9 Jan 2013
A series of large asteroid impacts in Southern Africa dramatically increased the Manganese concentration in the Paleoproterozoic oceans . This led to the enablement of photosynthesis.
1.The first traceable impact was about 3.5 Billion Bears Ago (BYA) . See appendix VII and Appendix III . At Barberton . Large amounts of Manganese in the asteroid was punched through to the magma just underneath the crust .
2.About 2.023 BYA (see Appendix I) , the Vredefort asteroid punched through the crust fairly close to the previous impact .
3.Mineralization was accelerated because of the compression wave of the Vredefort impact fractured the crust for thousands of kilometres in a circular pattern .
4.This enabled the minerals (Manganese , Platinum , Iron , etc) from the previous impact , which was loitering in the top magma , to percolate through the cracks to the surface .
Even today , the largest mineral deposits are in these areas . It needed that double whammy .
5. This was a low temperature process , hence the plethora of low-temperature volcanoes that enabled diamonds to reach the surface without being destroyed by high temperatures ,
See Appendix VIII .
6.This fits in with the approximate dates of Manganese sedimentation . See Appendix III .
7. The two pulses of manganese metal injections into the biosphere resulted in sufficient concentrations of Manganese in the biosphere to give rise to photosynthesis .
See Appendix VI .
8. Why ?
The Barberton Impact :
We suspect that a big asteroid fragmented . One big part was steered by the moon to impact on a particular part of the planet . The other part(s) was constrained into a resonant orbit by the Earth-Lunar-Sun system to impact in the same area about a few solar orbits later . Luna was closer to Earth then , and acted like a focussing lens for long-term solar orbitals .
As Luna spiralled outwards , this effect decreased drastically (third order , I would estimate)
9.Other sites should show the same double-whammy .
A handy lead for mineral deposits .
10. What does this mean ?
10.1 The impacts kick-started photosynthesis and multicellular life forms .
10.2 Fracking :
The South African region has been thoroughly Fracked about 2 BYA . Fracking sedimentary deposits on top of the old fracking fractures will result in some new cool volcanoes .
The ur-water that will be released to the surface can be sold as concentrated fertilizer.
The whole shield rock is built on a house of fractured sand .
Expect earthquakes (6-7 Richter) in Botswana-Zimbabwe . The Zambezi might reroute to the Makgadigadi sea
See Appendix IX
The containment caps of the gas-fields in the Mozambique channel and the Makgadigadi-basin (already rathe thin ) will fracture , releasing large amounts of gas to nobody's benefit .
This has already happened in history . The sudden disappearance of ships in the Mozambique Channel .
The bubbling gas reduces the density of seawater . Archimedes's Principle means that the little shippie goes straight to the bottom .
Interestingly enough , this nearly certainly means the closure of the Victoria Falls .
The escape of the gas will cause a percussive fall in the bottom of the Makgadigadi sea , causing a quake that closes the Zambezi exit to the Indian Ocean . This is part of its natural cycle . See Appendix IX .
10.3 The gas can be safely mined , but will anybody pay attention ?
Fat chance . Too much money .
11. Interesting times , like 2 Billion Years Ago .
12. The Venus Model .
The weight of the oceans keeps magma overflow in check . Large scale gas release (clathrates , fracking) decreases the local weight of water at critical fractures .
This results in magma paving . There is a positive feedback structure . (Cf Deccan or Siberian Traps) .
Why worry about global warming when humans are about to activate supervolcanoes ?
What a gas !
The Vredefort Crater's age is estimated to be 2.023 billion years (± 4 million years), which places it in the Paleoproterozoic era. It is the second-oldest known crater on Earth, a little less than 300 million years younger than the Suavjärvi Crater in Russia. In comparison, it is about 10% older than the Sudbury Basin impact (at 1.849 billion years).
From Wikipedia, the free encyclopedia
The Paleoproterozoic (pron.: /ˌpeɪlɪ.oʊˌproʊtərɵˈzoʊ.ɨk/; also Palaeoproterozoic) is the first of the three sub-divisions (eras) of the Proterozoic occurring between 2,500 to 1,600 million years ago. This is when the continents first stabilized. This is also when cyanobacteria evolved, a type of bacteria which uses the biochemical process of photosynthesis to produce energy and oxygen.
Mn ore deposits are not evenly distributed in geologic time. Instead they cluster in three groups, one in the Paleoproterozoic, the second in the Neoproterozoic and the third in the Cenozoic. There is also a striking disappearance of sediment-hosted deposits from 1800 to 1100 Ma:
Manganese ores occur in four main types in southern Africa.
(1) Primary (e.g. Mamatwan carbonates)
(2) Hydrothermally altered (e.g. Wessels)
(3) Supergene enriched (e.g. oxide ores at Mamatwan)
(4) Karstic (e.g. Postmasburg)
Mamatwan-type ore is by far the most extensive. Mineralogically it is dominated by kutnahorite and braunite.
Wessels-type ore is a higher grade ore produced by hydrothermal alteration, but is now largely mined out. Most common minerals are hausmannite and bixbyite.
Supergene enriched sections occur commonly with Mn carbonate ores, which is the case iwth the Mamatwan deposits. Here common minerals are manganomelane and todorokite.
Karst-type Mn develops by weathering of Mn-bearing dolomites. Because of low oxygen levels in the early part of the Precambrian, Mn was abundant in seawater and dolomites of that age have high Mn levels. Green-schist level metamporphism has produced partridgeite, braunite, and bixbyite from poorly crystaline protores.
From Wikipedia, the free encyclopedia
In ore deposit geology, supergene processes or enrichment occur relatively near the surface. Supergene processes include the predominance of meteoric water circulation with concomitantoxidation and chemical weathering. The descending meteoric waters oxidize the primary (hypogene) sulfide ore minerals and redistribute the metallic ore elements. Supergene enrichment occurs at the base of the oxidized portion of an ore deposit. Metals that have been leached from the oxidized ore are carried downward by percolating groundwater, and react with hypogene sulfides at the supergene-hypogene boundary. The reaction produces secondary sulfides with metal contents higher than those of the primary ore. This is particularly noted in copper ore deposits where the copper sulfide minerals chalcocite Cu2S, covellite CuS, digenite Cu1.8S, and djurleite Cu31S16 are deposited by the descending surface waters.
Captured: the moment photosynthesis changed the world
- 07 December 2012 by Colin Barras
- Magazine issue 2894. Subscribe and save
- For similar stories, visit the Evolution Topic Guide
BILLIONS of years ago, a tiny cyanobacterium cracked open a water molecule - and let loose a poison that wrought death and destruction on an epic scale. The microbe had just perfected photosynthesis, a process that freed the oxygen trapped inside water and killed early Earth's anaerobic inhabitants.
Now, for the first time, geologists have found evidence of the crucial evolutionary stage just before cyanobacteria split water. The find offers a unique snapshot of the moment that made the modern world. With the advent of photosynthesis came an atmosphere dominated by oxygen and, ultimately, the diversity of life forms that we know today.
"This was the biggest change that ever occurred in the biosphere," says Kevin Redding at Arizona State University in Tempe. "The extinction caused by oxygen was probably the largest ever seen, but at the same time animal life wouldn't be possible without oxygen."
Photosynthesis uses light and a source of electrons to generate energy and power an organism. In the world as we know it, that source of electrons is water, with oxygen the waste product. But there are no signs that oxygen was being formed when photosynthesis first appeared around 3.4 billion years ago, so early photosynthesisers probably scavenged electrons by splitting other molecules like hydrogen sulphide instead.
That had changed by about 2.4 billion years ago, when deposits of oxidised minerals tell us that oxygen was beginning to accumulate in the atmosphere. Photosynthesis as we know it had evolved.
To help work out how this happened, Woodward Fischer at the California Institute of Technology in Pasadena and his colleagues studied South African rocks that formed just before the 2.4-billion-year mark. Their analysis shows that although the rocks formed in the anoxic conditions that had prevailed since Earth's formation, all of the manganese in the rock was deposited in an oxidised form.
In the absence of atmospheric oxygen, manganese needs some sort of catalyst to help it oxidise - it won't react without a bit of help. The best explanation, say Fischer's team, is that a photosynthetic organism was using manganese as an electron source. That left unstable manganese ions behind, which reacted with water to form the oxides. Fischer presented the findings at the American Geophysical Union's conference in San Francisco on 6 December.
Every researcher contacted by New Scientist has hailed the significance of the study, in part because the evidence exactly matches what evolutionary theories have predicted.
A close look at today's plants and algae shows that manganese oxidation is still a vital part of photosynthesis. Within their photosynthetic structures are manganese-rich crystals that provide the electrons to drive photosynthesis. The crystals then snaffle electrons from passing water molecules to restore their deficit. It is this electron raid that cracks open water molecules and generates the oxygen we breathe.
This complicated process must have had simpler roots. In 2007, John Allen at Queen Mary, University of London, and William Martin at the University of Düsseldorf, Germany, suggested one scenario (Nature, doi.org/bs65kb). They believe that modern photosynthesis was born when early cyanobacteria by chance floated into a watery environment rich in manganese, and quickly adapted to take advantage of the new source of electrons.
Later, because manganese is a relatively scarce resource that can't be tapped indefinitely, the cyanobacteria evolved a different strategy. They incorporated manganese directly into their photosynthetic structures and used it as a rechargeable battery: draining it of its electrons, but allowing its supplies to be replenished by stealing electrons from another, more plentiful source - water.
What Fischer's team has found is evidence of the initial step in this process: an anoxic environment rich in manganese that has been stripped of electrons and left in an oxidised state, almost certainly by primitive cyanobacteria. "There had to be some intermediate step in the evolutionary process," says Redding.
"This is big news," says Martin. He adds that we can expect publications in the near future that provide more evidence compatible with the theory. "But this somewhat more direct geochemical evidence is really exciting."
∼3.25 Ga Barberton greenstone belt asteroid impact
The ∼3.26–3.24 Ga asteroid impact on the Barberton greenstone belt represents the first documented example of a "possible" cause–effect relation between extraterrestrial bombardment and major tectonic and igneous events. This study is by Glikson and Vickers(2006). The asteroid ejecta are located immediately above a sharp break between a >12 km-thick mafic–ultramafic volcanic crust and turbidite–felsic volcanic rift-facies association. A boundary there is correlated with break and peak magmatic and faulting events, represented by the truncation of a 3.255–3.235 Ga volcanic sequence at the Sulphur Springs Group (SSG) by a turbidite-banded iron formation–felsic volcanic association. These events are accompanied by ∼3.252–3.235 Ga granitoids. The top of the komatiite–tholeiite–rhyolite sequence of the SSG is associated with a marker chert defined at 3.238–3.235 Ga, abruptly overlain by an olistostrome consisting of mega-clasts of felsic volcanics, chert and siltstone up to 250×150 m-large, intercalated with siliciclastic sedimentary rocks and felsic volcanics.
The structure and scale of the olistostrome is interpreted as intense faulting and rifting, supported by topographic relief represented by deep incision of overlying arenites (the Corboy Formation) into underlying units. The age of these fault and rifts overlaps the 3.255–3.235 Ga peak igneous activity represented by the SSG and the Cleland plutonic suite and the 3.258 Ga Barberton impact unit. Should correlations between the Barberton impact units and magmatic and tectonic events in the Pilbara Craton be confirmed, this would imply impact-triggered reactivation of mantle convection, crustal anatexis, faulting and strong vertical movements in Archaean granite–greenstone terrains associated with a large asteroid impact, culminating in transformation from sima-dominated crust to continental rift environments.
8 Feb 2011
"Diamonds are a girl's best friends " Gaia
Earth is globed by a glittering shell of diamonds formed during the cooling phases of the planet about 3 to 1 billion years ago . A few of these survive transportation to the surface during some cool volcanic , tectonic and impact events .
See Appendices below below :
1.Lots of Carbon
A planet without a diamond necklace would not have enough carbon to give rise to a carboniferous life .
Startrek would say :
"No diamonds , no life as we know it , Jim ."
2.Neutrino Signature :
Large concentrations of diamonds have a distinct neutrino shadow (due to multiple refraction and absorption) .
Sufficient masses of diamonds in a semi-liquid matrix self-assemble into meta-materials to more efficiently absorb neutrinos . Cold volcanos result .
For the proof of this :
Either you see it , or else it will be a bit of a slog .
Remember , the surrounding semi-molten rock is transparent to neutrinos .
A lot of energy is absorbed by the diamond metamaterial . This plays a major part in the planetary energy balance .
This has obvious significance to detection of extra-solar planets capable of bearing carbon-based life .
Venus indicates too much energy can be transferred , leading to mantle-eruptions that paved the planet . The carbon went into CO2 in the atmosphere . Not that many diamonds left on Venus .
Mars should be lousy with diamonds . Just look around the hot pockets .
Or that big ,cool volcano . Or the fracture zones between the hemispheres .
Or … .
You get the drift .
Are there undiscovered diamond deposits in South Africa ?
The Vredefort impact created numerous near-contiguous fractures. The gave way under pressure to cool volcano's with very rapid exit velocities (ie the diamonds scooped up from the mantle did not have time to burn up . ) These weathered and water washed the diamonds away to be concentrated in places like Alexander bay .
This took a fairly long time . Rivers formed , vanished , reformed and the land twisted
To the West , many deposits have been found . Kimberley , etc
To the East , few .if any .
Draw a circle around Vredefort with radius at Kimberley . You will notice it encompasses most of the gold and platinum bearing areas towards all areas except East and South-East . This is because these areas got squinched up in subsequent tectonic movements . Nobody can un-squinch them , but we can say meaningful things on a macroscopic scale . Because the time-scale is relatively large , we can use
http://andreswhy.blogspot.com "Newtools" Nov 2008 . The Reserve and Error arguments indicate that we simply progressively shrink the East and South-East present map measurements to a third of the radii projected from Vredefort-Kimberley
radius . This gives a kidney shaped depression just east of the Orange River and west of the coastal escarpment . From Estcourt in the north to Colesberg-Noupoort in the south . Minerals should be concentrated here .
Note that the first diamond in South Africa was picked up at Colesberg . I could never figure out why this was not followed up .
Estimated diamond reserves :
About 1/3 of that found at Alexander bay .
Platinum etc : about 1/3 to ¼ found to the north .
Heavy metals would tend to settle at dead-ends or swirling lees .
The corridor from Colesberg to East London is the most remarkable geological trap system I have ever seen . It looks like a baleen whale's mouth .
It should be lousy with heavy metals .
A less remarkable system can be seen heading to Idutywa .
Read Appendix C link .
Would Luna have diamonds ?
Doubtful . Diamonds probably did form in Earth(0) before the impact event that resulted in Luna , but the impact temperatures probably cooked any diamonds .
But , some might have survived in pockets of Earth(0) ejecta in Trojan orbits . There is a distinct probability (+-15%) that large diamonds can be found in Earth-Lunar Trojans .
Re-entry diamonds with datable pyrodone garnet inclusions would then give formation dates before the Luna-forming impact . Has any been found ?
Unknown . On human form results like these have probably been swept under the carpet .
So , Gaia might have diamond earrings . These should be even easier to detect from really far away using neutrino shadowing .
Simply put , a planet with lots of carbon and a big moon can be detected from very far away .
So much for Ceti . Anyone interested already knows what is here , and has done so for millions of years .
Gaia will not be pleased .
You think I am joking ?
See http://andreswhy.blogspot.com "Inverse Anthropomorphisms" Feb 2011
See http://andreswhy.blogspot.com "Death of the Dinosaurs " Dec 2008
See http://andreswhy.blogspot.com "AI-1 " Jul 2008
See http://andreswhy.blogspot.com "AI update " Jun 2009
And sundry others .
I do not know how aware or self-aware Gaia is at the moment in logical terms , but both will follow in the near future .
See http://andreswhy.blogspot.com "Singularities " Feb 2011
And Gaia would not be pleased to be ignored . (Remember anthropomorphism)
Information (like this blog) would be open to her . (Memory)
I , for one , have no intention of pissing her off .
Maybe a teensy bit of exploration might be called for ?
A good general discussion :
Mine or Location
Premier, S. Africa
Finsch, S. Africa
Finsch, S. Africa
Kemberly, S. Africa
In the above listing, * means approximate. The Finch Mine, South Africa is listed twice because it includes two pipes featuring diamonds of differing ages. Note the vast difference between the ages of the diamonds and of the pipe material that carried them to the surface.
Impact considerations from Vredefort impact .
Formation and structure
The asteroid that hit Vredefort is one of the largest ever to strike Earth (at least since the Hadean) and is estimated at 5–10 km (3.1–6.2 mi) wide. The crater has a diameter of roughly 250–300 km (155–186 mi), larger than the 200 km (124 mi) Sudbury Basin and the 170 km (106 mi) Chicxulub crater. This makes Vredefort the largest known impact structure on Earth. (The Wilkes Land crater in Antarctica, if confirmed to be the result of an impact event, is even larger at 500 kilometers across.) The Vredefort crater's age is estimated to be more than 2 billion years (2,023 ± 4 million years), striking during thePaleoproterozoic era. It is the second-oldest known crater on Earth, a little less than 300 million years younger than the Suavjärvi crater in Russia.
It was originally thought that the dome in the center of the crater was formed by a volcanicexplosion, but in the mid 1990s evidence revealed that it was the site of a huge bolide impact, as telltale shatter cones are often discovered in the bed of the nearby Vaal River.
The Vredefort crater site is one of the few multi-ringed impact craters on Earth, although they are more common elsewhere in the Solar System. Perhaps the best-known example isValhalla crater on Jupiter's moon Callisto, although Earth's Moon has a number as well. Geological processes, such as erosion and plate tectonics, have destroyed most multi-ring craters on Earth.
The nearby Bushveld Igneous Complex (BIC) and Witwatersrand Basin were created during this same period, leading to speculation that the Vredefort bolide's mass and kinetics were of sufficient magnitude to induce regional volcanism. The BIC is the location of most of the world's known reserves of platinum group metals (PGMs), while the Witwatersrand basin holds most of the known reserves of gold.
The Vredefort Dome World Heritage Site is currently facing threats from unstructured property developments and the Parys Sewage Treatment Plant, which are in a dilapidated state and are pumping untreated sewage into the Vaal River and the crater site.
A more detailed consideration of impacts .
Note the general fractal nature of fractures in the scope of the supersonic impact wave and subsequent relaxation wave
Cool routes to the surface result .
Hence survival of diamonds .
Makgadikgadi Sea .
Andre Willers .
Update : 26 Oct 2010
Also Magadigadi sea , Makgadigadi sea , Magadikgadi sea .
Also shown in "DaMing Hun Yi Tu" ("Amalgamated map of the Great Ming Empire") dated 1398 AD on 17 square meters of silk , thought to be based on data about 1320-1380 AD , from preparation explorers before the Admiral He fleet .
This includes a map clearly showing the inland sea before it drained through Kariba , and Orange River as described below .
The latitudes could then be measured fairly accurately , but the longitudes seem slightly wonky . However , what is interesting is what is not shown : ie the outlets of the Zambezi or the Orange , though it does show the outlet of the Cunene at the correct latitude . Major mountain ranges are also shown at correct latitudes .
We suspect that at the time of the mapping (circa 1320 AD) , the outlets of the Zambezi and Orange rivers did not exist , but were opened shortly afterwards by tectonic action of the active faults in the regions .
What the map does show is the Caledon , ending in an endorheic basin roughly bounded today by Coleberg-Tarkastad-BarkleyEast.
The tributary/outflow shown to the south of the Makgadigadi Sea is more interesting . The flow here would be towards an endorheic basin roughly bounded by Prieska-VictoriaWest-Sutherland . The map shows the Makgadigadi Sea to be rather full at the time , so the water flow would have been into this endorheic basin .
In times of drought , the Makgadigadi Sea would shrink and the flow would reverse .
An alternate endorheic basin is roughly Upington-Garies-Calvinia . This would be accessable depending on tectonic activity . (It is a bit lower than the previous basin)
Tectonic activity would also periodically open the Orange and Zambezi outlets to the oceans .
Fluctuate this over geologic time , and you have diamond deposits from the weathering of the volcanoes formed after the Vredefoort impact .
These have been found at the Orange outlet , Upington-Garies-Calvinia basin (eg Hexriver diamonds) , Botswana , Zimbabwe .
But , nobody has really looked at the Prieska-VictoriaWest-Sutherland endorheic basin . There should be very rich alluvial diamond pockets in potholes in the old riverbeds as the water swished back and forth .
Gas and Oil :
Endorheic basins are usually associated with gas or oil if they fluctuated over geologic timespans . Biologic material gets washed into basins with no outlet , covered up and pressurized . Voila! At least gas . Maybe oil .
You know you have struck it rich when
Your borehole at Sutherland blows and the diamonds clog the oil-filters .
Makgadikgadi Sea .
28 Aug 2009
Southern Africa had a large interior freshwater sea until historical times , with major effects on human evolution and regional climates .
Map source : Reader's digest "Atlas of the World" (1993) ISBN 0-276-42001-264-7 .
P128 : Map of Southern Africa .
Wikipedia , Google . See appendices .
The topographical map clearly shows a major basin with 200 – 1000 meter elevation
Bounded by 16 to 28 degrees latitude (longest about 1 320 km) ,
The width varies : roughly hourglass-shape . At the narrowest in the middle : 23 to 25 degrees longitude (about 240 km) at about latitude 22 degrees .
The widest about 500 km . Bounded in the east by about 27 degrees longitude , and the west by 20 degrees longitude .
The basin is bounded by higher elevations and mountains on all sides , except for the breakthrough gap of the Zambezi at Victoria Falls .
Roughly the line from Worcester – Grootvlei – Kakamas – Khakea – Lake Ngami – Victoria Falls – Present course of Zambezi to Great Rift Valley .
Essentially a branch of the Great East African Rift . See the Luangwa river plains .
See also Zimbabwe – Kalahari Axis , Gumare fault .See Appendices .
Note that these faults runs right through the center of the old Kalahari Sea , and was thus sensitive to the changes in it's water level . This in turn was sensitive to rainfall and river-inflow / outflow balance . Changes in the weight of the water would cause changes in seismic activity .
The faults are quite active (cf Tulbagh earthquakes , when the southernmost end had a mild 6.8 tremor.) . The Zimbabwe – Kalahari Axis and Gumare fault have been active in historical times , but with long intervals . Overdue . .
Periodic fluctuations .
The entire system is seismically sensitive to climate fluctuations caused by the periodic filling and emptying of the Makgadikgadi Sea . Hence the zig-zag pattern of the Victoria Falls gorges .
There is also a complex feedback with rainfall patterns in the catchment areas of the feeder rivers . The system is an endorheic basin (internal drainage-see Appendix B)
But such a large body of water and concomitant vegetation drastically alters the rainfall in its region .
See http://andreswhy.blogspot.com "Biotic pump"
Notice the orientation of rivers on the sides of the old sea (ie Namibia , Angola) . They are all on the side of ridges facing the basin , ie from where moisture will come . A large percentage of moisture simply recirculated within the basin .
During the full episodes , it simply overflowed through the Limpopo .
Earthquakes opened the Victoria Falls portal . The water level fell . Moisture recirculation fell . The borders dried up . If this coincides with a dry climate period , we get the present shrinkage to marshes at the deepest parts .
Earthquakes sooner or later close the Victoria Falls portal , and the process reverses .
This has been going on for more than 3 million years (see Appendix C) .
The latest reversal started about 10 000 years ago , with the major climate shift at the end of the ice age .
Orange River .
Note the very peculiar fact that most major rivers in South Africa (Orange , Vaal , Harts , Modder , etc) are on top of ridges . This has led to some interesting squirming by geologists , since water has this well-known propensity to flow downhill . The explanations are suitably convoluted and involve escarpments , really long stretches of time and lots of erosion .
Whatever , it still means that the major rivers are unstable vis-a-vis major tectonic movements , but may be self-sealing due to heavy silting .Though this takes some heavy swallowing .
But the Orange river has a high probability of also periodically emptying into the Inland Sea . Most probably about 60 km downstream from Kakamas , where it comes nearest to the Molopo .
This is not an idle question , since such an old riverbed will be lousy with alluvial diamonds . Might even be gold-nuggets from the Vaal .
Human Evolution .
See Appendix D .
The point actually pinpointed is where the borders of present RSA , Namibia and Botswana meet . This is not an accident , since the borders follow habitability . This is where the Nossob river meets the westernmost part of the old inland sea . An ideal place for human evolution .
Lots of food , easily gathered . A whole sea of potable water .Lots of caves . An extended coastline to accommodate expanding population or climatic change . An outlet to the South-South-West with no unsurmountable barriers for the bored and rebellious .
The inhabitants of Pinnacle Point near Mosselbay were thus colonizers , migrating via the West Coast . They were stopped by the dense Tsitsikama forest and inhospitable terrain past that . The really inhospitable central plateaux were only the populated by outcasts , criminals and refugees .
Others on the inland sea would move northwards during fluctuations , eventually ending up in the Rift Valley system . From there they could easily move northwards , using well-known strategies and technologies next to the rift lakes . Bypassing the whole problem of latitude crossing (cf Jared Diamond) .
The periodic nature of the process means that after the first migration , and after Toba
(73 000 BP) , there would be people already there . But population density was low and newcomers (essentially refugees) , were helped on their way , eventually towards North Africa , Middle-East , Asia and Europe . This attitude (called Ubuntu) is still a characteristic of most ordinary people in Africa .
Interesting asides :
Aquatic human episode : a freshwater sea like the Magadikgadi Sea would be a much more benign environment for such evolutionary development than salt-water ocean . Note the trainable capability of humans to see underwater (not very well known , but well documented) .
More telling is Click . See http://andreswhy.blogspot.com "Click and human Evolution" Click sounds aid fishing . Do humans still use this ? (without technology)
The inland sea teemed with fish . Clicking would not only locate , but also chase fish into weirs or nets . We know they used weirs (stone weirs have been found by archeologists in areas like Mosselbay) . The efficiency of clicks (mimicking predators like dolphins) would be very efficient in chasing fish . They would also attract dolphins , which would share of the largesse . The beginning of a long cupboard love .
With the invention of agriculture , click-languages fell out of fashion .
"So last year .Who needs the effort ." But some aquaculture enclaves might still have it . Cf surprising Chinese efficiency in freshwater aquaculture . Do they cluck ?
Was the first domestication done simply by seeing which animals responded to clicks , then selecting and breeding . This could be easily tested .
Chickens and falcons also respond better to clicks . How deep does it go ? I will need a lot of convincing for a virus click-whisperer . What about a homeopathic click-whisperer ? The shaman has click-whispered into this large body of water and it is transmitted . Sigh . Many humans believe exactly that . Holy water .
See Appendix B
Basins which have internal drainage act like pumps to any living organisms inside them . Because of the interaction between rainfall and vegetation , there is a feedback oscillation . When times are good , populations increase . When times are bad , the tough emigrate , and export their troubles .
The Magadikgadi basin is probably the oldest , but the Tibetan Plateau is not far behind . Ditto the steppes of Mongolia , Aral and Black Seas . North Africa (Lake Fezzan , Lake Chad) , the whole Arabian and Sinai peninsulas , northern Mexico , Middle-West USA are examples . All the troublespots . Even small climatic fluctuations cause trouble if the population is over carrying capacity .
See http://andreswhy.blogspot.com "Fractal collapse of societies"
For about 2000 years , to about 1400 AD , there was a flourishing civilization around the borders of the inland sea . The climate in the highland-areas around it was very benign , with rain the year around . Extensive ruins of terraced agriculture are discernable . The center was in Zimbabwe .
Value added items were exported to India , Arabia mainly gold , minerals and precious stones Like now .
See the photo's in Adam's Calender by Heine and Tellinger . (ISBN 1-920153-07-1) .
Especially p25-p27 . Kilometers of ruins showing clear evidence of agriculture (terraced ,nogal) and husbandry , with market mechanisms (roads , but no evidence of wheel tracks) . Though the authors try hard , the ruins are patently fresh . They show less weathering than equivalent Roman ruins in Europe . They are younger than 1000 years . There is no evidence of Deep Time . Stone fences are still above ground . Terraces are evident . Not very old at all . But still indicative of a flourishing society about 100 BC to 1400 AD .
So what happened ?
A severe earthquake opened up Victoria Falls again and the inland sea started draining . This coincided with the latest long-term drying-up . A tipping point was reached (because of the feedback effect) , and things went to hell in a handbasket quickly after that . There was already shrinkage before that , but this was the coup-de-grace .
The overseas merchants (Dravidian South Indian merchant class – the Komati) cut their losses and departed . Markets shrunk . The locals abandoned expensive agriculture , especially as the climate changed . The shrinkage was gradual . When the final pull-out occurred , the remnants could live on the land in a simple subsistence economy .
What remained was kilometers of ruins (like Rome before the Renaissance.)
Note that this was not a failure of civilization , but an effect of climate change .
The market disappeared because the infrastructure to feed the labour force was no longer sufficient . A market cannot create a climate . (Not then , in case)
What can we do about it ?
Well , we can rob the Congo river or the Rift lakes , but that is inelegant .
An elegant solution is to punch a channel underground to below 1000 meters in the Atlantic , use the pressure to squirt the water into basin , after desalinating it .
The technology exists :
1.The tunnel :
Sub-Crustal torpedoes . Submarine versions are already in use with the Russian and USA navies . Simply a high-speed projectile that uses vaporized plasma ahead of it to change the phase of the material . A train of them condenses the plasma on the sidewalls as a strong material .Cheap .
2.The desalination :
See http://andreswhy.blogspot.com "Negative Pressure : an important update" 6 Mar 2009 .
The nanotechnology is due at any moment . By it's very nature , it is high throughput .
3. The ideal spot :
The top reaches of the Nossob river , about midway between Okanhanja and Epokira . From there is an uncomplicated run for a sub-crustal missile to the Atlantic towards the south-west .. The further advantage is that the flooding would be via a natural river . It would be truly spectacular . It is doubtful that they could get the right depth on first try , but would rather go too deep , than too shallow . A huge permanent geyser of water hundreds of meters high would result . An inverse waterfall , to rival Victoria Falls .
4. What if the desalination is not ready ?
(Yakkity-yak humans –most likely)
A sea-water sea would be nearly as acceptable . The climatic effects would be similar. We have a model in the Black Sea .
Do the same in other endorheic basins ? Libya might do it first . Or repopulating the Aral sea . The Black Sea can do with some topping up .
This can be done definitely within 6 months from now .
See map of endorheic basins in Arabia and Sinai .
Not to mention India . Or Australia . They really need it .
5. Ocean current climatology will suddenly assume a new strategic importance .
6. The defense strategic importance of sub-crustal missile technology .
They cannot defend against super-crustal missiles . So that is not applicable . The thing a nation or civilization has to worry about is resources . And this technology frees up the oceans' resources .
Ecology is the major worry , and avenues for that exist .
7. Money .
There is an incredible amount of money to be made .
Actually made . Real wealth creation . Millions of acres made fertile even with just saline water nearby . The carbon credits of a sub-ocean fountain dissolving CO2 alone will pay the fairly modest capital costs (about $500 million) . Sneer at iceberg-towing.
Global flooding ?. Rather worry whether there is enough water in the oceans to satisfy human demand .
An interesting exercise : calculate the remaining sea-level after maximal usage of sea-water . (Hint : look at ice-ages . Would we use the water-equivalent of miles thick glaciers on land ? Easily .Crops , drinking , industrial etc . But remember , if it is properly cleansed , it is borrowed . It does get returned to the ocean . But an awful lot of it is "in use" , in the air as it were . This percentage will increase .)
Industrial demand will lead to such a shortage of water that it would be economical to import water from the Saturn orbital clouds .
8. Parallel sub-crustal missiles .
I am deeply unhappy about the fact that major river systems in South Africa are on hard ridges . It is simply unstable , unless there is a deep trench in the river bed . The only way I can think of is a a collapsed tunnel . Drilled by a sub-crustal missile .
Meteor impact :
If you look at the paths of the Vaal ,Caledon and Orange rivers and backtrack , you see that the tracks meet at 36.67 degrees longtitude and 26.78 latitude . This would be the putative impact point of a meteorite that split into two and tunneled under the crust for about 1 620 km till the two plasma bodies slowed to a threshold velocity and they swerved sharply towards each other . They impacted roughly where Hopetown is now . (A bit to the south-east , actually .) Expect diamonds .
What to expect at the impact point :
This is about 200 km from Beira . This has been a carbon rich area for a long time . I do not know when the impact took place , but even if it was a fragment of the Vredefoort meteor there would still be gas and maybe oil deposits formed by the impact waves .
Note the lightning-like offshoots before the final .
At the end , quantum distribution of charge on the plasma body overwhelms internal coherence and the two bodies rush towards each other and self-annihilate .
Violent energy release results .
Hence the little stretch of the Orange river between Colesberg and Kimberley .
What to expect at the impact point (36.67 degrees longtitude and 26.78 latitude) .
This is in the Mozambique channel . There should be oil and gas in a radius of 120 km .
The two missile trajectories passed on either side of Nelspruit , with dense rock concentrators on either side . There should be at least gas , probably oil .
Something similar at Bloemfontein , but probably only gas .(Figures)
Notice all the thermal springs around .
At Nelspruit : narrow at the top and wide at the bottom . Quite large .
Geological changes to the course
More than two million years ago, the Upper Zambezi river used to flow south through what is now the Makgadikgadi Pan to the Limpopo River. The land around the pan experienced tectonic uplift (perhaps as part of the African superswell) and a large lake formed, and extended east.
Meanwhile, 1,000 kilometres (620 mi) east, a western tributary of the Shire River in the Great Rift Valley's southern extension through Malawi eroded a deep valley on its western escarpment. At the rate of a few cm per year, this river, the Middle Zambezi, started cutting back the bed of its river towards the west, aided by grabens (rift valleys) forming along its course in an east-west axis. As it did so it captured a number of south-flowing rivers such as the Luangwa and Kafue.
Eventually the large lake trapped at Makgadikgadi (or a tributary of it) was captured by the Middle Zambezi cutting back towards it, and emptied eastwards. The Upper Zambezi was captured as well. The Middle Zambezi was about 300 metres (980 ft) lower than the Upper Zambezi, and a high waterfall formed at the edge of the basalt plateau across which the upper river flows. This was the first Victoria Falls, somewhere down the Batoka Gorge near where Lake Kariba is now. For details of how the falls cuts back its bed to form the gorge, see How the Victoria Falls formed.
The Zambezi region was known to medieval geographers as the Empire of Monomotapa, and the course of the river, as well as the position of Lakes Ngami and Nyasa, were given broadly accurately in early maps. These were probably constructed from Arab information.
List of endorheic basins
From Wikipedia, the free encyclopedia
The following is a list of endorheic basins — watersheds which do not drain to the sea.
From Wikipedia, the free encyclopedia
Lake Makgadikgadi is an ancient lake that existed in what is now the Kalahari Desert in Botswana. It may have once covered as much as 80,000 km² and been 30 m deep. The Okavango, Zambezi, and Cuando rivers once all emptied into the lake.
Origin and History
Approximately 3 million years ago, strong easterly winds brought about the formation of elongated dunes which ran from east to west across the middle of the Kalahari Desert. During wetter times, these dunes channeled the flow of the great rivers of the area, the Okavango, Chobe, and Zambezi, eastwards with the Limpopo River into the Indian Ocean.
About 2 million years ago, the formation of the fault known as the Kalahari-Zimbabwe axis, which runs from the Zimbabwe
Harare through its second-largest city Bulawayo and ends in the eastern side of the Kalahari, created an enormous basin and forced these rivers to flow into and fill up the basin. Lake Makgadikgadi was thus created.
As the millennia passed, the lake was filled to capacity and began to overflow. About 20,000 years ago, as a result, it began to drain northwards and then eastwards. This caused the middle and lower Zambezi Rivers to connect, resulting in the formation of Victoria Falls. With the water now able to flow out of the basin, Lake Makgadikgadi was able to drain partially and its average level decreased.
A drier climatic period followed which caused an increase in evaporation and a decrease in the flow of the rivers that fed it. By about 10,000 years ago the drying of Lake Makgadikgadi was in an advanced stage. Sediment and debris from the Okavango River and windblown sand were gradually filling the lake.
The formation of the Gumare fault caused a reduction in the elevation of the land. As a result, the water of the Okavango River spread out over a much larger area of land than it previously did, forming the now characteristic fan-shaped inland delta of the Okavango, which further reduced the water that flowed into Lake Makgadikgadi and hastened its demise.
Lake Makgadikgadi is theorized to have been the birthplace of the vast number of cichlids that once swam the Congo River, Zambezi River, Okavango River and Limpopo River - as many as 100 to 400 new species, of which approximately 25 survive today. The lake's sheer size may have provided the ancestors of these fish with an extremely wide range of new ecological niches to exploit and thus could have served as the stimulus for the evolution of the new species, which they may have done in record time before the lake drained completely. The theory further says that the newly evolved species, after having evolved within the confines of the lake, could have escaped with the waters of the lake as it drained, and populated the rivers of the region to evolve into the cichlids that exist today.
- C. Michael Hogan (2008) Makgadikgadi, The Megalithic Portal, ed. A. Burnham 
- James Owen (May 4. 2005) Lost African Lake Spawned Fish Diversity "Beyond Belief. National Geographic News
Retrieved from "http://en.wikipedia.org/wiki/Lake_Makgadikgadi"
Human Evolution .
Snip from a NYT article about a new study by a group of geneticists which pins the origin of humankind to a spot on the coast of southwest Africa near the Kalahari Desert. The study is said to be the largest ever of its kind on African genetic diversity. The researchers say Africans are descended from 14 ancestral populations that typically correlate with language and cultural groups.
Locations for the Garden of Eden have been offered many times before, but seldom in the somewhat inhospitable borderland where Angola and Namibia meet.
A new genetic survey of people in Africa, the largest of its kind, suggests, however, that the region in southwest Africa seems, on the present evidence, to be the origin of modern humans. The authors have also identified some 14 ancestral populations.
The new data goes far toward equalizing the genetic picture of the world, given that most genetic information has come from European and Asian populations. But because it comes from Africa, the continent on which the human lineage evolved, it also sheds light on the origins of human life.
The research team was led by Sarah A. Tishkoff of the University of Pennsylvania, and reported in in a recent issue of Science: "The Genetic Structure and History of Africans and African Americans." (via Ned Sublette)
Greatest Places Physical Geography: Dr. Cecil Keen, July 1997
Geographic Description: Described as "the river which never finds the sea", the Okavango in northwestern Botswana disappears into a 6,000-square-mile maze of lagoons, channels, and islands. The river system annually brings more than 2 million tons of sand and silt into the Delta, yet less than three percent of the water emerges at the other end to either flood Lake Ngami or cross another 300 miles of the Kalahari, then to enter Lake Xau and the Makgadikgadi Pans.
It is a natural refuge and giant water hole for the larger animals of the Kalahari. The water gives rise to many forms of life unexpected in a "desert": There are fish, crocodiles basking on the sands, and hippopotamuses and swamp antelopes feeding on the vegetation.