Distinguishing fluvio‐deltaic facies by bulk geochemistry and heavy minerals: an example from the Miocene of Denmark

Abstract

Interpretations of seismic profiles, gamma‐ray logs and sediment descriptions were used to classify seven facies in Miocene fluvio‐deltaic deposits of Denmark. An impartial approach was adopted by not including analytical data in the facies definition. This approach allowed identification of significant differences between facies, where each fluvio‐deltaic facies can be distinguished by integrating geochemistry and mineralogy through a sedimentary succession. Variations in the heavy mineral assemblage between facies are caused primarily by sorting of hydraulically equivalent grains. Decreasing grain size of quartz and heavy minerals from the channel facies towards the delta shoreface facies and further along the coast to the spit shoreface facies is associated with an increase in sorting and textural maturity. This trend is related to longshore drift. Increasing heavy mineral grain size is found from the delta slope facies offshore to the delta toe and shelf facies. This trend is interpreted as a result of sorting by turbidity currents. The mixed origin of the transgressive lag facies is shown by the poorer sorting in this facies. By indicating the amount of alteration the sediments have been exposed to, the Ti‐mineral maturity has proven useful in characterizing the facies. This systematic approach of tying depositional environments to a well‐calibrated sequence stratigraphic model has generated analytical results which are valid as reference levels for future facies identifications.

Detailed mapping of marine erosional surfaces and the geometry of clinoforms on seismic data: a tool to identify the thickest reservoir sand

“…Apatite fission track data indicate initial uplift of present‐day Norway at the end of the Oligocene (Japsen et al , 2007). Heavy mineral studies of lower Miocene sediments show that present‐day Norway and western central Sweden formed the source area for the studied succession (Knudsen et al , 2005; Olivarius, 2008). As a consequence of the increased relief in the hinterland and the relatively high precipitation, ca .…”

Workflow for analysis of compositional data in sedimentary petrology: provenance changes in sedimentary basins from spatio-temporal variation in heavy-mineral assemblages

“…An amphibole-epidote-garnet assemblage is typically related to collision orogen or orogenic root provenance terranes (Garzanti & Andò, 2007). The orogenic source area for these deposits is inferred to be the Fennoscandian massif, as a similar heavy-mineral assemblage can be found on the Isle of Sylt, off the Danish coast (Edelman & Douglas, 1933;Olivarius et al 2011Olivarius et al , 2014. The Fennoscandian massif was drained by the large Baltic river system, which served as the major source of sediment to the North Sea Basin in the Late Miocene and Pliocene (Overeem et al 2001).…”

The Oligocene succession in the eastern North Sea: basin development and depositional systems

“…As uplift continued more landmasses were gradually exposed, forcing the drainage system to follow established N–S- and NE–SW-striking lineaments on present-day eastern and southern Norway. This probably continued during Miocene time, when the lower Miocene deposits of onshore Denmark were sourced from southern Norway (Olivarius, 2009) and south-westwards sediment dispersal and depocentre migration continued into the Central Graben area (e.g. Jarsve et al 2014).…”