erthsister
GC07 SouthKaibab 3923
Very hard, reddish purple Shinumo Quartzite near the "angular unconformity."
Abbott & Cook write: "You cross from the brown sandstones and thin, green mudstones belonging to the Tapeats onto extremely hard, reddish purple Shinumo Quartzite. With a single footfall, you step 550 million years back in time! This amazing gap in the rock record is marked by an angular unconformity..."
GC07 SouthKaibab 3923
Very hard, reddish purple Shinumo Quartzite near the "angular unconformity."
Abbott & Cook write: "You cross from the brown sandstones and thin, green mudstones belonging to the Tapeats onto extremely hard, reddish purple Shinumo Quartzite. With a single footfall, you step 550 million years back in time! This amazing gap in the rock record is marked by an angular unconformity..."