ammonites
Knowledge Creek (Cretaceous to of Australia)

Where: Victoria, Australia (38.8° S, 143.3° E: paleocoordinates 74.4° S, 117.2° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Otway Group, Late/Upper Aptian to Late/Upper Aptian (122.5 - 109.0 Ma)

• bed-level stratigraphic resolution

Environment/lithology: coarse channel fill; lithified, massive, medium-grained, coarse, concretionary, pebbly, conglomeratic sandstone

• "abandoned braided fluvial or alluvial channel fill that was cross-cut by subsequent sheet flows and small, shallow, and temporary channels"
• "In this study, the lithology surrounding the structures of interest is a very thick (>20 m) planar- to cross-bedded, conglomeratic lithic arenite with rounded or angular pebbles, cobbles, and boulders oriented parallel to bedding (Fig. 2). The lithology is well indurated, but eroded by shoreline processes. Laterally adjacent to and just above (1.5–2.0 m) the structures are a few medium- to very thick-bedded (0.2–1.5 m) lenticular sandstones of limited lateral extent (<5 m). Some of these sandstones follow concave bedding planes, hinting at channel bedforms. Sorting in the main lithology is moderate to poor, and the framework is primarily composed of medium- to coarse-grained sand composed of varying proportions of quartz, feldspars, and lithic clasts. Angular cobbles and boulders of lithic clasts are common in the basal 2–3 m of the outcrop, decrease in size and frequency for most of the succeeding section, and are common again in the upper part of the outcrop. A discontinuous breccia bed, about 30–40 cm thick, is lateral to (east of) the three structures and stratigraphically just above one of the structures, as explained later. Low-angle cross-bedding and horizontal, planar bedding is defined in places by aligned pebbles, cobbles, and a few bedding planes, but otherwise internal stratification is difficult to define, and the overall lithology is somewhat massive. Spherical to semispherical concretions, most of which are 2–15 cm in diameter, are evident in places; fractured examples of these reveal lithic clasts as nuclei."

Size class: macrofossils

Preservation: cast, mold/impression, trace

Collected by Rich & Martin in 1980, 2006-2009

Collection methods: surface (in situ),

Primary reference: P. V. Rich, T. R. Rich, B. E. Wagstaff, J. M. Mason, C. B. Douthitt, R. T. Gregory, and E. A. Felton. 1988. Evidence for low temperatures and biologic diversity in Cretaceous high latitudes of Australia. Science 242(4884):1403-1406 [M. Carrano/M. Carrano] more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 68967: authorized by Matt Carrano, entered by Matt Carrano on 14.02.2007