, Io 3 Congo Republic, 55 Fish Lake Valley, 268, 269 Contra Costa County, 252 Fisher's Hill, 189 Coso Formation, 248 Fithian illite, 32 Mt, southern, 247 Folkestone, 5 I Creetown granite, 93 Beds, 241 Crimea, 326 Fore-Caucasus, 237 Crocker's Well area, I84 Fort Lee, 9 Cronese basin, western, 275 Fort Ternan, 313 Crowsnest volcanics, 202 France, 4 I, 42, 63, 87, xI9, x7x-3, 22I-3, 244 Czechoslovakia, 174, 209, 21 o FranzJosephs (Kejser) Fjord, i Frontier Formation, 2o4 Daghestan, 138, I8I, 2o6 Front Range, 24 Dartmoor granite, 8 'Datsky Stage', 2o6 Gasp6, Cape, 3 Dayville, 253, 28o Gault, 5 t, 242 Del Rio Formation, 2o 5 Genesco County, I6 5 454 Alphabetical index to Items

Georgia, U.S.S.R., 20, 9o, t94, I95, 214 Idaho, 243, 250, 257, 308, 309, 33 ° Gering Formation, 285, 286, 316 batholith, 33 ° Germany, 3 I, 57-62, 73, 77, 78, 88, I io, I x I, Illinois, 32 :: 13o, 174, 228-3 x Indiga River, I2o Gien-sur-Cure granite, 173 Indonesia, 7 I Glenns Ferry Formation, 25o, 3o8, 3o9 Inguri River, 214 Golden, 3o6, 3o7 Irkutsk basin, z82 Gorodenko, 238 Isle of Wight, 239 Grand Gr~ve Formation, 3 Italy, io 9 Great Britain (see also separate counties) England, 6, 8, 49-52, 56, 9 I, 1o5, x62, 176-8o, Jackman monzonites, 7 I93, 227, 236, 239, 24 I, 242 Jackson Hole, 256 Scotland, 92, 93, 19z Jamaica, I98 Wales, 196 Jarbridge rhyolite, 28I Great Laba River, 212, 2 x3 John Day basin, 83

Green Cove, 3o 4 -- Formation, I97, 283, 284, 288, 289, 315 Greenland, i, 232 Grizzly Peak volcanics, basalt, 272-4; intru- Kadenberge, zxo sion, 27 o, 271 Kaiatan sediments, 123 Gros Ventre Shale, 48 Kalibergwerk, Upper Rhine, 130 Guichon Creek batholith, I o Kaluga district, 2 z I Gulf Coast, 54, 1oI, II4, 123, I24, I52 Kamchatka, i36, z37 Guria, 85 Kam Formation, 53 Kap Franklin granite, z Hagerman, 257 Kapiti phonolite, 3 I4 Haldon Hills, 227 Karatau Series, I x8 Hampshire, x79 Katanga, 55 Hanover, 57, 62, 73 Keeler quadrangle, 248 Harmon Shale, 2o3 Kejser Franz Josephs Fjord, I Harney County, 276, 277 Kelsaury, 9o Harrison Formation, 8o Kent, 5 i, i o5 Hartz, 3 I Kenya, 3z2-I 4 Harzburger gabbro, 3 I Kern County, 259 Haslemere Brook, 5o Kessyusse Beds, x85 Hatchetigbee Formation, zoI Khalzan granitoid massif, 324 Hecla Hock mica-schists, 4 Kharborovsk, 336, 337 H6rault, 244 Khavis-Jvary, 9 ° Herefordshire, I62 Kiahera Series, 312 Hermon Shale, 2o3 Kiera, Mt, 68 Hernandez Valley, 86 Kiev Tier, 23 Herne, 58 Kineo volcanics, 96 Hillhouse basalt sill, 191 Kingsclere, z 79 Hill of Fare granite, 92 Kinnekulle, 157 Holbrook, 25 I Kinnick Formation, 79 Holyhead basic dyke, 196 Kirkcudbrightshire, 93 Hordhorn, 11 x Kisinsk volcanic suite, 334 Hornerstown Formation, 14, 15 Kneehills tuft, 2oo Hotailuh batholith, 35 Koberzhik borehole, 2o 9 Hsanda Gol Formation, 311 Kodor River, 2o Hudson Hope, 2o 3 kolm, Swedish, 34 Huis Jacques, I 19 Kopkhp granitoid massif, 323 Hunter Valley, 3 o, 65, 66 Koshatki deposit, 2 IO Hutchinsonion sediments, x28 Kreyenhagen, z46- 5 z Hythe Beds, 5o Kristianstad, 225

455 Alphabetical index to Items

Kruisschens, 36 Mount Capanne granodiorite and veins, 109 Kuibyshev area, 16 Mowry Shale, 204 Kutais region, I95 Miinster basin, 58 Kuttung series, Upper, 3 ° Murray Shale, I83 Lavas, 66 Nacatoch Sand, 224 La Foux, 221 Narrangansett basin, 43 La Grulla, 217 Nataneby River, 85 Lake Victoria, 3 x2 Natrona County, 29 i-6 Laminarites Beds, I 17 Navesink Formation, i3 Leningrad, IOO Nebraska, 8o, 278, 285, 286, 316 Lenin Hills, 215 Nevada, 27, 28, 155 , 262-9, 28i, 282, 297 L'Epiphanie, i87 Nevenhaus, i I t Lethbridge, 2oI New Guinea, 318 Lodo Formation, x 13 New Jersey, 9, 12- x5 Lone Tree Gulch Ash B, 29I, 292; Ash F, 293, New Mexico, i32 294; Ash G, 295; Ash J, 296 New South Wales, 3o, 65-8 Loomis, 76 New York, x59, x64-8 Lower Greensand, 49, 5 °, 239, 24I New Zealand, I7, I8, x25-9, I35, 32o Lvov region, 238 Nicola area, IO Lyme Regis, 56 Nictaux granites, 99 Lysaya Hill, 207, 208 Ni6vre, x 19, 173 Norfolk, 177, x78 Maardu deposit, I63 Normandy, 4I, 42 MacMurray area, 2 x6 North Island, New Zealand, I8, 126, I~7, 129, Magadan batholith, 328 I35 Maine, 5, 7, 96 Norway, 45, 46 , I92 Malheur County, 255, 279 Norwood tuff, 3oo Manche, 42 Nova Scotia, 7o, 98, 99 Mannville Formation, 219 Group, 233 Oberpfalz, 77, 78 Manzat basin, I72 Ohio, I58 Marshalltown Formation, 12 Okhotsk sea, 328 Martinsburg Shale, I89 Oklahoma, 29, 47, x86 Mascall Formation, 28o Olary district, I84 Massachusetts, 44 Olduvai Gorge, 245 Massacre Lake, 282 Olenek Highland, I85 Mathews' Landing Marl, I52 Olga-Tetyukhinsk region, 332-5 Melnyk district, 21 o Olodonin granitoid, 325 Mendocino County, 25 Onon River, 324 Merriam's Middle Member, 3 t 5 Ontario County, I64 Mexico, 217, 33 I Oporto, 122 Mill Creek, 202 Oregon, 83, I97, 253, 255, 276, 277, 279, 280, Milne Land, 232 283, 284, 288, 289, 298 , 299, 315 Mitchell, 283, 284, 289, 298, 299, 3 I5 Orne, 4 I Monastirsk volcanics, 332 Oslo nordmarkite, 46 Mongolia, 311 Otibanda Formation, 318 Montana, 37, 204 Oxfordshire, I8O Moodys Branch Formation, I 14 Moose River synclinorium, 96 Pala mine, 3 x9 Morgan County, 30o Palisade sill, 9 Ranch Formation, 28 Paris basin, 87 Morrill County, 286, 316 Patagonia, 31 o Moscow, 72, 215, 234, 322 Paterson toscanite, 3o, 65 456 Alphabetical index to Items

Payette Formation, 279 Siesta Formation, 258 Pembina coal seam, 199 Sikhota-Alin, 329 Pinole tuff, 252 Silver Lake, 260, 261 Pont-Erambourg, 4 I Sioux County, 8o, 278 Porterville, 3oo Skryleyeva Ravine, 2 t 2 Portland Sand, 52, 179, 18o Smith Valley, 28 Portugal, 122 Smithville, 94, IO2 Potosi volcanic series, 134 Snobs Creek rhyodacite, 95 Predkavkaz'e, 23 Snoqualmie granite batholith, 4o Presidio County, 84, 287, 290 Snowy River granite, 97 Primorye, 139-45 , 332-5 Sodus Formation, 168 Puy-de-Dtme, 63, I72 Soester Greensand, 59 Sokolki, 19 Quebec, 3, 17°, I87 South Island, New Zealand, I7, 125, I28, 320 Queensland, 69, 12 i, x75 South Table Mr, 3o6, 3o7 Quincy granite, 44 Speeton Clay, 236 Spitsbergen, 4 Rattlesnake Formation, 253 Sprucefield, 219 Raudfjorden, 4 Stade, x io Reculver, io 5 Staffordshire, 162 Red Hill dyke, 190 Stalingrad borehole 4o77, 22 Rhine, Upper, 13o Stanthorpe granite, 69 Rhode Island Formation, 43 Stave Creek Formation, 124 Rochester, i66--8 Steens basalt, 276, 277 Shale, 166 Stoney Athi River, 314 Rocky Boy stock, 37 Strawberry Creek, 2oo Ricardo Formation, 259 Stroud Claim, 257 Rio Gallegos, 3 Io Summit tuff, I55 Ripley Formation, 54 Surrey, 49, 5 ° , 241 Rusinga Island, 312 Survilliers, 87 Ryazan beds, 235 Sussex, 242 Sutter Buttes, io8 Sacramento, 1o8 Sutter Formation intrusion, 246 Sakmarlan limestone, 12o Sweden, 34, 157, I69, 225 Salzgitter, 6o, 228-3i Swindon, 52 Sande, 192 Swingle quarry, 44 Sandringham Sands, 177, i78 San Jose pluton 33 i Table Mt, South, 307 San Juan Mountains, 13 I, 134 Talkeetna Mrs, 89 Santa Cruz Formation, 31 o Tanganyika, 245 Saratov, 2o7, 2o8, 24° Tas-Aran series, 2 i Scaldisian sediments, 36 Tasmania, 19o Scotland, see Great Britain Tassaranskaya suite, 2 i Scott's Bluff County, 285 Tavari intrusions, 194 Settons Lac de, 175 Teewinot Formation, 256 Severn River, 12 i Tehachapi Mountains, 79 Shap granite, 6 Tehama Formation, 249 Shasta Bally batholith, 75 Teisendorf (Ob.), 88 Shasta County, 75, 249 Tennessee, 2, 94. 156, 183 Sheep Creek Formation, 278 Tenterfield, 67 Shinkolobwe uraninite, 55 Teton County, 256 Shropshire, I62 Texas, 84, lOt, Io2, 2o5, 287, 29% 3ol Siberia, I85 Thanet Sands, xo5 Sierra Nevada, 76, Io7 Thetford Mines, i7o 457 Alphabetical index to Bems

Timan, northern, 120 Volga basin, 240 Tintic district, i33 River area, 22, 207, 208 Tongaporutuan, I35 Vosges granites, 17 i Topley intrusions, 1 i Vya, 282 Transbaikalia, 324, 325 Vyatka River, 19 Turgay, 2 I Twin Falls County, 308, 309 Wagonbed Springs, 303 Waiauan sediments, I29 Uksk beds, I I8 Waipawan stage, 17 Ullu-Chay, 206 below, I8 United Kingdom, see Great Britain Waitakian sediments, I27 United States of America, see U.S.A. Wales, see Great Britain Upper Greeensand, 56, 227 Warburton, 95 Urals, middle, 33; southern, I 16, I 18 Warwickshire, i62 Urm River, 337 Washington, 4 ° U.S.A., 2, 5, 7, 9, I2-I5, 24-9, 32, 37-4o, 43, Greensand, 224 44, 47, 48 , 54, 75, 76, 79--8I, 83, 84, 86, 89, Watut basin, 318 94, 96, Ioi, Io2, Io4, Io6--8, II2-15, I23, Weardale granite, 9 r I24, I3I-4, I46-56, ~58-6o, 164-8, I83, I86, Weches Formation, Io2 I89, I97~ 9o4, 2o5, 224, 226, 243, 246-3o9, Weno Formation, 2o 5 315-I7, 319, 33o; (see also individual States) West Dereham, 177, 178 U.S.S.R., I6, I9-23, 33, 53, 64, 72, 85, 9 o, IOO, Western Hill County, Bearpaw Mountains, 37 xo3, I I6-I8, I2o, 136-45 , I63, I8I, I82, I85, Westland, 32o I94, i95, 2o6-8, 2II-15, 22o, 234, 235, 237, West Lothian, 19 x 238, 24 o, 32I-9, 332-7; (see also individual Westmorland, 6 republics) West Walker River Canyon, 26 Utah, ~33, 3 °o Whaingaroon sediments, 126 Utica Shales, i8 7 Wheatley, 18o Vakis-Jvary, 85 Wheeler County, 288 Valentine, 290 Whin sill, 176 Valros basalt, 244 Whitecourt, I99 Ventura County, 39 Whitneyan sequence, 83 Veraya Tier, I6, 64 Wichita Mt granite, x86 Verkhnekamensk, Formation 53 Wight, Isle of, 239 Verkhoyano-Kolyma fold-belt, 32 x Williamson Shale, I67 Vestergotland, I69 Wiltshire, 52 Vestfold, I92 Windous Butte, 297 Victoria, Australia, 95, 97 Wind River basin, 3o5 Victoria, Lake, 3 ~2 Winona Sand, I23 Victoria Land, i88 Worcestershire, I62 Vieja Group, 84, 287 Wrecclesham, 24 I Series, 29 ° Wyoming, 48, 2o 4, 256, 29x--6, 3o2-5 Viking Formation, 2 x8 Vire-Carolles granite, 42 Yano-Kolyma region, 327 Virginia, i89 Yorkshire, 236 Vladimirsk granite, 333 Young's Bend area, 2

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All the essential features of both a

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r _ JAMES SWIFT 8= SON LTD Full details of this unique instrument are given in 113"115A, Camberwell Road, catalogue PMO which we shall be pleased to send on London S.E.5 RODney 5441 request.

o., 111 '" There are many separations which would prove impossible without the...

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Model L-I set for Inclined Feed. Vortical Feed Attachments available. The selectivity of the Isodynamic Separator is due to the shape of the pole pieces. This Write for BULLETIN. produces a magnetic field of such configura- tion that a uniform force is produced on a particle of given susceptibility anywhere in S. G. FRANTZ CO. Inc. the working space. Feeding at slow rates, using the vibrator and E N G I N E ERS inclined feed chute shown at the right, the most delicate separations of fine powders, 3412 KLINE AVE, at BRUNSWICK PIKE down to 200 mesh are made even on feebly magnetic materials. The intensity of vibration P.O. Box 1138 Trenton 6, N.J., U.S.A. may be adjusted to suit various materials. Oable Address: MAGSEP, Trentonnewjersey

LABORATORYPAPERWORK AND PAPERWARE SPECIMEN TRAYS MADE TO ANY DIMENSIONS LABELS OR CARDS TO FIT THE TRAYS OR ANY SIZE, PRINTED OR PLAIN, GUMMED OR NOT, WHITE OR COLOURED BLOCKS OF MAPS AND DRAWINGS, LINE OR HALFTONE ORIGINAL DRAWINGS FOR BLOCKMAKING MADE FROM YOUR MATERIAL PRINTED SHEETS FROM THE BLOCKS, ETC. LISTS, CHARTS, TABLES, INSTRUCTION SHEETS, MONO- GRAPHS, BOOKLETS, LEAFLETS . . . If you need something made from, or printed on or in any way connected with paper or card, please communicate w/th us. We know a great deal about the difficulties of obtaining exactly what is required in the field, the laboratory and the lecture theatre and would welcome the opportunity to solve your particular problem. THE CYGNUS PRESS 32 MEYRICK ROAD LONDON N.W.10 • ENGLAND Telephone: WILlesden 4048

iv GEOLOGICAL SOCIETY OF LONDON

MEMOIR No. 1 Ring-complexes in the Younger Granite province of Northern Nigeria

R. R. E. JACOBSON, W. N. MacLEOD & R. BLACK 72 pages, 13 text-figures, 6 half-tone plates, 3 plates of geological maps

MEMOIR No. 2 Geological results of petroleum exploration in Britain 1945-1957 by N. L. FALCON & P. E. KENT

56 pages, 26 text-figures, 5 plates of geological maps and sections, 5 tables of data from exploration wells

Each 25s per copy. Fellows of the Society may purchase (from the Society's office) one copy each for 10s. Postage and packing Is 6d.

Available from the Geological Society of London, Burlington House, Piccadilly,London, W. I, and from Messrs H. K. Lewis & Co. Ltd, 136 Gower Street,London, W.C.I. GEOLOGICAL SOCIETY OF LONDON

MEMOIR No. 3 The Barr and Lower Ardmi!ian Series (Caradoc) of the Girvan district, south-west Ayrshire, with descriptions of the Brachiopoda by ALWYN WILLIAMS Professor of Geology, the Queen's University, Belfast

267 pages, 13 text-figures, 5 plates of geological maps and sections, 20 collotype plates of fossil brachiopods

THE author reviews the stratigraphy of the Caradoc rocks north and south of the Stinchar Valley and suggests that Lapworth's classification (1882) was based on a mistaken theory of isoclinal folding. He finds such folding to be rare in the area and concludes that the succession is much thicker than has hitherto been believed. The study includes the systematic revision of the Caradoc Brachiopoda; 180 species (27 new) and 11 new subspecies are described and figured and 5 new genera erected. Correlations are established among the Caradoc rocks within the area and between these rocks and the standard successions of Alabama, Tennessee, and West Virginia.

Price £5 per copy. Fellows of the Society may purchase (from the Society's office) one copy each for £2 10s. Postage and packing 3s 6d.

Available from the Geological Society of London, Burlington House, Piccadilly, London, W. 1, and from Messrs H. K. Lewis & Co. Ltd, 136 Gower Street, London, W.C.1. vi