B.S. in Earth Science, Geology , Montana State University, 2010
M.S. in Earth Sciences
Title of Research Project:
Stratigraphic modulation of turbidite architecture generated by syn-sedimentary structural growth: The Marnoso-arenacea Formation surrounding the Coniale Anticline, Northern Apennines, Italy
Sedimentology, stratigraphy, and structural geology of deep-marine fan depositional systems contained within active submarine fold-and-thrust belts.
- American Association of Petroleum Geologists (member)
- Geological Society of America (member)
- Society for Sedimentary Geology (member)
- Slope and Basin Consortium (student researcher)
Understanding the link between depositional patterns and contractional fold development on the ocean floor is critical for predicting reservoir presence and architecture in deep-marine turbidite fan systems. Most sedimentation regions within deep marine fan environments, regardless of basin type, contain surficial gradient-modifying structural deformation that is contemporaneous with episodes of sedimentation. Submarine contractional fold belts in a peripheral foreland basin system represent an excellent example where a variety of sedimentary attributes are controlled by the rates and timing of the structural deformation generated from the continental-continental collision.
This study focuses on the documentation and explanation of change in a hierarchy of sedimentary attributes in the Marnoso-arenacea Formation surrounding the Coniale Anticline of northeastern Tuscany, Italy. This anticline provides an excellent, but poorly understood exposure of a deepwater fan deposited adjacent to a once growing fault-propagation-fold. The thick deposits of base of slope to basin plain turbidites surrounding the structure have been hypothesized to record the incipient growth of this structure thereby subdividing the proto-foredeep structural domain into younger foredeep and wedge-top structural domains. The sedimentary attributes that record this change include a) the sedimentology of multipartite turbidity current deposits, b) the differentiation and stacking patterns of individual turbidite sedimentation events, c) the change in sedimentary body type and aspect ratio through time and space, and d) the distribution of pre-kinematic and syn-kinematic sedimentation regions around the structure. Key issues to be addressed include:
- The proportions and genetic origin of mudclast-bearing and mudclast-deficient debrite deposits surrounding the structure.
- Identifying quantitative patterns of change in sedimentation event thickness with proximity to the structure during deposition of both pre-kinematic and syn-kinematic strata.
- Identifying quantitative patterns of change in component hydronamic-facies proportions per sedimentation events with proximity to the structure.
- Examining mudrock composition and fabrics using XRD and SEM analytical techniques to differentiate turbiditic mudrocks, hemipelagic mudrocks, and mixed turbiditic/hemipelagic mudrocks.
- Differentiation of mudrock intraclast-bearing horizons into amalgamation surfaces and reflected flows (termed sandwich beds by other authors) to delineate temporal phases of structural growth and quiescence.
- Statistical analysis of abundant paleo-flow data in syn-kinematic stratigraphy to examine nature of structural growth as episodic or continuous.
- Topographic, aerial photo, and photopanel mapping of geology to document spatial changes in the sedimentary attributes with proximity to structure.
- Geologic mapping to identify structural deformation features related to Miocene contraction, Plio-Pleistocene extension, and Holocene landslides.
- Computer simulation of geo-spatially referenced sedimentary attributes in stratigraphic cross sections to predict expected petrophysical variation in subsurface reservoir models in fields that may be analogous to this outcrop.
- Compilation of hierarchy of sedimentary attributes to define AIGR phases (Adjustment, Initiation, Growth, Retreat model of Gardner et al., 2008) to explain sedimentary patterns related to pre-kinematic and syn-kinematic stratigraphy.
- Computer-aided structural restoration of the modern geometry of the Coniale anticline to test the kinematic pathway indicated by the stratigraphic attributes.
- Construction of relational GIS database to spatially link sedimentary attributes with four time-space domains surrounding the structure:
- Pre-kinematic Hangingwall Domain
- Pre-kinematic Footwall Domain
- Syn-kinematic Hangingwall Domain
- Syn-kinematic Footwall Domain
The application of the results from this study will aid in predicting reservoir presence and architecture in analogous deep-marine clastic environments including, but not limited to: Gulf of Mexico, Offshore Angola, Equatorial Margin of Brazil, Offshore Brunei, and the California Borderland Basins.
Atwood N, Gardner, M.H., 2012, Structural restoration of the syn-sedimentary Coniale anticline and its control on the modulation of sedimentary attributes in the Marnoso-arenacea Fm., Northern Apennines, Italy; Internal Company Publication, BHP Billiton Petroleum, Houston, Texas.
Atwood, N., Stratigraphic modulation of turbidite architecture generated by syn-sedimentary structural growth: The Marnoso-arenacea Formation at the Coniale Anticline, Northern Apennines, Italy; Slope and Basin Annual Meeting, Oral Presentation Session, Tuesday, October 23.
Atwood, N. and Gardner, M.H., 2012, Reservoir-scale modulation of turbidite architecture related to paleo-gradients generated by syn-sedimentary structural growth and segmentation of an overfilled foreland basin system: The Marnoso-arenacea Formation at the Coniale Anticline, Northern Apennines, Italy; AAPG American Conference and Exhibition, Poster Presentation, Long Beach, California.
Gardner, M.H., Anderson, B., Ochoa, J., Atwood, N. and Jester, T., 2012, Tectonic stratigraphy of convergent plate boundaries: A holistic perspective from Paleozoic to Cenozoic deepwater systems of western North America and the Gulf of Mexico; AAPG American Conference and Exhibition, Poster Presentation, Long Beach, California.
- Internship with Deep Skills Team at BHP Billiton Petroleum, Houston, Texas - June-August 2012.
- AAPG Annual Convention and Exposition - April 2012
- Slope and Basin Consortium Annual Field Conference in New Plymouth, New Zealand, March 2012.
- Structural Modelling and Analysis using Move™ Workshop, Houston, Texas – September 2011.
- Internship with Brazil Exploration Team at BHP Billiton Petroleum, Houston, Texas – June – August 2011.
- Slope and Basin Consortium Annual Field Conference in Northern California – October 2010.
- GAIA 2010 field excursion; Geological mapping and structural geology team, Ainsa, Spain – Annot, France – Coniale, Italy.
- 2012-2013 BHP Billiton Excellence in Student Research Grant
- 2012 MSU Earth Sciences Colloquium Best Poster Award
- 2011 Big Sky Conference Student Athlete of the Year Award