ANNEXURE TABLE 3:
LOCATION AND ROAD BUILDING PROPERTIES OF ROCKS IN NAMIBIA
VAALIAN AND MOKOLIAN ROCK
|=================================================================================================================|
| AGE/ | GROUP/ | FORMATION/| LITHOLOGY: SEDIMENTARY,
| PROPERTIES: APPLICATIONS AND EXPERIENCES
|
| SEQUENCE | SUBGROUP |COMPL/SUITE| VOLCANIC AND INTRUSIVE ROCKS |
|
|----------------------------------------------------------------|------------------------------------------------|
| VAALIAN ERATHEM: ISOTOPIC AGE: >2.100 Ma TO 2.000 Ma
|
|
|----------------------------------------------------------------|
|
| >2.100 Ma| | Epupa
| Paragneiss,metasedimentary. | No systematic experience as
road building |
| |
| Complex |
| material as
yet.
|
| |
| (Ve)
|
|
|
|----------|----------|-----------|------------------------------|
|
| 2.100 Ma | | Kunene
| Anorthosite,dunite,gabbro, |
|
| |
| Complex |
norite,syenite,foyaite. |
|
| |
| (Vk) |
intrusive into Epupa and
|
|
| |
|
|
older
|
|
|----------------------------------------------------------------|------------------------------------------------|
| MOKOLIAN ERATHEM: ISOTOPIC AGE: 2.000 Ma TO 1.000 Ma
|
|
|----------------------------------------------------------------|------------------------------------------------|
| 2.000 Ma | Haib (Mh)| |
Andesite,dacite,rhyolite. |
|
|----------|----------|-----------|------------------------------|
|
| 1.960 to | |Vioolsdrift|
Granodiorite,leucogranite, | Not very much is known about the road
|
| 1.810 Ma | | Suite
| gabbro,diorite.
| building
properties of these rocks. |
| |
| (Mgv) |
intrusive into Haib and |
|
|
| |
|
older
|
|
|----------|----------|-----------|------------------------------|------------------------------------------------|
| 1.800 Ma | |Huab,Grootf|
Para-/orthogneiss,granite, ,| A paragneiss of the Hohewarte Formation found |
|and older | | Abbabis, |
metabasite dykes, |
between Oamites and Brack was used for the |
| |
| Hohewarte,| metasedimentary
rocks. | subbase of TR 1/5 between Rehoboth and Aris
|
|
| | Mooiriver,|
(Mhu,Mgr,Mab,Mho,Mmo,Mnh) | with no negative experiences on record for
|
|
| | Neuhof |
| these rocks.
|
|----------|----------|-----------|------------------------------|------------------------------------------------|
| 1.800 Ma |Khoabendus| Okapuka, | Rhyolite,basalt,andesite, |
|
| | (Mk)
| (Mok) |ortho-amphibolite,greenschist | Only randomly used. No
systematic experiences |
| |
| Elim (Me)
|quartzite,phyllite,limestone, | known.
| | |
| |
magnetite-quartzite,gneiss. |
|
|----------|----------|-----------|------------------------------|------------------------------------------------|
| 1.860 to | | Franzfont-|
Granite,granodiorite. | Only randomly used for
gravel wearing courses |
| 1.730 Ma | | ein Suite | intrusive
into Khoabendus | in Damaraland. No systematic experiences on
|
| |
| (Mgf) | Group
and Huab |
record.
|
| Rehoboth | | Marienhof |
Quartzite,phyllite,weakly | The Rehoboth Sequence granites which
intruded |
| Sequence | | (Mm)
|metamorphosed basalt,rhyolite | older formations like Mk and the
paragneisses |
| 1.670 to | |Gaub Valley| and
conglomerate. | of Mh
were used for the basecourses for TRs |
| 1.420 Ma | | (Mvy)
|Quartzite,schist,conglomerate | 1/4 and 1/5 and gravel wearing
courses: |
| |
| Billstein | and quartz
porphyry. | Rehoboth west area: No
negative experiences. |
| |
| (Mbi) |
|
|
| |
|
| Metabasite dykes.
(Mm,Mvy)
|
|
| |
|
| intrusive into Gaub &
older | Nothing is known about the road properties |
|----------|----------|-----------|------------------------------| of these rocks.
|
| 1.500 Ma | | Alberta
|Ortho-amphibolite,anorthosite
|
|
| minimum | | Doornboom |
serpentinite,hornblendite,
|
|
| |
| Complexes | talc and chlorite
schist. |
|
| |
| (Mal,Mu) | intrusive into Gaub
& older |
|
| |
| Piksteel | Granodiorite,quartz
diorite. | No systematic experiences are on record |
| |
| Weener |
| for these rocks.
|
| |
| (Mgp,Mge) | intrusive into Gaub &
older |
|
|----------|----------|-----------|------------------------------|------------------------------------------------|
| |
|Namaqualand|
|
|
| |
|Metamorphic|
|
|
| |
|Complex |
|
|
| |
| (Mn)* |
|
|
| |
|
|
|
|
|>1.200 Ma | | (Mp)
|Gneiss,metasedimentary rocks ,| No systematic experiences are on
record |
| |
|
| ortho-amphibolite.
| for these rocks.
|
| |
|
|
|
|
| |
| (Mgj) |
Charnockite,gabbronorite, | Some granites and gneisses have
favourable |
| |
|
| ultramafic rocks.
| road construction
properties and they have |
|±1.200 Ma | | (Mgb)
| Biotite-rich augen gneiss. | been used for the basecourse
construction |
| |
|
|
|
for TR 4/2: Lüderitz-Aus and also for coarse |
| |
| (Mgw) |
Gneissic granite,pegmatite. | concrete aggregate with good
successes. |
| |
|
|
| However, soluble salt contents need to be |
| |
|
| all are intrusive into Mp
| watched.
|
|----------|----------|-----------|------------------------------|------------------------------------------------|
| Sinclair | | Tumuab |
Granites
|
|
| Sequence | | (Mgt)
| intrusive into older |
|
| 1.300 to |----------|-----------|------------------------------|
|
| 1.000 Ma | | Nagatis |
Rhyolite,quartz porphyry, | No systematic experiences.
|
| |
| (Mna) |
arkose,shale,basalt. |
|
|
|----------|-----------|------------------------------|------------------------------------------------|
| |
| Houmoed
|Granodiorite,diorite,granite | No systematic experiences.
|
| |
| (Mgh) |
intrusive into Mna. |
|
|
|----------|-----------|------------------------------|------------------------------------------------|
| |
| Kunjas |
Conglomerate,arkose,shale, |
|
| |
| (Mku) |
quartzite.
| Randomly used for some gravel wearing courses |
| 1.265 Ma | | Barby
| Basalt,andesite,arkose,tuff | No systematic experiences.
|
| |
| (Mba)
|felsite,conglomerate,quartz. |
|
|
|----------|-----------|------------------------------|------------------------------------------------|
| |
| Nubib(Mgn)| Granite.
| No systematic experiences.
|
| |
| Spes Bona |
Syenite,diorite,monzonite |
|
| |
| (Msy) |intrusive
into Barby & older. |
|
|
|----------|-----------|------------------------------|------------------------------------------------|
| |
|Guperas(Mg)|
Rhyolite,ignimbrite,basalt, | No systematic experiences.
|
| |
| Nuekopf |
conglomerate,shale,quartzite.|
|
| |
| (Mnu) |
|
|
|
|----------|-----------|------------------------------|------------------------------------------------|
| 1.210 to | | Gamsberg |
Granite intrus. into Nuekopf | Randomly used for gravel wearing courses.
|
| 1.160 Ma | | Suite
| and older.
|
|
| |
| Sonntag | Granite:
intrusive into | No systematic experiences.
|
| |
|(Mgg + Mgs)| Guperas and older.
|
|
|
|----------|-----------|------------------------------|------------------------------------------------|
| |
|Aubures(Ma)| Quartzite and red
quartzite, | The red quartzites and conglomerates of the |
| |
| Grauwater |
conglomerate,shale,basalt, | Doornpoort Sub-formation can be found around
|
| |
| (Mga)
|rhyolite,ignimbrite,argillite | Witvley and Gravenstein. The red
quartzites |
| |
|Doornpoort |
| were used as crusher-run basecourse for |
| |
| (Md) |
Formations from Grauwater | TR 6/1 between Witvley and Gobabis and
also |
| |
| Klein Aub | to Klein Aub are the
equiv. | for coarse concrete aggregate with favourable |
| |
| (Mka) | in the
Rehoboth/Witvley | experiences. Also randomly used for
gravel |
| |
|
| areas to the Sinclair Sequ.
| wearing courses in the Gobabis area.
|
|----------|----------|-----------|------------------------------|------------------------------------------------|
| 920 Ma | | Richters- |
Granite (Ngr),Syenite (Nsy) | Due to remoteness in extreme south-western
|
| |
| feld |
intrusiv into older | corner in Namibia no
systematic experiences |
| |
| Complex |
formations.
|
|
|=================================================================================================================|
NAMIBIAN AND CAMBRIAN ROCKS
|=================================================================================================================|
| AGE/ | GROUP/ | FORMATION/| LITHOLOGY: SEDIMENTARY,
| PROPERTIES: APPLICATIONS AND EXPERIENCES
|
| SEQUENCE | SUBGROUP |COMPL/SUITE| VOLCANIC AND INTRUSIVE ROCKS |
|
|-----------------------------------------------------------------|-----------------------------------------------|
|NAMIBIAN/CAMBRIAN ERATHEMS: ISOTOPIC AGES: +/-1.000 Ma TO 450 Ma |
|
|-----------------------------------------------------------------|-----------------------------------------------|
| Damara | Nosib |
|
|Nosib quartzite: MR 92: near Ruacana: very |
| Sequence | (Nn) |
|
|hard and little affected by weathering: is |
| |(Central) |
|
|visible as reddish rock with layers and lenses |
| 850 to | | Nauuwpoort
|Metamorph.acid volcanic rocks |of conglomerate in road excavations.
|
| 700 Ma | | (Nnp)
|(Nn);alk.ingnimbrite+rhyolite |Nosib quartz was used for
fill layers and |
| |
|
|quartzite,conglomerate,schist |selected layers (subbase and basecourse) with |
| |
|
|minor
andesite,bostonite(Nnp) |good results on MR 67/MR 92: near
Ruacana. |
| |
|
|
|Premix aggregate: TR 1/11: Oshivelo-Ondangwa |
| |
|
|
|with satisfactory results.
|
| |
|------------|------------------------------|(experience for Nosib: northern
zone) |
| |
| Duruchaus | (Ndu,Nka,Nb and
Nsb) |
|
| |
| Kamtsas
|Quartzite,conglomerate,schist |Further no systematic experiences.
|
| |
| Blaubeker |marble mixtite.
|
|
| |
|Spencer Bay |
|
|
| |
|------------|------------------------------|-----------------------------------------------|
| 900 to |
|Nauuwpoort |Subvolcanic bostonite,syenite | No systematic experiences reported.
|
| 720 Ma | | (Nnp)
|
foyaite,gabbro.
|
|
| |
| | intrusive into Nn
and older. |
|
| |
|
|
|
|
|
|----------|------------|------------------------------|-----------------------------------------------|
| | Nosib |
Askevold | Epidosite,agglomerate |
Nosib quartz Nn forms in the north-east of |
| | (Nn) |
(Nas) |
| Namibia near Andara/Okavango the only source |
| |(Northern)| Varianto |
Mixtite,quartzite,schist, | of crusher-run basecourse material, was
also |
| |
| (Nv) |
conglomerate,dolomite. | used as concrete aggr. for
Bagani Bridge. |
|----------|----------|------------|------------------------------|-----------------------------------------------|
| 900 to | Swakop |
|
| No systematic experiences reported.
|
| 700 Ma |(Central) |
|
|
|
| |Ugab (Nu) |
|
Marble,schist,quartzite, |
|
| |Kudis(Nku)|
| graphitic schist.
|
|
|
|----------|------------|------------------------------|-----------------------------------------------|
| | Khomas | Chuos
|Mixtite,schist,iron-formation | Calcareous and dolomitic marbles
of Karibib, |
| |(Central) | (Nc)
|ortho-amphibolite,quartzite, | Usakos and Swakopmund
used for surfacing |
| | Ugab, |
(Central) |graphitic schist.
| chips and concrete
aggregates.
|
| |Kudis and | Karibib
|Marble,ortho-amphibolite, | Due to absence of other suitable road
buil- |
| |Khomas are| (Nkb)
|quartzite.
| ding materials biotite mica schist is used. |
| |sub groups| Auas (Nau)
|Schist,quartzite. | as
gravel for subgrade and subbase layers |
| |
| Kuiseb |Mica
schist;marble (Nge), | for paved roads but avoided as
basecourse, |
| |
| (Nk)
|quartzite,graphitic schist, | also as wearing coarse for gravel roads: test |
| |
|
|Calcsilicate (Nti:
Tinkas | sections on MR 49 with surprisingly good
|
| |
|
|Member).
| successes.
|
| |
|
|Ortho-amphibolite
(Nml: | For many road projects in the Windhoek
area |
| |
|
|Matchless Member).
| mica schist was
successfully used as selected |
| |
|
|Nsc* comprises
Nu,Nku,Nc,Nkb, | subgrade, often blended with quartz gravel. |
| |
|
|and Nau.
| For gravel wearing courses it was found that |
| |
|
|Nd* comprises Nosib
and | mica schists need less maintenance than
|
| |
|
|Swakop Groups.
|
quartzitic gravels (Tests: MR 49). Cracking |
| |
|
|
| problems: formation: MR 52: Windhoek-Keres. |
|----------|----------|------------|------------------------------|-----------------------------------------------|
| Damara | Otavi |
|
Dolomite,limestone,shale, | Dolomites of Otavi Group have typical karst
|
| Sequence | (No)* |
| quartzite.
| features with possibilities of sinkholes: |
| 900 to |(Northern)|
|
| example: TR 1/9 on farm Ubi Bene 768. |
| 700 Ma |Abenab(Na)|
|
|
|
| |Tsumeb(Nt)|
|
Dolomite,limestone,shale, |
|
| |Abenab + |
| chert.
| Dolomites quarried at Grootfontein, Tsumeb, |
| |Tsumeb are| Chuos (Nc) |
Mixtite,shale,quartzite | Otavi and Outjo for surfacing
chips and |
| |sub groups|(Northern) | No*
comprises Na and Nt. | coarse concrete aggregates.
|
| |
|
|
| Limestone crushed for base on TR 1/10. |
|----------|----------|------------|------------------------------|-----------------------------------------------|
| 650 to |Mulden(Mn)|
|
Phyllite,quartzite,schist | Engineering properties of Mulden rocks not
|
| 570 Ma |(Central &|
| conglomerate
| well known, but phyllites successfully used |
| 570 Ma |Northern) |
|
| for basecourse, subbase: TR 8/1: Otavi. |
|----------|----------|------------|------------------------------|-----------------------------------------------|
| 650 to | | (Ngl)
| Gneissic leucogranite. |
Weathered Salem granite of a pegmatitic type |
| 470 Ma | (Cgd)* |Salem Suite | Granite,granodiorite,diorite |
was used with no negative experiences so far |
| | Granites | (Cgs)
| monzonite.
| for selected subgrade and subbase for the |
| 560 to |from Salem| Sorris- | Red granite: gneissic.
| building of TR 2/3 between Karibib and
|
| 510 Ma | to | Sorris
|
|
Omaruru.
|
| |Dachsberg | (Cgss)
|
|
|
| |
| Ozombanda | Red granite:
homogeneous. |
|
| |
| (Cgo) |
|
|
| |
|both: (Cgl)*|
|
|
| 530 to | | Donkerhoek
| Granite,alask., pegmatitic. |
|
| 470 Ma | | (Cgdh)
|
|
|
| |
| Dachsberg | Quartz diorite.
|
|
| |
| (Cgdb) |
|
|
| |
|both: (Cgi)*|
Serpentinite,schist,silcrete |
|
| |
| (Cu) |
Gabbro,norite.
|
|
| 530 Ma | | (Cnd)
| All 3 complexes:
|
|
| |
| Haruchas | Granite (Cgr),syenite.(Csy) |
|
| |
| Bremen |
Bostonite.(Cbo) |
|
| 500 Ma | |
Tatasberg | Diatremes and sills:alnoitic |
|
| |
| Complexes | tuffisite.
|
|
| |
| Garub | All
granites:intrusive into |
|
| |
| Suite | Damara
Sequence and older. |
|
|----------|----------|------------|------------------------------|-----------------------------------------------|
| 530 to | |
Naukluft |
|
|
| 500 Ma | | Nappe
|
|
|
| |
| Complexes |
|
|
| |LowerNappe| Rietoog
| Quartzite,black limestone, |
|
| |
| Nappe (Nr) |
conglomerate,shale,dolomite | Not systematically tested as yet.
|
| |UpperNappe| Dassie
| Limestone,dolomite,shale. |
|
| |
| Nappe (d) |
|
|
| |
| Zebra |
Quartzite,black limestone, |
|
| |
| Nappe (z) |
conglomerate,shale,dolomite |
|
| |
| Pavian |
Dolomite,shale,conglomerate. |
|
| |
| Nappe (p) |
|
|
| |
| Kudu |
Dolomite,limestone,shale, |
|
| |
| Nappe (k) | conglomerate.
|
|
|----------|----------|------------|------------------------------|-----------------------------------------------|
| 650 to | | Gariep
|
|
|
| 500 Ma | | Complex
|
|
|
| |
| Rosh Pinah |
Felsite,tuff,quartzite,schist| As a result of the remoteness of this area |
| |
| (Nrp) |
| and the fact that due to political reasons no |
| |
| (Ng)* |
Dolomite,shale,schist,ortho+ | direct connections between the RSA controlled |
| |
|
|
para-amphibolite,quartzite, | diamond concern 'CDM' and the Namibian
|
| |
|
| intraformational
mixtite,grit| concern exist very little is known about the |
| |
| Numees Nmu | basal mixtite,Numees
mixtite.| engineering properties of these rocks. |
|----------|----------|------------|------------------------------|-----------------------------------------------|
| 600 to | Nama |
|
|
|
| 450 Ma | |
|
|
|
| | Kuibis |
| Sandstone,black
limestone, | Quartzites and sandstones are suitable: coarse|
| | (Nks) |
| conglomerate,shale.
| concrete aggr. Quartz rich varieties of
silt- |
|
|----------|------------|------------------------------| stone can be used for rockfills.
|
| | Schwarz- |
| Green+red
shale,sandstone. | (Niederhagen quartzites).
|
| | rand |
|
|
|
| | (Ns) |
Huns Nh | Limestone.
| Slabby nature of Nasep sandstone: less |
|
|----------|------------|------------------------------| suitable for road construction.
|
| |FishRiver | Stockdale | Red
sandstone and shale. | Ns: Red sandstone: suitable for coarse
|
| |(Kuibis, | (Cs)
|
| concrete
aggregate.
|
| | Schwarz- | Breckhorn | Red
and grey sandstone and | Rosenhof member of Cg: slightly slabby red
|
| | rand |
|
|
|
| | and Fish | (Cb)
| shale.
| shales with red sandstones: suitable for |
| | River are| Nababis
| Red sandstone and shale. | concrete aggregate and rock
fills. |
| |subgroups)| (Cn)
|
| Problems of all Nama rocks:
|
| |
| Gross Aub | Red shale and
sandstone. | High soluble salt contents.
|
| |
| (Cg) |
| Ns solid sandstones and shales: MR 34 and |
| |
|
|
| TR 3/1 for natural basecourses and coarse |
| |
|
|
| concrete aggregates.
|
| |
|
|
| Also favourable for gravel wearing courses: |
| |
|
|
| MR 31:especially for areas with high N-values |
| |
|
|
| but tend to be slippery during rains. |
|=================================================================================================================|
NOTA: '* ' means "stratigraphy
undifferentiated"; 'COMPL' means COMPLEX;
'**' means no specific subgroup or formation has been identified so far
KAROO ROCKS
|=================================================================================================================|
| AGE/ | GROUP/ | FORMATION/| LITHOLOGY: SEDIMENTARY,
| PROPERTIES: APPLICATIONS AND EXPERIENCES
|
| SEQUENCE | SUBGROUP |COMPL/SUITE| VOLCANIC AND INTRUSIVE ROCKS |
|
|-----------------------------------------------------------------|-----------------------------------------------|
| CARBONIFEROUS/CRETACEOUS ERATHEMS:ISOTOPIC AGES: 400 Ma TO 70 Ma|
|
|-----------------------------------------------------------------|-----------------------------------------------|
| Karoo | | Dwyka
(Cd) | Tillite,boulder shale,shale, |Tillites:Good for natural basecourses: TR 1/3, |
| Sequence | |
| sandstone,limestone.
|TR 4/1, also favourable for subgrade
layers: |
| 400 to | |
|
|TR 1/3 and TR 5/1 also for gravel wearing c.: |
| 120 Ma | |
|
|MR 27 but not for surfacing chips (flakiness). |
|
|----------|------------|------------------------------|-----------------------------------------------|
| | Ecca |
Prince | Shale,mudstone,sandstone. |Karoo
sandstones: Unfavourable as coarse |
| | sub group| Albert(Pp) | Nossob
(Pn); Auob (Pau). |concrete aggregates, baked shales are
more |
| |
| Whitehill | Carbonaceous
shale. |suitable: bridges 205,211 on
TR 1/3. Sandstone |
| |
| (Pw)
|
|can be used as natural basecourse provided it |
| |
|Aussenkjer | Shale, limestone,
siltstone. |has a 10% FACT (Fines Aggregate Crushing Test) |
| |
| (Pa)
|
|larger than 140 kN.Mudrocks play a great role |
| |
| Amibberg | Sandstone, mudstone,
shale. |in the south.Conglomerates of sandstones,til- |
| |
| (Pm) |
|lites and shales were used favourably as base |
| |
|
|
|course on TRs 1/3,1/2 and 4/1. Sandstones, |
| |
|
|
|shales,mudrocks favourable as subgrades: TR 3/1|
| |
|
|
|Shales and mudrocks favourable as gravel |
| |
|
|
|wearing courses: MRs 25,30,39. Problems:TR 1/3:|
| |
|
|
|Itzawisis:weak subsurface drainage. Sandstone |
| |
|
|
|gravel wearing courses due to weak PI and lack |
| |
|
|
|of binder on isolated gravel roads:south-east. |
| |
|
|
|Baked shales:not suitable for surfacing chips. |
|
|----------|------------|------------------------------|-----------------------------------------------|
| |
| Gai-As(TRg)| Red
mudstone,siltstone,grit, |TRo sandstone: good as subbase/basecourse on |
| |
| Omingonde |
sandstone,conglomerate |TR 1/11 and MR 92 and
rehabilitation:TR 1/7. |
| |
| (TRo) | From
Ecca to Omingonde: |It was also favourably used for
surfacing |
| |
|
|
CTR*
|chips (indurated mudrocks).
|
| |
|------------|------------------------------|-----------------------------------------------|
| |
| Etjo Je | Aeolian
sandstone.
|
|
| |
|
|
| Not systematically tested as yet.
|
| |
| |
|
|
| |
|
|
|
|
|
|----------|------------|------------------------------|-----------------------------------------------|
| 180 Ma | - (**) |(Jd)and(Jr) | Extrusive dolerite+rhyolite
|Volcanic Karoo rock good for surfacing chips |
| |
| (**)
|into Karoo Sequence and older |and coarse concrete
aggregate:TR 5/1 and MR 61 |
| 180 Ma | | Kalkrand
| Basalt, minor sandstone. |Ke basalts with high PI are
good as wearing |
| 120 Ma | | (Jk)
| (Je)*
|course for salt-gypsum roads along the coast |
| |
| Etendeka | High-silica
basalt,latite, |of the Damaraland, although not systematically |
| |
| (Ke) |
quartz latite,minor aeolian |tested yet but unfavourable as gravel wearing |
| |
|
| sandstone.
|course for district roads in the interior. |
| |
|
|
|Karoo dolerite successfully used:coarse concr. |
| |
|
|
|aggr. all over the south, surfacing chips for |
| |
|
|
|nearly all paved roads in the south, as |
| |
|
|
|crusher-run and natural basecourse on TR 1/1 |
| |
|
|
|and TR 1/7, weathered dolerite as subbase/sub- |
| |
|
|
|grade on many paved roads in the south, also |
| |
|
|
|used with good results as gravel wearing |
| |
|
|
|course: MR 21, 22 and 30 and many others. |
|-----------------------------------------------------------------|-----------------------------------------------|
|CARBONIFEROUS/CRETACEOUS ERATHEMS: ISOTOPIC AGES: 400 Ma TO 70 Ma|
|
|-----------------------------------------------------------------|-----------------------------------------------|
|+-< 100 Ma| | Post Karoo |
Granite (Kgr),syenite (Ksy), |
|
| |
| Complexes |
foyaite(Kfo),granophyre(Kgy),| Not systematically tested as yet.
|
| |
|
| rhyolite (Krh),tuff (Ktu),
|
|
| |
|
| breccia (Kbr),diorite
(Kdi), |
|
| |
|
| picrite (Kpi),gabbro (Kg),
|
|
| |
|
| pyroxenite(Kpy),diatreme
(*) |
|
| |
|
| intrusive into older rocks.
|
|
|----------|----------|------------|------------------------------|-----------------------------------------------|
| |
| Pomona |
Marl,grit,conglomerate, |
|
| |
| (Kp) |
chalcedonic limestone. | Not systematically tested as yet.
|
| |
|
| Breccia of Brukkaros Mountain|
|
| |
|
| Kimberlite intrusive
|
|
| |
|
| into older rocks.
|
|
|=================================================================================================================|
NOTA: '* ' means " stratigraphy undifferentiated"; 'COMPL' means COMPLEX;
'**' means no specific subgroup or formation has been identified so far
10% FACT: The "10% Fines Aggregate Crushing Value" is the force in kN required
to crush a sample of
-13,2 -9,5 mm aggregate so that 10% of the total test sample will pass a 2,36 mm sieve.
TERTIARY AND QUATERNARY ROCKS
=================================================================================================================|
| AGE/ | GROUP/ | FORMATION/|
LITHOLOGY: SEDIMENTARY, | PROPERTIES: APPLICATIONS AND EXPERIENCES
|
| SEQUENCE | SUBGROUP |COMPL/SUITE| VOLCANIC UND INTRUSIVE ROCKS|
|
|------------------------------------------------------------------|----------------------------------------------|
| TERTIARY TO QUATERNARY ERATHEMS: ISOTOPIC AGES: FROM 65 Ma
|
|
|------------------------------------------------------------------|----------------------------------------------|
| |
|Tertiary(T)| Marine
clay,marly sandston | Phonolite is a hard rock which in its fresh |
|39 to 32 Ma| |Auas
Mount.| Phonolite,trachyte (Tr) | state is extensively quarried at Aris,
south |
| |
|Klinghardt | intrusive
into older rocks.| of Windhoek. It is used as a high quality |
| |
|Mountains |
| surfacing aggregate for most of the paved |
| Kalahari |
|(Tk) & (Pp)| Suboutcrops under Tk and Qn| roads in the vicinity of Windhoek as far
|
| Tk |
|
|+ other superficial deposits|
south as Mariental and as far north as Sukses|
| |
|
| (e.g.:
Pp).
| between Okahandja and Otjiwarongo.
|
| |
| (Tn)
| Calcrete terraces+red,part.| Kalahari sands: uniform grading
with good |
| |
|
| consol.dune deposits:Namib | CBRs
and binding properties: suitable for |
| |
| (Tk)
| Sand,calcrete and gravel of| road layers and asphalt aggregate
but |
| |
|
| Kalahari.
| collapsing fabric.
|
|
|-------------|-----------|----------------------------| Namib sands: single graded and
fine with no |
| |
| (Qn)
| Sand sea of the Namib. | CBRs:
unsuitable for road layers and asphalt |
| |
|
| Alluvium,sand,gravel and |
aggregates: See Section 4.6
|
| |
|
| pedocretes like calcrete. |
Pedocretes like calcretes: Namibia's natural |
| |
|
|
| road building material number one due to |
| |
|
|
| self-stabilising effects: It has been used |
| |
|
|
| with great success for load bearing layers |
| |
|
|
| for paved roads and for wearing courses for |
| |
|
|
| unpaved roads: Even sub-standard calcrete |
| |
|
|
| has been proved successful for bearing and |
| |
|
|
| wearing layers: See Section 4.7.
|
|=================================================================================================================|
NOTA: '* ' means " stratigraphy
undifferentiated"; 'COMPL' means COMPLEX;
'**' means no specific subgroup or formation has been identified so far
|
