The Upper Cretaceous and Lower Paleocene of the Eastern Bogota Plateau and Llanos Thrustbelt, Colombia: Alternative Appraisal to the Nomenclature and Sequence Stratigraphy

The Upper Cretaceous stratigraphic record of the Eastern Bogota Plateau and Llanos Thrustbelt of Colombia was studied in several outcrop sections and oil wells, leading to an alternative scheme of stratigraphic nomenclature and sequence stratigraphic interpretation. The Chipaque Formation (Cenomanian-Campanian) is overlain by the Guadalupe Group in the Bogota Plateau and by the Palmichal Group in the Llanos Thrustbelt. From oldest to youngest, the correlation between the subdivisions of these two groups is as follows: The Arenisca Dura Formation (Campanian) of the Guadalupe Group, corresponds to the Arenitas de San Antonio Formation of the Palmichal Group; the Plaeners Formation (Campanian-Maastrichtian) to the Lodolitas de Aguacaliente Formation; the Arenisca de Labor, the so-called "Lutitas y areniscas finas" and the Arenisca Tlerna Formations of the Guadalupe Group correspond to the Arenitas de San Luis de Gaceno Formation of the Palmichal Group. In turn, a lower part of the Guaduas Formation of the Bogota Plateau is equivalent to the Guaduas Formation of the Palmichal Group. The Palmichal Group is redefined by excluding the overlying Socha Inferior Formation from it, mainly because the Socha Inferior's lower limit is represented in some places by an unconformity. Additionally, the above mentioned formations are included now in the Palmichal Group. Major depositional environments shift according to sea level fluctuations of second and third order. The Chipaque Formation of the Bogota area is a second order (super)cycie where at least four third order sequences are circumscribed. Likewise, the Guadalupe Group and the Guaduas Formation aresupersequences that bear higher frequency sequences. A major erosion period, documented here in the Medina-1 well, cannibalized part of the Maastrichtian of the Palmichal Group. The youngest sequence studied is represented in its lower portion by the lowstand deposits of the Socha Inferior Formation.The Upper Cretaceous stratigraphic record of the Eastern Bogota Plateau and Llanos Thrustbelt of Colombia was studied in several outcrop sections and oil wells, leading to an alternative scheme of stratigraphic nomenclature and sequence stratigraphic interpretation. The Chipaque Formation (Cenomanian-Campanian) is overlain by the Guadalupe Group in the Bogota Plateau and by the Palmichal Group in the Llanos Thrustbelt. From oldest to youngest, the correlation between the subdivisions of these two groups is as follows: The Arenisca Dura Formation (Campanian) of the Guadalupe Group, corresponds to the Arenitas de San Antonio Formation of the Palmichal Group; the Plaeners Formation (Campanian-Maastrichtian) to the Lodolitas de Aguacaliente Formation; the Arenisca de Labor, the so-called "Lutitas y areniscas finas" and the Arenisca Tlerna Formations of the Guadalupe Group correspond to the Arenitas de San Luis de Gaceno Formation of the Palmichal Group. In turn, a lower part of the Guaduas Formation of the Bogota Plateau is equivalent to the Guaduas Formation of the Palmichal Group. The Palmichal Group is redefined by excluding the overlying Socha Inferior Formation from it, mainly because the Socha Inferior's lower limit is represented in some places by an unconformity. Additionally, the above mentioned formations are included now in the Palmichal Group. Major depositional environments shift according to sea level fluctuations of second and third order. The Chipaque Formation of the Bogota area is a second order (super)cycie where at least four third order sequences are circumscribed. Likewise, the Guadalupe Group and the Guaduas Formation are supersequences that bear higher frequency sequences. A major erosion period, documented here in the Medina-1 well, cannibalized part of the Maastrichtian of the Palmichal Group. The youngest sequence studied is represented in its lower portion by the lowstand deposits of the Socha Inferior Formation.
The Upper Cretaceous stratigraphic record of the Eastern Bogota Plateau and Llanos Thrustbelt of Colombia was studied in several outcrop sections and oil wells, leading to an alternative scheme of stratigraphic nomenclature and sequence stratigraphic interpretation. The Chipaque Formation (Cenomanian-Campanian) is overlain by the Guadalupe Group in the Bogota Plateau and by the Palmichal Group in the Llanos Thrustbelt. From oldest to youngest, the correlation between the subdivisions of these two groups is as follows: The Arenisca Dura Formation (Campanian) of the Guadalupe Group, corresponds to the Arenitas de San Antonio Formation of the Palmichal Group; the Plaeners Formation (Campanian-Maastrichtian) to the Lodolitas de Aguacaliente Formation; the Arenisca de Labor, the so-called "Lutitas y areniscas finas" and the Arenisca Tlerna Formations of the Guadalupe Group correspond to the Arenitas de San Luis de Gaceno Formation of the Palmichal Group. In turn, a lower part of the Guaduas Formation of the Bogota Plateau is equivalent to the Guaduas Formation of the Palmichal Group. The Palmichal Group is redefined by excluding the overlying Socha Inferior Formation from it, mainly because the Socha Inferior's lower limit is represented in some places by an unconformity. Additionally, the above mentioned formations are included now in the Palmichal Group. Major depositional environments shift according to sea level fluctuations of second and third order. The Chipaque Formation of the Bogota area is a second order (super)cycie where at least four third order sequences are circumscribed. Likewise, the Guadalupe Group and the Guaduas Formation aresupersequences that bear higher frequency sequences. A major erosion period, documented here in the Medina-1 well, cannibalized part of the Maastrichtian of the Palmichal Group. The youngest sequence studied is represented in its lower portion by the lowstand deposits of the Socha Inferior Formati

EI registro estratigratico de la parte oriental de la Saban a de Bogota y el Piedemonte L1anero ha sido estudiado con base en columnas estratigraticas y pozos petroleros, 10 cual ha conducido a un esquema alternative de nomenclatura estratiqratica y de estratigrafia secuencial. La Forrnacion Chipaque (Cenomaniense-Campaniense) est a suprayacida por el Grupo Guadalupe en la Saban a de Bogota y por el Grupo Palmichal en la zona del Piedemonte L1anero. De base a tope la correlacion entre las formaciones de estos grupos se propone asi: La Forrnacion Arenisca Dura (Campaniense) del Grupo Guadalupe corresponde a la Forrnacion Arenitas de San Antonio del Grupo Palmichal; la Forrnacion Plaeners (Campaniense-Maastrichtiense) a la Forrnacion Lodolitas de Aguacaliente. La Forrnacion Arenisca de Labor, el lIamado nivel de "Lutitas y areniscas finas" y la Forrnacion Arenisca Tierna del Grupo Guadalupe correspond en a la Forrnacion Arenitas de San Luis de Gaceno del Grupo Palmichal. Una parte de la porcion inferior de la Formacion Guaduas de la Sabana de Bogota es equivalente ala Formacion Guaduas del Grupo Palmichal. EI Grupo Palmichal se redefine excluyendo a la Forrnacion Socha Inferior, principalmente por existir una discordancia en su limite inferior, y se incluyen en el las Formaciones anteriormente mencionadas. Los ambientes deposicionales varian de acuerdo a los cambios del nivel del mar, tanto de segundo como de tercer orden. La Forrnacion Chipaque en la Sabana de Bogota representa un (super)cicio de segundo orden que comprende por 10 menos cuatro secuencias de tercer orden. De manera similar, el Grupo Guadalupe y la Forrnacion Guaduas son supersecuencias, en las cuales otras secuencias de mayor frecuencia se pueden delinear. Un periodo de erosion mayor, documentado aqui en el pozo Medina-Ilia causado perdida parcial del registro del piso Maastriclltiense. La siguiente secuencia esta representada en su parte inferior par un sistema de nivel ba]o, dentro de la Formaci6n Socha Inferior.