Open-ocean, off-bank transport of fine-grained carbonate sediment in the Northern Bahamas

Heath, Kathryn C.; Mullins, Henry T.

doi:10.1144/gsl.sp.1984.015.01.13

Cited by 26 publications

(26 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2. mechanism of formation of these deposits is difficult to evaluate. As proposed by Heath and Mullins (1984) and Wilson and Roberts (1992), the sediment probably formed through suspension settling, but according to Stow et al (1984) turbiditic processes as a sediment-dispersal mechanism may be involved. Regardless of the mode of formation, the composition of these layers is to a large extent controlled by processes acting in the shallow-water carbonate factory.…”

Section: Light-grey Wackestones/packstonesmentioning

confidence: 92%

Carbonate shedding and sedimentary cyclicities of a distally steepened carbonate ramp (Miocene, Great Bahama Bank)

Betzler¹,

Pfeiffer²,

Saxena³

2000

International Journal of Earth Sciences

View full text Add to dashboard Cite

Depositional geometries as imaged in seismic lines, logging data, and quantitative petrographic data were used to analyse the slope and toe of slope deposits of the Miocene distally steepened carbonate ramp of Great Bahama Bank. The shedding pattern along the slope of this ramp is more complex than it is along the slope of the Pliocene±Pleistocene flattopped carbonate platform. Compositional changes and compositional trends of periplatform sediments correlate with the positions of geophysically-defined sequence boundaries. Two types of depositional sequences occur. The first sequence is characterised by laterally traceable sequence-internal reflections, whereas the second type contains major intrasequential incisions. Erosional incisions and sedimentary infills of these canyons by turbidites formed during sea-level lowstands, as is indicated by the composition of the turbidites having a mixture of shallow-water and pelagic particles. Highstand turbidites are characterised by more extensive, laterally traceable geometries and by the occurrence of abundant shallow-water particles. In contrast to highstand turbidites shed from the Pliocene±Pleistocene flat-topped platform, shallow-water components in highstand turbidites of the Miocene ramp are of skeletal origin. The stacking pattern of the periplatform deposits is controlled by sealevel fluctuations. Four orders of sea-level changes are distinguished. Third-order cycles are delimited by sequence boundaries, and fourth (100,000 a) order cycles govern the bundling of turbidites into packages. Fifth (40,000 a) and sixth (23,000 a) order cycles are recorded in the background sediments and resolvable with spectral analysis.

show abstract

Section: Light-grey Wackestones/packstonesmentioning

confidence: 92%

Carbonate shedding and sedimentary cyclicities of a distally steepened carbonate ramp (Miocene, Great Bahama Bank)

Betzler¹,

Pfeiffer²,

Saxena³

2000

International Journal of Earth Sciences

View full text Add to dashboard Cite

show abstract

“…2) support suspension-driven transport. It thus seems likely that Middle Miocene off-bank transport of aragonite needles occurred in a similar way as the presentday sediment export processes on the Bahamas (McCave 1972;Neumann and Land 1975;Schlager and Chermak 1979;Droxler and Schlager 1985;Heath and Mullins 1984;Shinn et al 1989;Wilber et al 1990;Roberts 1992, 1995;Rendle-Bühring and Reijmer 2005). Next to storms and hurricanes, which occasionally may cause aragonite export, long-term fine-grained sediment transport patterns from this production zone are related to the winddriven surface currents (Roth and Reijmer 2005).…”

Section: Aragonite Needles: Precipitation Sitementioning

confidence: 90%

“…The mean aragonite content of the modern Bahamian whiting-related particles is 86% (Shinn et al 1989), and the aragonite needles represent up to 85-90% of the modern fine sediments of the Bahamian banks (Milliman 1974;Heath and Mullins 1984). A direct isotopic analysis of the aragonite of individual Miocene granulometric fractions could not be made because of the limited amount of this mineral in the fractions analysed (maximum of 38%, Table 3; Fig.…”

Section: Aragonite Needles: Precipitation Sitementioning

confidence: 99%

See 1 more Smart Citation

Whiting-related sediment export along the Middle Miocene carbonate ramp of Great Bahama Bank

Turpin

Emmanuel²,

Reijmer³

et al. 2011

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

Modern aragonite needles are present all along the modern leeward margin of Great Bahama Bank (ODP Leg 166), while Middle Miocene sediments contain needles only in more distal areas (Sites 1006 and 1007). In contrast to the rimmed, flat-topped platform topography during the Plio-Pleistocene, the Miocene Great Bahama Bank morphology is a carbonate ramp profile. This might imply a different location and precipitation type for Miocene aragonite needles. In this study, aragonite needles in Miocene sediments were isolated using a granulometric separation method. Furthermore, the isolation of the various carbonate components enables the identification of primary versus diagenetic components. The Miocene aragonite needles are concentrated in the finest granulometric sediment fractions (\12 lm). The fraction-specific geochemical analyses (d 13 C, d 18 O and Sr elemental abundance) represent useful tools to assess the possible sources of the aragonite mud. The geochemical variation of the fractions, rich in pristine aragonite needles, and the characteristics of the needle morphology point to whiting phenomena as the main sediment source and algal fragmentation as a minor component. Both components indicate shallow-water environments as the main sediment source area. Ramp-top-related fine-grained particles now present at distal sites were likely exported as suspended material similar to present-day transport mechanisms. The scarcity of needles at proximal sites is probably linked to hydrodynamic processes but dissolution and recrystallization processes cannot be excluded. The granulometric separation approach applied here enables a better characterization of the finest carbonate particles representing an important step towards the discrimination between primary and diagenetic fine-grained components.

show abstract

“…The modern Little Bahama Bank produces up to three times the amount of carbonate mud that can be stored on its platform top area [Neumann and Land, 1975]. Excess sediment is exported to the periplatform realm [Supko, 1963;Kier and Pilkey, 1971;Lynts et al, 1973;Neumann and Land, 1975;Hana and Moore, 1979;Hine et al, 1981;Kendall and Schlager, 1981;Boardman and Neumann, 1984;Heath and Mullins, 1984;Schlager et al, 1994], where an admixture of pelagic and bank-top derived material accumulates.…”

Section: Introductionmentioning

confidence: 99%

Nature and origin of carbonate particles along a transect on the western margin of Great Bahama Bank (Middle Miocene): sedimentary processes and depositional model

Turpin

Emmanuel

Renard

2008

Bulletin De La Société Géologique De France

View full text Add to dashboard Cite

During ODP Leg 166, Middle Miocene sediments were collected along the western margin of the Great Bahama Bank (GBB) at four sites, distributed along a proximal-distal transect. Site 1006 is located in the basin, Site 1007 at the toe-of-slope and Sites 1003 and 1005 on the mid and upper slope. The carbonate slope deposits of GBB consist of periplatform oozes, an admixture of platform-derived aragonite and high-magnesium calcite particles, and pelagic low-magnesium calcite. An assessment of carbonate sedimentation is made in order to estimate the proportion of platform-derived versus pelagic components. The originality of this study is based on the application of a separation method giving access to homogeneous granulometric fractions, ranging from 63 to 3 µm in grain diameter. This method, associated with a multidisciplinary approach (micropaleontology, optical and electronic microscopy, mineralogy -X-ray diffractometry, and trace elements geochemistry -strontium and magnesium), allows the quantification and characterization of different kinds of carbonate particles. In Miocene sediments, three types of particles display a biogenic structure: planktonic foraminifera, calcareous nannofossils and fragments of neritic organisms. Two types of particles do not exhibit any structures that allow for a determination of their origin. Based on their size and their mineralogy, we have distinguished macroparticles (calcite and dolomite) and microparticles (calcite and aragonite).The detailed study of the composition of the separated fractions highlights major differences in carbonate ooze composition between the different sites along the transect. The unlithified samples of Sites 1006 and 1007 are dominated by pelagic components (planktonic foraminifera and calcareous nannofossils) and contain aragonite microparticles. In contrast, lithified sediments of Sites 1003 and 1005 (and 1007) are characterized by higher proportions of neritic debris and particles without biologic structure, the pelagic phase is impoverished and aragonite needles are absent. The origin of particles without biological structure has been demonstrated by their spatial distribution and by mineralogical as well as geochemical criteria. The rhombohedral calcitic microparticles mainly occur at slope sites. Their high magnesium contents support a formation on the bank implying an allochthonous origin. This suggests that calcitic microparticles correspond to the bank micrite exported towards slope environments. Rhomboedral calcitic macroparticles, which fill sediment voids, originate from in situ transformations of metastable carbonates due to pore fluids, which preferentially flow in the slope permeable sediments. Two sedimentary sources are proposed: 1) an autochthonous pelagic source with low-magnesium calcitic components and 2) an allochthonous neritic source with both aragonitic and calcitic components. Export and depositional processes can be differentiated for the allochthonous particles. The neritic debris and calcitic microparticles in slope Sites 100...

show abstract

Open-ocean, off-bank transport of fine-grained carbonate sediment in the Northern Bahamas

Cited by 26 publications

References 13 publications

Carbonate shedding and sedimentary cyclicities of a distally steepened carbonate ramp (Miocene, Great Bahama Bank)

Carbonate shedding and sedimentary cyclicities of a distally steepened carbonate ramp (Miocene, Great Bahama Bank)

Whiting-related sediment export along the Middle Miocene carbonate ramp of Great Bahama Bank

Nature and origin of carbonate particles along a transect on the western margin of Great Bahama Bank (Middle Miocene): sedimentary processes and depositional model

Contact Info

Product

Resources

About