Paleontology Meandering Channel
Fossil remains most often preserved by this environment include plant debris, vertebrate bones, freshwater mollusks and gastropods, and, in greater abundance, spores and pollen. Low-grade coals derived from backwater swamp peat deposits may also contain some indicative remains. Rootlet horizons and burrowing, as well as surface sedimentary structures, such as raindrop impressions and desiccation cracks, are seen in modern-day settings and in outcrops, but the chances of discovering any of these in cores is, at best, slim.
Geometry Meandering Channel
The size of an individual meander belt has already been mentioned. Given an open basin setting, this — as well as the frequency of meander migration — will be determined by climate, slope, and sediment supply. Vertical thicknesses for preserved meander channel facies vary from about 10 ft to 1000 ft (3 m to 300 m). As a whole, a meander belt will trend perpendicular to a paleoshoreline, but this will normally become clear only where a great and regional abundance of well data exists. It may, however, be used as an overall predictive concept if other large-scale factors, such as valley or basin trends, become known. Most modern-day meander belts are limited to about twice the average meander amplitude, and this can also be used as a general guide for diagnosing at least the lateral extent of a given reservoir. As mentioned, shoestring sand bodies are a common result of this facies. These can be less than 2 m or more than 30 m thick, and either continuous or sporadic.
Associated Meandering Channel Facies
Meandering stream deposits very often grade basinward into deltaic and shoreline-shelf facies, which, in turn, pass into distinctive deeper water sands and shales. Lacustrine sediments are another common associated environment. Of these, the deltaic association is probably the most important for petroleum geology. Normally, the transition from the meandering channel flood plain will be gradational if a delta is actively prograding out into a basin, and sharp if it is inactive (Cant 1982), i.e., being reworked by marine transgression.
As mentioned, braided streams often form the proximal associated facies for this environment. Other common associations are with large inland lakes and mountain streams. In contrast to many braided stream deposits, those of the meandering channel facies are normally devoid of oxidized iron coloring, being greet and drab. The much higher clay component, smaller grain size, and textural characteristics, such as better sorting, generally provides a basis for roughly distinguishing the two facies where they grade into each other.
