Publicaciones Geolo_gicas Especiales Del lngeominas

More documents

Recommendations

Info

ZONA'riON OF THE CRETACEOUS OF CENTRAL COLOMBIA BY AMMONITES 25 seems to be a tendency to decrease the number of the ribs on venter between the constrictions, from 8 to 6 or 5. The living chamber has been preserved as a quarter of a volution. DIAGNOSIS. This species is characterized by: A) the decreasing number of the ribs between contrictions from...S to 5 through growth, B) the stressed ribs gathered in bundles toward the umbilical margins, ands C) the inflated whorl section. Meuurements Holotype Puatype D Euw 57 22 37 ? H W DfEuw% D/H % 22a 20a 38 38 ? ? 7 7 COMMENTS. The disposition of the constriction in this species is close to that des· cribed by Jacob (1905, p. 402, pl. 12, Fig. 1) for ''Desmocerasakuschaense Anthula" although in the French species the flare is divided at the bend at the midpoint of the flank. This species resembles "Desmoceras " sparsicosta Boese (1923, p. 107, pl. 7, fig. 1-3) from Mexico; the latter, however, possesses intermediate ribs that bifurcate twice at differente levels on flank (Boese, ibid., p. 107), whereas in the Colombian species the bifurcation occurs only once; the ribbing is much more prominent on theMexican species, which in addition, is less inflated than the Colombian species. OCCURRENCE. Socota Member. Upper Aptian. == pseu doha plc er a s }.!:1!-oo:_ Pseudohaploceras Hyatt, 1900, p. 570. TYPE SPECIES. Haploceras liptoviense Zeuschner, in Uhlig 1883, original designation. uf!l!jaeJ ceras leivaense.l}· sp. P g:-'1 , Text-fig. au, au. Holotype. VI-10-17 (U. N. C. M. H. N. C. P. Ht. N. 10). The inner whorls are apparently smooth. The section of the second whorl is vaulted. Flanks diverging from the rather narrow venter, reach their maximum width near the external part of the adumbiliclil third of the flank and then grade abruptly into the vertical umbical wall. The last whorl has a cross section much the same but more inflated. The test of the last preserved whorl is ivided into seven trapezoidal areas by flared nbs which begin irregularly on the adumbilical thir of the flank although the growth lines project obliquely onto the umbilical wall. The intercostal distance between flaring ribs increases toward the aperture; between two of the fiared major ribs there are from 7 to 9 finer alcoi ribs which begin as stressed growth lines. Independently or in bundles (barely bulgmg), and which become clearly defined just adumbilical to mid-venter; they are rounded and are half as wide as Ule intercostal spaces; some of Ulem widen irregularly on venter. On the living chamber Ule ribs become very accen· tuated especially where Uley fonn bundles but they do not develop real bullae. DIAGNOSIS. This species in characteri· zed by: A) its ogival whorl section, B) the in· creasing width between its flaring ribs or constrictions through growth, and C) the progressive stressing of the primary ribs on the flanks. COMMENTS. There is some resemblance between this species and "Puzosia Douvillei" Fallot rFallot, 1920, p. 259, pro. "Puzosia Matherom d'Orbigny" H. Douville (1916, p. 103, pl.13, Figs. 1 to 7)'J, especially"in the tendency of ribs to gather in prominent bundles adumbi· lically without, however, Conning heavy bullae as in Uhlige lla (Jacob, 1907). The African spe· cies shows more discrete and finer ribbing. Mo· re similar in appearance, however are several of the specimens figured by Boese from Mexico as different species of "Desmoceras " in which the tendency of the ribs to gather in umbilical bundles is much more accentuated; one of the most similar species would be "Desmoceras alzatei" Boese (1923, p. 114, pl. 8, Fig. 15-18) but the Mexican species has closer, less distinct ribbing than the Colombian species. OCCURRENCE. Paja Formation. (Arcillolitas abigarradas;segment E). Upper Aptian . · ·-ae-nus __ -- · ·_-r:coae-;c!{.3n.· g. ;;. _; J _ TYPE SPECIES. Carloscaceresiceras caceresi n. sp. DIAGNOSIS. Moderately evolute conchs, with low ogival whorl section; the umbilical wall is vertical and merges abruptly into the flanks. The ornament consists of sinuous to bi· concave growth striae gathered in bundles or weak riblets which sometimes produce on the internal mold a ribbon-like subdued costation, particularly visible on venter. There are cons· trictions preceded by a prominent rounded swelling visible both on test and the internal mold but which develop on the adventral third of the flank only; adorally the constric· tion is margined by a blunt ridge extending across the flank down to the umbilical edge, it is not noticeable on the test. The constrictions are accentuated progressively with growth, from almost incospicuos on the early wh·oris to very wide on the living chamber. The constric· tions cross normal to the ventral median line. The apertural border is plain and follows the path of the growth striae. The suture line has E shorter than L, which is deep and very incised. COMMENTS. . This _ _new _ __genus .. difters JI(J.ffi_}3_eudanticeras m_i! ... 19_95) because of its lomr ·mer wider whorl section, its more evolute whorl and the strengthening of the internal sculpture during growth. It differs from Pseudorbulites [Casey , 1961, p.145, ex Breistro·
26 F. ETAYO · SERNA ffer, 1963, p.74, nom. nudum type species UhligellD convergens Jacob, 1907, p.29, pl.2, fig. 25a, b,c} because the latter lacks flanges bordering tlie constrictions, has narrow and falcate constrictions and has a funnel-like umbilicus. From Puzosia (Bayle , 1878) it diffen in the lack of linguifonn projection of the constrictions on the venter and the suture line with only feebly retracted suspensive lobe. This genus is named in honor of geologist Carlos Caceres. Holotype. C - 170 · 20 (U.N.C.M.H.N.C.P.Ht. N.lll Paratypes. C· 1 · 1,2,3- (U.N.C.M.H.N.C.P.Pt. 8,9,10). A) Up to 20 mm (C-13·1,2 ). The first whorl after the protoconch is subcircular in sc· tion, the second whorl is slightly higher than wide but already has a steep umbilical wall; on the third whorl the vaulted shape of the whorl section is reached. The test has growth striae that extend obliquely from the umbilical rim and describe a feeble concavity on the umbilical third of the flank; on the central third of the flank they fonn an adoral arc and on the adven· tral third of the flank they fonn one acute concavity, next they project mode!ately on the • - venter. B) Up to 26 mm diameter (C- 13-3]. Up to this size no special change occurs on the test ornament except that the umbilicus has already begun to widen. The growth striae tend to form irregular bundles which may leave slight bands or rib-like impressions on the internal mold; some striae appear more accentuated than others especially on venter. C) Up to 50 mm D (C-13- The specimens are septate; weak elongated S·h e constrictions appear; the remainder of the conch corresponC:.s to the living chamber. Approaching the beginning of the living chamber the constrictions become progressively more accentuated; the constrictions are preceded adapically by a flange-like bulging on the periventral margins and vent.er only, but the adoral margin of the constrictions fonn a short vertical ·wall on the internal mold. Very wide and · slightly arched constrictions tP.nd to divide the internal mold corresponding to the living chamber into triangular segments, and on these there are htdications of tenuous ribs that cross the venter, they are narrower than the intercostal spaces and extend down to the umbilical seam. These ribs correspond to bundles of growth striae on the test. The living chamber occupies half the length of a whorl. On venter there are ridge-like thickenings of the test co· rresponding to the constrictions on the inter· nal mold, but the thickenings are restricted to the venter and are not noticeable on the flanks. DIAGNOSIS. The same as for the genus. Meuurement 0 Euw H W Vw O{Euw O{H W{Vw % % ,Ofo C- 13• 1 26 6 12 10 6 24 48 50 c- 13· 2 19 4 9 8 4 21 47 50 C- 13· 3 26 6 13 10 5 24 62 50 c- 13- 4 20 4 10 9 4 20 1>0 44 C· 13· 5 17 3 9 7 1 17 52 1 c- 13·12 25 6 13 7 1 24 62 1 c- 13-13 29 7 14 11 6 24 48 45 c- 13·14 18 4 9 8 4 22 60 50 c- 13·1fi 28 7 14 10 6 25 60 60 C- 13·17 29 7 14 10 6 24 48 60 c- 1a-1s 30 6 16 11 6 20 40 1>4 C- 13·19 32 8 16 7 ? 26 50 7 C· 13·20 35 9 17 14 7 26 48 50 C· 13·22 34 9 16 13a 7a 26 47 40 C- 13·23 37 10 17 13 8 27 47 61 C• 13·26 41 12 18 14 9 29 44 64 C· 13·27 42 11 20 16 9 26 47 60 C- 13-28 42 12 20 16 9 28 47 60 C· 13·29 48 13 21 18 11 27 44 60 C- 13-30 48 14 20 17 10 29 41 59 C- 13·33 34 8 16 13 8 23 47 61 C- 13-34 50 17 21 7 1 34 42 ? C· 13·36 53 17 23 18 9 32 43 50 C- 13·36 68 20 21 ? ? ? 34 7 ? C- 1 3·37 52 21 18 ·u 18 36 40 60 C·170· 1 20 6 12 8 4 25 60 50 C-1 70· 2 22 6 12 9 5 23 M 56 C-170· 3 30 6 16 10 5 20 53 60 C-170· 4 32 7 16 12 7 22 60 68 C-170· 7 29 7 14 10 6 24 48 60 C-170· 9 41 10 20 15 8 24 48 63 C-170·11 48 14 21 18 9 29 46 50 C-170·12 46 13 20 17 9 29 44 53 C-170·13 46 12 ,20 17 10 26 ' 43 58 C-170·14 44 12 20 16 9 27 45 56 C·170·16 44 15 19 16 8 34 43 60 C-170-16 44 13 19 16 9 29 43 66 C-170·17 46 14 20 17 9 30 43 63 C-170-1 8 64 18 22 18 10 33 40 65 C-170·19 60 14 23 18 12 28 46 65 C-170·20 62 19 26 21 11 30 42 62 C-170·21 5 7 17 - -24 20 11 31 44 56 C-1 7D-22 76 27 29 28 15 36 38 63 C·17D-23 79 31 31 28 13 39 39 46 COMMENTS. Same as for the genus. A Peruvian species of ammonites descri· bed by Gabb (1881, p. 268, pl. 37, fig.l, 1r£! as "A [mmonites Hyatti", has (ibid.) "su ace smooth, or on y marked by indistinct lines of growth, which bend forward on the inner margin of the whorl, slightly backwards. on the middle, and then fonnard towards the dorsum .. ' Lisson (1937, p. 23) renamed this species "Des- mocera$_ Hyattum ", and pointed out (ibid p.25) that it lacks constrictions and ribs. These characteristics recall those of the genus Carloscaceresiceras; however the stratigraphic position of Gabb's species remains undetermined (BenavideS'-Caceres, 1956, p. 439). OCCURRENCE. Capotes Member Lower ---... Albian. .,e.aroscgce!]§Jc!lro maat!lmLn. sp. Pl. 0. Fig. 5; Text-figs. 4E; 10.
Page 1 and 2: Publicaciones Geolo_gicas Especiale
Page 3 and 4: PUBLICACIONES GEOLOGICAS ESPECIALES
Page 5 and 6: CONTENTS ABSTRACT . . . . .. . . .
Page 7 and 8: Pl ate 4. Plate 6. Plate 6. Plate 7
Page 9 and 10: 2 F. ETA YO· SERNA The materials t
Page 11 and 12: 4 F. ETA YO· SERNA PHYSICAL STRATI
Page 13 and 14: FIGLH 1\ 2 2AJ Vl:LLA DE LEIVA CD -
Page 15 and 16: 8 Gloriaceras paulinae n. sp. Zumpa
Page 17 and 18: 10 F. ETA YO -SERNA coarse grained
Page 19 and 20: 12 F. ETA YO · SERNA trated in sev
Page 21 and 22: 14 F. ETA YO · SERNA ated. In the
Page 23 and 24: 16 F. ETA YO · SERNA TABLE I ASSEM
Page 25 and 26: 18 F. ETA YO ·SERNA tion consisfli
Page 27 and 28: 20 F. ETA YO ·SERNA increasing ove
Page 29 and 30: 22 has a subelliptical to subcircul
Page 31: 24 F. ETAYO ·SERNA rounds abruptly
Page 35 and 36: 28 F. ETA YO - SERNA this is partic
Page 37 and 38: 30 F. ETAYO ·SERNA and bifurcate;
Page 39 and 40: 32 F. ETA YO · SERNA thirds of the
Page 41 and 42: 34 F. ETA YO · SERNA Hypotype. (U.
Page 43 and 44: 36 F. ETA YO - SERN A tuberculation
Page 45 and 46: 38 F. ETAYO - SERNA they project sl
Page 47 and 48: 40 last whorl the ribs are inconspi
Page 49 and 50: 42 Hypacanthoplites dognaliciae n.
Page 51 and 52: 44 F. ETA YO · SERNA One large spe
Page 53 and 54: 46 F. ETAYO - SERNA "Acanthoplites
Page 55 and 56: 48 F. ETA YO · ERNA These tubercle
Page 57 and 58: 50 .,CQ.IQmQ.ik.er::fJ§. W forg.ro
Page 59 and 60: 52 Among the subsequent flared ribs
Page 61 and 62: ZONATION OF THE CRETACEOUS OF CENTR
Page 65 and 66: zoNATION OF THE CRETACEOUS OF CENTR
Page 71 and 72: ? ? ZONATION OF THE CRETACEOUS OF C
Page 83 and 84:
ZONATION OF THE CRETACEOUS OF CENTR
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
86 F. ETA YO - SERNA rent localitie
Page 93 and 94:
88 The adapical end of this conch h
Page 95 and 96:
90 F. ETAYO · SERNA dies out near
Page 97 and 98:
92 OCCURRENCE. La Frontera Fonnatio
Page 99 and 100:
94 re is an asymmetrical sulcus bor
Page 101 and 102:
96 (1898, p. 198, figs. 23a,b,c), w
Page 103 and 104:
98 the flank and have a periventral
Page 105 and 106:
100 F. ETA YO - SERNA On the adapic
Page 107 and 108:
102 ventral third of the whorl side
Page 109 and 110:
104 but "Fundort: Von Stiibel im Be
Page 111 and 112:
106 F. ETA YO · SERNA En dos regio
Page 113 and 114:
108 In due regioni della Cordiglier
Page 115 and 116:
110 REFERENCES ANDERSON, F. M. 1938
Page 117 and 118:
112 -- 1963.- Atlas des fossiles ca
Page 119 and 120:
114 KARSTEN, H. 1858.- Vber die geo
Page 121 and 122:
116 Colon. Geol. min. Resourc., uol
Page 123 and 124:
118 F. ETA YO • SERNA WIEDMANN, J
Page 125:
120 A) B) C) D) E) F) G) H) I) L) M
Page 129:
124 F. ETA YO • SERNA A) B) C) D)
Page 133 and 134:
FIGURA 7 A Q 8 ) / ! E I c K FIGUR
Page 136 and 137:
132. A) B) C) D) E) F) G) H) I) J)
Page 138 and 139:
134 Scatter diagram of the distribu
Page 140 and 141:
136 Scatter diagram of the relation
Page 142 and 143:
Page 144 and 145:
140 F. ETA YO · SERNA Scatter diag
Page 146 and 147:
Page 148 and 149:
144 F, ETAYO ·SERNA Scatter diagra
Page 150 and 151:
146 F. ETA YO · SERNA FIGURE 16 Sc
Page 152 and 153:
148 F. ETA YO · SERNA Scatter diag
Page 154 and 155:
PLATES 1-15
Page 157:
154 F. ETA YO · SERNA Fig. 1) Chel
Page 161:
158 F. ETA YO · SERN A PLATE 4 Fig
Page 165:
162 Fig. 1) Vectisites (Zambranoite
Page 169:
166 F. ETA YO · SERNA Fig. 1) Eodo
Page 173:
170 Fig. 1) Carloscaceresiceras cac
Page 179:
176 Fig. 1) Fig. 2) Fig. 3) Fig. 4)
Page 183:
180 Fig.1) Codaziceras scheibei (Ri
Page 186 and 187:
184 Engonoceras, 74. duartci, n. sp
Page 188:
186 Tegoceras, 82. benavidescaceres
show all

Publicaciones Geolo_gicas Especiales Del lngeominas

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?