Geology Reference
In-Depth Information
N
Snow covered
C
Exposed
D
32
5
B
7
A
11
8
16
13
4
14
6
9
20
18
10
19
12
15
17
Blue ice
76° 45
ʹ
S
159° E
0
5
Kilometers
Antarctic meteorite discovery area
Figure 1.5.
The geodetic network across the Main Icefield. Note Stations 1 and 2 on bedrock and the rest in auger holes bored in
the ice. The small strain net with Stations A, B, C, and D was added three seasons after the original was completed. The meteorite
distribution under the net is not shown.
plumbing, and an electric generator. There was a pad
outside with three helos, one of which always was avail-
able for emergencies. A cook rustled up three meals a day
for everybody.
On the high plateaus within helicopter range of the
Darwin camp, Cassidy and Shiraishi found large patches
of ice with no meteorite concentrations on them. They
collected only eight stones up there. However, a major
attraction at that site proved to be the scattered fragments
of an iron meteorite that geologists from New Zealand
had discovered and from which they had already recov-
ered six fragments on the rocky, ice-free slopes of Derrick
Peak. They radioed Bill to come and take a look, so
searching jointly with them, Cassidy and Shiraishi found
six more irons, which the Kiwis urged them to keep. All
of these irons were coarsest octahedrites that appeared to
lie in a strewnfield on the mountainside. One of these
pieces was the enormous 160-kg iron that Bill found and
photograped (Figure 1.6a; see also Plate 78).
After this run of remarkably good luck, Cassidy
departed from the Darwin Camp, leaving Shiraishi to act
as a guide for Dean and me when we would arrive there.
On 20 December after a couple of days of being socked
in at McMurdo, we took off from the ice at Williams
field, next to Scott Base, in a Hercules LC-130, and flew
to the Darwin Camp. There, I was happily surprised to
discover that the chief scientist at the Darwin Camp was
Dr. George Denton, who had been my best student back
in 1960 when I was teaching mineralogy at Tufts College.
On 21 December, Shiraishi led us to a moraine near the
head of the Darwin Glacier where there seemed to be
nothing in view except a broad, closely packed assemblage
of terrestrial boulders. I thought it would be helpful to
look closely at a few of the boulders to get an idea of what
sort of rocks were there. I reached out with my pick and
pulled up a big stone at random, took it in my hands
(which I should not have done), and saw that it was a
meteorite! My first meteorite from Darwin was already
