School of Earth and Environment

Oscar Arevalo Oscar Arevalo

Postgraduate Researcher

Email address: eeoja@leeds.ac.uk
Room: G19 28 University Road

Affiliation: Institute of Applied Geoscience

Qualifications

2003 BSc Geology, National University of Colombia. GPA: 4.0/5.0
Final project: geological mapping, stratigraphic surveying and petrographic description of Early Cretaceous marine sedimentary rocks in the Western Andes of Colombia.

Memberships/Fellowships

American Association of Petroleum Geologists (AAPG)
British Sedimentological Research Group (BSRG)
International Association of Sedimentologists (IAS)
International Association for Mathematical Geosciences (IAMG)
Society for Sedimentary Geology (SEPM)
Society of Exploration Geophysicists (SEG)

Research Interests

Recognition of relative influence of tectonics, climate and sea-level changes in the preserved record of fluvial successions.
Sedimentological and petrographic characterization of sedimentary rocks, particularly potential reservoir rocks.

Teaching Interests

Sedimentology
Sedimentary basins and hydrocarbon resources
Geological Materials

Project details

Project title

Stratigraphic Heterogeneity in a Low Net-to-Gross Fluvial Succession Induced by Allogenic and Autogenic Factors

Supervisors

Dr Nigel Mountney and Dr Luca Colombera

Funding

Main funding bodies

Fluvial Research Group (FRG)
Colfuturo

Fieldwork grants

AAPG Foundation - Harold J. Funkhouser Memorial Grant (2015)
International Association of Sedimentologists Grant (2015)
British Sedimentological Research Group - Steve Farrell Memorial Fund (2016)
AAPG Foundation - Sherman A. Wengerd Memorial Grant (2016)
Gilchrist Educational Trust (2016)

Conference travel grants

Society of Exploration Geophysicists (2016) - Grant to attend the AAPG/SEG International Conference and Exhibition (Barcelona)
LeedsforLife (2016) - Grant to attend the AAPG/SEG International Conference and Exhibition (Barcelona)
Society for Sedimentary Geology (2016) - Grant to attend the AAPG/SEPM Annual Convention and Exhibition (Calgary)

Start date

1 January 2015

Project outline

The preserved sedimentary record of fluvial successions is governed by the interaction of one or more principal allogenic factors: tectonics, climate and eustasy. These factors are interdependent and their effects, in many cases, can be superimposed; consequently, discriminating their relative roles is not straightforward. For recent deposits, implementation of different radiometric, isotopic and palaeontological tools to constrain climatic, sea-level and tectonic changes often facilitates evaluation of the relative roles of allogenic factors. However, in ancient deposits, where the accessible information is more limited, this task is more complex. Additionally, the geometry of channel bodies and the evolution of surrounding floodplain elements in fluvial environments are also controlled by intrinsic (autogenic) factors such as bank erodibility and stream power.

The approach proposed involves acquisition of quantitative and qualitative sedimentological data from synorogenic Paleogene fluvial deposits of the Tremp-Graus basin, in the Arén-Esplugafreda sector, located in the central southern Pyrenees (Spain). The study of these deposits represents an ideal opportunity to evaluate the role of tectonics, climate and eustasy in controlling preserved fluvial architecture. Excellent time constraints exist for both the syn-sedimentary tectonic activity and the occurrence of climatic changes. Additionally, the regional and temporal context of the basin serves to constrain the extent and timing of eustatic influence. This anticipated knowledge about extrinsic sedimentation factors will facilitate the interpretation of signatures present in the preserved lithological record of an ancient fluvial system in relation to these precursor allogenic drivers. Additionally, this succession has been interpreted as the product of an ephemeral fluvial system in an arid environment, where multiple streams undertook repeated and apparently frequent avulsions. Therefore it is also possible to interpret the evolution of this fluvial system in terms of the intrinsic processes responsible of these multiple avulsions.

Potential reservoirs in low net-to-gross successions commonly occur as isolated bodies separated by thick floodplain deposits; however the interrelation of allogenic and autogenic factors can produce multi-scale lateral and vertical variations in the internal architecture, lateral continuity and connectivity of these bodies. The studied succession has been considered as an analogue of certain oil-bearing successions in the North Sea. Therefore, this study will also focus on the characterisation of the potential reservoirs within this unit. Preliminary results indicate the existence of four types of channelized elements: single-story ribbon and sheet-like bodies, multi-storey and multilateral compound bodies, and amalgamated complexes. A later phase of this work will implement a software-based numerical modelling analysis (e.g. Reckonnect, Petrel, FAKTS-based tools) in order to evaluate the connectivity of these channelized elements and the probability of connection of vertically isolated channel belts.

Publications

Conference Proceedings

Arévalo, O.J., Mountney, N. & Colombera, L., (2016): Role of tectonics and climate on the preserved record of a low net-to-gross ephemeral fluvial succession, South-Central Pyrenees. British Sedimentological Research Group (BSRG) Annual Meeting, Cambridge, UK.

Arévalo, O.J., Colombera, L. & Mountney, N., (2016): Multi-Scale Stratigraphic Heterogeneity Induced by Allocyclic and Autocyclic Factors in a Low Net-to-Gross Fluvial Succession. AAPG Annual Convention & Exhibition, Calgary, Canada.

Arévalo, O.J., Mountney, N. & Colombera, L., (2016): Reservoir architecture of a low net-to-gross fluvial succession based on integration of channel-body geometry and paleosol characterization. AAPG/SEG International Conference & Exhibition 2016, Barcelona, Spain.

Arévalo, O.J., Mountney, N. & Colombera, L., (2015): Stratigraphic heterogeneity induced by allogenic and autogenic factors in a Paleogene low net-to-gross fluvial succession, Tremp-Graus Basin, southern Pyrenees, Spain. British Sedimentological Research Group (BSRG) Annual Meeting, Keele, UK.

Colombera L., Mountney N. & Arévalo O.J., (2015): Climate change and the response of river landscapes: insights from the sedimentary architecture of fluvial systems across the Paleocene-Eocene boundary. British Sedimentological Research Group (BSRG) 54th Annual Meeting, Keele, UK.

Colombera L., Mountney N., Plink-Björklund P., Arévalo O.J. & McCaffrey W.D., (2015): Climate change and geomorphic evolution: insights from meta-analysis of the sedimentary architecture of fluvial systems across the Paleocene-Eocene boundary. IAS International Meeting of Sedimentology, Krakow, Poland.

Mojica, J., Arévalo, O.J. & Ibañez-Mejía, M., (2007): Pliocene - Quaternary faults hidden under the sediments of the urban area of Bogotá: Importance for assessing the potential seismic hazard (in Spanish). Memoirs XI Colombian Congress of Geology. Bucaramanga, Colombia.

Mojica, J. & Arévalo, O.J., (2005): Occurrence and possible significance of Cretaceous turbidites in the Western Colombian Andes. 6th International Symposium on Andean Geodynamics (ISAG), Extended Abstracts: 512-515. Barcelona, Spain.

Correa A.M., Sial, A.N., Mojica, J. & Arévalo, O.J., (2003): δ13C and δ18O in Late Aptian Limestones of Quindio, Colombian Central Cordillera. In: Short Papers – IV South American Symposium on Isotope Geology, Volume I: 331-333. Salvador, Brasil.

Mojica, J. & Arévalo, O.J., (2002a): Environment, provenance and paleogeographic setting of two Late Aptian-Early Albian open sea sedimentary sequences in the western piedmont of the Central Cordillera, south Pijao, Quindío Department, Colombia. 5th International Symposium on Andean Geodynamics (ISAG), Extended Abstracts: 417-420. Toulouse, France.

Mojica, J. & Arévalo, O.J., (2002b): Geology of the Western Andes of Colombia: Facts and Problems. Memoirs V Week of Geology and Geological Engineering (in Spanish). Bogotá, Colombia.

Mojica, J., Arévalo, O.J. & Patarroyo, P., (2002): New findings in stratigraphy and paleontology of Aptian-Albian sedimentites in the Quindío Department, Western Andes of Colombia. 3rd European Meeting on the Paleontology and Stratigraphy of Latin American (EMPSLA), Extended Abstracts: 69-72. Toulouse, France.

Mojica, J., Patarroyo, P., Camargo G. & Arévalo O.J., (2001): Late Aptian sedimentites in the western flank of the Central Cordillera, Lejos River, Pijao, Quindío-Colombia (in Spanish). Memoirs VIII Colombian Congress of Geology. Manizales, Colombia.

Journals

Arévalo, O.J., Mojica, J. & Patarroyo, P., (2001): Late Aptian sedimentites south of Pijao, La Maizena Creek, western flank of Central Cordillera, Quindío Colombia (in Spanish). Geología Colombiana, 26: 29-43.

Newsletters

Arévalo, O.J., (2015): Stratigraphic heterogeneity induced by allogenic and autogenic factors in a Paleogene low net-to-gross fluvial succession, Tremp-Graus Basin, Southern Pyrenees, Spain. IAS Newsletter 259-260: 55-61.