Figure 4.9A illustrates two areas within the Umingmak train with coarse Cr-pyrope.The first peak is 500 m down ice of the Umingmak kimberlite and the second peak, 1500 m down ice. The peaks are relatively small, with the first (highest) having an interpolated tk
value slightly above 1 (Fig. 4.9B) and the second tk peak <0.5. Medium Cr-pyrope (Fig. 4.9C) defines the train well with three peaks (Fig. 4.9D): the first peak located at the kimberlite; the second, 500 m down ice; and the third, 1500 m down ice. The highest medium Cr-pyrope peak is at the same location (500 m down ice) as for coarse Cr- pyrope. Fine Cr-pyrope (Fig. 4.9E) is more abundant than coarser size fractions with a profile similar to the medium fraction (Fig. 4.9F), having the highest tk peak 500 m down ice.
4.14.2 Orange garnet
Orange garnet is absent in the coarse size fraction, and sparse in the medium fraction (Fig. 4.10A) with tk values of 0.5 and less (Fig. 4.10B), with the highest peak present at the kimberlite. Fine orange garnet is present (Fig. 4.10C), with tk values <1.5. The fine orange garnet profile (Fig. 4.10D) indicates the highest peak occurs 750 m down ice from the Umingmak kimberlite.
4.14.3 Mg-ilmenite
Figure 4.11A illustrates low abundance of coarse Mg-ilmenite, with greatest tk values 500 m down ice (Fig. 4.11B) from the kimberlite. Medium Mg-ilmenite (Fig. 4.11C) is more abundant than the coarse fraction with a peak interpolated tk value of ~105 located 500 m down ice (Fig. 4.11D). Fine Mg-ilmenite is most abundant (tk >200) in the fine fraction (Fig. 4.11E) located 500 m down ice from the kimberlite (Fig. 4.11F). The profile (Fig. 4.11F) indicates fine Mg-ilmenite is distributed from the kimberlite at least 2000 m down ice.
Figure 4.9A. Interpolated dispersal pattern of 1.0 – 2.0 mm Cr-pyrope in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.9B. Interpolated profile of 1.0 – 2.0 mm Cr-pyrope dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.9C. Interpolated dispersal pattern of 0.5 – 1.0 mm Cr-pyrope in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.9D. Interpolated profile of 0.5 – 1.0 mm Cr-pyrope dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.9E. Interpolated dispersal pattern of 0.25 – 0.5 mm Cr-pyrope in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.9F. Interpolated profile of 0.25 – 0.5 mm Cr-pyrope dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.10A. Interpolated dispersal pattern of 0.5 – 1.0 mm orange garnet in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.10B. Interpolated profile of 0.5 – 1.0 mm orange garnet dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.10C. Interpolated dispersal pattern of 0.25 – 0.5 mm orange garnet in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.10D. Interpolated profile of 0.5 – 1.0 mm orange garnet dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.11A. Interpolated dispersal pattern of 1.0 – 2.0 mm Mg-ilmenite in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.11B. Interpolated profile of 1.0 – 2.0 mm Mg-ilmenite dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.11C. Interpolated dispersal pattern of 0.5 – 1.0 mm Mg-ilmenite in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.11D. Interpolated profile of 0.5 – 1.0 mm Mg-ilmenite dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.11E. Interpolated dispersal pattern of 0.25 – 0.5 mm Mg-ilmenite in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.11F. Interpolated profile of 0.25 – 0.5 mm Mg-ilmenite dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
4.14.4 Mg-olivine
Coarse Mg-olivine is present in two locations in the Umingmak train (Fig. 4.12A) with peak abundance 500 m down ice (Fig. 4.12B). Medium Mg-olivine is present throughout the train axis (Fig. 4.12C) and is most abundant 500 m down ice with tk values >200 (Fig. 4.12D), similar to fine Mg-ilmenite, and is distributed at least 2000 m down ice from the kimberlite. Fine Mg-olivine is the most abundant KIM in the Umingmak train (Fig. 4.12E) with tk values of ~4000 located 750 m and 1500 m down ice(Fig. 4.12F). Approximately 1500 m northeast of Umingmak (Fig. 4.12E) and 600 m south-southeast of the Umingmak-2 kimberlite is an area with interpolated Mg-olivine values greater than in the Umingmak train. This area may represent an undiscovered olivine-rich intrusion.
4.14.5 Cr-diopside
Coarse Cr-diopside is present only in immediate vicinity of the Umingmak kimberlite (Fig. 4.13A) with interpolated tk values <1 (Fig. 4.13B). Medium Cr-diopside is present along most of the train axis (Fig. 4.13C) with two peaks of similar tk values (5.4 and 5.3 respectively) located at the kimberlite and 500 m down ice (Fig. 4.13D). Cr-diopside is most abundant in the fine fraction (Fig. 4.13E) with a peak at the kimberlite location, however, a higher peak occurs 500 m down ice (Fig. 4.13F). Fine Cr-diopside drops rapidly between 500 and 1200 m, then increases between 1200 and 2000 m. Another slight increase in fine Cr-diopside appears between 2400 and 3200 m, which could represent grains from a different source.
4.14.6 Chromite
Coarse chromite is absent in the Umingmak train and sparse in the medium size fraction (Fig. 4.14A) with greatest abundance (<3) located at the kimberlite (Fig. 4.14B).
Distribution of fine chromite (Fig. 4.14C) is unusual compared to most other species because it exhibits increasing abundance from 250 m up ice of the kimberlite to 1500 m down ice (Fig. 4.14D).
Figure 4.12A. Interpolated dispersal pattern of 1.0 – 2.0 mm Mg-olivine in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.12B. Interpolated profile of 1.0 – 2.0 mm Mg-olivine dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.12C. Interpolated dispersal pattern of 0.5 – 1.0 mm Mg-olivine in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.12D. Interpolated profile of 0.5 – 1.0 mm Mg-olivine dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.12E. Interpolated dispersal pattern of 0.25 – 0.5 mm Mg-olivine in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.12F. Interpolated profile of 0.25 – 0.5 mm Mg-olivine dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.13A. Interpolated dispersal pattern of 1.0 – 2.0 mm Cr-diopside in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.13B. Interpolated profile of 1.0 – 2.0 mm Cr-diopside dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.13C. Interpolated dispersal pattern of 0.5 – 1.0 mm Cr-diopside in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.13D. Interpolated profile of 0.5 – 1.0 mm Cr-diopside dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.13E. Interpolated dispersal pattern of 0.25 – 0.5 mm Cr-diopside in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.13F. Interpolated profile of 0.25 – 0.5 mm Cr-diopside dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.14A. Interpolated dispersal pattern of 0.5 – 1.0 mm chromite in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.14B. Interpolated profile of 0.5 – 1.0 mm chromite dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.
Figure 4.14C. Interpolated dispersal pattern of 0.25 – 0.5 mm chromite in till for the Umingmak kimberlite dispersal train. Red line represents train axis used for profile.
Figure 4.14D. Interpolated profile of 0.25 – 0.5 mm chromite dispersal in till for the Umingmak kimberlite. Kimberlite is at location 0 on x axis.