TY - JOUR
T1 - Oncolites from lacustrine sediments in the Cretaceous of north‐eastern Spain
AU - FREEMAN, TOM
AU - ROSELL, JUAN
AU - OBRADOR, ANTONIO
PY - 1982/1/1
Y1 - 1982/1/1
N2 - Compact micritic oncolites up to 8 cm in maximum diameter occur within Maestrichtian (Upper Cretaceous) Garumniense continental marls of Sierra del Montsec (Lerida Province) of north‐eastern Spain. Synsedimentary development is documented by patches of terrigenous quartz that occur among oncolitic protuberances. Soluble nuclei (limestone fragments and bivalves) further suggest an origin through accretion, rather than that of soil pisolite. Similarities between the petrography and isotopic compositions of the oncolites and those of interbedded Garumniense limestones suggest similar sedimentary origins. However, these lacustrine oncolites, like modern counterparts described by others, probably developed through in situ metabolic precipitation of calcium carbonate. Evidence of this origin is their high degree of concentricity, which is unlikely to have developed through sedimentary accretion, inasmuch as the oncolites ‘float’ in quiet‐water marls. Copyright © 1982, Wiley Blackwell. All rights reserved
AB - Compact micritic oncolites up to 8 cm in maximum diameter occur within Maestrichtian (Upper Cretaceous) Garumniense continental marls of Sierra del Montsec (Lerida Province) of north‐eastern Spain. Synsedimentary development is documented by patches of terrigenous quartz that occur among oncolitic protuberances. Soluble nuclei (limestone fragments and bivalves) further suggest an origin through accretion, rather than that of soil pisolite. Similarities between the petrography and isotopic compositions of the oncolites and those of interbedded Garumniense limestones suggest similar sedimentary origins. However, these lacustrine oncolites, like modern counterparts described by others, probably developed through in situ metabolic precipitation of calcium carbonate. Evidence of this origin is their high degree of concentricity, which is unlikely to have developed through sedimentary accretion, inasmuch as the oncolites ‘float’ in quiet‐water marls. Copyright © 1982, Wiley Blackwell. All rights reserved
U2 - 10.1111/j.1365-3091.1982.tb01806.x
DO - 10.1111/j.1365-3091.1982.tb01806.x
M3 - Article
VL - 29
SP - 433
EP - 436
JO - Sedimentology
JF - Sedimentology
SN - 0037-0746
IS - 3
ER -