v!ˆNSACLASSNLABELCNAMECHAGEC8DESCRIPTIOCþSOURCESCþSYMBOLNOVERPRINTN 103 Qtf Modern tidal flat and estuarine deposits Quaternary, Holocene Well-sorted, sub-tidal, stratified silt and some sand and local gravel deposited in shallow embayments Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 100 Qs Unconsolidated surficial deposits, undivided Quaternary Mainly unsorted boulders, cobbles, gravel, sand, and silt produced, deposited, and reworked by action of wind, water, glaciers, and frost, including solifluction. Includes deposits of present streams, colluvial and alluvial fans; glaciofluvial, glaciolaWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 295 Qs Unconsolidated surficial deposits, undivided Quaternary Mainly unsorted boulders, cobbles, gravel, sand, and silt produced, deposited, and reworked by action of wind, water, glaciers, and frost, including solifluction. Includes deposits of present streams, colluvial and alluvial fans; glaciofluvial, glaciolaWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 105 Qat Alluvial and terrace deposits Quaternary Flood-plain alluvium and stream terrace deposits. Consists of poorly- to well-sorted silt, sand, pebbles, cobbles, and boulders. Also includes abandoned channel deposits in outwash above modern floodplains or underfit stream channels, inferred to be reWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 109 Qat Alluvial and terrace deposits Quaternary Flood-plain alluvium and stream terrace deposits. Consists of poorly- to well-sorted silt, sand, pebbles, cobbles, and boulders. Also includes abandoned channel deposits in outwash above modern floodplains or underfit stream channels, inferred to be reWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 110 Qat Alluvial and terrace deposits Quaternary Flood-plain alluvium and stream terrace deposits. Consists of poorly- to well-sorted silt, sand, pebbles, cobbles, and boulders. Also includes abandoned channel deposits in outwash above modern floodplains or underfit stream channels, inferred to be reWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 111 Qat Alluvial and terrace deposits Quaternary Flood-plain alluvium and stream terrace deposits. Consists of poorly- to well-sorted silt, sand, pebbles, cobbles, and boulders. Also includes abandoned channel deposits in outwash above modern floodplains or underfit stream channels, inferred to be reWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 114 Qat Alluvial and terrace deposits Quaternary Flood-plain alluvium and stream terrace deposits. Consists of poorly- to well-sorted silt, sand, pebbles, cobbles, and boulders. Also includes abandoned channel deposits in outwash above modern floodplains or underfit stream channels, inferred to be reWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 106 Qls Landslide and colluvial deposits Quaternary Unsorted, angular rock debris and mud in slumps, earth-debris flows, block glides, and debris avalanches, and poorly- to well-sorted silt to boulders in alluvial fans and cones, and unsorted rock talus (Riehle and Emmel, 1980; Waythomas and Miller, 1999;Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 107 Qls Landslide and colluvial deposits Quaternary Unsorted, angular rock debris and mud in slumps, earth-debris flows, block glides, and debris avalanches, and poorly- to well-sorted silt to boulders in alluvial fans and cones, and unsorted rock talus (Riehle and Emmel, 1980; Waythomas and Miller, 1999;Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 108 Qls Landslide and colluvial deposits Quaternary Unsorted, angular rock debris and mud in slumps, earth-debris flows, block glides, and debris avalanches, and poorly- to well-sorted silt to boulders in alluvial fans and cones, and unsorted rock talus (Riehle and Emmel, 1980; Waythomas and Miller, 1999;Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 128 Qls Landslide and colluvial deposits Quaternary Unsorted, angular rock debris and mud in slumps, earth-debris flows, block glides, and debris avalanches, and poorly- to well-sorted silt to boulders in alluvial fans and cones, and unsorted rock talus (Riehle and Emmel, 1980; Waythomas and Miller, 1999;Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 112 Qsl Lacustrine, swamp, and fine silt deposits Quaternary Chiefly silt, clay, fine sand, peat, and other organic material generally of lacustrine origin (Riehle and Emmel, 1980; Richter and others, 2005; F.H. Wilson, unpub. data) Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 113 Qsl Lacustrine, swamp, and fine silt deposits Quaternary Chiefly silt, clay, fine sand, peat, and other organic material generally of lacustrine origin (Riehle and Emmel, 1980; Richter and others, 2005; F.H. Wilson, unpub. data) Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 115 Qb Beach deposits Quaternary Sand, gravel, and cobbles of present and former beaches, beach ridges, spits, and tidal flats (Tysdal and Case, 1979; Winkler and Plafker, 1993; Detterman and Hartsock, 1966; Riehle and Emmel, 1980; F.H. Wilson, unpub. data). Wave-deposited, coarse-graiWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 116 Qes Estuarine deposits Quaternary Fine-grained silt rich in organic material, mud, and peat (Winkler and Plafker, 1993). Includes salt-marsh deposits of Detterman and Hartsock (1966) and grades into tidal flat deposits (Riehle and Emmel, 1980; F.H. Wilson, unpub. data). Also includes mWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 117 Qes Estuarine deposits Quaternary Fine-grained silt rich in organic material, mud, and peat (Winkler and Plafker, 1993). Includes salt-marsh deposits of Detterman and Hartsock (1966) and grades into tidal flat deposits (Riehle and Emmel, 1980; F.H. Wilson, unpub. data). Also includes mWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 119 Qd Eolian deposits Quaternary Dunes consisting of well sorted, fine-grained sand and silt aligned in longitudinal ridges on the Cooper River delta (Winkler and Plafker, 1993). Also includes dunes on top of river bluffs, windblown flats, and river bars (Richter and others, 2005). InWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 120 Qd Eolian deposits Quaternary Dunes consisting of well sorted, fine-grained sand and silt aligned in longitudinal ridges on the Cooper River delta (Winkler and Plafker, 1993). Also includes dunes on top of river bluffs, windblown flats, and river bars (Richter and others, 2005). InWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 170 Qdl Deltaic deposits Quaternary Deltaic deposits, including outwash and alluvial deposits (F.H. Wilson, unpub. data) Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 123 Qgl Glaciolacustrine deposits Quaternary Largely ephemeral glacial lake and lake-related deposits. Well-sorted, well-stratified clay, silt, and fine sand deposited in ephemeral glacial and postglacial lakes. Thought to be typically covered by several feet of muck and peat (F.H. Wilson, unpub.Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 124 Qgl Glaciolacustrine deposits Quaternary Largely ephemeral glacial lake and lake-related deposits. Well-sorted, well-stratified clay, silt, and fine sand deposited in ephemeral glacial and postglacial lakes. Thought to be typically covered by several feet of muck and peat (F.H. Wilson, unpub.Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 125 Qm Glacial deposits Quaternary Glacial drift consisting of sand, gravel, and boulders. Includes ground, recessional, end, medial, and lateral moraine deposits; as well as colluvium, talus, landslide debris, alluvium, and silt, locally (Riehle and Emmel, 1980; F.H. Wilson, unpub. dataWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 126 Qm Glacial deposits Quaternary Glacial drift consisting of sand, gravel, and boulders. Includes ground, recessional, end, medial, and lateral moraine deposits; as well as colluvium, talus, landslide debris, alluvium, and silt, locally (Riehle and Emmel, 1980; F.H. Wilson, unpub. dataWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 127 Qm Glacial deposits Quaternary Glacial drift consisting of sand, gravel, and boulders. Includes ground, recessional, end, medial, and lateral moraine deposits; as well as colluvium, talus, landslide debris, alluvium, and silt, locally (Riehle and Emmel, 1980; F.H. Wilson, unpub. dataWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 130 Qag Drift of Neoglacial age Quaternary, Holocene Neoglacial terminal, recessional, lateral, and ground moraine consisting of unsorted boulders, cobbles, gravel and sand deposited during retreat of glaciers. Includes deposits of the Tunnel and Tustumena Stade (Detterman and Hartsock, 1966); Tunnel StadWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 131 Qao Outwash of the Neoglacial age Quaternary, Holocene Outwash deposits associated with modern and Holocene glaciers (Karlstrom, 1964; F.H. Wilson, unpub. data). Consist of poorly- to well-sorted silt, sand, and gravel in terraces and outwash fan plains (Detterman and Hartsock, 1966; Riehle and Emmel, 1980)Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 135 Qgn Glacial deposits of the Naptowne and Brooks Lake Glaciations Quaternary, Pleistocene Terminal, recessional, lateral, medial, and ground moraine and other deposits. Moderately weathered moraine along Cook Inlet shoreline; heavily spruce and brush covered (Detterman and Hartsock, 1966; F.H. Wilson, unpub. data). Internal contacts on westWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 136 Qgn Glacial deposits of the Naptowne and Brooks Lake Glaciations Quaternary, Pleistocene Terminal, recessional, lateral, medial, and ground moraine and other deposits. Moderately weathered moraine along Cook Inlet shoreline; heavily spruce and brush covered (Detterman and Hartsock, 1966; F.H. Wilson, unpub. data). Internal contacts on westWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 137 Qgn Glacial deposits of the Naptowne and Brooks Lake Glaciations Quaternary, Pleistocene Terminal, recessional, lateral, medial, and ground moraine and other deposits. Moderately weathered moraine along Cook Inlet shoreline; heavily spruce and brush covered (Detterman and Hartsock, 1966; F.H. Wilson, unpub. data). Internal contacts on westWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 138 Qgn Glacial deposits of the Naptowne and Brooks Lake Glaciations Quaternary, Pleistocene Terminal, recessional, lateral, medial, and ground moraine and other deposits. Moderately weathered moraine along Cook Inlet shoreline; heavily spruce and brush covered (Detterman and Hartsock, 1966; F.H. Wilson, unpub. data). Internal contacts on westWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 140 Qgno Outwash and valley train deposits Quaternary, Pleistocene Silt, sand, and gravel graded to moraines of Naptowne age (map unit Qgn) on the Kenai Peninsula (Karlstrom, 1964) and to Brooks Lake age moraines on the west side of Cook Inlet (F.H. Wilson, unpub. data) Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 190 Qog Older glacial deposits Quaternary, Pleistocene Included here are the prominent, but modified morainal deposits of the Knik and Eklutna Glaciations. These deposits are widely exposed north of Homer on the Kenai Peninsula (Karlstrom, 1964). On the Kenai Peninsula, moraines of Knik and Eklutna age areWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 194 Qog Older glacial deposits Quaternary, Pleistocene Included here are the prominent, but modified morainal deposits of the Knik and Eklutna Glaciations. These deposits are widely exposed north of Homer on the Kenai Peninsula (Karlstrom, 1964). On the Kenai Peninsula, moraines of Knik and Eklutna age areWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 195 Qogo Outwash associated with older glacial deposits Quaternary, Pleistocene Silt, sand, and gravel graded to moraines of Knik and Eklutna age on the Kenai Peninsula (Karlstrom, 1964) Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 200 Qch Moraine of the Caribou Hills Glaciation Quaternary, Pleistocene Highly modified morainal deposits in the Caribou Hills and exposed as remnant deposits elsewhere on the Kenai Peninsula (Karlstrom, 1964). These deposits are terraced below elevations of about 305 m (1,000 ft) and discontinuously mantled by proglacial lWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 201 Qch Moraine of the Caribou Hills Glaciation Quaternary, Pleistocene Highly modified morainal deposits in the Caribou Hills and exposed as remnant deposits elsewhere on the Kenai Peninsula (Karlstrom, 1964). These deposits are terraced below elevations of about 305 m (1,000 ft) and discontinuously mantled by proglacial lWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 560 Tkn Kenai Group Tertiary, Pliocene to Oligocene Coal-bearing clastic unit consisting of, in descending order, the Sterling, Beluga, and Tyonek Formations and Hemlock Conglomerate in the vicinity of Cook Inlet. According to Calderwood and Fackler (1972) unit is at least 8,000-m-thick in the subsurfaceWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 540 Ts Sterling Formation Tertiary, Pliocene and Miocene Weakly lithified massive sandstone, conglomeratic sandstone and interbedded claystone; includes interbedded lignitic coals typically less than 1-m-thick in the upper part of the unit, but may be as much as 3-m-thick in the lower part of the unit (CalderwWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 545 Tb Beluga Formation Tertiary, Miocene Nonmarine, interbedded, weakly lithified sandstone, siltstone, mudstone, carbonaceous shale, coal, and minor volcanic ash (Bradley and others, 1999). Calderwood and Fackler (1972) reported a distinctive feature of the Beluga Formation is its lack of masWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 600 Tty Tyonek Formation Tertiary, Miocene and Oligocene Nonmarine conglomerate and subordinate sandstone, siltstone, and coal within the map area as described by Bradley and others (1999). However, in general, the Tyonek Formation is identified by the presence of massive sandstone beds and lignitic to subbitWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 630 Th Hemlock Conglomerate Tertiary, Oligocene Sandstone, conglomerate, and siltstone assigned to this unit, as defined by Calderwood and Fackler (1972) occur only in the vicinity of Harriet Point in the Kenai quadrangle on the west side of Cook Inlet. On the basis of the description in Detterman anWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 855 Twf West Foreland Formation Tertiary, Eocene and Paleocene Exposed only on the west side of Cook Inlet, thin unit consists of tan to light-yellow-brown cobble conglomerate interbedded with lesser sandstone, laminated siltstone, and silty shale (Detterman and Hartsock, 1966). Thin coal beds are interbedded with Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1961Ksm Saddle Mountain section of Magoon and others (1980) Upper Cretaceous, Maastrichtian Nonmarine sandstone, conglomerate, and minor siltstone and coal found northeast of Chinitna Bay in a section 83-m-thick (Magoon and others, 1980). Consists dominantly of fine- to medium-grained sandstone that becomes finer grained upward. Unit is generWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3014Jnp Naknek Formation, Pomeroy Arkose Member Upper Jurassic, Kimmeridgian and Oxfordian? Massive light-gray, medium- to coarse-grained arkose containing many interbedded thin beds of dark-gray to brownish siltstone and pebble conglomerate (Detterman and Hartsock, 1966). The sandstone is rich in quartz (40-45 percent) and sodic feldspar (30-Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3013Jnst Naknek Formation, Snug Harbor Siltstone Member Upper Jurassic, Kimmeridgian and Oxfordian Dominantly massive to thin-bedded, dark-gray to black siltstone; calcareous gray sandstone beds are minor part of the unit (Detterman and Hartsock, 1966). Hard gray limestone concretions and lenses are locally abundant; rare thin layers of volcanic ash Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3012Jnn Naknek Formation, Northeast Creek Sandstone Member Upper Jurassic, Oxfordian Light-gray, thin-bedded to massive arkosic sandstone, graywacke, and siltstone. Originally called the "lower sandstone member" by Detterman and Hartsock (1966) who considered this unit to have only local significance. Later work on the Alaska PeninsulaWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3016Jnc Naknek Formation, Chisik Conglomerate Member Upper Jurassic, Tithonian to Oxfordian Consists of massive to thick-bedded conglomerate and interbedded, crossbedded, quartzose sandstone. Clasts, as large as 2 m, are mainly granitic rocks, but up to 20 percent metamorphic and volcanic rocks are present (Detterman and others, 1996). The unWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3020Jcp Chinitna Formation, Paveloff Siltstone Member Middle Jurassic, Callovian Consists of massive dark-gray arenaceous siltstone in the upper part and a thick sandstone unit at its base (Detterman and Hartsock, 1966). Large ellipsoidal concretions and lenticular beds of limestone occur throughout the unit and thin interbeds of saWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3030Jct Chinitna Formation, Tonnie Siltstone Member Middle Jurassic, Callovian Massive dark-gray to brownish-gray arenaceous siltstone, which weathers brownish-gray to red-brown (Detterman and Hartsock, 1966). Numerous small yellowish-brown weathering limestone concretions occur in parallel bands and randomly throughout the sectioWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3181Jtb Tuxedni Group, Bowser Formation Middle Jurassic, Callovian and Bathonian Heterogeneous assemblage of sandstone, conglomerate, shale and siltstone characterized by rapid facies changes (Detterman and Hartsock, 1966). Massive light- to dark-gray sandstone and conglomerate are the dominant lithologic types on the Iniskin PeninsWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3182Jtt Tuxedni Group, Twist Creek Siltstone Middle Jurassic, Bajocian Soft, poorly consolidated, thin-bedded to massive siltstone and silty shale as much 125-m-thick (Detterman and Hartsock, 1966). The siltstone is dark-gray, weathers to dark-rusty brown, and contains many thin beds of volcanic ash that weather a bright-oWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3183Jtc Tuxedni Group, Cynthia Falls Sandstone Middle Jurassic, Bajocian? Massive to thick-bedded graywacke sandstone and pebble conglomerate about 200-m-thick (Detterman and Hartsock, 1966). The sandstone is medium- to coarse-grained, greenish-gray to dark-green, has graded bedding and weathers mottled light-gray due to the Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3184Jtf Tuxedni Group, Fitz Creek Siltstone Middle Jurassic, middle Bajocian Thick sequence (up to 400-m-thick) of massive, bluish dark-gray, arenaceous, coarse- to fine-grained siltstone that commonly weathers rusty orange and contains many small limestone concretions (Detterman and Hartsock, 1966). Fine-grained sandstone and, Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3185Jtg Tuxedni Group, Gaikema Sandstone Middle Jurassic, lower middle Bajocian Resistant, cliff-forming, massive to thin-bedded graywacke sandstone and cobble conglomerate 150- to 260-m-thick (Detterman and Hartsock, 1966). Sandstone commonly occurs in graded beds up to 3-m-thick, whereas conglomerate is well-sorted within individWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3250Jtk Talkeetna Formation, undivided Lower Jurassic Bedded volcanic rocks widely distributed in the Seldovia and Kenai quadrangles west of Cook Inlet. Where undivided, unit consists of flows, breccia, tuff, and agglomerate and locally interbedded minor sandstone and shale, all typically somewhat altered Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3251Jtkh Talkeetna Formation, Horn Mountain Tuff Member Lower Jurassic Bedded tuff and tuffaceous feldspathic sandstone, locally containing porphyritic andesite flows. Bedded tuff is tan, red, green, purple, or mottled-color, thin-bedded to massive and fine- to coarse-grained (Detterman and Hartsock, 1966). Locally, tree Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3252Jtkp Talkeetna Formation, Portage Creek Agglomerate Member Lower Jurassic Reddish fragmental volcanic debris, primarily rounded volcanic bomb-like fragments and lapilli tuff grading to fine-grained tuff, clastic sedimentary rocks and flows northward in the map area (Detterman and Hartsock, 1966). Interbedded flows, tuff, and Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3253Jtkm Talkeetna Formation, Marsh Creek Breccia Member Lower Jurassic Massive dark-green to green volcanic breccia having a tuff matrix (Detterman and Hartsock, 1966). Consists of angular fragments of aphanitic pink and green volcanic rocks ranging in size from 1 cm to nearly 1 m and in general, fine upward. Interbedded Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3265Jp Pogibshi formation of Kelley (1980), undivided Lower Jurassic, Sinemurian to Hettangian and older? Informally named Pogibshi formation of Kelley (1980) is exposed on east side of Cook Inlet and consists of volcaniclastic rocks interbedded with small amounts of limestone, coal, and tuffaceous argillite. Kelley (1980) divided the unit into three memberWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 4019Trpg Port Graham formation of Kelley (1980) Upper Triassic; Norian Dominantly dark-gray, carbonaceous limestone and silty limestone containing varying amounts of silica cement (Kelley, 1980). Fine-grained, dark-gray siliceous to limy mudstone, silty sandstone, and dark-gray to dark-olive-gray, thin- to medium-bedded chWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 5220JPk Kakhonak Complex Jurassic, Triassic, and Permian(?) or older(?) The Kakhonak Complex, defined by Detterman and Reed (1980) is a lithologically diverse and complex assemblages of metamorphosed mafic plutonic, volcanic, and sedimentary rocks found on the west side of Cook Inlet. Detterman and Hartsock (1966) mapped "mWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 300 Qv Volcanic rocks, undivided Quaternary Andesite, dacite, and basalt lava flows, volcanic breccia, lahar deposits, and debris-flow deposits. Includes air-fall tuff, volcanic dome deposits, block-and-ash-flow deposits, ash-flow tuffs, volcanic-rubble flows, debris flows, and hot-blast avalanchWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 305 Qv Volcanic rocks, undivided Quaternary Andesite, dacite, and basalt lava flows, volcanic breccia, lahar deposits, and debris-flow deposits. Includes air-fall tuff, volcanic dome deposits, block-and-ash-flow deposits, ash-flow tuffs, volcanic-rubble flows, debris flows, and hot-blast avalanchWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 311 Qv Volcanic rocks, undivided Quaternary Andesite, dacite, and basalt lava flows, volcanic breccia, lahar deposits, and debris-flow deposits. Includes air-fall tuff, volcanic dome deposits, block-and-ash-flow deposits, ash-flow tuffs, volcanic-rubble flows, debris flows, and hot-blast avalanchWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 312 Qdf Debris-flow deposits Quaternary, Holocene Volcanic debris-flow and mudflow deposits from Redoubt Volcano in the Crescent River valley. Includes several small (older?) deposits in the upper valley and a 3,500-year-old debris flow in the lower valley (F.H. Wilson, unpub. data). The older depositWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 313 Qdf Debris-flow deposits Quaternary, Holocene Volcanic debris-flow and mudflow deposits from Redoubt Volcano in the Crescent River valley. Includes several small (older?) deposits in the upper valley and a 3,500-year-old debris flow in the lower valley (F.H. Wilson, unpub. data). The older depositWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 314 Qdf Debris-flow deposits Quaternary, Holocene Volcanic debris-flow and mudflow deposits from Redoubt Volcano in the Crescent River valley. Includes several small (older?) deposits in the upper valley and a 3,500-year-old debris flow in the lower valley (F.H. Wilson, unpub. data). The older depositWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 402 Qad Andesite and dacite domes Quaternary, Pleistocene Composite dome complex of Double Glacier Volcano consisting of medium- to coarsely porphyritic hornblende andesite and dacite. Three K-Ar andesite whole-rock ages were determined on these domes, two are considered minimum ages at 627ñ24 and 763ñ17 ka onWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1000Tvu Lava flows middle? to late? Tertiary A small exposure of dark-blue-gray to black, cryptocrystalline to vesicular basalt and andesite occurs on the mainland northwest of Chisik Island (Detterman and Hartsock, 1966) and is one of a number of scattered exposures in their map area. As describeWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1660TKgd Granodiorite Tertiary and [or] Cretaceous Medium-grained, hypidiomorphic granular, seriate granodiorite. Biotite tends to more abundant than hornblende. Occurs in the northwest corner of the Kenai quadrangle west of the Lake Clark fault and also in the adjacent Lake Clark quadrangle (Reed and Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2430Kqd Quartz diorite Cretaceous Locally foliated, largely medium-grained hornblende-biotite quartz diorite, but includes hornblende-pyroxene gabbro and diorite, quartz diorite, tonalite, and minor granodiorite (Magoon and others, 1976; Nelson and others, 1983; Reed and others, 1992). Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2900KJg Quartz monzodiorite Cretaceous and (or) Jurassic Medium-gray, medium-grained, hypidiomorphic granular hornblende-biotite quartz monzodiorite containing variable amounts of clinopyroxene located in the extreme northwest part of the Kenai quadrangle. Flow structures locally present and hornblende and plWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3380Jtr Alaska-Aleutian Range batholith,Trondhjemite Late Jurassic Medium- to coarse-grained, seriate, leucocratic trondhjemite containing 10 percent muscovite and about 5 percent interstitial, perthitic potassium feldspar. Occurs in two bodies in the Kenai quadrangle immediately west of Redoubt Volcano and in the headWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3404Jg Alaska-Aleutian Range batholith, Quartz diorite, tonalite, and diorite Jurassic Locally foliated medium-grained quartz diorite and tonalite; this is by far the dominant map unit of the Alaska-Aleutian Range batholith in this area. Hornblende is the primary mafic mineral, biotite increases in proportion to the presence of quartz andWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 4310Trdt Quartz diorite and tonalite Late Triassic In the Seldovia quadrangle, this unit includes the diorite of Point Bede and the tonalite of Dogfish Bay of Bradley and others (1999), both on the east side of Cook Inlet. The diorite of Point Bede of Bradley and others (1999) is fine- to medium-grainedWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3610Jsch Seldovia metamorphic complex Early Jurassic Marble, quartzite, garnet-mica schist, and glaucophane-bearing amphibolite whose protoliths were interpreted to consist of limestone, chert, argillite, and greenstone by Bradley and others, (1999). This unit occurs as narrow fault slices within the BordWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 565 QTy Yakataga Formation Quaternary, Pleistocene to Tertiary, Miocene "Consists of diverse marine and glaciomarine clastic rocks more than 1,670-m-thick on Kayak and Wingham Island and at least an additional 1,200-m-thick on Middleton Island (Plafker and Addicott, 1976). Much of the continental shelf between Middleton IslWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 675 Tr Redwood Formation Tertiary, Pliocene to Oligocene? Marine mudstone, siltstone, sandstone, and conglomerate (Winkler and Plafker, 1981). "Lower unnamed sandstone member consists of about two-thirds thick-bedded sandstone and one-third silty sandstone and siltstone. Upper Puffy Member is more diverse andWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 680 Tps Poul Creek Formation, Sedimentary rocks Tertiary, early Miocene to late Eocene "Concretionary, pyritic, glauconitic, reddish-weathering, dark-gray to greenish-gray siltstone, claystone, and sandstone; subordinate dark-brown, laminated shale that is rich in organic material, silty shale, and gray calcareous sandstone; locally includWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1080Tpv Poul Creek Formation, Volcanic rocks Tertiary, early Miocene to late Eocene "Basaltic pyroclastic and flow rocks, including minor pillowed lava flows; locally interbedded with marine sedimentary rocks, including tuffaceous or glauconitic strata, probably related genetically to mafic dikes, sills, and plugs unit (Tm)" (Winkler anWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 810 Tt Tokun Formation Tertiary, Eocene "Consists predominantly of concretionary siltstone and lesser, variable amount of interbedded sandstone, chiefly in lower part of formation. Thick sandstone beds exposed near Point Hey and on Kayak and Wingham Islands presumably correlate with lower parWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 860 Tkt Kulthieth Formation Tertiary, Eocene "Includes at least 1,500 m of interbedded, massive to thin-bedded, coal bearing arkosic sandstone, dark-gray to black carbonaceous siltstone and shale, and minor coal. Sandstone to shale ratios in measured sections of the Kulthieth Formation (Martin, 19Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 820 Tsw Stillwater Formation Tertiary, Eocene "Primarily consists of dense hard dark-gray siltstone. Where siltstone is carbonaceous, it has a coal-like appearance; where it is calcareous, it may be variegated from reddish brown to pale green and usually contains foraminifers" (Winkler and Plafker,Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 950 Tos Orca Group, Sedimentary rocks, undivided Tertiary, early middle Eocene to late Paleocene Thin- to thick-bedded graywacke sandstone, siltstone, mudstone, slate, and locally, minor conglomerate, which display abundant sedimentary structures, such as graded bedding, crossbedding, and ripple marks, along with flute, groove, and load casts, indicWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 952 Toc Orca Group, Conglomerate Tertiary, early middle Eocene to late Paleocene "Ranges from matrix-supported pebbly mudstone and sandstone to massive clast-supported pebble, cobble, and boulder conglomerate" (Nelson and others, 1985). Generally well-rounded clasts consist primarily of extrabasinal felsic volcanic and igneous rocksWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2700Kvs Valdez Group, Metasedimentary rocks, undivided Upper Cretaceous Dark-gray, thin- to thick-bedded, laumontite to mid-greenschist facies metamorphosed, moderately to poorly sorted sandstone, siltstone, and mudstone flysch; sandstone is fine- to coarse-grained and mainly composed of plagioclase, quartz, and igneous rockWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2702Kvvs Valdez Group, Interbedded metavolcanic and metasedimentary rocks Upper Cretaceous Approximately equal portions of interbedded metavolcanic and metasedimentary rocks (Winkler and Plafker, 1981; Nelson and others, 1985; Winkler and Plafker, 1993). Metavolcanic rocks include semischistose volcanic breccia, tuff, tuffaceous sediment, andWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2705Kvv Valdez Group, Metavolcanic rocks, undivided Upper Cretaceous Tholeiitic metabasalt, massive greenstone, and basaltic metatuff, including local pillow lava, pillow breccia, and gabbroic dikes and sills (Winkler and Plafker, 1993) in the Cordova quadrangle. Metabasalt forms rugged, nearly massive outcrops, whereas Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2706Kvt Valdez Group, Aquagene tuff Upper Cretaceous Metamorphosed aquagene tuff is green to dark-gray, fine-grained, and finely laminated containing plagioclase phenocrysts; metamorphosed to chlorite and biotite zones of greenschist facies; chlorite, epidote, and locally, actinolite are abundant; remnantsWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2710Kvgs Valdez Group, Schist Upper Cretaceous In the Valdez Group, schistose metamorphic rocks are found in two general modes of occurrence. In the Cordova quadrangle, Winkler and Plafker (1993) describe a "chiefly homogenous pelitic schist and minor amphibolite; [unit which] also includes spotted Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2715Kvgg Valdez Group, Gniess Upper Cretaceous "Muscovite-biotite-quartz-plagioclase (ñ sillimanite and garnet) schist, banded gneiss, and migmatitic gneiss; potassium-feldspar-bearing segregations in migmatite; many local intrusive stringers, dikes, and sills of granodiorite and granite; transitionaWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2708Kvm Valdez Group, M‚lange of Iceworm Peak of Kusky and others (1997) Upper Cretaceous Tectonic m‚lange consisting of blocks of graywacke in a phacoidally cleaved matrix of slate having a Valdez Group protolith for both matrix and blocks (Bradley and others, 1999; Bradley and Wilson, 2000). Mapped only in the Seldovia and Kenai quadrangleWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2190KMm McHugh Complex Cretaceous to Mississippian "M‚lange of siltstone, sandstone, mud-chip sandstone, conglomeratic sandstone, tuff, and less abundant gabbro, serpentinite, bedded chert, and pillow basalt; fine-grained sedimentary strata commonly streaked out; sedimentary and igneous rocks are broken Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2198KJms McHugh Complex, graywacke and conglomerate Early Cretaceous to Early Jurassic, Pliensbachian Consists of fault-bounded blocks of massive conglomerate and graywacke that range up to several kilometers in structural thickness (Bradley and others, 1999). Bradley and others (1999) reported that deformation has generally obliterated primary sedimentWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2199KTrmcMcHugh Complex, basalt and chert Early Cretaceous, Albian to Middle Triassic, Ladinian "Pillow and massive basalt, depositionally overlain by complexly folded and faulted radiolarian chert" (Bradley and others, 1999). Bradley and others (1999, citing a C.D. Blome, USGS written commun. of 1994) reported radiolaria in bedded chert ranging iWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 4880Mzg McHugh Complex, Gabbro Mesozoic Dark-green, medium- to coarse-grained gabbro and minor leucogabbro and plagiogranite (Bradley and others, 1999). Occurs as fault-bounded bodies in the McHugh Complex; following Bradley and others (1999), only the larger bodies are shown here; others areWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 4890Mzu McHugh Complex, Ultramafic plutonic rocks Mesozoic Predominantly layered, variably serpentinized dunite containing rare to locally abundant layers of chromite and pyroxenite and fault slices of garnet pyroxenite and serpentinite (Bradley and others, 1999). Bradley and others (1999) reported at least 7 fWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1053Tdc Dacite of Cape Saint Elias Tertiary, Pliocene or Miocene Described by Winkler and Plafker (1993) as follows: "Prominent very pale gray dacite plug complex that forms Cape Saint Elias and Pinnacle Rock at the southwestern end of Kayak Island (Plafker, 1974). Dacite is very dense and hard and is conspicuously Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1090Tm Mafic plugs Tertiary, Oligocene? Strongly altered dikes, sills, and plugs of diabase, alkalic basalt, olivine basalt, and lamprophyre, mostly on or near Kayak Island. Winkler and Plafker (1993) suggested these hypabyssal rocks were probably genetically related to extrusive volcanic rocWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1270Tg Granitic rocks Tertiary, Oligocene? and latest Eocene Plutons in the Seward quadrangle are dominantly light-gray, medium- to coarse-grained biotite ñhornblende granodiorite and granite stocks; larger stocks commonly grade inward from marginal zones containing more biotite (and locally hornblende) to more leWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1294Tgd Gabbro and diorite Tertiary, Oligocene and older Dominantly, dark-gray medium- to coarse-grained gabbro and subordinate diorite, both having finer grained borders of quartz gabbro and quartz diorite (Tysdal and Case, 1979; Nelson and others, 1985). Gabbro generally composed of subequal amounts of labrWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1300Tgg Granite and granodiorite Tertiary, Eocene Generally medium- and medium- to coarse-grained hypidiomorphic-granular biotite granite having border phases of biotite-hornblende granite, granodiorite, and tonalite (Nelson and others, 1985) located in the Cordova quadrangle. Also includes uncommon daWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1310Tgg Granite and granodiorite Tertiary, Eocene Generally medium- and medium- to coarse-grained hypidiomorphic-granular biotite granite having border phases of biotite-hornblende granite, granodiorite, and tonalite (Nelson and others, 1985) located in the Cordova quadrangle. Also includes uncommon daWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1320Tgh Granitic rocks of Harding Icefield region Tertiary, Eocene and Paleocene Primarily "medium- to dark-gray foliated medium- to coarse-grained biotite-muscovite-(hornblende) granite and granodiorite; marginal phases are locally biotite-muscovite-(hornblende) tonalite" (Tysdal and Case, 1979). Consists of a large batholith extenWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1135Tov Ophiolitic rocks of Prince William Sound, Volcanic rocks, undivided Tertiary, Eocene "Thick and thin tabular bodies of altered tholeiitic basalt consist of pillowed, massive, or crudely columnar flows, but also include pillow breccia, aquagene tuff, and diabase or gabbro sills; pillows have chilled margins that are palagonitic and amygdaWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1136Tov Ophiolitic rocks of Prince William Sound, Pillow basalt Tertiary, Eocene "Pale- to dark-green aphyric to porphyritic, frequently amygdaloidal, pillow basalt composed of plagioclase and clinopyroxene; plagioclase commonly replaced by albite and epidote, and clinopyroxene by hornblende, actinolite, and(or) chlorite; vesicles moWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 951 Tovs Ophiolitic rocks of Prince William Sound, Volcanic and sedimentary rocksTertiary, Eocene Consists of locally variable amounts of tholeiitic basalt, and tuffaceous and generally minor turbiditic sedimentary rocks (Winkler and Plafker, 1993; Nelson and others, 1985; Tysdal and others, 1976). The lithology is quite variable throughout the studWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 953 Tovs Ophiolitic rocks of Prince William Sound, Volcanic and sedimentary rocksTertiary, Eocene Consists of locally variable amounts of tholeiitic basalt, and tuffaceous and generally minor turbiditic sedimentary rocks (Winkler and Plafker, 1993; Nelson and others, 1985; Tysdal and others, 1976). The lithology is quite variable throughout the studWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1137Tod Ophiolitic rocks of Prince William Sound, Sheeted basalt dikes Tertiary, Eocene Mafic sheeted-dike complexes consisting of dark-green, gray, and brown, aphanitic to porphyritic; chiefly basaltic, but locally gabbroic to dioritic, dikes (Tysdal and others, 1977; Tysdal and Case, 1979). In the Knight Island area, felsic plagioclase-qWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1374Togb Ophiolitic rocks of Prince William Sound, Gabbro Tertiary, Eocene "Medium- and dark-gray to green coarse-grained chiefly clinopyroxene-plagioclase rocks with ophitic to subophitic texture and gabbroic to dioritic composition; locally pegmatitic with clinopyroxene crystals as much as 5 cm long; clinopyroxene commonly isWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1375Tou Ophiolitic rocks of Prince William Sound, Ultramafic rocks Tertiary, Eocene "Dunite, locally with layers of chromite, moderately to mostly altered to serpentine, serpentine-talc, and talc schist; lustrous pale- to dark-green and black, locally reddish weathering rock that forms dike-like and irregularly shaped intrusive bodies" Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1380Tmu Mafic and ultramafic plutonic rocks Tertiary, Eocene and Paleocene? "Compositionally and texturally variable unit consists mainly of clinopyroxene gabbro, two-pyroxene gabbro, and local diabase, hornblende gabbro, peridotite, and orthopyroxenite. Gabbro commonly is medium-grained and equigranular and is slightly to modeWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1011TKd Dikes early Tertiary to Early Cretaceous Dikes of dacite, rhyolite, andesite, and rare basalt intrude rocks of the Valdez Group (Kvs) and McHugh Complex (KMm) (Bradley and others, 1999). Analyzed samples of dikes yield a wide range of ages, as shown in Table 1. A basaltic-andesite dike intrudWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 1301TKd Dikes early Tertiary to Early Cretaceous Dikes of dacite, rhyolite, andesite, and rare basalt intrude rocks of the Valdez Group (Kvs) and McHugh Complex (KMm) (Bradley and others, 1999). Analyzed samples of dikes yield a wide range of ages, as shown in Table 1. A basaltic-andesite dike intrudWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 2401TKd Dikes early Tertiary to Early Cretaceous Dikes of dacite, rhyolite, andesite, and rare basalt intrude rocks of the Valdez Group (Kvs) and McHugh Complex (KMm) (Bradley and others, 1999). Analyzed samples of dikes yield a wide range of ages, as shown in Table 1. A basaltic-andesite dike intrudWilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 99 bu Bedrock unknown Unit does not appear on published map Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien 3186Jtg Tuxedni Group, Red Glacier Formation Middle Jurassic, lower Bajocian to lower middle BajocianThin-bedded to massive, red-brown weathering, dark-gray to moderate olive-gray, highly arenaceous siltstone, locally containing lenticular interbeds and concretions of reddish-gray, dense limestone and very minor coal seams (Detterman and Hartsock, 1966)Wilson, F.H., and Hults, C.P., in press, Geology of the Prince William Sound and Kenai Peninsula region, Alaska; Including the Kenai, Seldovia, Seward, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles: U.S. Geological Survey Scien