Theme: Geologic Map from USGS Branch of Alaska Geology Data Theme Name: GEOLOGY Coverage Pathname/Name(s): /fsfiles/ref/library/gis/chugach/geology Coverage Type: Polygon Coverage Geographic Extent and Projection: Chugach NF (Forest-wide); UTM Zone 6, NAD27 Source Media/Scale: paper map Manuscript Media/Scale: 1:250,000 Date of Source Data: 1985 Date of most recent update: 03/11/97 Source Agency/Organization: USGS Branch of Alaska Geology Digitization Method: Chugach NF staff using ARC/INFO Cell Size or Minimum Mapping Unit: Last Update/Maintenance Schedule: Known Problems, Technical Limitations, or Constraints (Accuracy): Remarks: Digitized from the Geologic Map of the Chugach National Forest, AK prepared by Steven W Nelson, JA Dumoulin, & Marti L Miller, 1985. <><><><> Data File and Item Definitions <><><><> Theme File Description Item Re- BEG WI O- TY DE ALT Item Description Name --------------- ----- DEF COL DE WI PE CI Name ---------------- GEOLOGY Geologic Map AREA 1 8 18 F 5 Polygon Area in Square Meters Polygons PERIMETER 9 8 18 F 5 Distance Around the Polygon in Meters GEOLOGY# 17 4 5 B 0 Coverage Feature Number - System Generated Page 1 of 3 GEOLOGY-ID 21 4 5 B 0 Coverage Feature ID - System Generated ============ THEME SPECIFIC INFORMATION FOLLOWS ============ GEO-CODE 25 4 4 I - CODE Geologic Feature Code Valid Codes 100 = Surficial deposits, undifferentiated 101 = Ice fields or Glaciers 102 = Water contacts (Lakes and Ocean) 220 = Yakataga Formation (Miocene) 230 = Redwood Formation (Miocene and Oligocene?) 235 = Sedimentary rocks, undivided Poul Creek Formation (Miocene, Oligocene, and Eocene) 240 = Tokun Formation (Oligocene and Eocene) 250 = Kulthieth Formation (Eocene) 255 = Stillwater Formation (Eocene) 270 = Conglomerate, Orca Group (Eocene? and Paleocene) 271 = Sedimentary rocks undivided, Orca Group (Eocene? and Paleocene) 272 = Tuffaceous sedimentary rocks, Orca Group (Eocene? and Paleocene) 320 = Volcanic rocks, undivided, Poul Creek Formation (Miocene, Oligocene, and Eocene) 330 = Pillow basalt, Orca Group (Eocene? and Paleocene) 331 = Pillow basalt and sedimentary rocks, Orca Group (Eocene? and Paleocene) 332 = Interbedded sedimentary and mafic volcanic rocks, Orca Group (Eocene? and Paleocene) 333 = Volcanic rocks, undivided, Orca Group (Eocene? and Paleocene) 334 = Sheeted dikes, Orca Group (Eocene? and Paleocene) 405 = Dacite of Cape Saint Elias (Miocene) 420 = Granite and qranodiorite (Oligocene) 421 = Gabbro and diorite (Oligocene) 422 = Miners Bay pluton (Oligocene) 423 = Mafic plugs (Oligocene) 440 = Granite granodiorite (Eocene) 455 = Felsic dikes (Eocene? and Paleocene?) <><><><> Data File and Item Definitions <><><><> Theme File Description Item Re- BEG WI O- TY DE ALT Item Description Name --------------- ----- DEF COL DE WI PE CI Name ---------------- GEOLOGY Geologic Map 470 = Gabbro, Orca Group (Eocene? and Paleocene) Polygons 471 = Ultramafic rocks, Orca Group (Eocene? and Paleocene) 510 = Sedimentary rocks, undivided, Valdez Group Page 2 of 3 553 = Ultamafic rocks, Valdez Group 554 = Interbedded volcanic and sedimentary rocks, Valdez Group 610 = Paragneiss, Valdez Group 611 = Greenstone, Valdez Group 650 = McHugh Complex melange GEO-TYPE 29 8 8 C - TYPE Geologic Feature Type Valid Codes Fresh = Fresh water (lakes) Glacier = Ice fields or Glaciers Km = McHugh Complex melange Kvg = Paragneiss, Valdez Group Kvgr = Greenstone, Valdez Group Kvs = Sedimentary rocks, undivided, Valdez Group Kvu = Ultamafic rocks, Valdez Group Kvvs = Interbedded volcanic and sedimentary rocks Valdez Group Qu = Surficial deposits, undifferentiated Salt = Salt water (ocean) Td = Dacite of Cape Saint Elias (Miocene) Tfd = Felsic dikes (Eocene? and Paleocene) Tg = Granite and qranodiorite (Oligocene) Tgd = Gabbro and diorite (Oligocene) Tgg = Granite granodiorite (Eocene) Tk = Kulthieth Formation (Eocene) Tm = Mafic plugs (Oligocene?) Tmb = Miners Bay pluton (Oligocene) Toc = Conglomerate, Orca Group (Eocene? and Paleocene) Tod = Sheeted dikes, Orca Group (Eocene? and Paleocene) Togb = Gabbro, Orca Group (Eocene? and Paleocene) Top = Pillow basalt, Orca Group (Eocene? and Paleocene) Tops = Pillow basalt and sedimentary rocks, Orca Group (Eocene? and Paleocene) Tos = Sedimentary rocks undivided, Orca Group (Eocene? and Paleocene) Tosv = Interbedded sedimentary and mafic volcanic rocks, Orca Group (Eocene? and Paleocene) Tots = Tuffaceous sedimentary rocks, Orca Group (Eocene? and Paleocene) Tou = Ultramafic rocks, Orca Group (Eocene? and Paleocene) Tov = Volcanic rocks, undivided, Orca Group (Eocene? and Paleocene) Tps = Sedimentary rocks, undivided, Poul Creek Formation (Miocene, Oligocene, and Eocene) Tpv = Volcanic rocks, undivided, Poul Creek Formation (Miocene, Oligocene, and Eocene) Tr = Redwood Formation (Miocene and Oligocene?) Ts = Stillwater Formation (Eocene) Tt = Tokun Formation (Oligocene and Eocene) Ty = Yakataga Formation (Miocene) <><><><> Data File and Item Definitions <><><><> Theme File Description Item Re- BEG WI O- TY DE ALT Item Description Name --------------- ----- DEF COL DE WI PE CI Name ---------------- GEOLOGY Geologic Map FNODE# 1 4 5 B 0 The Arcs's From-Node ID Arcs TNODE# 5 4 5 B 0 The Arc's To-Node ID LPOLY# 9 4 5 B 0 The Poly-ID on the Left Side of Arc Page 3 of 3 RPOLY# 13 4 5 B 0 The Poly-ID on the Right Side of Arc LENGTH 17 8 18 F 5 Length of the Arc in Meters GEOLOGY# 25 4 5 B 0 Coverage Feature Number - System Generated GEOLOGY-ID 29 4 5 B 0 Coverage Feature ID - System Generated ============ THEME SPECIFIC INFORMATION FOLLOWS ============ ARC-CODE 33 3 3 I - AC Geologic arc code Valid Codes 1 = Stratigraphic contact, certain 2 = Stratigraphic contact, approximate 4 = Normal fault, certain 5 = Normal fault, approximate 7 = Shoreline or riverbank 10 = Thrust fault, certain 11 = Thrust fault, approximate 15 = Ice contact (glacier limit) 51 = Concealed contact 52 = Concealed fault 53 = Concealed thrust fault 93 = Lineament 99 = Bounding line(neatline) of coverage