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Sonntagsbrunn Farm, Nomtsas Fm., Valley Fill 2, Visionarium (Ediacaran to of Namibia)

Where: Namibia (27.3° S, 17.6° E: paleocoordinates 41.2° S, 172.9° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Nomtsas Formation (Nama Group), Ediacaran to Ediacaran (635.0 - 530.0 Ma)

• Ediacaran-Cambrian Boundary.

• formation-level stratigraphic resolution

Environment/lithology: offshore; lithified sandstone and siltstone

• Nomtsas Formation incises into the upper two members of the underlying Urusis Formation, forming two discrete incised valleys (Fig. 2). These are exposed in cross section in the walls of the present-day canyon, carved by a tributary of the Fish River. Valley fill units are superimposed on one another, and can be traced for hundreds of meters in plan view; incised valley widths appear to be on the order of 200 m.

•Lower shoreface, just above SWB at its deepest, and tide-influenced on the basis of bidirectional paleocurrents and the presence of trough cross-bedding, based on sedimentary structures, including flaser to lenticular bedding and unidirectional current ripples (Fig. 9). Fine-grained sandstone with mud drapes was probably deposited by waning flows following storm or tidal flows, as described by Saylor (2003).

• fine-grained sandstone, siltstone, and shale

Size classes: macrofossils, mesofossils

Preservation: trace

Primary reference: J. P. Wilson, J. P. Grotzinger, W. W. Fischer, K. P. Hand, S. Jensen, A. H. Knoll, J. Abelson, J. M. Metz, N. Mcloughlin, P. A. Cohen, and M. M. Tice. 2012. Deep-water incised valley deposits at the Ediacaran-Cambrian boundary in Southern Namibia contain abundant Treptichnus pedum. Palaios 27:252-273 [W. Kiessling/M. Krause] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 139838: authorized by Wolfgang Kiessling, entered by Mihaela Krause on 18.02.2013

Creative Commons license: CC BY (attribution)