Joint clay–heavy–light mineral analysis: a tool to investigate the hydrographic–hydraulic regime of Late Cenozoic deltaic inland fans under changing climatic conditions (Cuvelai-Etosha Basin, Namibia)

Dill, Harald G.; Kaufhold, Stephan; Lindenmaier, Falk; Dohrmann, R.; Ludwig, R.; Botz, R.

doi:10.1007/s00531-012-0770-7

Cited by 19 publications

(5 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The redeposition of sediments in aeolian, fluvial or beach environments results in an abundance of the mechanically resistant garnet (Marcinkowski and Mycielska-Dowgiałło 2013). Tourmalines are similarly resistant to long-lived aeolian transformation (Dill et al 2012;Marcinkowski and Mycielska-Dowgiałło 2013). The latter evidence supports an observed lack of biotite, chlorite and muscovite being selectively destroyed by winnowing out as non-durable minerals.…”

Section: Sedimentary Patternssupporting

confidence: 57%

The fan-like forms in the southern margin of the Mazovian Lowland area (Central Poland): a new high-resolution textural-timing study

Kalińska

Nartišs

2015

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

Section: Sedimentary Patternssupporting

confidence: 57%

The fan-like forms in the southern margin of the Mazovian Lowland area (Central Poland): a new high-resolution textural-timing study

Kalińska

Nartišs

2015

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

“…A multiproxy dataset from clastic sediments can help with understanding of palaeoenvironmental changes and their dynamics (Sun et al 2006;Mycielska-Dowgiałło and Ludwikowska-Kędzia 2011;An et al 2012;Liu et al 2012;Smedt et al 2013;Vandenberghe et al 2013;Immonen et al 2014;Zieliński et al 2014b). For example, the textural characterisation of clastic sediments, such as grain-size parameters (Folk and Ward 1957;Visher 1969;Syvitski 1991), the character of quartz grains within the sand fraction (Cailleux 1942;Velichko and Timirieva 1995;Mycielska-Dowgiałło and Woronko 1998), surface microtextures (Krinsley and Doornkamp 1973;Mahaney 2002), and mineral content (Vieira et al 2003;Muhs 2004;Kasper-Zubillaga and Zolezzi-Ruiz 2007;Dill et al 2012), can be potential sources of information on the nature of the sedimentary environment. Depositional timing can be obtained from the constituent mineral grains (Aitken 1998), thus providing a direct estimate of sediment age.…”

Section: Introductionmentioning

confidence: 99%

Sandy fan‐like forms in the central‐eastern mazovian lowland (central poland): textural record and chronology

Kalińska

Nartišs

2016

Geografiska Annaler: Series A, Physical Geography

View full text Add to dashboard Cite

A unique, continuous, fan‐shaped belt of sandy landforms in the central‐eastern Mazovian Lowland, Central Poland has been investigated using a multiproxy dataset of sediment physical properties and chronological framework. Although there are several previous studies of similar fan‐like forms elsewhere in Central Poland, this central‐eastern part has not been investigated in detail. A combined methodological approach, using grain‐size distributions, the roundness, surface character and microtexture of quartz grains, and the mineral composition of the light and heavy fractions, indicate a predominantly aeolian origin for the fan‐like forms. Overlying them are dunes, the sediment within which is derived mainly from the fan‐like forms. Two main aeolian phases are distinguished based on luminescence ages: (1) between around 15 and 16 ka, possibly correlated with the Pomeranian Phase of the last (Vistulian) glaciation in Poland, and representing a phase with a poorly recorded deflation event; and (2) around 12 ka, associated with the Younger Dryas onset, when fresh, non‐aeolian material was delivered to the system. Overall, the palaeoenvironmental pattern of the fan‐like forms is controlled by the Upper Pleistocene aeolian trends.

show abstract

“…The high preservation potential of grain morphology sparked an intensive study whether the crystal morphology of zircon is a function of its physical-chemical conditions of [82][83][84][85][86]. The investigations of crystal morphology of zircon are very encouraging and the results can also be applied to heavy mineral accumulations in order to identify the source rock [87]. The three crystal morphologies 1-3 feature stubby crystals with a predominance of the pyramid over the prism, which becomes almost nil in type 3 (Figure 12d).…”

Section: Zirconium-bearing Gemstone Placers-zirconmentioning

confidence: 99%

“…A well known example of this manganese variety named, due to its color, as "Mandarin Garnet" and after the most prominent river in the region as "Kunene Garnet" was mined in the Marienfluss-Hartmannberge claims, an area where metamorphosed Mn-bearing rocks of probable sedimentary-exhalative origin occur [90]. It was found in alluvial-fluvial sediments of the Cuvelai-Etosha Basin, Namibia, close by [87]. Grossular originating from metacarbonate rocks is also a common garnet in placer deposits (Figure 13g).…”

Section: Garnet-bearing Gemstone Placersmentioning

confidence: 99%

Gems and Placers—A Genetic Relationship Par Excellence

Dill¹

2018

Minerals

View full text Add to dashboard Cite

Gemstones form in metamorphic, magmatic, and sedimentary rocks. In sedimentary units, these minerals were emplaced by organic and inorganic chemical processes and also found in clastic deposits as a result of weathering, erosion, transport, and deposition leading to what is called the formation of placer deposits. Of the approximately 150 gemstones, roughly 40 can be recovered from placer deposits for a profit after having passed through the “natural processing plant” encompassing the aforementioned stages in an aquatic and aeolian regime. It is mainly the group of heavy minerals that plays the major part among the placer-type gemstones (almandine, apatite, (chrome) diopside, (chrome) tourmaline, chrysoberyl, demantoid, diamond, enstatite, hessonite, hiddenite, kornerupine, kunzite, kyanite, peridote, pyrope, rhodolite, spessartine, (chrome) titanite, spinel, ruby, sapphire, padparaja, tanzanite, zoisite, topaz, tsavorite, and zircon). Silica and beryl, both light minerals by definition (minerals with a density less than 2.8–2.9 g/cm3, minerals with a density greater than this are called heavy minerals, also sometimes abbreviated to “heavies”. This technical term has no connotation as to the presence or absence of heavy metals), can also appear in some placers and won for a profit (agate, amethyst, citrine, emerald, quartz, rose quartz, smoky quartz, morganite, and aquamarine, beryl). This is also true for the fossilized tree resin, which has a density similar to the light minerals. Going downhill from the source area to the basin means in effect separating the wheat from the chaff, showcase from the jeweler quality, because only the flawless and strongest contenders among the gemstones survive it all. On the other way round, gem minerals can also be used as pathfinder minerals for primary or secondary gemstone deposits of their own together with a series of other non-gemmy material that is genetically linked to these gemstones in magmatic and metamorphic gem deposits. All placer types known to be relevant for the accumulation of non-gemmy material are also found as trap-site of gemstones (residual, eluvial, colluvial, alluvial, deltaic, aeolian, and marine shelf deposits). Running water and wind can separate minerals according to their physical-chemical features, whereas glaciers can only transport minerals and rocks but do not sort and separate placer-type minerals. Nevertheless till (unconsolidated mineral matter transported by the ice without re-deposition of fluvio-glacial processes) exploration is a technique successfully used to delineate ore bodies of, for example, diamonds. The general parameters that matter during accumulation of gemstones in placers are their intrinsic value controlled by the size and hardness and the extrinsic factors controlling the evolution of the landscape through time such as weathering, erosion, and vertical movements and fertility of the hinterland as to the minerals targeted upon. Morphoclimatic processes take particular effect in the humid tropical and mid humid mid-latitude zones (chemical weathering) and in the periglacial/glacial and the high-altitude/mountain zones, where mechanical weathering and the paleogradients are high. Some tectono-geographic elements such as unconformities, hiatuses, and sequence boundaries (often with incised valley fills and karstic landforms) are also known as planar architectural elements in sequence stratigraphy and applied to marine and correlative continental environments where they play a significant role in forward modeling of gemstone accumulation. The present study on gems and gemstone placers is a reference example of fine-tuning the “Chessboard classification scheme of mineral deposits” [1] and a sedimentary supplement to the digital maps that form the core of the overview “Gemstones and geosciences in space and time” [2].

show abstract

Joint clay–heavy–light mineral analysis: a tool to investigate the hydrographic–hydraulic regime of Late Cenozoic deltaic inland fans under changing climatic conditions (Cuvelai-Etosha Basin, Namibia)

Cited by 19 publications

References 80 publications

The fan-like forms in the southern margin of the Mazovian Lowland area (Central Poland): a new high-resolution textural-timing study

The fan-like forms in the southern margin of the Mazovian Lowland area (Central Poland): a new high-resolution textural-timing study

Sandy fan‐like forms in the central‐eastern mazovian lowland (central poland): textural record and chronology

Gems and Placers—A Genetic Relationship Par Excellence

Contact Info

Product

Resources

About