Integrating traditional field methods with emerging digital techniques for enhanced outcrop analysis of deep water channel-fill deposits

Abstract

The development of emerging digital technologies that allow the collection and analysis of field data represents a significant innovation in field-based geological studies. The integration of these digital techniques with traditional sedimentological field methods facilitates considerable improvements in outcrop characterization. An example of this integrated modern approach for geological data collection is employed for the detailed characterization of a turbidite channel-lobe system of the Gorgoglione Flysch Formation in Southern Italy. The study area, exposed above the village of Castelmezzano, has been measured and described in detailed stratigraphic sections, providing data for both sedimentological analysis and correlation of the stratigraphy. In order to gain a complete perspective on the exposure and stratigraphic elements, analysis of physical outcrop data was enhanced by the use of high-resolution Gigapixel imagery and 3D photogrammetric outcrop reconstructions. The Santa Maria section has been assessed in terms of vertical and lateral facies stacking arrangements and subdivided into two component facies associations separated by a prominent concave-up erosional boundary. The lower facies association, interpreted as a frontal lobe complex, consists of tabular, thick-bedded coarse sandstones interbedded with persistent heterolithic packages of thin-bedded sandstones and mudstones, and minor soft-sediment deformed strata. The upper facies association represents the infill of a channel-form and consists of a basal conglomerate, passing gradually upwards into massive amalgamated sandstones overlain by large-scale cross-laminated sandstones. The excellent exposure of the Santa Maria section records the complete evolution of a channel-lobe system, transitioning from frontal lobe deposition through channel incision and bypass, to progressive backfilling. This study shows how facies characterization, stratigraphic correlations and reconstruction of the depositional architectures have been substantially enhanced by the use of emerging digital techniques for geological data collection

Multi‐scale analysis of a migrating submarine channel system in a tectonically‐confined basin: The Miocene Gorgoglione Flysch Formation, southern Italy

“…The deep‐water strata of the GF system have been studied using both standard sedimentary facies analysis and digital field techniques, such as high‐resolution photomosaics and structure from motion (SFM) three‐dimensional photogrammetry (Pitts et al ., ). Traditional methods included bed‐scale characterization of sedimentological and stratigraphic elements and palaeoflow analysis.…”

“…(B) The monoclinal configuration of the Gorgoglione Flysch (GF) formation, dipping south-west by nearly 40°, which defines the spectacular cliffs that inspired the local name of 'Lucanian Dolomites'location in (A). photogrammetry (Pitts et al, 2017). Traditional methods included bed-scale characterization of sedimentological and stratigraphic elements and palaeoflow analysis.…”

“…Additional digital data collection methods included the construction of ultra-high-resolution outcrop panoramas produced by the GigaPan â imagery system (GigaPan Systems, Portland, OR, USA) and 3D outcrop models produced from aerial and ground based imagery using SFM 3D photogrammetry, built to aid in the identification of key surfaces and to improve the analysis of depositional architectures (Pitts et al, 2017). Where possible, key stratigraphic surfaces have been walked and mapped using a GPS to improve their spatial reconstruction.…”

“…The primary basal surfaces commonly exhibit steep notches, which produce a stepped cross‐sectional geometry (Fig. A and B) and are locally ornamented by sole structures up to 20 cm long and minor loading features (Pitts et al ., ). Palaeocurrent measurements from these basal indicators across the study area reveal an average flow towards 149°, ranging from 100° to 206° (Fig.…”

“…Moreover, for some elementary channel units, the widths have been calculated for reconstructed strike-oriented crosssections by projecting the apparent dimensions onto a surface normal to the average palaeocurrent direction ( Fig. 9; Pitts et al, 2017).…”