In:
Basin Research, Wiley, Vol. 33, No. 6 ( 2021-12), p. 2960-2983
Abstract:
We propose that a more readily studied, secondary source‐to‐sink (S2S) systems can be formed on direct‐fed margins, in which shelf‐edge deltas are ‘sources’ and deep‐water fans are terminal depositional ‘sinks’, with channels working as delivery ‘conduits’ in between. DionisosFlow stratigraphic‐forward model, coupled to seismic and borehole data from middle Miocene Pearl River margin, are used to explore physical and conceptual linkages of delta‐to‐fan S2S systems, with a focus on the predictability of when and how coarse clastics are delivered from the deltas down to the submarine fans. Middle Miocene Pearl River delta‐to‐fan S2S coupling was stratigraphically enacted in three main ways: (a) deltas that lack downdip fans: high sea level or low sediment supply caused coarse clastics to be stored mainly on inner to outer shelf areas; (b) deltas that are linked downdip to fans: coarse clastics were funneled to submarine fans through slope channels, via direct delta‐to‐fan S2S linkages created by delta overreach at shelf break or channels extending back to shelf‐margin prodeltas; (c) fans that lack updip, coeval deltas: coarse shelf clastics were carried laterally by longshore or other shelf currents, but eventually captured by canyon heads, and then delivered directly to the basin floor. Moreover, our DionisosFlow stratigraphic‐forward models suggest that an oscillation in sea‐level behaviour from slowly falling to rapidly falling would result in a within‐system tract surface occurring within the falling‐stage systems tract. This surface is identified as a significant lower‐order unconformity in its proximal reaches and as a correlative conformity distally. Within‐system tract surfaces are identified by a change in shelf‐edge trajectory regimes from flat to slight falling to moderately falling and in architecture from mixed progradation and degradation to dominant degradation. They are coeval with the onset of the deposition of submarine fans linked updip to deltas or lacking updip deltas, highlighting that sandy deposits can be compartmentalized even within a single systems tract.
Type of Medium:
Online Resource
ISSN:
0950-091X
,
1365-2117
Language:
English
Publisher:
Wiley
Publication Date:
2021
detail.hit.zdb_id:
2019914-4
SSG:
16,13
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