Actual development of the chenier coast of suriname (South America)

Abstract

Augustinus, P.G.E.F., 1980. Actual development of the chenier coast of Suriname (South America). Sediment. Geol., 26: 91--113.The Holocene coastal plain of Suriname is a chenier plain. Its actual sedimentological development has been studied during three field-work periods (1966, 1967/1968, 1972). Clay is the predominant sediment in this low-to medium-energy environment. It accumulates in extensive shoreface-attached mudfiats (sometimes considered as giant mudwaves), which migrate continuously to the west due to deposition of slingmud at their west side and simultaneous erosion of the east side. In between the mudflats cheniers may develop.Thin-section analysis of the clay deposits revealed that they are built up of an alternation of thick clayey laminae and thin laminae of silt and fine sand. The clayey laminae chiefly show a unistrial plasmic fabric. Disturbaces in the upper zone are caused by bioturbation.Two types of cheniers can be distinguished. One type contains fine sand which has been winnowed out of the pelite deposits. Since this sand is brought from the shelf the chenier formation begins at approximately mean low-water level. Longshore bars are formed and these are driven shoreward by wave action. The other type is built up of medium to coarse sand supplied by a local river. It is transported westward by beachdrift in a narrow zone around the mean high-water line. These cheniers develop therefore at or just above the mean high-tide level.The sedimentary structures of both types of cheniers have many characteristics in common. However, each type also has its own distinct features.

Mangroves, mudbanks and seawalls: whose environmental knowledge counts when adapting to sea level rise in Suriname?

“…These periods were always followed by phases of coastal accretion (Figure 3). Augustinus (1978;1980;2004), a physical geographer who has spent much of his career studying the coastal geomorphology of the Guiana coast, provides a scientific explanation of the role that mudbanks play in mangrove ecology. Fine silt and clay particles, originating in the Amazon River, are transported via the Guiana Stream along the northeast coast of South America where they interaction with northeast trade winds and create a system of migrating mudbanks that dampen wave energy, thus protecting coastal mangroves (Allison et al 2000;Augustinus 2004).…”

Late Holocene evolution of a coupled, mud-dominated delta plain–chenier plain system, coastal Louisiana, USA

“…In addition to changes in the MDP, McBride et al (2007) suggest that the formation of the Little Chenier and the Grand Chenier palaeo-shorelines is linked to periods of higher than present-day sea levels. Other potential factors influencing chenier formation are storm frequency, wave and tidal regime changes, and bay geometry (Augustinus, 1989). This shows that when studying the sensitivity of the CP to changes in the MDP, the influence of these changes has to be separated from more local influences on CP formation.…”

“…For example, Augustinus (1980) describes two types of cheniers along the shoreline of Surinam: medium to coarse sandy cheniers with a base at the mean high-tide level and fine sandy cheniers with a (Fig. 13).…”

“…Cheniers form when progradation is interrupted by a phase of erosion and transgression and mainly consist of (very) fine sand and shells due to winnowing processes. Once formed, they usually migrate landward due to washover process until the crest becomes high enough to withstand the highest spring tides (Augustinus, 1989). From that point on they are rather stable, accretionary features that sometimes start to prograde seaward (Gould and McFarlan, 1959) and become regressive cheniers (cf.…”

The Dobrotiv Formation (Miocene) in the Boryslav-Pokuttya and Sambir nappes of the Ukrainian Carpathians: a record of sedimentary environmental change in the development of the Carpathian Foredeep basin

“…Field ing et al, 2005), in clud ing many lac ustrine del tas (e.g., Thomas et al, 2006), sug gests a mud-dom inated delta on a mud-dom i nated coast. Such depositional settings are still poorly un der stood, but known from re cent and fossil ex am ples (Augustinus, 1980;Hovikoski et al, 2008). Delta - A -rain drop casts; B -raindrop im prints; C -wind ing in ver te brate bur rows; D, E -bird foot prints; F -Gazellipeda -mam mal foot print; G -mammal trackway Gazellipeda, bird foot prints, rain drop casts -front fa cies in such del tas can be com posed mostly of mud (Tanabe et al, 2003).…”