Basin analysis from Colombian Caribbean is particularly important given the interest in finding hydrocarbon reservoirs, but their complex geological evolution, and the frequent lateral and vertical variation of facies difficult a conclusive characterization, highlights the need for detailed sedimentological and ichnological studies. The study succession corresponds to an interval of a well core drilled in the south of the Sinú-San Jacinto Basin (Colombian Caribbean), with 1069 ft (~326 m) thick of an Oligocene siliciclastic succession, interpreted in general terms, as deposited in a deltaic system. The integrated sedimentological/ichnological analysis allows the differentiation of dominant facies, with predominant lithologies such as conglomerates, sandstones, mudrocks, bioclastic sediments, as well as coal beds. The ichnological assemblage is low in abundance and moderately diverse, composed by Conichnus, Cylindrichnus, Dactyloidites, Macaronichnus, Ophiomorpha, Phycosiphon, Skolithos, Taenidium, Teichichnus, and Thalassinoides, as well as rhizoliths.

The complexity of the sedimentary system is reflected in its evolution throughout the Oligocene. A type succession with coarsening-upward trend was identified and it is repeated through the succession studied. It presents a general trend from bioclastic sediments (bioclastic conglomerates, sandstones and mudrocks) that pass into horizontal lamination and massive mudrocks occasionally bioturbated by Phycosiphon, and interbedded by mudrocks and sandstones with lenticular bedding, and the occurrence of Teichichnus. Above, bioturbated muddy sandstones with Ophiomorpha, Taenidium, Thalassinoides, and rarely Teichichnus, muddy sandstones with planar cross-lamination, and horizontal lamination sandstones with Dactyloidites, Ophiomorpha, Skolithos, and Thalassinoides are registered. Transition to carbonaceous mudrocks with Teichichnus, coal medium beds, and fine-to coarse-grained sandstones sometimes with Macaronichnus and/or Ophiomorpha is observed. Towards the top, are observed mudrocks with rhizoliths. This succession is interrupted by massive and horizontal lamination sandstones with low bioturbation index generated by the ichnological assemblage and/or by the exclusive occurrence of Ophiomorpha and/or Taenidium. Massive sandstones with erosive bases, asymmetrical ripples, and high content of organic debris are occasionally recorded. This succession reflects a progradational trend similar to those of fluvial-dominated deltaic sequences.

Detailed analysis revealed that even the fluvial processes were dominant in the deltaic system; however, local tidal and wave influence is recorded. Moreover, integration of sedimentological and ichnological information allows characterizing the evolution of the different sub-environments of the deltaic system, as prodelta bay, distal delta front, proximal delta front, distributary channels, mouth bars, and lower delta plain, and this is essential for areas of economic interest.

鉴于对寻找油气藏的兴趣，哥伦比亚加勒比地区的盆地分析尤为重要，但其复杂的地质演化以及相的频繁横向和垂直变化难以得出结论性特征，突出了详细的沉积学和地质学研究的必要性。研究序列对应于在 Sinú-San Jacinto 盆地（哥伦比亚加勒比海）南部钻探的井芯层段，具有 1069 英尺（~326 m）厚的渐新世硅质碎屑层序，一般解释为沉积于三角洲系统。综合沉积学/地质学分析可以区分优势相，主要岩性包括砾岩、砂岩、泥岩、生物碎屑沉积物以及煤层。Conichnus，Cylindrichnus，Dactyloidites，Macaronichnus，Ophiomorpha，Phycosiphon，Skolithos，Taenidium，Teichichnus和Thalassinoides，以及根石。

沉积系统的复杂性反映在其整个渐新世的演化过程中。确定了一种具有向上粗化趋势的类型演替，并在所研究的演替中重复。呈现出生物碎屑沉积物（生物碎屑砾岩、砂岩和泥岩）进入水平层理和块状泥岩的总趋势，偶尔被Phycosiphon生物扰动，并与具有透镜状层理的泥岩和砂岩互层，以及Teichichnus的产状。上图是含有Ophiomorpha、Taenidium、Thalassinoides和很少Teichichnus 的生物扰动泥质砂岩、具有平面交叉层理的泥质砂岩，以及具有Dactyloidite、Ophiomorpha、Skolithos和Thalassinoides 的水平层状砂岩。观察到含有Teichichnus 的碳质泥岩、煤中层和细粒至粗粒砂岩的过渡，有时含有Macaronichnus和/或Ophiomorpha。在顶部，观察到带有根石的泥岩。这种演替被由时间学组合和/或Ophiomorpha和/或Taenidium的独家产区产生的具有低生物扰动指数的块状和水平层状砂岩中断. 偶尔会记录到具有侵蚀性基底、不对称波纹和高含量有机碎片的大块砂岩。这种演替反映了类似于以河流为主的三角洲层序的进积趋势。

详细分析表明，在三角洲系统中，即使是河流过程也占主导地位；然而，当地的潮汐和波浪影响被记录下来。此外，沉积学和地质学信息的整合可以表征三角洲系统不同亚环境的演化，如前三角洲湾、远端三角洲前缘、近端三角洲前缘、分流河道、河口坝和下三角洲平原，这是必不可少的对于经济利益领域。