n Alas - Alaska Division of Geological & Geophysical Surveys - State ...

terrane extends at least 300 krn to the west, beyond
Mount McKinley, end about 100 km to the southeast
(Jones and others, 1981). Pnrt of this terrane occurs
-in a fault-bounded block Immediately south of the
HInes Creek fault In the western part of the Mount
Hayes quadrculgle, where it is structurally juxtaposed
against rocks of the Yukon-Tanma Upland to the
north, which, in this area, consists of the schist of Jarvis
Creek (area 13, fig. 44; fig. 45). The Plngston terrane
is bounded to the south by the intensely deformed
McKinley terrane and by numerous fault-bounded
slivers of liighly deformed and metamorphosed flysch
of presumed Jurassic or Cretaceous age (don- and
others, 1981).
Par to the west of the Mount II~yes quadrangle,
the Pingston terrmc has been described as an intensely
deformed suite of deepwater upper Paleozoic phyllite
and chert, minor limestone, and Triassic black argil-
Ute, gray limestone, and calcareous siltstone and sandstone
intruded by younger diab~se and gabbro dikes and
sW (Jones and others, 1981). Previous studies of the
Pingston terrane in the western part of the Mount
Figree 44.-Areas and Iocalltles in southern Alaska
discussed in this volume. A Wing of authorship,
applicable figures and tables, and articIe paginatton (in
parentheses) relating to the numbered meas follows.
1, Ager and Slms, figure 65 (p. 103-1051; 2, Aleinikoff
and Nokleberg, figure 46, table 15 (p. 73-75); 3,
Bartsch-Winkler and SchmoU, figures 66 through 70 (p.
105-108); 4, Connor, figure 64 (p. 102-103); 5, Csejtey
and others, figure 49 (p. 77-79); 6, Cuctin and othem,
fiwe 58 @. 92-93); 7, Dumoulln and Miller, figures 47
Hayes and eastern part of the Healy quadrangles indicate
that the terrane consists of varying amounts of
highly deformed and metamorphosed limestone, black
shale and phyute, argillite, graywacke, conglomerate,
and submarine basalt (~allrhahig and others, 1975) or
varying amounts of metavolcanlc rock, metatuff, pillow
greenstone, and sparse marble (Sherwood and
Craddock, 1979).
Recent field, petrologic, snd structural studies
of the Pingston terrane in the Mount Hayes C-5 and G
6 quadrangles reveal that in this area the terrane: (1)
has a highly distinctive stratigraphy, age, petrology
(relict textures, relict minerals, and metamorphic
facles), and structure; and (2) dlffers markedly from
that described in previous studie. These more recent
studies indicate that the major rock types, In order of
decreasing abundance, are met.-andesite, metadacite
and netarhyodacite flows and (or) tuff, metabasalt,
metagabbro, metgvolcanic graywacke, metagraywacke,
me tasil tstone, metaquartzjte or rnetaehert,
and very sparse marble. Table 14 lists the general
petrography of the major rock units in the Pingston
and 48 (p. 75-77); 8, Evenson and others, figures 59
through 61 (p. 94-95); 9, Goldfmb, figure 57, tables 18
and 19 (p. 89-9211 lo, HUUlouse and Gromme, figures
50 and 51 (p. 80-82); 11, Kachadoorian end Ovenshine,
figure 71 (p. 108-110); 12, Mamay and Reed, figures 62
and 63 (p. 98-102); 11, Nokleberg and others, figure 45,
table 14 (p. 70-73); 14, Nckthorn and Silberman,
figures 54 through 58 (p. 86-89}! 15, SUberman and
Grantz, figures 52 and 53, tabIes 16 and 17 (p. 82-86);
16, Yeend (p. 95-98).