
Zane Richards JobeColorado School of Mines · Department of Geology and Geological Engineering
Zane Richards Jobe
Ph.D., Stanford University
About
98
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Introduction
Turbidite sedimentologist that aims to better understand deepwater depositional systems, and particularly the evolution of submarine channels. Much of my work has focused on ancient outcrops, but lately I have become very interested in modern (i.e. seafloor) systems.
Publications
Publications (98)
Submarine and fluvial channels exhibit qualitatively similar geomorphic patterns, yet produce very different stratigraphic records. We reconcile these seemingly contradictory observations by focusing on the channel belt scale and quantifying the time-integrated stratigraphic record of the belt as a function of the scale and trajectory of the geomor...
High-resolution bathymetry, seismic reflection, and piston core data from a submarine channel on the western Niger Delta slope demonstrate that thick, coarse-grained, amalgamated sands in the channel thalweg/axis transition to thin, fine-grained, bedded sands and muds in the channel margin. Radiocarbon ages indicate that axis and margin deposits ar...
Near-seafloor core and seismic reflection-data from the western Niger Delta continental slope document the facies, architecture, and evolution of submarine channel and intra-slope submarine fan deposits. The submarine channel enters an 8-km-long by 8-km-wide intraslope basin, where more than 100 m of deposits form an intraslope submarine fan. Lobe...
Changes in sediment supply and caliber during the last ∼ 130 ka have resulted in a complex architectural evolution of the Y channel system on the western Niger Delta slope. This evolution consists of four phases, each with documented or inferred changes in sediment supply. Phase 1 flows created wide (1,000 m), low-sinuosity (1.1) channel forms with...
Most submarine canyons are erosive conduits cut deeply into the world’s continental shelves through which sediment is transported from areas of high coastal sediment supply onto large submarine fans. However, many submarine canyons in areas of low sediment supply do not have associated submarine fans and show significantly different morphologies an...
Mass‐transport complexes undergo fabric modification during emplacement that results in the alignment of elongated grains. Grain‐fabric alignments promote mechanical and petrophysical anisotropy, which has broad implications for hydrocarbon extraction, carbon sequestration and geohazard assessment. These implications are likely more pronounced in m...
Mixed siliciclastic–carbonate mudrocks have variable depositional processes and diagenetic pathways, creating mineralogical complexity and thus difficulty in characterizing reservoir quality using typical subsurface datasets (e.g., well logs) as well as conventional visual core-description techniques. Core-based X-ray fluorescence (XRF) data quanti...
Sediment-gravity flows coursing through submarine channels are the most important conveyors of sediment and organic carbon to submarine fans. Submarine channel deposits, therefore, should record the archive of this sediment transfer. However, channel deposits have often been considered to be dominated by erosion and bypass, and thus an incomplete a...
Facies models for basin‐plain turbidite systems often depict very simplistic event‐bed geometries that are tabular at the kilometre scale. However, recent studies have demonstrated more complex facies architectures, including rapid changes in event‐bed thickness and facies composition. This lateral event‐bed heterogeneity can have a significant imp...
A thorough understanding of the mineralogy
and geochemistry of rocks in the subsurface is key to
exploration and assessments for (critical) mineral
resources. To achieve this, datasets of various types must
be rapidly acquired and interpreted across a range of
scales in 3-D. This approach was applied to the stratabound
Iron Creek Co-Cu deposit in t...
Submarine channels deliver vast quantities of sediment into ocean basins and the deposits left by these systems host important archives of paleoenvironmental change and are major targets for hydrocarbon production and carbon sequestration. However, similarities between channel subenvironments often make their identification difficult, particularly...
Deepwater carbonate deposition is relatively poorly understood but an area of vigorous research in academia and industry, where these deposits are a significant component of many unconventional petroleum reservoirs. Recent studies of modern deepwater carbonates have highlighted the wide variety of depositional processes, sediment types and resultan...
The fluvial sedimentary record is largely composed of deposits from relatively common flow events, rather than more catastrophic scour-and-fill events. At the scales of bedforms, such deposits are preserved within the stratigraphic record because they rapidly accumulate within, and are protected by, morphodynamic topographic depressions that occur...
Aeolian deposits form noteworthy reservoirs (for example, Norphlet Formation and Rotliegend Group) in hydrocarbon extraction and carbon capture and storage contexts, but stratigraphic architecture imparts significant heterogeneity. Bounding surfaces result from autogenic and allogenic controls and can represent important changes in dune‐field dynam...
Machine-learning algorithms have long aided in geologic property prediction from well-log data, but are primarily used to classify lithology, facies, formation, and rock types. However, more detailed properties (e.g., porosity, grain size) that are important for evaluating hydrocarbon exploration and development activities, as well as subsurface ge...
Submarine canyons are major conduits for sediment transfer from continental shelf to deep marine environments. Mass failures and faults play a key role in the initiation and evolution of submarine canyons along convergent tectonic margins, in addition to continental sediment supply. Here we analyze high-resolution bathymetry and seismic data from t...
Submarine fan deposits are volumetrically the largest sediment accumulations on Earth and host significant hydrocarbon reserves. Extensive research has documented the bed‐scale architecture of high sand‐to‐mud ratio, proximal and axial environments, which can have bed thicknesses of several metres; however less well‐understood are thin‐bedded turbi...
Submarine fans deposited in structurally complex settings record important information on basin evolution and tectonic–sedimentary relationships but are often poorly preserved in outcrops due to syndepositional and post depositional deformation. This study aims to understand the influence of tectonics on the deposition of the synorogenic Pennsylvan...
Over the last several years, numerous outcrop localities have been revisited to add quantitative detail to submarine lobe facies models that previously focussed on facies relationships in a qualitative sense. This study utilises well-exposed submarine lobe deposits of the Point Loma Formation in Cabrillo National Monument (San Diego, CA) to provide...
Our knowledge of submarine fan deposits has historically relied heavily on qualitative field and subsurface observations and interpretations, but recent studies using statistical analyses have enhanced the understanding of submarine fan sub‐environments, including the degree of confinement, stratigraphic patterns and potential control factors. The...
The San Gabriel and Canton faults represent early stages in the development of the San Andreas fault system. However, questions of timing of initiation and magnitude of slip on these structures remain unresolved, with published estimates ranging from 42–75 km and likely starting in the Miocene. This uncertainty in slip history reflects an absence o...
Machine-learning algorithms have been used by geoscientists to infer geologic and physical properties from hydrocarbon exploration and development wells for more than 40 years. These techniques historically utilize digital well-log information, which, like any remotely sensed measurement, have resolution limitations. Core is the only subsurface dat...
Sediment transport and distribution are the keys to understanding slope-building processes in mixed carbonate-siliciclastic sediment routing systems. The Permian Bone Spring Formation, Delaware Basin, west Texas, is such a mixed system and has been extensively studied in its distal (basinal) extent but is poorly constrained in its proximal upper-sl...
In a ‘source to sink’ sedimentary system, multiple processes have the potential to modify the sediment composition during sediment generation at the source, through transport, deposition and burial. To investigate these issues, a multi-proxy provenance study of deep-water and shallow-marine sandstones from the mid-Carboniferous Clare Basin was unde...
Submarine landscapes, like their terrestrial counterparts, are sculpted by autogenic sedimentary processes toward morphologies at equilibrium with their allogenic controls. While submarine channels and nearby, inter-channel continental-margin areas share boundary conditions (e.g., terrestrial sediment supply, tectonic deformation), there are signif...
Our knowledge of submarine fan deposits has historically relied heavily on qualitative field and subsurface observations and interpretations, but recent studies using statistical analyses have enhanced the understanding of submarine fan sub-environments, including the degree of confinement, stratigraphic patterns, and potential control factors. The...
Deep-water fold and thrust belts often develop in convergent tectonic margins, creating irregular slope profiles that control the distribution of deep-water gravity deposits. However, in areas with high sediment supply, the erosion and sedimentation can minimize structural relief and smooth the slope. Using multibeam bathymetry with 3D seismic data...
We investigate the relationship between the cross-sectional geomorphic expression of a submarine channel as observed on the seafloor and the stratigraphic product of long-lived erosion, bypass, and sediment deposition. Specifically, by reconstructing the time–space evolution of an individual channel fill (i.e., channel element) exposed in outcrop,...
Submarine fans deposited in structurally complex settings record important information on basin evolution and tectonic-sedimentary relationships but are often poorly preserved in outcrops due to post-depositional deformation. This study integrates both new field data as well as data compiled from literature to demonstrate the spatial facies variabi...
Deep‐water deposits are important archives of Earth’s history including the occurrence of powerful flow events and the transfer of large volumes of terrestrial detritus into the world’s oceans. However the interpretation of depositional processes and palaeoflow conditions from the deep‐water sedimentary record has been limited due to a lack of dire...
Constraining the avulsion dynamics of rivers and submarine channels is essential for predicting the distribution of sediment, organic matter, and pollutants in alluvial, deltaic, and submarine settings. We create a geometric channel-belt framework relating channel, levee, and floodplain stratigraphy that allows comparative analysis of avulsion dyna...
Submarine mass‐transport deposits are important in many ancient and modern basins. Mass‐transport deposits can play a significant role in exploration as reservoir, seal or source units. Although seismic data has advanced the knowledge about these deposits, more outcrop studies are needed to better understand gravity mass flows and predict the prope...
The interplay between sedimentation and salt rise around a diapir results in distinct geometries that can be used to determine the structural and stratigraphic history within a basin. Using new geologic mapping, measured stratigraphic sections, and subsurface interpretations of seismic and well logs, we describe circum-diapir stratal geometries and...
IN REVIEW IN "FRONTIERS IN EARTH SCIENCE" (30 Aug 2019). Constraining the avulsion dynamics of rivers and submarine channels is essential for predicting the distribution and architecture of sediment, organic matter and pollutants in alluvial, deltaic, and submarine settings. Submarine channels are well known to be more aggradational than rivers, an...
Sediment transport and partitioning are important for understanding slope-building processes in mixed carbonate-siliciclastic sediment routingsystems. The Permian-aged Bone Spring Formation, Delaware Basin, west Texas is a mixed carbonate-siliciclastic system that has beenextensively studied in its basinal extent, but poorly constrained at its prox...
Submarine channel and fan deposits form the largest sediment accumulations on Earth and host significant reservoirs for hydrocarbons. While many studies of ancient fan deposits describe architectural variability along 2D transects (e.g., axis‐to‐fringe, proximal‐to‐distal), these relationships are often qualitative, and are rarely quantified at the...
The deposits of ancient sediment-routing systems in basins adjacent to the Andes offer key perspectives into the geologic evolution of South America, and can provide insight into basin-evolution-controlling mechanisms that operate on time scales spanning millions of years. The Andes and associated basins of southernmost South America are important...
As of Feb. 5th, 2019, this study has been submitted to Marine and Petroleum Geology (Elsevier). Topographic confinement can impose significant control on depositional styles of deepwater fan deposits. Currently, there is a lack of quantitative documentation on the spatial variation of topographic confinement in segmented deepwater basins. Herein, w...
As of August 2018, this work is in review in "The Depositional Record", a journal from the IAS (International Association of Sedimentologists) Submarine-fan deposits form the largest sediment accumulations on Earth and host significant reservoirs for hydrocarbons. While many studies of ancient fan deposits qualitatively describe lateral architectur...
Submarine channels share morphological similarities with rivers, but observations from modern and ancient systems indicate they are formed under processes and controls unique to submarine settings. Morphologic characteristics of channels-e.g., width, depth, slope, and the relationships among them-can constrain interpretations of channel-forming pro...
Morphometric analysis of submarine fan systems, the largest sedimentary deposits on Earth, demonstrates scaling relationships between genetically related channels and lobeshaped bodies (LBs) deposited beyond the channel terminus, providing insight into the architectural development of these systems. Compiling dimensional data from depositional syst...
Large fluvial fan systems can cover areas of over 103 km2, and have significant hydrocarbon reservoir potential. Although morphologically similar to alluvial fans, fluvial fans are an order of magnitude larger and are characterized by lacking sediment gravity flow processes. Fluvial fans are unconfined river systems, where a river builds a fan-shap...
Deepwater channel systems can host significant petroleum and hydrological resources and be used as repositories for carbon capture and sequestration applications. They can form unique stratigraphic stacking patterns by undergoing differing degrees of the following morphodynamic processes: incision, lateral migration and aggradation. This 3D movemen...
Submarine fans are archives of Earth‐surface processes and change, recording information about the turbidity currents that construct and sculpt them. The volume and recurrence of turbidity currents are of great interest for geohazard assessment, source‐to‐sink modeling, and hydrocarbon reservoir characterization. Yet, such dynamics are poorly const...
High-resolution bathymetry, seismic reflection, and piston core data from a submarine channel on the western Niger Delta slope demonstrate that thick, coarse-grained, amalgamated sands in the channel thalweg/axis transition to thin, fine-grained, bedded sands and muds in the channel margin. Radiocarbon ages indicate that axis and margin deposits ar...
Changes in sediment supply and caliber during the last ~130 ka have resulted in a complex architectural evolution of the Y channel system on the western Niger Delta slope. This evolution consists of four phases, each with documented or inferred changes in sediment supply. Phase 1 flows created wide (1,000 m), low-sinuosity (1.1) channel forms with...
Near-seafloor core and seismic-reflection data from the western Niger Delta continental slope document the facies, architecture, and evolution of submarine channel and intraslope submarine fan deposits. The submarine channel enters an 8 km long x 8 km wide intraslope basin, where more than 100 m of deposits form an intraslope submarine fan. Lobe de...
Climbing-ripple cross-lamination (CRCL) is most commonly deposited by turbidity currents when suspended load fallout and bedload transport occur contemporaneously. The angle of ripple climb reflects the ratio of suspended load fallout and bedload sedimentation rates, allowing for the calculation of the flow properties and durations of turbidity cur...
(in review at "Depositional Record")Submarine fans are archives of Earth-surface processes and change, recording information about the turbidity currents that construct and sculpt them. The volume and recurrence of turbidity currents are of great interest for geohazard assessment, source-to-sink modeling, and hydrocarbon reservoir characterization....
Submarine and fluvial channels exhibit qualitatively similar geomorphic patterns, yet produce very different stratigraphic records. We reconcile these seemingly contradictory observations by focusing on the channel-belt scale and quantifying the time-integrated stratigraphic record of the belt as a function of (1) the geometric scale and (2) the tr...
Cross-sectional asymmetry is characteristic of sinuous channels, in both fluvial and submarine settings. Less well documented are the facies distributions of asymmetric channels, particularly in submarine settings. Exposures of the axial channel-belt in the Magallanes retro-arc foreland basin on Sierra del Toro represent the fill of a 3.5 km wide,...
Most submarine canyons are erosive conduits cut deeply into the world’s continental shelves through which sediment is transported from areas of high coastal sediment supply onto large submarine fans. However, many submarine canyons in areas of low sediment supply do not have associated submarine fans and show significantly different morphologies an...
In southern Patagonia, outcrops of the Upper Cretaceous Cerro Toro Formation preserve a >150 km long deep-water axial channel belt in the Magallanes–Austral Basin, providing a unique opportunity to investigate longitudinal variations in the depositional characteristics of a deep-water channel system. This study documents sedimentological, stratigra...
Landslides are common in aquatic settings worldwide, from lakes and coastal environments to the deep sea. Fast-moving, large-volume landslides can potentially trigger destructive tsunamis. Landslides damage and disrupt global communication links and other critical marine infrastructure. Landslide deposits act as foci for localized, but important, d...
Landslides are common in aquatic settings worldwide, from lakes and coastal environments to the deep-sea. Fast-moving, large volume landslides can potentially trigger destructive tsunamis. Landslides damage and disrupt global communication links and other critical marine infrastructure. Landslide deposits act as foci for localised, but important de...
Digital outcrop models help to constrain the interactions of stratigraphic and structural heterogeneity on ancient depositional systems. This study uses a stochastic approach that incorporates stratigraphic and structural modeling to interrogate the three-dimensional morphology of deep-water channel strata outcropping on Sierra del Toro in the Maga...
Deep-water channel fill comprises thick-bedded sandstone in the thalweg that transitions laterally to thin-bedded
deposits toward the margins. Channel fills stack to form composite channel systems, which commonly exhibit an
evolution of early channel incision and lateral migration to late-stage aggradation. This stratigraphic evolution
ultimatel...
Submarine fans are the largest sediment accumulations on Earth and represent the ultimate sink for clastic detritus. The sediment budget and frequency of turbidity currents that construct submarine fans are poorly understood due to lack of modern flow measurements. Only in the past few years have reliable flow measurements been made in submarine ca...
This study aims to delineate the stratigraphic expressions in response to the increasing tectonic activity, structural confinement, and continuing influx of large volume of sediments of an early foreland basin from deep water to shallow water settings. Quantitative and semi-quantitative data collections of the facies, facies associations, architect...
Submarine-channel systems record basin-margin sediment dispersal and can host significant natural resources. We review the facies architecture (i.e., facies heterogeneity and stacking patterns) of outcropping submarine-channel systems, focusing on the Cretaceous Tres Pasos Formation, Magallanes basin, southern Chile. The fundamental building block...
Submarine gullies are ubiquitous on the modern seafloor of both passive and active continental margins. However, the processes dictating gully formation and the role of gullies in deep-water sediment transport are topics of debate. In this study, through 3D seismic reflection interpretation of Pliocene-Pleistocene continental slope strata in the Ta...
Near-seafloor core and seismic-reflection data from the western Niger Delta continental slope document the facies, architecture, and evolution of a submarine channel-to-lobe transition zone. At an abrupt decrease in slope, a submarine channel transitions into an 8 km long x 8 km wide intraslope submarine fan. This fan’s surface is not channelized,...
Submarine channels are the primary conduits for the transport of clastic detritus from the continents into the deep sea. During their evolution, these channels migrate, forming channel belts that record a complex history of vertical degradation, lateral migration, and vertical aggradation. Previous work drawing on seismic, outcrop, and modeled exam...