CT&F Ciencia, Tecnología y Futuro ISSN: 0122-5383 ctyf@ecopetrol.com.co ECOPETROL S.A. Colombia
Bayona, German; Jaramillo, Carlos; Rueda, Milton; Reyes-Harker, Andrés; Torres, Vladimir Paleocene-middle Miocene flexural-margin migration of the nonmarine llanos foreland basin of Colombia CT&F Ciencia, Tecnología y Futuro, vol. 3, núm. 3, diciembre, 2007, pp. 51-70 ECOPETROL S.A. Bucaramanga, Colombia
Available in: http://www.redalyc.org/articulo.oa?id=46530303
How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION OF THE NONMARINE LLANOS FORELAND BASIN OF COLOMBIA
German Bayona1*, Carlos Jaramillo1, Milton Rueda2, Andrés Reyes-Harker2, and Vladimir Torres2
1Smithsonian Tropical Research Institute, Balboa, Ancon, Panamá; Corporación Geológica ARES, Bogotá, Colombia 2Ecopetrol S.A.- Instituto Colombiano del Petróleo, A.A. 4185, Bucaramanga, Santander, Colombia
e-mail: [email protected]
(Received Aug. 23, 2007; Accepted Oct. 12, 2007)
foreland basin is a dynamic system whose depositional systems migrate in response to changes in tectonic uplift patterns, sedimentary filling processes and isostatic rebound of the lithosphere. The APaleocene-middle Miocene foreland system of the Llanos foothills and Llanos basin of Colombia includes regional unconformities, abrupt changes in lithology/stacking patterns and flooding surfaces bound- ing reservoir and seal units. Here we integrate a systematic biostratigraphic study, stratal architecture and tectonic subsidence analyses, regional seismic profiles, and provenance data to define the diachronism of such surfaces and to document the direction of migration of foreland depozones.
In a flexurally-deformed basin, sandstone composition, rates of accommodation and sediment supply vary across and along the basin. We show how a coeval depositional profile in the Llanos foothills-Llanos foreland basin consists of litharenites interbedded with mudstones (seal rock, supplied from the orogenic front to the west) that correlate cratonward with organic-rich mudstones and coal (source rock), and to amalgamated fluvial-estuarine quartzarenites (reservoir rock, supplied from the craton to the east) adjacent to a subaerial forebulge (unconformity). This system migrated northward and eastward during the Paleocene, westward during the early-middle Eocene, and eastward during the Oligocene. In the lower-middle Miocene succession of the Llanos basin, identification of flooding events indicates a westward encroaching of a shallow-water lacustrine system that covered an eastward-directed fluvial-deltaic system. A similar process has been documented in other basins in Venezuela and Bolivia, indicating the regional extent of such flooding event may be related to the onset of Andean-scale mountain-building processes.
Keywords: nonmarine foreland, sequence stratigraphy, Colombia, Andes, tectonics, depositional system, biostratigra- phy analysis, subsidence, paleocene, miocene, Mirador formation, Barco formation, Llanos Orientales.
* To whom correspondence may be addressed
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 51 una cuenca de antepaís es un sistema dinámico cuyos sistemas deposicionales migran en respuesta a cambios en los patrones de deformación, relleno de cuenca y rebote isostático de la litosfera. La Ucuenca de antepaís de los Llanos Orientales de Colombia incluye registro del Paleoceno-Mioceno medio con discordancias regionales, cambios abruptos de patrones de apilamiento/litologías, y superficies de inundación, limitando unidades reservorios y sellos. En este estudio integramos análisis de bioestratigrafía, arquitectura estratigráfica, subsidencia tectónica, perfiles sísmicos regionales y procedencia para definir el diacronismo de dichas superficies y para documentar la dirección de migración de los sistemas deposicio- nales en una cuenca antepaís.
En una cuenca flexural, la composición de las areniscas, los patrones de acomodación y aporte de sedimentos varían dentro de la cuenca. Este artículo presenta un perfil deposicional entre el Piedemonte hasta la cuenca de los Llanos el cual incluye litoareniscas interestratificadas con lodolitas (roca sello derivada del frente de deformación) que correlacionan hacia el Este con lodolitas carbonosas y carbón (roca fuente). Siguiendo hacia el Este continúan cuarzo areniscas fluvio-estuarino (roca reservorio derivada de áreas cratónicas) adyacentes a la zona de levantamiento flexural, con exposición subaérea (discordancia). Este sistema migró hacia el Norte y Este durante el Paleoceno, hacia el Oeste durante el Eoceno temprano-medio, y hacia el Este durante el Oligoceno. En la sucesión del Mioceno inferior-medio de los Llanos, la identificación de eventos de inundación indica un avance hacia el Oeste de sistemas lacustre someros, cubriendo el sistema fluvio-deltaico que avanzaba hacia el Este desde el Piedemonte. Un proceso similar ha sido documentado en otras cuencas en Venezuela y Bolivia, indicando la extensión regional de este evento de inundación, el cual puede estar relacionado con el inicio del levantamiento de los Andes.
Palabras clave: cuenca de antepaís continental, estratigrafía de secuencias, Colombia, Andes, tectónica, sistemas deposicionales, análisis bioestratigráficos, subsidencia, tectónica, Paleoceno, Mioceno, formación Mirador, formación Barco, Llanos Orientales.
52 CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION
INTRODUCTION SURGXFHVWKHYHUWLFDOMX[WDSRVLWLRQRI¿QHJUDLQHGRQ coarse-grained lithologies due to a rise of base-level position. When foredeep migration occurs in the oppo- Sequence stratigraphy models have emphasized site direction, coarse-grained lithologies unconformably in the utility of correlating key stratigraphic surfaces overlie the former depositional sequence due to a base- with chronostratigraphic value, such as unconformities level drop. Those abrupt changes in lithology/stacking DQGPDULQHÀRRGLQJVXUIDFHV *DOORZD\ 9DQ SDWWHUQVFDQEHLGHQWL¿HGLQRXWFURS &pVSHGHV 3HxD :DJRQHU0LWFKXP&DPSLRQ 5DKPDQDLQ -DUDPLOOR *yPH]et alD%D\RQDet rather than using lithostratigraphic units. The sequence al RUZHOOV )DMDUGR5RMDV&ULVWDQFKR &RQ- stratigraphic approach has proved to be very powerful VRUFLR* **RLQJ6\VWHP 6SDWLDODQGWHPSRUDO along marine to marginal passive-margin basins for variations of rates of accommodation space/sediment GH¿QLQJUHVHUYRLUXQLWV¿OOLQJLQFLVHGYDOOH\VDQGIRU supply in the nonmarine Paleogene Magdalena-Llanos predicting the position of reservoir units in offshore foreland basin of Colombia have been associated with VHWWLQJV 9DLO0LWFKXP 7KRPSVRQ 9DQ PLJUDWLRQRIDÀH[XUDOZDYH *yPH]et alD Wagoner et al ,QWHFWRQLFDOO\DFWLYHFRQWLQHQ- Bayona et al WDOEDVLQVKRZHYHUXSVWUHDPULYHUSUR¿OHVDUHPRUH YXOQHUDEOHWRWHFWRQLFDQGFOLPDWHÀXFWXDWLRQVZKHUHDV This paper determines whether those abrupt GRZQVWUHDPULYHUSUR¿OHVDUHPRUHVXVFHSWLEOHWRVHD FKDQJHVLQOLWKRORJ\VWDFNLQJSDWWHUQV RU³EDVHOHYHO OHYHOÀXFWXDWLRQV VHHUHYLHZLQ+ROEURRN6FRWW turnarounds” in the terminology of Ramon and Cross, 2ERK,NXHQREH 7KLVSDSHUFRQFHQWUDWHVRQFRU- FDQEHXVHGIRUFRUUHODWLRQRIUHVHUYRLUXQLWV relation of the Paleocene-middle Miocene succession between the Llanos foothills and Llanos foreland basin. that includes two reservoir units in the Llanos foothills, We focus on compositional and stratal architecture of WKH%DUFRDQG0LUDGRUIRUPDWLRQV7KHVHÀXYLDOXQLWV reservoir units, as well as in abrupt changes in lithology/ accumulated in upstream settings and at the migrating stacking patterns in units overlying reservoir units. The boundary of the forebulge-foredeep depozones of the diachronism of such changes is documented by rigorous Llanos foothills and Llanos foreland basin of Colombia SDO\QRORJLFDODQDO\VLVRI¿QHJUDLQHGVWUDWDRYHUO\LQJ %D\RQDet al reservoir beds. Provenance is also addressed by com- paring units above and below base-level turnarounds 7KHÀH[XUDOJHRPHWU\RIDIRUHODQGEDVLQFRP- because a compositional variation of framework sand bined with the lateral changes in rates of accommo- JUDLQVPD\LQGLFDWHZKHWKHUWHFWRQLFXSOLIWKDGH[SRVHG dation space/sediment supply, makes it possible to QHZVRXUFHDUHDVLQWKHRURJHQ 5RJHUV correlate the unconformity formed by forebulge uplift with areas where the rate of accommodation space/ sediment supply is the highest within the foredeep. Regional setting and study areas The merging of different key stratigraphic surfaces and Three major orogenic belts are the result of the migration of foreland depozones is well documented FRPSOH[LQWHUDFWLRQRIWKH1D]FD&DULEEHDQDQG E\HPSLULFDOGDWD *yPH]-RUGDQ$OOPHQGLQJHU 6RXWK$PHULFDSODWHV WKH:HVWHUQ&RUGLOOHUD :& &DUGR]RD DVZHOODVFRQFHSWXDO 'H&HOOHV WKH&HQWUDO&RUGLOOHUD && DQGWKH(DVWHUQ&RUGLOOHUD *LOHV &XUULH DQGQXPHULFDO )OHPLQJV (& )LJXUH 7KH(&LVDGRXEO\YHUJHQWWKUXVWEHOW -RUGDQ PRGHOV placing Cretaceous and Paleogene rocks over a thick Cenozoic succession in the Magdalena Valley to the ,QRQHVHFWLRQRUZHOOGHSRVLWLRQDOVHTXHQFHVLQD west and the Llanos basin to the east. Paleozoic and migrating nonmarine foreland system are recognized RWKHUEDVHPHQWURFNVDUHH[SRVHGDWWKHD[LDO]RQHRI on the basis of regional unconformities and changes of WKH(DVWHUQ&RUGLOOHUD 6DQWDQGHUDQG)ORUHVWDPDV- facies assemblages with distinctive architectural ele- VLIV DQGDORQJWKHVRXWKHUQ/ODQRVIRRWKLOOVVHJPHQW PHQWV HJORZVLQXRVLW\YHUVXVKLJKVLQXRVLW\ÀXYLDO 4XHWDPHDQG*DU]RQPDVVLIV $VXPPDU\RIJHRORJL- V\VWHPV &XUULH :KHQWKHIRUHGHHSGHSR]RQH FDOHYROXWLRQRIWKH&RORPELDQ$QGHV :HVWHUQ&HQWUDO migrates cratonward, the rapid increase of rate of ac- DQG(DVWHUQ&RUGLOOHUDV FDQEHIRXQGLQ&HGLHO6KDZ commodation space and decrease of sediment supply DQG&iFHUHV
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The Paleocene-Miocene succession in the Llanos IRRWKLOOVDQG/ODQRVEDVLQUHFRUGWKH¿OOLQJRIDFRPSOH[ nonmarine foreland system that developed since latest 0DDVWULFKWLDQWLPH 6DUPLHQWR5RMDV %D\RQDet al &RUWpVet al 7KHGHSRVLWLRQDOHQYL- ronment changed from dominantly marine during the latest Cretaceous to marginal and continental during the Paleocene. The primary mechanisms driving this shift is the increasing rate of sediment supply associated with H[KXPDWLRQDQGGHQXGDWLRQRIWKH&HQWUDO&RUGLOOHUD DFFRUGLQJWR*yPH]et al D 8SOLIWVRUE\SDVVLQJ DUHDVGLVUXSWHGWKH3DOHRFHQHIRUHODQGFRQ¿JXUDWLRQ DORQJWKHD[LDO]RQHDQGHDVWHUQERUGHUVRIWKHEDVLQ )DEUH 6DUPLHQWR5RMDV %D\RQD &RUWpV-DUDPLOORDQG/OLQiV 5HVWUHSR3DFHet al&RUWHV %D\RQDet al 8SOLIWV DORQJWKHZHVWHUQPDUJLQRIWKHEDVLQLQ(DUO\(RFHQH time are recorded by an angular unconformity under- O\LQJ(RFHQHVWUDWDLQWKH0DJGDOHQD9DOOH\)RUWKH /DWH(RFHQH2OLJRFHQH7RURet al *yPH]et al D DQG%D\RQDet al XVHGWKHHYLGHQFH RIJURZWKVWUDWDSDWWHUQVÀH[XUDOVXEVLGHQFHDQGWKHU- mochronology to document the presence of a western 0DJGDOHQD9DOOH\ DQGDQHDVWHUQ D[LDO(&/ODQRV GHSRFHQWHUV¿OOHGZLWKFRQWLQHQWDODQGPDUJLQDOV\QR- Figure 1. Regional setting of the Eastern Cordillera and Llanos basin, rogenic strata. There is no record of Miocene strata in and location of Stratigraphic Lines of Correlation (SLC). Sections/ wells are listed from west to east for each SLC. For simplicity, sections WKHD[LDO]RQHRURQWKHÀDQNVRIWKH(&EXWFRQWLQHQWDO and wells were projected to each SLC to construct the stratigraphic synorogenic deposition continued both in the Llanos correlations shown in Figures 2 to 4. Geographic coordinates of /HRQ)RUPDWLRQ DQG0DJGDOHQDEDVLQV sections and wells are given in Table 1 Stratigraphic correlation of the paleocene-middle 6HYHUDOVWDJHVRIGHIRUPDWLRQZLWKLQWKH(&KDYH miocene succession been recognized, including deformation in the lat- The Paleocene - middle Miocene foreland succes- HVW&UHWDFHRXV %UDQTXHW/DXPRQLHU&KHLOOHW] sion of the Llanos foothills and Llanos basin includes, *LXOLDQL %D\RQDet al HDUO\3DOHRJHQH in stratigraphic order, the Barco, Cuervos, Mirador, 6DUPLHQWR5RMDV 5HVWUHSR3DFH&ROPHQDUHV &DUERQHUDDQG/HRQIRUPDWLRQ$WOHDVWHLJKWÀRRGLQJ +LJXHUD 0D\RUJD DQG2OLJRFHQH 7RUR DQGXQFRQIRUPLWLHVVXUIDFHV &RRSHUet al RU 5RXUH%RUGDV/H)ORQFK/H&RUQHF/DQFH 6DVVL EDVHOHYHOWXUQDURXQGV 5H\HVet al )DMDUGRet *yPH]et alD 3UHYLRXVVWXGLHVRIWKH al KDYHEHHQLGHQWL¿HGLQWKHHDVWZDUGWKLQQLQJ &HQR]RLFHYROXWLRQRIWKH(&KDYHDJUHHGWKDW FODVWLFZHGJHRIWKH/ODQRVEDVLQ &RRSHUet al XSOLIWRIWKH&&SUHGDWHGWKDWRIWKH(& &RRSHUet al., 7KHVHVWXGLHVSURSRVHGWKDWWKH3DOHRFHQH%DUFR)RUPD- *yPH]et alD WKH(&UHSUHVHQWVWKH WLRQDQGWKH(RFHQH0LUDGRU)RUPDWLRQWKHUHVHUYRLU LQYHUVLRQRI0HVR]RLFJUDEHQERXQGLQJIDXOWV VHHD units in the Llanos foothills, are bounded at the base by an review and details in Mora et al DQG WKH XQFRQIRUPLW\ RUDQDEUXSWGHFUHDVHRIDFFRPPRGDWLRQ PDMRUSXOVHRIURFNDQGVXUIDFHXSOLIWRIWKH(&RF- VSDFHVHGLPHQWVXSSO\UDWHV DQGDWWKHWRSE\DÀRRGLQJ FXUUHGLQWKH/DWH0LRFHQH3OLRFHQH &RRSHUHt al., VXUIDFH RUDQDEUXSWLQFUHDVHRIDFFRPPRGDWLRQVSDFH 7RURet al *yPH]et alD VHGLPHQWVXSSO\UDWHV ,QWKH/ODQRVEDVLQVDQGVWRQHVRI
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Table 1. Palynological analysis carried out at different sections/wells in each stratigraphic line of correlation (SLC). Only palynological samples with more of 50 grain counts were used to calculate the percentage of marine influence (sum of dinoflagellate, foram linings and marine acritarcha over the total number of palynomorphs)
Geographic Total of samples Samples with coordinates analyzed >50 points Interval sampled Section (*)/ North West rock ditch rock ditch Well (º) (º) sample cutting sample cutting Northern SLC Va* 7,16 72,45 81 31 Maastrichtian-Eocene G1 7,04 72,17 125 84 Eocene-Oligocene G2 7,04 72,17 132 103 Oligocene-Miocene A1 6,95 71,85 16 17 Campanian-Oligocene A3 6,98 71,82 1 3 30 31 Turonian-Miocene CL1 6,94 71,13 4 4 Campanian-Oligocene Central SLC La (Paz de 6,02 72,74 27 18 Middle Eocene - mid-Oligocene Rio)*
La (Cosgua)* 5,93 72,78 24 18 Paleocene-Middle Eocene / Pardo (2004) TN (Q. San 4,84 73,21 15 15 Maastrichtian-Paleocene / Guerrero and Sarmiento Antonio)* (1996) TN (Q. 4,96 73,04 69 39 Paleocene-Eocene / Jaramillo (1999); Jaramillo and Dilcher Piñalerita)* (2001); Jaramillo (2002) TN (Q. 4,8 73,19 55 44 Late Eocene - mid-Oligocene Guadualera)* C 5,11 72,66 111 55 Turonian-Eocene BA 4,98 72,74 76 75 Oligocene-Miocene BA 4,98 72,74 144 124 Turonian-Eocene LM 5,07 72,51 14 2 Campanian-Oligocene LC 5,05 72,45 11 6 Campanian-Oligocene LG 5,03 72,35 22 15 Campanian-Oligocene LG 5,03 72,35 2 2 Oligocene Ce 4,9 72,25 13 3 Campanian-Oligocene LP 4,81 72,08 22 12 Campanian-Oligocene Southern SLC Co-1 3,77 73,73 100 62 Turonian-Miocene Ar-1 3,52 73,69 65 30 Turonian-Miocene Cu-1 (near 3,79 72,04 34 4 Paleozoic; Oligocene-Miocene Ga-1) SA-5 3,25 73,23 47 Eocene-Miocene Ca-1 3,64 73,4 13 Paleozoic; Oligocene SV-4 3,53 71,64 11 Paleozoic; Oligocene-Miocene SA-10 3,06 72,83 27 Paleozoic; Oligocene-Miocene SA-14 3,4 73,05 56 43 Oligocene-Miocene PR-1 3,12 72,7 32 20 Miocene
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 55 GERMAN BAYONA et al.
Figure 2. Correlation of Paleocene strata along the northern SLC. See Figure 1 for sections locations and codes. Datum is at the uppermost record of Paleocene strata. Gamma-ray profiles or grain-size trends are duplicated for each section/well. Sandstone beds of the Barco Formation correlate westward with fine-grained strata of the Cuervos Formation. In an eastward (basinward) direction, younger strata onlap older strata as predicted by the migration of depozones in a foreland basin
WKHORZHUPRVW&DUERQHUD)RUPDWLRQRYHUOLH3DOHRFHQH palynological samples from wells and outcrops were strata or the basal Cenozoic unconformity in distal set- DQDO\]HGWRVXSSRUWVWUDWDOFRUUHODWLRQV 7DEOH VHH WLQJV -DUDPLOORet al details for construction of the Cenozoic palynological ]RQDWLRQLQ-DUDPLOOR 5XHGD -DUDPLOOR0XxR] We studied the Paleocene-middle Miocene suc- &RJROOR 3DUUD $OOWKHDERYHGDWDLQFRQ- cession along three Stratigraphic Lines of Correla- junction with the vertical arrangement of lithofacies, WLRQ 6/& QDPHGWKHQRUWKHUQFHQWUDODQGVRXWKHUQ provide the support for the interpretation of depositional 6/& )LJXUH LQRUGHUWRFKDUDFWHUL]HWKHUHJLRQDO environments. H[WHQWDQGVWUDWLJUDSKLFVLJQL¿FDQFHRIWKRVHEDVH level turnarounds in the Llanos foothills and Llanos 0DMRUXQFRQIRUPLWLHVDQG0LRFHQHÀRRGLQJVXU- basin. Key sedimentological, vertical stacking patterns, faces were selected mainly as stratigraphic datums for framework sandstone composition, and paleontological VWUDWLJUDSKLFFRUUHODWLRQVSUHVHQWHGLQ)LJXUHVWR SROOHQVSRUHGLQRÀDJHOODWHIRUDPLQLIHUDPDFURIRVVLOV Stratigraphic descriptions focus on intervals of change FRQWHQW GDWDZHUHDQDO\]HGIRUDWRWDORIZHOOVXV- LQOLWKRORJ\VWDFNLQJSDWWHUQV)URPEDVHWRWRSWKHVH ing electric logs, cores and cuttings. Three composite intervals are: the Barco-Cuervos contact, the Cuervos- VWUDWLJUDSKLFVHFWLRQVRQWKH/ODQRVIRRWKLOOVDQGD[LDO Mirador contact, the Mirador-Carbonera contact, lower ]RQHRIWKH(DVWHUQ&RUGLOOHUDZHUHFRQVWUXFWHGWROLQN and upper contacts of basal Carbonera sandstones in the depositional systems between the Llanos foothills and Llanos basin, and changes across Lower and Middle /ODQRVEDVLQ2QHWKRXVDQGWKUHHKXQGUHG¿IW\WZR 0LRFHQHÀRRGLQJVXUIDFHV,QRUGHUWRXQGHUVWDQGWKH
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION
Figure 3. Correlation of Paleocene to Oligocene strata along the central SLC. See Figure 1 for location and code definition of sections. Note change of scale to the west of the Llanos foothills. Datum is uppermost oligocene strata. gamma-ray profiles or grain-size trends are duplicated for each section/well. There are no Eocene strata in the Llanos basin, whereas in the axial zone of the EC the thickness reaches approximately 900 m. Basal sandstone beds of the Carbonera Formation on the Llanos basin correlate with thick fine-grained strata of the Carbonera Formation in the Llanos foothills. See Figure 8 for chronostratigraphic correlation diachronism of changes in lithology/stacking patterns IRRWKLOOVDQG/ODQRVEDVLQ7KH%DUFR)RUPDWLRQXQFRQ- within the Paleocene-middle Miocene succession, we IRUPDEO\RYHUOLHV¿QHJUDLQHGVWUDWDRIWKH&RORQ0LWR used our palynological control as a guide to the place- -XDQ)RUPDWLRQ RU*XDGXDV)RUPDWLRQLQWKHD[LDO]RQH PHQW&HQR]RLFHSRFKERXQGDULHV HJORZHU3DOHRFHQH RIWKH(DVWHUQ&RUGLOOHUD 7KH%DUFR&XHUYRVVXFFHV- XSSHU3DOHRFHQH 2OLJRFHQH0LRFHQH DVSUHFLVHO\DV sion is recorded in the northern and central SLC, but co- age resolution allowed. HYDOVWUDWDDUHWUXQFDWHGNPQRUWKRIWKHVRXWKHUQ SLC. The Barco-Cuervos succession thins eastward and Barco-Cuervos and Cuervos-Mirador contacts forms an eastward-stepping stratal package onlapping Distribution and age. The Barco and Cuervos for- the basal Cenozoic unconformity in the western Llanos PDWLRQV RU/RZHU6RFKD8SSHU6RFKDIRUPDWLRQVLQ basin. Strata beneath the unconformity are older toward WKHD[LDO]RQHRIWKH(DVWHUQ&RUGLOOHUD FRPSULVHWKH the craton, whereas strata above the unconformity are lowermost nonmarine foreland succession in the Llanos \RXQJHUFUDWRQZDUG7KHDJHRIWKH%DUFR)RUPDWLRQLV
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 GERMAN BAYONA et al. lower Paleocene in the central SLC and mostly upper 9HUJDUD 5RGUtJXH] 0HVD 3DOHRFHQHLQWKHQRUWKHUQ6/&7KH8SSHU3DOHRFHQH /LWKLFIUDJPHQWVFRPSULVHXSWRWKHRI &XHUYRV)RUPDWLRQFRUUHODWHVHDVWZDUGLQWKH/ODQRV the framework grains and include mainly sedimentary EDVLQZLWKWKH%DUFR)RUPDWLRQ )LJXUHVDQG /RZHU IUDJPHQWV VLOWVWRQHVFKHUW DQGDPLQRUFRPSRQHQW Mirador beds accumulated earlier in the Llanos foothills RIPHWDPRUSKLF JQHLVVVFKLVWSK\OOLWH DQGLJQHRXV WKDQHTXLYDOHQWVDQGVWRQHVEHGVLQWKHD[LDO]RQHRIWKH URFNIUDJPHQWV4XDUW]DUHQLWHFRPSRVLWLRQGRPLQDWHV (DVWHUQ&RUGLOOHUD )LJXUHVDQG LQORZHU0LUDGRU)RUPDWLRQVDQGVWRQHEHGV 0HVD EXW&UHWDFHRXVIRUDPLQLIHUDIUDJPHQWV Lithology and stacking patterns.7KH%DUFR)RU- RFFXUORFDOO\LQWKHPDWUL[RIFRQJORPHUDWHV &pVSHGHV PDWLRQUHVWVXSRQDUHJLRQDOGLVFRQIRUPLW\ )LJXUHV 3HxD DQGFKHUWDUJLOODFHRXVJQHLVVVFKLVW DQG 7KLVXQLWFRQVLVWVRIDPDOJDPDWHGTXDUW]RVH DQGLJQHRXVIUDJPHQWV 0HVD KDYHEHHQ sandstones with sedimentary structures that change reported. XSVHFWLRQIURP FURVVEHGGHG¿QHWRFRDUVHJUDLQHG ¿QLQJXSZDUGVDQGVWRQHVWKDWDUHORFDOO\FRQJORPHUDWLF Palynological association.,QWKHD[LDO]RQHRIWKH LQ&RFX\ VRXWKRIQRUWKHUQ6/&LQ)LJXUH )DEUH (&WKH/RZHU6RFKD)RUPDWLRQLQFOXGHVFRQWLQHQWDO WR LQWHUEHGVRI¿QLQJXSZDUGVDQGVWRQHDQG SDO\QRIORUDV DQJLRVSHUPVPRVWO\SDOPV 3DUGR PXGVWRQHEHGVDQGWR ELGLUHFWLRQDOFURVVEHGGHG ,QWKH/ODQRVIRRWKLOOVSDO\QRÀRUDVLQWKH and bioturbated heterolithic laminated sandstones at %DUFR)RUPDWLRQDUHGRPLQDWHGE\YHU\IHZVSHFLHV the top with organic rich mudstones and coal beds in ZLWK1\SDSROOHQ DEUDFNLVKZDWHUSDOP DVWKHPRVW WKH/ODQRVIRRWKLOOV,QWKH/ODQRVEDVLQWKH%DUFR)RU- FRPPRQHOHPHQW)HZGLQRÀDJHOODWHVJUDLQVZHUHUH- PDWLRQFKDQJHVIURPDJJUDGHG¿QHWRFRDUVHJUDLQHG ported in the Llanos foothills of the central SLC near VDQGVWRQHVWR¿QLQJXSZDUGVDQGVWRQHVDWWKHWRS WKHWRSRIWKH%DUFR)RUPDWLRQ ZHOO& %$LQ)LJXUH /RZHUEHGVRI&XHUYRVDQG8SSHU6RFKDIRUPDWLRQV The contact between the Barco and Cuervos forma- are dominated by a low-diversity assemblage composed tions in the northern and central SLC is marked by an mainly of palms, Araceaea, Proteaceae, Bombacacae LQFUHDVHRI¿QHJUDLQHGOLWKRORJLHVZLWKDGRPLQDQW DQGOHJXPHVVXJJHVWLQJDIRUHVWZLWKWURSLFDODI¿QLWLHV aggradational stacking pattern. Lower beds of the $WWKH/RZHU6RFKD8SSHU6RFKDFRQWDFWWKHSROOHQ &XHUYRV)RUPDWLRQFRQVLVWPDLQO\RIODPLQDWHGWROR- FRQWHQWLQFUHDVHVVLJQL¿FDQWO\ 3DUGR ZKHUHDV cally bioturbated dark-gray organic-rich claystones and morphospecies diversity increases at the Cuervos- mudstones with thin coal seams and pass upsection to 0LUDGRUFRQWDFW -DUDPLOORet al ¿QLQJDQGFRDUVHQLQJXSZDUGVXFFHVVLRQVZLWKFURVV bedded, ripple and wavy laminated sandstones. Depositional environment. The vertical arrange- ment of lithofacies and palynological association of the $PDOJDPDWHGVDQGVWRQHVRIWKH0LUDGRU)RUPDWLRQ Barco-Cuervos-Mirador succession has been interpreted RU3LFDFKR)RUPDWLRQLQWKHD[LDO]RQHRIWKH(DVWHUQ DVSURGXFWRIGHSRVLWLRQLQÀXYLDOV\VWHPV7KHXSSHU- &RUGLOOHUD GLVFRQIRUPDEO\RYHUOLHPXGVWRQHVDQG PRVW%DUFRVDQGVWRQHVVKRZPRUHÀXYLDOLQÀXHQFHLQ OLWKDUHQLWHVRIWKH&XHUYRV)RUPDWLRQ6DQGVWRQHEHGV WKHD[LDO(DVWHUQ&RUGLOOHUDWKDQLQWKH/ODQRVIRRWKLOOV DUH¿QHWRPHGLXPJUDLQHGDQGORFDOO\FRQJORPHUDWLF in the latter area, bi-directional cross beds, heterolithic Sedimentary structures are massive, cross-bedded and ODPLQDWLRQ &D]LHUet al 5H\HV DQGIHZ wavy-laminated to the top. Thin-to medium-bedded GLQRÀDJHOODWHJUDLQVVXJJHVWPRUHWLGDOO\LQÀXHQFHG lenses of gray massive sandy mudstones are locally GHSRVLWLRQ7KH&XHUYRV8SSHU6RFKDDFFXPXODWHGLQ preserved. FRDVWDOSODLQVZLWKPRUHHVWXDULQHLQÀXHQFHWRZDUGWKH Sandstone composition. An upward increase in /ODQRVIRRWKLOOV7KHH[FHOOHQWSROOHQUHFRYHU\LQORZHU polycrystalline quartz and unstable lithic fragments has EHGVRIWKH&XHUYRVDQG8SSHU6RFKDXQLWVVXJJHVWD been documented from quartzarenites to sublitharenites YHU\KXPLGHQYLURQPHQWZLWKVPDOOÀXFWXDWLRQVRIWKH in the Barco - Lower Socha units, and to litharenites in ZDWHUWDEOHWKDWZDVQHDUWKHVXUIDFH 3DUGR WKH&XHUYRV8SSHU6RFKDIRUPDWLRQV )DEUH Summary. The Barco-Cuervos succession com- -DUDPLOOR5RD 7RUUHV &pVSHGHV 3HxD SULVHVDFRQIRUPDEOHÀXYLDOFRDVWDOSODLQSDFNDJH
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION
ERXQGHGE\WZRGLVFRQIRUPLWLHV RUDEUXSWGHFUHDVHRI grained quartzarenites have more interbeds of organic DFFRPPRGDWLRQVHGLPHQWVXSSO\UDWH 7KLVVXFFHVVLRQ mudstones with plant remains that show evidence of is an eastward-stepping stratal package onlapping the deposition in a brackish-water environment, including: basal Cenozoic unconformity. Amalgamated quartzose DGLYHUVHLFKQRIDFLHVDVVRFLDWLRQ 2SKLRPRUSKD VDQGVWRQHEHGVRYHUOLHWKHORZHU %DUFR)RUPDWLRQ 7KDODVVLRQRLGHV3VLORQLFKQXVDQG'LSORFUDWHULRQ DQGXSSHU 0LUDGRU)RUPDWLRQ GLVFRQIRUPLWLHVEXW 3XOKDP0LWFKHOO0DF'RQDOG 'DO\ Barco sandstones are younger eastward, whereas FRXSOHWVLQIRUHVHWODPLQDWLRQVDQG ZDY\DQG Mirador sandstones are younger westward. The Barco- ÀDVHUODPLQDWLRQ2YHUO\LQJ&DUERQHUDVWUDWDLQWKH &XHUYRVFRQWDFWLV\RXQJHUFUDWRQZDUGDQGUHFRUGV Llanos foothills of the northern and central SLC DQDEUXSWLQFUHDVHRIDFFRPPRGDWLRQVSDFHDQG FRQVLVWGRPLQDQWO\RIPWKLFNGDUNJUHHQDQG input of sedimentary and metamorphic lithic fragments gray laminated and poorly bioturbated mudstones to the coastal plain system. The Barco-Cuervos contact -DUDPLOOR -DUDPLOOR 'LOFKHU 0RUD records the lateral migration of depositional environ- 3DUUD JUDGLQJWRFRDUVHQLQJXSZDUGVXFFHV- ments, whereas the Cuervos-Mirador contact records VLRQV )LJXUH an abrupt decrease of accommodation/sediment supply rate within a continental setting. ,QWKH/ODQRVEDVLQWKHEDVDOVDQGVWRQHRIWKH &DUERQHUD)RUPDWLRQFRQVLVWVRIDPDOJDPDWHGWR Mirador-Carbonera contact in the Llanos foothills; ¿QLQJXSZDUGVXFFHVVLRQVRI¿QHWRFRDUVHJUDLQHG lower and upper contacts of the basal Carbonera TXDUW]DUHQLWHVORFDOO\FRQJORPHUDWLF,QWKHFHQWUDO SLC, both the thickness of this basal sandstone and the sandstones in the Llanos basin thickness of the sandstone-mudstone transition increase Distribution and age. Strata of lower and middle HDVWZDUG )LJXUH ,QWKHVRXWKHUQ6/&WKHWKLFNQHVV (RFHQHDJH 0LUDGRUDQG3LFDFKRIRUPDWLRQV DUHUH- LQFUHDVHVHDVWZDUGXSWR!P ZHOOV)DQG&D SRUWHGRQO\WRWKHZHVWRIWKH/ODQRVIRRWKLOOV -DUDPLOOR LQ)LJXUH DQGGHFUHDVHVIDUWKHUHDVW7KHWKLFNQHVV et al )LJXUH 8SSHU(RFHQHVWUDWDLQFOXGHWKH FKDQJHVDUHDWWULEXWHGWRWKH¿OOLQJRILQFLVHGYDOOH\V contact between the Mirador-Carbonera formations in RURQODSRYHUVWUXFWXUDOKLJKV HJ/DV%UXMDVKLJK WKH/ODQRVIRRWKLOOV RUWKH3LFDFKR&RQFHQWUDFLRQIRU- 'DUNFRORUHGPXGVWRQHVVKDOHVDQGWKLQFRDOLQWHUEHGV PDWLRQVLQWKHD[LDO(DVWHUQ&RUGLOOHUD ,QWKH/ODQRV diachronously overlie these basal sandstones. At the EDVLQHLWKHUDEDVDOVDQGVWRQHRU¿QHJUDLQHGVXFFHV- ZHVWHUQVHJPHQWRIWKHVRXWKHUQ6/&WKLV¿QHJUDLQHG VLRQVRIWKH&DUERQHUD)RUPDWLRQXQFRQIRUPDEO\FRYHU LQWHUYDOLVIROORZHGE\D¿QLQJXSZDUGVXFFHVVLRQ Paleocene and Campanian beds in the northern and which is not present in any other area. FHQWUDO6/& )LJXUHVDQG DQG8SSHU&UHWDFHRXV DQG3DOHR]RLFEHGVLQWKHVRXWKHUQ6/& )LJXUH 7KH Sandstone composition. Sandstone of the Mirador age of lower Carbonera strata is younger northward and )RUPDWLRQDQGWKHEDVDOVDQGVWRQHVRIWKH&DUERQHUD HDVWZDUGDQGYDULHVIURPODWH(RFHQHWRPLG2OLJRFHQH DUHTXDUW]DUHQLWHV 0HVD 7KHORZHUKDOI 2OLJRFHQHIRUHODQGGHSRVLWVRIWKH&DUERQHUD)RUPD- RIWKH&DUERQHUD)RUPDWLRQLVFRPSULVHGRITXDUW] WLRQIRUPHGDZHGJHOLNHEDVLQJHRPHWU\ WKHWKLFNQHVV DUHQLWHVDQGVXEOLWKDUHQLWHV )DEUH 0RUHQR of Oligocene strata in the Llanos basin is at least half of 9HOiVTXH] &DUGRQD *XWLpUUUH] ,QWKH WKHWKLFNQHVVSUHVHUYHGLQWKH/ODQRVIRRWKLOOV )LJXUHV D[LDO]RQHRIWKH(DVWHUQ&RUGLOOHUDFRQJORPHUDWH DQG 8SSHU2OLJRFHQHVWUDWDFRPSOHWHO\FRYHUHG EHGVRIWKH&RQFHQWUDFLRQ)RUPDWLRQFRQWDLQFKHUW WKH/ODQRVEDVLQZLWKH[FHSWLRQRIGLVWDOXSOLIWHGEORFNV DQGIRVVLOLIHURXVOLPHVWRQHVRI&UHWDFHRXVDJH 5H\HV LQWKHVRXWKHUQ/ODQRVEDVLQ )LJXUH 9DOHQWLQR Lithology and stacking patterns. Lithofacies as- Palynological association. Palynoflora assem- VRFLDWLRQVRIWKHXSSHU0LUDGRU)RUPDWLRQYDU\DORQJ blages of the upper Mirador and lower Carbonera in WKH/ODQRVIRRWKLOOV,QWKHQRUWKHUQ6/&WKHXSSHU the Llanos foothills are very similar to each other. The 0LUDGRUVDQGVWRQHVVKRZFRPSOHWH¿QLQJXSZDUG (RFHQH2OLJRFHQHERXQGDU\LVZHOOGRFXPHQWHGE\ VXFFHVVLRQVDQGFRDOLQWHUEHGV 5H\HV ,QWKH DODUJHH[WLQFWLRQRISDO\QRPRUSKV -DUDPLOORet al., /ODQRVIRRWKLOOVRIWKHFHQWUDO6/&¿QHWRPHGLXP 3DO\QRORJLFDOVDPSOHVIURPWKH8SSHU0LUDGRU
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 GERMAN BAYONA et al.
Figure 4. Schematic correlation of upper Eocene - middle Miocene strata using 10 wells projected along the southern SLC (**wells SA-5 and PR-1 are more than 40 km from SLC and are used only for reference). See Figure 1 for section locations and codes. Datum is the lower marine flooding surface of early Miocene age. Gamma-ray profiles are shown for each well, except for PR-1 which shows the spontaneous potential profile and F1 which shows a resistivity log. Basal sandstone beds of the Carbonera Formation on the eastern segment correlate with thick fine-grained strata of the Carbonera Formation in the western segment. Note lateral change of gamma-ray profiles in the correlation of the flooding surface
LQWKHFHQWUDO6/&LQGLFDWHDPDULQHLQÀXHQFHWKDW Depositional Environment.8SSHU0LUDGRUVDQG- UDQJHVIURPWR6DPSOHVIURPWKHORZHUPRVW VWRQHVKDYHEHHQLQWHUSUHWHGDVÀXYLDOFKDQQHOVDQG &DUERQHUD)RUPDWLRQLQWKHZHVWHUQVLGHRIWKHVRXWKHUQ mouth-bar sands deposited on a coastal plain in the 6/& ZHOOV&RDQG$U LQWKHD[LDO]RQHRIWKH FHQWUDO/ODQRVIRRWKLOOV &D]LHUet al )DMDUGR (DVWHUQ&RUGLOOHUDDQG/ODQRVIRRWKLOOVRIWKHFHQWUDO :DUUHQ 3XOKDP ZLWKPRUHFRQWLQHQWDO 6/& VHFWLRQV/DDQG71 DQGLQWKH/ODQRVIRRWKLOOV LQÀXHQFHLQWKHQRUWKHUQ/ODQRVIRRWKLOOV 5H\HV RIWKHQRUWKHUQ6/& ZHOO* * LQGLFDWHPDULQH Lithological associations of lowermost Carbonera beds LQÀXHQFHRIRUOHVV,QWKH/ODQRVEDVLQWKHUHDUH in the Llanos basin have been interpreted as a change only isolated occurrences of brackish-water palynologi- IURPFKDQQHO¿OOSURFHVVHVLQÀXYLDOV\VWHPVWRWLGDOO\ cal assemblages to the top of the basal sandstone and LQÀXHQFHGFRDVWDOSODLQVDQGGHOWDED\VWRWKHWRSRI algae colonies in the southern Llanos basin. WKHEDVDOVDQGVWRQHV )DMDUGRet al
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION
Summary.4XDUW]RVHVDQGVWRQHVRIWKH0LUDGRU south and east, to variable grain-size trends toward the )RUPDWLRQLQWKH/ODQRVIRRWKLOOVDQGWKHEDVDO ZHVWHUQPDUJLQ )LJXUH VDQGVWRQHVRIWKH&DUERQHUD)RUPDWLRQLQWKH/ODQRV basin overlie two different stratigraphic surfaces. The /RZHUVWUDWDRIWKH/HRQ)RUPDWLRQFRQVLVWRIZDY\ former unit disconformably overlies Paleocene strata, laminated, bioturbated, and varicolored mudstones whereas the latter is an eastward-stepping stratal interbedded with tabular-bedded, bioturbated quartza- package that onlap the basal Cenozoic unconformity UHQLWHV *HRHVWUDWRV'XQLD LQWKH/ODQRVIRRW- in the Llanos basin. The nature of the upper contacts KLOOV,QWKH/ODQRVEDVLQORZHU/HRQVWUDWDFRQVLVWRI of these sandstone units also differ. The Carbonera- a thick interval of dark-colored laminated mudstones Mirador contact in the Llanos foothills area shows DQGVKDOHV6DQGVWRQHLQWHUEHGVLQWKH/HRQ)RUPDWLRQ HYLGHQFHRIDODWH(RFHQHPDULQHWUDQVJUHVVLRQDV LQFUHDVHQRUWKZDUGDQGZHVWZDUG &RRSHUet al documented by ichnofossils and paleontological data. )DMDUGRet al ,QFRQWUDVWWKHXSSHUFRQWDFWRIWKHEDVDOVDQGVWRQHV Sandstone composition. Compositional analysis in the Llanos basin is more transitional, and the of well cuttings indicates an increment of feldspar and RYHUO\LQJ¿QHJUDLQHGVWUDWDRQO\VKRZHYLGHQFHRI lithic fragments, and the sandstones at the western eastward and northward migration of coastal-plain margin of the Llanos basin are compositionally more environments. immature than sandstones at the eastern margin of the basin. /RZHUDQG0LGGOH0LRFHQHÀRRGLQJVXUIDFHVRIWKH upper Carbonera-Leon formations Palynological association. Poaceae and Mauritia Distribution and age. Strata deposited during early PRQRVWDQGSDOPVFRPPRQO\IRXQGRIULSDULDQIRUHVWV and middle Miocene time correspond to the upper Car- dominate the assemblage in upper Oligocene strata, sug- bonera and Leon formations in the Llanos foothills and gesting development of savannas. Lower-middle Miocene Llanos basin. Sandstones of the upper Carbonera record SDO\QRÀRUDVKDYHDORZHUGLYHUVLW\WKDQ(RFHQHORZHU the last pulses of pre-Andean deformation, whereas 2OLJRFHQHSDO\QRÀRUDV,QVRPH¿QHJUDLQHGLQWHUYDOVLQ VKDOHVRIWKH/HRQ)RUPDWLRQUHFRUGDEDVLQZLGHÀRRG- the upper Carbonera and at the Carbonera-Leon contact, ing event during the Middle Miocene. The Carbonera- IUHVKZDWHU ODFXVWULQHDOJDH EXWDOVREUDFNLVKZDWHU /HRQFRQWDFWLVGH¿QHGE\WKHRQVHWRI¿QHJUDLQHG SDO\QRORJLFDODVVRFLDWLRQVGLQRÀDJHOODWHF\VWVDQGIRUD- deposition that occurred earlier in the eastern Llanos PLQLIHUDWHVWOLQLQJVDUHREVHUYHG )LJXUH DQGFRQWULE- EDVLQWKDQLQWKH/ODQRVIRRWKLOOV )LJXUH XWHGWRWKHHYLGHQFHIRUGH¿QLQJÀRRGLQJHYHQWVLQWKH lower-middle Miocene strata. Samples from these levels Lithology and stacking patterns.,QWKH/ODQRV have been analysed for foraminifera and thecamoebians foothills of the northern and central SLC, lower Mio- content, showing strong evidences of alternating fresh to cene Carbonera strata consist of coarsening-upward EUDFNLVKZDWHUFRQGLWLRQV )ODYLD)LRULQL675,SRVWGRF- successions that begin with laminated mudstones grad- WRUDOIHOORZSHUVRQDOFRPPXQLFDWLRQ 7KHUHIRUH ing to tabular and wavy laminated, locally bioturbated, ÀRRGLQJVXUIDFHVZHUHLGHQWL¿HGLQZHOOVRQWKHEDVLVRI ¿QHJUDLQHGVDQGVWRQHV )DMDUGRet al ,QWKH biostratigraphic data and the shale signature at the base of central Llanos foothills, these successions include FRDUVHQLQJXSZDUGVXFFHVVLRQVLQJDPPDUD\SUR¿OHV FRDOLQWHUEHGVIHOGVSDUEHDULQJ¿QHJUDLQHGPXGG\ sandstones and locally conglomeratic massive to cross- Depositional Environment. The northward and EHGGHGVDQGVWRQHV 0RUD 3DUUD eastward lateral change of depositional patterns in the XSSHU&DUERQHUD)RUPDWLRQVXSSRUWVDQLQWHUSUHWDWLRQ ,QWKHQRUWKHUQDQGFHQWUDO/ODQRVEDVLQ¿QLQJ RIDQHDVWZDUGSURJUDGLQJÀXYLDOGRPLQDWHGGHOWD and coarsening-upward successions constitute the SODLQWKDWGHYHORSHGLQWRDFRDVWDOSODLQ RUVDYDQQDV &DUERQHUD)RUPDWLRQ7KLVXQLWJUDGHVHDVWZDUGWRD and a coeval shallow lacustrine system in the Llanos ¿QHUJUDLQHGVXFFHVVLRQ,QWKHVRXWKHUQ6/&XSSHU EDVLQWRWKHHDVW 0RUD 3DUUD 7KHODFXVWULQH Carbonera strata change from coarsening-upward suc- V\VWHPZDVERXQGHGRQWKHHDVWE\DÀXYLDOV\VWHP cessions, which include calcareous mudstones to the draining the Guyana craton, and it eventually has an
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 GERMAN BAYONA et al.
LQÀX[RIEUDFNLVKZDWHUV7KHFKDQJHRISDWWHUQRI SEISMIC IMAGES OF STRATIGRAPHIC deposition and depositional environments from Car- SURFACES ERQHUDWR/HRQEHGVLQGLFDWHVDZHVWZDUGÀRRGLQJRID EURDGÀXYLDOGHOWDLFV\VWHPIROORZHGE\UHJLRQDORQVHW Seismic facies, unconformity surfaces, and onlap/trun- DQGHVWDEOLVKPHQWRIIUHVKVKDOORZZDWHU ODFXVWULQH FDWLRQVRIUHÀHFWRUVZHUHLGHQWL¿HGRQ'VHLVPLFUHÀHF- HQYLURQPHQWVZLWKOHVVHVWXDULQHLQÀXHQFHWKDQWKDW WLRQSUR¿OHV8QFRQIRUPLWLHVDEUXSWFKDQJHVLQOLWKRORJ\ UHSRUWHGLQ(RFHQHVWUDWD VWDFNLQJSDWWHUQVDQGÀRRGLQJHYHQWVLGHQWL¿HGLQZHOOV Summary.)OXYLDOGHOWDLFGHSRVLWLRQDOV\VWHPV ZHUHWLHGWRVHLVPLFUHÀHFWRUVDQGWUDFHGUHJLRQDOO\DORQJ of the lower Miocene Carbonera formation advanced FRPSRVLWHVHLVPLFOLQHV8SSHU3DOHRFHQH%DUFR&XHUYRV eastward, transporting synorogenic detritus toward VWUDWDLQWKHQRUWKHUQ6/&DUHGH¿QHGDVGLVFRQWLQXRXV VKDOORZODFXVWULQHHQYLURQPHQWV)OXYLDOV\VWHPVGUDLQ- VHLVPLFUHÀHFWRUVRQODSSLQJRQWRDQXQFRQIRUPLW\WRZDUG ing the Guyana craton also supplied detritus into the WKHHDVWZDUGWUHQG )LJXUH 7KHXQFRQIRUPLW\XQGHUO\- lacustrine setting. Westward-stepping and encroaching LQJ&DUERQHUDVWUDWDLQWKH/ODQRVEDVLQLVLGHQWL¿HGE\ RI¿QHJUDLQHGODFXVWULQHGHSRVLWVLQGLFDWHDGHFUHDV- WUXQFDWLRQRIVHLVPLFUHÀHFWRUV )LJXUH LQJLQÀX[RIV\QRURJHQLFGHWULWXVDQGDQLQFUHDVHRI 6WURQJVHLVPLFUHÀHFWRUVLQWKHVRXWKHUQ6/&FDQ accommodation space in the Llanos basin. be traced for several tens of kilometers, providing op-
Figure 5. Composite seismic line along the northern SLC. See Figure 1 for location and code definition of sections. These seismic images show the onlap of upper Paleocene strata, truncation of upper Cretaceous beds, and the lateral continuity of the middle Miocene flooding surface (top of the Carbonera Formation)
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION
Figure 6. Composite seismic line along the southern SLC. See Figure 1 for location and code definition of sections. These seismic images show the onlap of upper Eocene and Oligocene strata, Paleozoic structures beneath the unconformity (no interpreted here), eastward thinning of synorogenic strata, and the lateral continuity of seismic reflectors corresponding to lower and middle Miocene strata. Only two surfaces are shown for simplicity, the first at the top of the Oligocene, and the other at the middle Miocene flooding surface of Figure 4. Note the lateral change of seismic facies above and below the middle Miocene flooding surface
SRUWXQLWLHVWRGHFLSKHURQODSRIVHLVPLFUHÀHFWRUVDQG ONE DIMENSIONAL SUBSIDENCE lateral continuity of seismic facies. The eastward onlap ANALYSIS AND EUSTASY RIUHÀHFWRUVRIWKHGLDFKURQRXVEDVDOVDQGVWRQHDQG PXGVWRQHVRIWKHORZHU&DUERQHUD)RUPDWLRQFDQEH Backstripping techniques were used to decompact WUDFHGODWHUDOO\IRUVHYHUDOWHQVRINLORPHWHUV )LJXUH the measured stratigraphic thickness of each section to ,QWKHHDVWHUQVLGHRI)LJXUHUHÀHFWRUVFRUUHVSRQGLQJ GH¿QHDUHODWLRQEHWZHHQFKDQJHVLQOLWKRORJ\VWDFNLQJ to lower Miocene strata tend to be more continuous. SDWWHUQDQGVORSHFRQ¿JXUDWLRQVRIWHFWRQLFVXEVLGHQFH 7KHXSSHUPRVWFRQWLQXRXVUHÀHFWRUFRUUHVSRQGVWR FXUYHV:HIROORZHGWKHPHWKRGVVSHFL¿HGLQ$OOHQDQG the Carbonera-Leon contact that separates a seismic $OOHQ IRUFRQVWUXFWLRQRIWHFWRQLFVXEVLGHQFH VWUDWLJUDSK\IDFLHVRIVHYHUDOFRQWLQXRXVUHÀHFWRUV FXUYHVDQGZHXVHG¿UVWRUGHUVHDOHYHOFXUYHRI+DT from a facies with fewer and more discontinuous re- +DUGHQERODQG9DLO IRUFRUUHFWLRQRIHXVWDV\ ÀHFWRUV7KHIRUPHUUHSUHVHQWVWKHVDQGVWRQHPXGVWRQH VXFFHVVLRQVRIWKH&DUERQHUD)RUPDWLRQDQGWKHODWWHU The results of our one-dimensional backstripping UHSUHVHQWVWKHGRPLQDQFHRI¿QHJUDLQHGOLWKRORJLHV indicate that in most cases the tectonic subsidence RIVLPLODUDFRXVWLFLPSHGDQFHRIWKH/HRQ)RUPDWLRQ curves are not straight lines, suggesting changes in their +RZHYHUZKHQWKHWRSRIWKH&DUERQHUD)RUPDWLRQ tectonic subsidence history. The Barco-Cuervos and UHÀHFWRULVWUDFHGZHVWZDUGWKHHTXLYDOHQWUHÀHFWRURQ Mirador-Carbonera contacts do not necessarily coincide WKHZHVWHUQVLGHRI)LJXUHFRUUHVSRQGVWRUHÀHFWRUV with the point of an abrupt increase of tectonic subsid- ZLWKLQWKH&DUERQHUD)RUPDWLRQ HQFH )LJXUH 7KHLQFUHDVHRIWHFWRQLFVXEVLGHQFH
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Figure 7. Tectonic subsidence curves for selected wells and sections in the northern and central SLC. Times of increases tectonic subsidence rate are indicated for each curve. Three conformable contacts overlying reservoir units are indicated by rectangles: I Barco-Cuervos contact; II Mirador- Carbonera contact in the llanos foothills and axial zone of the eastern Cordillera; III basal sandstones of the Carbonera Formation on the llanos basin. The width of each rectangle corresponds to the resolution of age for each contact. Note the relation between the event of middle Miocene flooding and the abrupt increase of tectonic subsidence rates across the Barco-Cuervos contact occurred earlier in LQHDUO\2OLJRFHQH P\ DQGUHDFKHGVWUXFWXUDO WKH/ODQRVIRRWKLOOVDQGD[LDO(DVWHUQ&RUGLOOHUDRIWKH highs on the northern and southern Llanos basins at the FHQWUDO6/& P\ WKHQDGYDQFHGWRWKHQRUWKHUQ 2OLJRFHQH0LRFHQHERXQGDU\ P\ $VOLJKW 6/& P\ DQG¿QDOO\PLJUDWHGWRWKH/ODQRV increase in the rate of tectonic subsidence occurs nearly EDVLQDWDURXQG P\ at the top of the Carbonera-Leon formations in the /ODQRVIRRWKLOOVDQG/ODQRVEDVLQ DSUR[P\ DQG 7KH/DWH(RFHQHLQFUHDVHLQWHFWRQLFVXEVLGHQFH WKHVORSHJHQWO\LQFUHDVHVDIWHUP\ DQGWKHRQVHWRI¿QHJUDLQHG&DUERQHUD&RQFHQWUD- cion deposition become younger basinward. However, ¿QHJUDLQHGGHSRVLWLRQRFFXUUHGVOLJKWO\HDUOLHULQWKH DISCUSSION /ODQRVIRRWKLOOV 0LGGOH/DWH(RFHQH P\ WKDQ LQWKHD[LDO(DVWHUQ&RUGLOOHUDDQGLQWKHZHVWHUQVLGH The Barco and Mirador formations, the two main RIWKHVRXWKHUQ6/& /DWH(RFHQHP\ ,QWKH reservoir units in the Llanos foothills, are bounded at central segment of the southern SLC and in the Llanos the base by an unconformity and at the top by abrupt EDVLQRIWKHFHQWUDO6/&¿QHJUDLQHGGHSRVLWLRQEHJDQ FKDQJHVLQOLWKRORJ\VWDFNLQJSDWWHUQV RUEDVHOHYHO
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WXUQDURXQGV (YHQWKRXJKWKHVHVXUIDFHVFDQEH to the forebulge. At the same time and toward the west, recognized in outcrops, wells and seismic lines, our DFRQIRUPDEOHFKDQJHIURPDPDOJDPDWLRQRIÀXYLDO palynological data indicate that strata overlying those HVWXDULQHVDQGEDUV UHVHUYRLUXQLWV WRGHSRVLWLRQRI VXUIDFHVDUHGLDFKURQRXV,QDGGLWLRQFKDQJHVLQVWUDWDO fine-grained siliciclastic sediments on coastal and architecture and sandstone composition across these ÀRRGSODLQVUHSUHVHQWWKHDEUXSWFKDQJHLQOLWKRORJ\ VXUIDFHVDQGWKHHDVWZDUGRQODSRIVHLVPLFUHÀHFWRUV VWDFNLQJSDWWHUQVRI¿QHJUDLQHGVWUDWD HJ&XHUYRV RQWKHXQFRQIRUPLW\PD\EHH[SODLQHGE\PLJUDWLRQ )RUPDWLRQ RYHUO\LQJWKRVHTXDUW]RVHXQLWV HJ%DUFR RIDÀH[XUDOEDVLQ )RUPDWLRQ 7KHVHFKDQJHVDUHQRWÀRRGLQJVXUIDFHV since there is not a marine transgression or accumula- 7KH3DOHRFHQH%DUFR&XHUYRVVXFFHVVLRQDQG8S- WLRQEHORZDGHHSZDWHUFROXPQ LHDODNH 7RZDUG SHU(RFHQH2OLJRFHQHVWUDWDGRFXPHQWWKHFUDWRQZDUG the western side of the foredeep depozone, sedimentary migration of depositional environments as the foredeep and metamorphic rock fragments in upper Paleocene GHSR]RQHPLJUDWHGHDVWZDUG,QERWKFDVHVWKHRQVHW Cuervos sandstones, and feldspar-bearing sandstones of sandstone deposition is diachronous and becomes in Oligocene Carbonera strata accumulated adjacent \RXQJHUHDVWZDUG )LJXUH 7KHRQODSRIVHLVPLFUH- WRXSOLIWHGKLQWHUODQGEORFNV %D\RQD et al ÀHFWRURQWKHXQFRQIRUPLW\DQGWKHTXDUW]RVHFRPSRVL- Therefore, the Barco-Cuervos succession and the lower tion of sandstone beds indicate accumulation adjacent
Figure 8. Chronostratigraphic correlation of Campanian - middle Miocene strata along the central SLC showing events of foredeep migration and the westward direction of lower-middle Miocene flooding event. See Figure 1 for section locations and codes. Note change of scale to the west of the Llanos foothills. Sandstones of the upper Paleocene Barco Formation and upper Eocene-Oligocene Carbonera Formation are younger eastward or basinward, whereas lower-middle Eocene mirador sandstones are younger westward. Lower-middle Miocene flooding surfaces may be considered as the surfaces with the least diachronism and the broadest lateral extension in the Paleocene-middle Miocene succession
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 GERMAN BAYONA et al.
EHGVRIWKH&DUERQHUD)RUPDWLRQUHFRUGWZRHSLVRGHV WKH0LRFHQH IURP$UJHQWLQDWR9HQH]XHOD HJ&RRSHU RIHDVWZDUGPLJUDWLRQRIWKHIRUHODQGEDVLQ )LJXUH et al +RRUQet al %DE\5RFKDW0DVFOH which are also coincident with events of increasing +HUDLO $XGHPDUG $XGHPDUG PD\ rates of tectonic subsidence. H[SODLQWKHEURDGLQFUHDVHRIDFFRPPRGDWLRQVSDFHLQ interior zones as a response to Andean loading. This The diachronous onset of Mirador and Carbonera shift in the scale of the orogen, as documented by geo- GHSRVLWLRQLQWKH/ODQRVIRRWKLOOVDQG(DVWHUQ&RUGLOOHUD G\QDPLFPRGHOV 2MHGDet al LVUHODWHGWRWKH indicate a period of westward migration of the foreland collision of the Panama arch with the northern South basin. Amalgamated quartzose sandstones of the Mira- $PHULFDSODWHLQWKHPLGGOHWRODWH0LRFHQH &RDWHV dor and Picacho formations in the Llanos foothills and &ROOLQV$XEU\ %HUJJUHQ 'XULQJWKH0LGGOH D[LDO]RQHRIWKH(DVWHUQ&RUGLOOHUDDFFXPXODWHGLQD Miocene, it is probable that both eustasy and Andean- period of very slow tectonic subsidence during early VFDOHPRXQWDLQEXLOGLQJSURFHVVHVLQÀXHQFHGUDWHVRI DQGPLGGOH(RFHQHWLPH7KHWKLFNUHFRUGRI(RFHQH generation of accommodation space in the continental GHSRVLWLRQLQWKHD[LDO]RQHRIWKH(DVWHUQ&RUGLOOHUD foreland. DQGWKHDEVHQFHRI(RFHQHVWUDWDLQWKH/ODQRVEDVLQ VXSSRUWWKHZHVWZDUGPLJUDWLRQRIWKHÀH[XUDOZDYH )LJXUH CONCLUSIONS The westward encroaching of shallow-water de- position during early to middle Miocene time caused The Paleocene-Oligocene succession between the the flooding of the fluvial-deltaic system in the D[LDO]RQHRIWKH(DVWHUQ&RUGLOOHUDDQGWKH/ODQRV ZHVWHUQSDUWRIWKH/ODQRVEDVLQ)ORRGLQJHYHQWVDUH foreland basin of Colombia records three migration well recognized across the Llanos basin, allowing a events of the foreland depozones that controlled chronostratigraphic correlation in the foreland basin WKHSUHVHQWJHRPHWU\RIUHVHUYRLUXQLWV'LDFKURQ- )LJXUHVDQG 7KLVSDWWHUQRIGHSRVLWLRQVXJJHVWV ous deposition of the Barco-Cuervos formation a regional transgression of a broad shallow-water during the Paleocene recorded the eastward onlap lacustrine system, as reported in other South American of foreland deposits and the northward advance of basins. Miocene lacustrine and lagoonal deposits have V\QRURJHQLFGHSRVLWLRQ/DWHULQ(RFHQHWLPHZHVW- been also documented in the Colombian Amazonas ward migration of the foredeep depozone favored EDVLQ +RRUQ*XHUUHUR6DUPLHQWR /RUHQWH deposition of amalgamated quartzose sandstones of LQVRXWKHUQ$QGHDQIRUHODQGEDVLQV WKH3HEDVVHD WKH0LUDGRU)RUPDWLRQDQGE\SDVVRQWKH/ODQRV RI0DUVKDOO /XQGEHUJ 8ED+HXEHFN EDVLQ,QODWH(RFHQHWR2OLJRFHQHWLPHWKHIRUHGHHS +XOND DQGLQWKHQRUWKHUQ0DJGDOHQD9DOOH\ depozone advanced rapidly eastward, favoring thick *yPH]et alD DVZHOODVLQVHGLPHQWDU\EDVLQV ¿QHJUDLQHGGHSRVLWLRQLQWKH/ODQRVIRRWKLOOVDQG ZLWKRWKHUWHFWRQLFUHJLPHVVXFKDVLQWKHNPWKLFN GLDFKURQRXVRQVHWRIÀXYLDOVDQGVWRQHGHSRVLWLRQ H[WHQVLRQDO8UXPDFREDVLQLQQRUWKHUQ9HQH]XHOD on the Llanos basin. +DPEDOHNet al 8QFRQIRUPLWLHVWKDWXQGHUOLHDPDOJDPDWHGÀXYLDO 7KHH[WHQWRI0LRFHQHÀRRGLQJHYHQWVLQFUHDVHV sandstones of the Barco and Mirador formations ZLWKWLPHUHÀHFWLQJHLWKHUDPDMRULQÀXHQFHRIHXVWDV\ in the Llanos foothills should be considered only RUDFKDQJHLQVFDOHRIWHFWRQLFHYHQWV$¿UVWRUGHU as the base of synorogenic successions, whereas VHDOHYHOULVHRIOHVVWKDQPGXULQJWKHHDUO\PLGGOH WKHFRQIRUPDEOHFRQWDFWEHWZHHQÀXYLDOHVWXDULQH 0LRFHQH +DTet al FDQQRWH[SODLQDQLQFUHDVH sandstone and marginal mudstones should be used of accommodation space in the interior of the South LQD¿UVWLQVWDQFHWRFRQVWUDLQWKHGLDFKURQRXVPL- $PHULFDSODWH HJ/ODQRVEDVLQ $VKLIWIURPORFDO JUDWLRQRIWKHÀH[XUDOZDYH uplift of internal massifs and other local blocks of WKH(DVWHUQ&RUGLOOHUDVLQFHWKH2OLJRFHQH 7RUR et 'XULQJWKHHDUO\DQGPLGGOH0LRFHQHWKHIRUHODQG al et al *yPH] D 2MHGD%D\RQD3LQLOOD basin recorded a westward-stepping transgression of &RUWpV *DPED WRDUHJLRQDO$QGHDQXSOLIWLQ
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VKDOORZZDWHUV\VWHPVRQWRÀXYLDOGHOWDLFV\VWHPV REFERENCES /RZHUWRPLGGOH0LRFHQHÀRRGLQJVXUIDFHVDUHWKH most appropriate for strata correlation in the Llanos $OOHQ3 $OOHQ- Basin analysis, principles and IRUHODQGEDVLQEHFDXVHRIWKHEDVLQZLGHH[WHQVLRQ applications. London, Blackwell Scientific Publications. VHLVPLFVLJQDWXUHDQGODFNRIVLJQL¿FDQWGLDFKURQ- ism of strata bounding those surfaces. Andean-scale $XGHPDUG)( $XGHPDUG)$ 6WUXFWXUHRI mountain-building processes and rise of sea level in the Merida Andes, Venezuela: relations with the South the Miocene interacted to generate the conditions America-Caribbean geodynamic interaction. Tectono- for rapid and basinwide encroaching of a lacustrine- physics lagoonal system over a nonmarine foreland basin. %DE\35RFKDW30DVFOH* +HUDLO* 1HRJHQH shortening contribution to crustal thickening in the back Although lithology and vertical stacking patterns arc of the Central Andes. Geology are fundamental for the understanding of stratal architecture, the success of correlation in a con- Bayona, G., Cortés, M., Aristizabal, J.J., Jaramillo, C., Ojeda, tinental nonmarine foreland basin depends upon *5H\HV+DUNHU$5XHGD0 9LOODPDUtQ3 the integration of data from other techniques. The Pinch out of upper cretaceous-oligocene reservoir units correlation relies primarily on recognition of the LQWKH/ODQRV%DVLQRI&RORPELD DUHVXOWRIIOH[XUDOGH- diachronism of potential key stratigraphic surfaces formation in a broken foreland. America Association of ZLWKLQDFKURQRVWUDWLJUDSKLFIUDPHZRUN )LJXUH Petroleum Geologists, Annual Meeting, Abstract Volume, +RXVWRQ86$ 6HFRQGO\WHFWRQLFVXEVLGHQFHDQGSURYHQDQFH analyses supply important evidence to determine %D\RQD*&RUWpV0-DUDPLOOR& /OLQiV5' whether deposition took place during an episode 7KH)XVDJDVXJiVXFFHVVLRQ DUHFRUGRIWKHFRPSOH[ RILQFUHDVLQJWHFWRQLFVXEVLGHQFHDQGXQURR¿QJRI Latest Cretaceous-pre-Miocene deformation between new source areas. The tracing of key stratigraphic the Magdalena Valley and Sabana de Bogotá areas. VIII surfaces along seismic lines allows consideration Simposio Bolivariano de Exploración en las Cuencas lateral changes of lithofacies and strata stacking Subandinas pattern within the basin. The integration of all these elements is fundamental to the determination of Branquet, Y., Laumonier, B., Cheilletz, A., & Giuliani, G. depositional sequences within a tectonically-active (PHUDOGVLQWKH(DVWHUQ&RUGLOOHUDRI&RORPELD two tectonic settings for one mineralization. Geology continental foreland basin.
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CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 GERMAN BAYONA et al.
&pVSHGHV6 3HxD/ 5HODFLRQHVHVWUDWLJUiILFDV gráILFRHQHOLQWHUYDOR&UHWiFHRWDUGtRDPLRFHQRPHGLR \DPELHQWHVGHGHSyVLWRGHODVIRUPDFLRQHVGHOWHUFLDULR en la cuenca Llanos Orientales y Piedemonte llanero. LQIHULRUDIORUDQWHHQWUH7XQMD\3D]GHO5tR%R\DFiTesis Informe final(FRSHWURO6$,QVWLWXWR&RORPELDQRGHO de pregrado Fac. de Ciencias,8QLYHUVLGDG1DFLRQDOGH 3HWUyOHR ,&3 Colombia, BogotáSS )OHPLQJV3% -RUGDQ7( 6WUDWLJUDSKLFPRGHO- Coates, A. G., Collins, L. S., Aubry, M., & Berggren, W.A. OLQJRIIRUHODQGEDVLQV ,QWHUSUHWLQJWKUXVWGHIRUPDWLRQ 7KHJHRORJ\RIWKH'DULHQ3DQDPiDQGWKH and lithosphere rheology. Geology late miocene-pliocene collision of the Panamá arc with northwestern South America. Geological Society of *DOORZD\:( *HQHWLFVWUDWLJUDSKLFVHTXHQFHVLQ America, Bulletin ± GRL basin analysis in: architecture and genesis of flooding- % surface bounded depositional units. America Association of Petroleum Geologists Bulletin &RRSHU0$$GGLVRQ)7$OYDUH]5&RUDO0*UDKDP 5++D\ZDUG$%+RZH60DUWtQH]-1DDU- *HRHVWUDWRV'XQLD &RQWUROJHROyJLFRGHFDPSRGHO 3HxDV53XOKDP$- 7DERUGD$ %DVLQ EORTXH6LULUt\iUHDVDOHGDxDVInforme final(FRSHWURO development and tectonic history of the Llanos basin, 6$,QVWLWXWR&RORPELDQRGHO3HWUROHR ,&3 eastern cordillera, and middle Magdalena Valley, Co- lombia. America Association of Petroleum Geologists, *yPH](-RUGDQ7$OOPHQGLQJHU5: &DUGR]R1 Bulletin D 'HYHORSPHQWRIWKH&RORPELDQIRUHODQGEDVLQ V\VWHPDVDFRQVHTXHQFHRIGLDFKURQRXVH[KXPDWLRQRI Cortés, M., Bayona, G., Aristizabal, J., Ojeda, G., Reyes- the northern Andes. Geological Society of America Bul- +DUNHU$ *DPEDQ1 6WUXFWXUHDQGNLQH- letin GRL % matics of the eastern foothills of the eastern cordillera of colombia from balanced cross-sections and forward *yPH](-RUGDQ7$OOPHQGLQJHU5:+HJDUW\. PRGHOOLQJ$VRFLDFLyQFRORPELDQDGHJHyORJRV\JHRItVL- .HOOH\6 E 6\QWHFWRQLFFHQR]RLFVHGLPHQWDWLRQ FRVGHOSHWUyOHRMemorias del IX Simposio Bolivariano in the northern middle Magdalena valley basin of Co- de Cuencas SubandinasLQ&' ORPELDDQGLPSOLFDWLRQVIRUH[KXPDWLRQRIWKHQRUWKHUQ Andes. Geological Society of America Bulletin &XUULH% 6HTXHQFHVWUDWLJUDSK\RIQRQPDULQH ± Jurassic-Cretaceous rocks, Central Cordilleran foreland- basin system. Geological Society of America Bulletin. *XHUUHUR- 6DUPLHQWR* (VWUDWLJUDItDItVLFD SDOLQROyJLFDVHGLPHQWROyJLFD\VHFXHQFLDOGHOFUHWiFLFR superior y paleoceno del Piedemonte Llanero, implica- 'H&HOOHV3 *LOHV. )RUHODQGEDVLQV\VWHPV FLRQHVHQH[SORUDFLyQSHWUROHUDGeología Colombiana, Basin Research
)DEUH$ (VWUDWLJUDItDGHOD6LHUUD1HYDGDGHO&RFX\ +DPEDOHN15XOO9'H'LJLDFRPR( 'LD]GH %R\DFi\$UDXFD&RUGLOOHUD2ULHQWDO &RORPELD Ge- *DPHUR0/ (YROXFLyQSDOHRHFROyJLFD\SD- ología Norandina OHRDPELHQWDOGHODVHFXHQFLDGHO1HRJHQRHQHOVXUFRGH 8UXPDFR HVWXGLRSDOLQROyJLFR\OLWROyJLFRBoletín de la )DEUH$ 7HFWRQLTXHHWJpQHUDWLRQG K\GURFDUEXUHV Sociedad Venezolana de Geología XQPRGqOHGHO HYROXWLRQGHOD&RUGLOOqUH2ULHQWDOHGH Colombie et dubBassin de Llanos pendant le crétacé et le +DT%8+DUGHQERO- 9DLO3 &KURQRO- tertiaire. Archives des Sciences Genève ogy of fluctuating sea levels since the triassic. Science, )DMDUGR$ '6WUDWLJUDSKLFDUFKLWHFWXUHDQG'UHV- ervoir fluid-flow model of the Mirador formation, Cusiana +ROEURRN-6FRWW5: 2ERK,NXHQREH) %DVH field, foothills area of the Cordillera Oriental, Colombia. level buffers and butresses: a model for upstream versus Master’s Thesis&RORUDGR6FKRRORI0LQHV86$ downstream control on fluvial geometry and architecture within sequences. Journal of Sedimentary Research )DMDUGR$5RMDV(&ULVWDQFKR- &RQVRUFLR* * *RLQJ6\VWHP/ 'HILQLFLyQGHO0RGHORHVWUDWL-
CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 PALEOCENE-MIDDLE MIOCENE FLEXURAL-MARGIN MIGRATION
Hoorn, C., Guerrero, J., Sarmiento, G.A., & Lorente, M.A. (RFHQH /ODQRVEDVLQ&RORPELDPh. D. Thesis, Johannes $QGHDQWHFWRQLFVDVDFDXVHIRUFKDQJLQJGUDLQDJH *XWHQEHUJ8QLYHUVLWDW0DLQ]*HUPDQ\SS patterns in Miocene northern South America. Geology, ± 0HVD$ 'HVFULSFLyQSHWUROyJLFDGHPXHVWUDVGH zanja del pozo Gibraltar 1, ST-3 y ST-5 durante las ac- -DUDPLOOR& 0LGGOHSDOHRJHQHSDO\QRORJ\RI WLYLGDGHVGHSHUIRUDFLyQInforme final(FRSHWURO6$ Colombia, South America: Biostratigraphic, sequence ,QVWLWXWR&RORPELDQRGHO3HWUyOHR ,&3 stratigraphic and diversity implications. Ph. D. Thesis, 8QLYHUVLW\RI)ORULGD86$ 0HVD$ 'HVFULSFLyQGHWDOODGDSHWURJUiILFDGHO pozo Gibraltar 2. Informe final(FRSHWURO6$,QVWLWXWR -DUDPLOOR& 5HVSRQVHRIWURSLFDOYHJHWDWLRQWR &RORPELDQRGHO3HWUyOHR ,&3 paleogene warming. Paleobiology 0RUD$ 3DUUD0 6HFFLRQHVHVWUDWLJUiILFDVGH -DUDPLOOR& 'LOFKHU'/ 0LGGOHSDOHRJHQH las formaciones Guadalupe, Barco y Carbonera, anticlinal palynology of central Colombia, South America: A study del Guavio, Piedecuesta. Informe final,QVWLWXWR&RORP- of pollen and spores from tropical latitudes. Palaeonto- ELDQRGHO3HWUyOHRSS graphica B 0RUD$3DUUD06WUHFNHU05.DPPHU$'LPDWH -DUDPLOOR&0XxR])&RJROOR0 3DUUD) & 5RGUtJXH]) &HQR]RLFFRQWUDFWLRQDO 4XDQWLWDWLYHELRVWUDWLJUDSK\IRUWKH&XHUYRVIRUPDWLRQ UHDFWLYDWLRQRI0HVR]RLFH[WHQVLRQDOVWUXFWXUHVLQWKH SDOHRFHQH RIWKHOODQRVIRRWKLOOV&RORPELD ,PSURYLQJ (DVWHUQ&RUGLOOHUDRI&RORPELDTectonics7& SDO\QRORJLFDOUHVROXWLRQIRURLOH[SORUDWLRQin Powell, GRL 7& A.J., & Riding, J.B., eds., recent developments in Ap- plied Biostratigraphy. The Micropalaeontological Society, 0RUHQR- 9HOiVTXH]0 (VWUDWLJUDItD\WHFWyQLFD Special Publications± HQORVDOUHGHGRUHVGHOPXQLFLSLRGH1XFKLDGHSDUWDPHQWR de Casanare, Colombia. Tesis de Pregrado Fac. Ciencias, -DUDPLOOR&5XHGD0 0RUD* &HQR]RLFSODQW 8QLYHUVLGDG1DFLRQDOGH&RORPELD%RJRWi diversity in the neotropics. Science 2MHGD*%D\RQD*3LQLOOD-&RUWpV0 *DPED1 6XEVLGHQFHDQGJHRG\QDPLFDQDO\VLVRI7KH -DUDPLOOR& 5XHGD0 ,PSDFWRIELRVWUDWLJUDSK\ Llanos Basin. Linking mountain building and basin RQRLOH[SORUDWLRQ0HPRULDVGHODWHUFHUDFRQYHQFLRQ ILOOLQJSURFHVVHV$VRFLDFLyQ&RORPELDQDGH*HyORJRV WpFQLFDGHOD$VRFLDFLyQ&RORPELDQDGH*HyORJRV\ \*HRItVLFRVGHO3HWUyOHRMemorias del IX Simposio *HRItVLFRVGHO3HWUyOHR%RJRWi&RORPELD Bolivariano de Cuencas SubandinasLQ&'
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CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007 GERMAN BAYONA et al.
WKH(DVWHUQ&RUGLOOHUDRI&RORPELD6W\OHNLQHPDWLFVDQG 9DLO350LWFKXP50- 7KRPSVRQ6, timing constraints derived from seismic data and detailed Seismic stratigraphy and global changes of sea level, surface mapping, in McClay, K., ed., Thrust tectonics and part 3, relative changes of sea level from coastal onlap, hydrocarbon systems, Colombia. America Association of in3D\WRQ&(HG6HLVPLFVWUDWLJUDSK\DSSOLFDWLRQV Petroleum Geologists Memoir, WRK\GURFDUERQH[SORUDWLRQAmerican Association of Petroleum Geologists Memoir 5H\HV$ 6HGLPHQWRORJ\DQGVWUDWLJUDSK\DQGLWV control on porosity and permeability Barco formation, Van Wagoner, J., Mitchum, R.M.J., Campion, K., & Rahma- &XVLDQDILHOG&RORPELD0DVWHU¶VWKHVLV8QLYHUVLW\RI QDLQ9 6LOLFLFODVWLFVHTXHQFHVWUDWLJUDSK\LQZHOO 5HDGLQJ3RVWJUDGXDWH5HVHDUFK,QVWLWXWHRI6HGLPHQWRO- ORJVFRUHVDQGRXWFURSV FRQFHSWVIRUKLJKUHVROXWLRQ RJ\SS FRUUHODWLRQRIWLPHDQGIDFLHV0HWKRGVLQH[SORUDWLRQ VHULHV&RORPELDAmerica Association of Petroleum 5H\HV$ 7DOOHUFRUD]yQ*LEUDOWDU %XFDUDPDQJD Geologists, 55. Reporte Interno,(FRSHWURO6$ 9HUJDUD/ 5RGUtJXH]* &RQVLGHUDFLRQHVVR- 5H\HV, 9DOHQWLQR07 *HRORJtDGHO\DFLPLHQWR EUHODSHWURJUDItD\GLDJpQHVLVGHORVJUXSR*XDGDOXSH \YDULDELOLGDGGHODVFDUDFWHUtVWLFDVJHRTXtPLFDVGHO &RUGLOOHUD2ULHQWDO \3DOPLFKDO 3LHGHPRQWH/ODQHUR PLQHUDOGHKLHUURHQODUHJLyQGH3D]9LHMD PXQLFLSLRGH Geología Colombiana 3D]GHO5tRGHSDUWDPHQWRGH%R\DFi Primer Congreso Colombiano de Geología, Memorias, Bogotá, Colombia, :DUUHQ($ 3XOKDP$- $QRPDORXVSRURVLW\ and permeability preservation in deeply buried tertiary and mesozoic sandstones in the cusiana field, llanos 5H\HV-6LOYD00XQDU)/DVVR$%RKyUTXH]- foothills, colombia. Journal of Sedimentary Research, 9DOGHUUDPD-&DGHQD$9HODVFR-5HQGyQ$ %ODQFR1 2EMHWLYRV(VWUDWLJUiILFRVHQOD subcuenca Apiay-Ariari. Memorias del IV Simposio Bolivariano%RJRWi&RORPELD
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CT&F - Ciencia, Tecnología y Futuro - Vol. 3 Núm. 3 Dic. 2007