The depositional model of the Festningen Member of the Barremian Helvetiafjellet Formation is that fluvial to inner deltaic-plain conditions were established as deltas that built southeastward into the Barents Sea basin from an unknown source northwest of present-day Svalbard. Currently, models of Artic drainage provinces are nascent to non-existent. Here, evidence for a large artic drainage basin into the Cretaceous Barents Sea is suggested by using established scaling relationships and the fulcrum method in the Festningen Sandstone.
Data from several locations in Svalbard: Konusdalen, Revneset, Criocerasaksla, and Hanaskogdalen. The Festningen Member sandstone sections were all initially photographed by drone in order to determine channel body dimensions and architecture in the sandstone as well as to record data for 3D photogrammetric construction of virtual outcrop models. Paleohydraulic estimates based on the fulcrum method use bankfull channel dimensions, specifically the height and width, and the D16, D50, D84, and D90 grainsizes to develop basin-process models and infer past catchment constraints. Festningen Member sandstone sections were logged and found to represent braided fluvial systems with mid-channel bars up to 3 m thick and channel-fills up to 4 m thick. Representative bedload samples were taken from approximately 10 cm above the base of channel scours for analysis and model input. The coarse grainsize and large clasts, frequently 3-4 cm and up to 15 cm in diameter, in the Festningen Member sandstone samples show that this was a large river capable of moving a coarse bedload. Scaling relationships equivalent to 4 m channels and coarse grained D-values is on the order of the modern braided Missouri River, on the South Dakota/Nebraska border.
The Bjarmeland Platform and Fingerdjupet Subbasin in the western Barents Sea have a potential petroleum play in the Lower Cretaceous strata, which are, in part, considered to have been fed by the same Festningen fluvial system that is represented in cliff sections on Svalbard. Seismic profiles show clinoforms that may suggest deltaic facies, but remains unknown due to lack of well data.
Seismic data shows that the Cretaceous Festningen fluvial system was able to deliver enough sediments onto the Bjarmeland Platform area to build clinoforms. The size of the source area sufficient to produce a trunk river on this scale remains unconstrained, but an area of at least 100,000 km2 is necessary to produce the river found in the rock record, if the Fulcrum method is applied. Existing Arctic tectonic reconstructions do not consistently show a land area of sufficient size to accommodate this magnitude of drainage area, but results from this study may provide further input to the discussion on timing and land-mass configuration in the present day arctic during the Early Cretaceous.

The 1.2 Ga volcanic arc rocks in the Barby Formation are well exposed in desert terrain in SW Namibia - this formation records the establishment of a major continental margin arc following earlier accretionary events. Recent field work has shown that large portions of the formation consist of pyroclastic fall deposits erupted from small volcanoes (fissures and scoria or spatter cones) in a region with poor drainage and abundant lakes.

Detailed mapping of a well-exposed section of the Barby Formation provides a cross-sectional view of a succession of pyroclastic fall units intercalated with planar bedded lacustrine sediments. Massively bedded units up to ~80 m thick show abundant bombs up to 60 cm across in a matrix of fluidal to angular lapilli, indicating deposition close to source vents undergoing primarily Strombolian-type eruptions. Hypabyssal dikes and sills are common, often cutting through the massively bedded pyroclastic units.

Also present are pyroclastic deposits that intrude lacustrine sedimentary packages at 12 locations spread out over a horizontal distance of ~600 m and a vertical stratigraphic sequence of ~300 m. These deposits contain similar bombs and lapilli as the pyroclastic fall deposits, but show clear fluidal intrusive relations with adjacent sedimentary units. In most cases, zones of peperite are formed in between the pyroclastic intrusions and the lacustrine sediments, consisting of fluidal bodies of vesicular basaltic andesite mingled with fine-grained sediment with preserved lamination. We infer that jets of intrusive pyroclastic material were blasted laterally into weak, unlithified lake sediments from one or more vent conduits feeding explosive eruptions at the surface; these jets are likely to have been forced out by collapse of the conduit inward. Fluidization of the sediment would have occurred as pore water was converted to steam, which would have facilitated lateral motion of the pyroclastic jets.

Landsat-8 data was used to test the effectiveness of using spectral analysis and remote sensing in the differentiation of lithological units and mapping geology in Namibia. The study area is located in SW Namibia, in an arid region with little vegetation, making it an ideal place for remote sensing analysis. Different color composites and band ratios were compared to find the image providing the most geologic information and highest contrast between units. A false color composite (6,3,2 in red-green-blue) was first created to to show differences in bare earth, and from there, various band ratio combinations were created. Geologic maps were used to verify the results and select the best band combination. The best color composite image was created using band ratios from (7/6, 6/5, 4/2), and allowed identification of lithological units and vegetation. The results show that it is possible to draw valid lithological conclusions from spectral patterns, and that high quality imagery can be used to update existing geologic maps or used for exploration.

SRS Abstract Drainage Area Climate Classification

For my SRS project I will be determining the climate(s) within a given polygon. The Polygon size and shape will be determined from a specified drainage area for a given stream. I will be using over 400 stream data points with a series of drainage area shape files given to me by Nicole Wilson. I will base the climate on the gauge site location within the drainage area. The koppen climate classification scheme will then be used to specify each drainage area.

Unconventional shale plays have been a significant source of natural gas, gas condensates, and crude oil through much of North America. The Eagle Ford Shale in south Texas has been a prolific unconventional play since the mid-2000’s. It was deposited in the Gulf Coast basin along the southern rim of Texas. This play covers a vast area that stretches approximately 7 million acres (2.8 hectares) and extends from the College Station to the USA-Mexico Border near Del Rio. The majority of the Eagle Ford has been thoroughly studied and analyzed, however, there is much to learn about the basal member, the Maness Shale.
The Maness Shale was deposited 97 million years ago; it is the basal member of the Eagle Ford Group and lies directly above the Buda Limestone. The formation does not occur continuously throughout the entire Eagle Ford deposition and varies in thickness. Whereas the lateral extent still remains unknown, it has previously been mapped across the San Marcos Arch. The geophysical and geochemical properties of this member create drilling stability issues if encountered while drilling horizontal Eagle Ford wells. To further understand its geomechanical properties, two hand-held devices will be used on cores taken near the San Marcos Arch that contain the Maness Shale to determine rock strength variations of the Eagle Ford section. The Equotip Bambino is a micro-rebound hammer that provides hardness data values that can be used to estimate unconfined compressive strength. The dimpler is a micro-indentation device that infers rock strength by generating a “dimple” created by the tool and then measuring the depth and diameter of the dimple. These measurements are then correlated on graphs against the unconfined compressive strength for the regional Eagle Ford. The Maness has a neutron density range of 20-30%, indicating a high clay content. The x-ray diffraction (XRD) will be used to determine the content of the clay minerals. Geophysical well logs have been collected and correlated across the San Marcos Arch region; the initial maps identified the thickest Maness interval within the Karnes trough.