Construction of a high-resolution spatial and temporal alluvial facies model for the Sonsela Member, Chinle Formation (Mid Norian), Arizona, USA A - Map of the study area within the Petrified Forest National Park. Colored areas show the panoramic photo location and view of each sub-divided Area (shown below is Area 1). Petrified Forest National Park
N
I-40
Map Area Hwy 180
5km
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This study examines a 1km long exposure of Late Triassic cyclic alluvial deposits and paleosols within the Petrified Forest National Park. The study area was separated into 5 individual study areas (see A) for which high-resolution panoramic photos were taken. During the summer of 2008, eight measured sections and 60 paleosols were described as to grain size, depositional style, and pedogenesis. Observed field characteristics were mapped on high-resolution panoramic photos to determine the 2-D distribution of alluvial features (see B). Samples of paleosols and sandstones were obtained and will be analyzed for grainsize, bulk geochemistry, thin section petrography and micromorphology, and isotopes. The main goals of the study are:
Blue Mesa Lookout Road Photopan viewpoint Highest Elevation Lowest Elevation
Area 1 Area 2 Area 3 Area 4 Area 5
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To document changes in paleosol and depositional style, and develop a conceptual model that relates the two. To combine information about changing alluvial style through time in order to develop a better understanding of the relationship between reservoir quality and evolving fluvial style and climate.
1km
B - Detailed 2-dimensional map of Sonsela Area 1 butte (see A) showing fluvial architectural elements, pedogenic development, paleosol tops, and location of both measured sections and paleosol profiles.
Petrified Forest - Sonsela - Area 1 S1C9 Sonsela Member
Blue Mesa Lookout
S1C7 S1C6 S1C6P1
S1C5.5 S1C5 S1C4
Paleosol Top Downstream Accretion Lateral Accretion Overbank Fines Pedogenic Alteration
Blue Mesa Member
Measured section traverse
S2C5
S1C5
S1C5P1
Paleosol Profile Location
S1C9 S1C8 S1C7 S1C6 S1C5.5
S1C4P1 S1C3P1 S1C2.5
0S1C2
S1C1P1
0
50m
