90
145,
80-71
1,140*
931*
2,071*
34 %
Mezozoic
Total sum:
MZ
2,031*=54%
2,571*=51%
4,602*=52%
Cenozoic provinces:
Tanzania
Eq. Africa
53-
45
22*
168*
190
20%
0.5*
9.5*
10
80%
PrairiaCreek
N.America
38-
20
0.1
7.5
7.6
70%
0.1*
0.3*
0.4
30%
Slave craton
N.Canada
71-
53
22*
203*
225
75%
25%
Ellendale
W.Australia
22-
18
0.2*
2*
2.2
Namibia
SW Africa
5-1.8,
2-0
88*
716*
804
10%
90%
Cenozoic
provinces
53-45
22-18
5-0
44.1*
378.5*
422.6*
25* %
88.6*
725.8*
814.4
75* %
Cenozoic
Total sum:
KZ
133*=3.5%
1,106*=22%
1,239=14%
Archean-
Cenozoic
Total sum:
AR-
KZ
3,776=100%
5,022=100%
8,798=100%
*Expert
estimate
Table 3. Resources of diamond in placers of the Earth
( in million carat - Mc )
Placers
Era
Recovered
diamonds
Reserves*
diamonds
Resources*
diamonds
Diamonds
technic %
Diamonds
jewel. %
Marine
KZ
88=6%
716=37%
804=24%
10%
90%
Continental
and Marine
KZ-
MZ
1,140=78%
931=48%
2,071=61%
56%
44%
Continental
PZ
3
80=6%
159=8%
239=7%
47%
53%
Continental
PR
2
145=10%
119=6%
265=8%
40%
60%
Continental
AR
2
1*=0.07%
9*=0.5%
10*=0.3%
10%
90%
Total sum
KZ-
AR
2
1,455=100
%
1,934=100
%
3,389=100%
We have to sum up the resources of diamonds from Cenozoic placers with the
Mesozoic dates, because basically, the primary sources of these diamonds, were
the Cretaceous and Jurassic kimberlites, especially on the African continent and
Sibirian, that total amount are no less than 60%. Thus, we come to the
conclusion that the resources of diamonds in the bowels of the Earth were
periodically increasing from ancient epochs to the present time.
The majority of rich and middle diamond-bearing kimberlite provinces and
deposits were opened on the subcontinent Gondwana, about 75% of them,
91
especially in Southern and Equatorial Africa. On the platforms of the
subcontinent Laurasia were detected mainly midlle and weakly diamond-bearing
kimberlites pipes, sills and dikes, among them there are only 25% rich deposits.
On the average of the Earth only about 2.5 % of the diamonds mines have been
explored. The relative amount of exploited bodies reaches 10-14% in the
central zones of diamond rich kimberlite provinces, whereas in the intermediate
zones of diamond-pyrope subfacies are known only rare and weakly diamond-
bearing kimberlites, in amount approximately 20% , and even mineralogical
presence of diamonds is established on peripheries of the provinces.
Table 4. Comparison of the amounts of recovered, reserves
and resources of
diamonds in the kimberlite, lamproite deposits and placers of the Earth
( in million carat - Mc).
Age
Ma
Recovered
diamond
Reserves
diamond
Resources
diamond
Sources
of diamonds
3300*
?
?
?
kimberlite
2700*
?
?
?
lamproite
1700
1580*
1450
5.7= 0.3%
30=1.1%
35.7=0.7%
kimberlite
20= 3.4%
60 =15.0%
80= 8.1%
lamproite
1200*
1140
177=10%
74=3%
251=5%
kimberlite
558.6=96%
186=46%
745=75%
lamproite
540-430
370-350,
300*
624=36%
716=27%
1,340=30%
kimberlite
230-145,
113-84,
80-71
886=51%
1,485=55%
2,371=53%
kimberlite
5=0.9%
156=39%
161=16%
lamproite
53-45
22-18
44= 2.5%
379=18%
423= 10%
kimberlite
0.2=0.03%
2=0.5%
2,2 =0.2%
lamproite
Sum
magmatic
PR-KZ
1,737=46%
2684=53%
4421=47%
kimberlite,
584 =15%
404=7%
988=11%
lamproite
Sum
placers
AR-KZ
1,455=38%
1,934=40%
3,389=42%
placers
Total
sum:
3,776=100%
5,022=100%
8798=100%
kimberlite,
lamproite,
placers
Thus, we come to the conclusion that the resources of diamonds in the
bowels of the Earth were periodically increasing from ancient epochs to the
present time. This conclusion has practical and scientific significance. In our
opinion, one of the possible reasons of the increasing resources of diamonds in