Geologic units containing breccia

Mineral Resources On-Line Spatial Data

Sedimentary breccia

A breccia (coarse-grained clastic rock composed of angular broken rock fragments held together by a mineral cement or a fine-grained matrix) formed by sedimentary processes

This category is also used for breccia.

Subtopics:
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Arizona

Cretaceous to Late Jurassic sedimentary rocks with minor volcanic rocks (Late Jurassic to Cretaceous): Sandstone and conglomerate, rarely forms prominent outcrops; massive conglomerate is typical near base of unit and locally in upper part. These deposits are nonmarine except in southeastern Arizona, where prominent gray marine limestone (Mural Limestone) forms the middle of the Bisbee Group. Sandstones are typically medium-bedded, drab brown, lithic-feldspathic arenites. Includes Bisbee Group (largely Early Cretaceous) and related rocks, Temporal, Bathtub, and Sand Wells formations, rocks of Gu Achi, McCoy Mountains Formation, and Upper Cretaceous Fort Crittenden Formation and equivalent rocks. (80-160 Ma)
Early Proterozoic metavolcanic rocks (Early Proterozoic): Weakly to strongly metamorphosed volcanic rocks. Protoliths include basalt, andesite, dacite, and rhyolite deposited as lava or tuff, related sedimentary rock, and shallow intrusive rock. These rocks, widely exposed in several belts in central Arizona, include metavolcanic rocks in the Yavapai and Tonto Basin supergroups. (1650 to 1800 Ma)
Early Tertiary to Late Cretaceous volcanic rocks (Late Cretaceous to Early Tertiary): Rhyolite to andesite and closely associated sedimentary and near-surface intrusive rocks; commonly dark gray to dark greenish gray or greenish brown. In the ranges west of Tucson, this unit includes thick welded ash-flow tuffs. Volcanic rocks of this unit are inferred to be derived from vents and volcanoes above magma chambers that solidified to form the granitic rocks of map unit TKg. These rocks are restricted to southeastern Arizona except for a small outcrop near Bagdad. (50-82 Ma)
Holocene to middle Pliocene basaltic rocks (Middle Pliocene to Holocene): Mostly dark-colored basaltic lava and cinders young enough that some original volcanic landforms are still apparent. Includes a small amount of andesite, dacite, and rhyolite. Rocks of this map unit are largely restricted to six areas widely distributed in Arizona: San Francisco and Uinkaret volcanic fields in northern Arizona (0-4 Ma); Springerville (0-4 Ma) and San Carlos (0-2 Ma) volcanic fields in east-central Arizona; and San Bernardino (0-1 Ma) and Sentinel (1-4 Ma) volcanic fields in southern Arizona. Rocks of this unit are also present in the extreme southwestern part of Arizona where they were erupted at the edge of the Pinacate volcanic field (0-2 Ma) in northwestern Sonora. (0-4 Ma)
Jurassic sedimentary and volcanic rocks (Jurassic): Sandstone and conglomerate derived from volcanic rocks with associated intermediate-composition lava flows, breccias, and tuffs. In southern Arizona this unit includes rocks of the Artesa sequence, Pitoikam Formation, Mulberry Wash volcanics, Rudolfo Red Beds, Recreation Red Beds, and Gardner Canyon Formation. In western Arizona it includes the Harquar Formation, rocks of Slumgullion, and related(?) unnamed units in the Kofa and Middle Mountains. This unit is characterized by maroon, brown, and purplish-gray volcanic-lithic sandstone and siltstone, with subordinate to abundant conglomerate, quartz-rich sandstone and sparse limestone. (150-170 Ma)
Late to middle Miocene basaltic rocks (Middle to Late Miocene): Mostly dark, mesa-forming basalt deposited as lava flows. Rocks of this unit are widely exposed south of Camp Verde (Hickey Formation basalts), in the Mohon Mountains north of Bagdad, "The Mesa" east of Parker, and at other scattered locations in western Arizona. Rocks of this unit were not tilted by middle-Tertiary normal faulting except in a narrow belt from north of Phoenix to the northwest corner of the state. (8-16 Ma)
Middle Miocene to Oligocene sedimentary rocks (Oligocene to Middle Miocene): Con-glomerate, sandstone, mudstone, limestone, and rock-avalanche breccia (sheet-like deposits of crushed rock) deposited and tilted during widespread normal faulting and basin development. Sediments, mostly conglomerate and sandstone, are commonly medium to dark brown, reddish brown, or brownish gray; younger strata are generally lighter colors. Most deposits are 20 to 30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona. (11-32 Ma)
Middle Miocene to Oligocene shallow intrusions (Oligocene to Middle Miocene): Generally very fine-grained, porphyritic rhyolite to dacite in small, irregular-shaped bodies formed as subvolcanic intrusions in volcanic fields of southern and western Arizona, or in concentrated zones of dikes in the Mohave and Black Mountains of northwestern Arizona. The unit consists of mafic tuff, breccia and shallow intrusions at Buell Park in northeastern Arizona. (14-35 Ma)
Middle Miocene to Oligocene volcanic and sedimentary rocks, undivided (Oligocene to Middle Miocene): Sequences of diverse volcanic rocks with abundant interbedded sedimentary rocks. (11-32 Ma)
Middle Miocene to Oligocene volcanic rocks (Oligocene to Middle Miocene): Lava, tuff, fine-grained intrusive rock, and diverse pyroclastic rocks. These compositionally variable volcanic rocks include basalt, andesite, dacite, and rhyolite. Thick felsic volcanic sequences form prominent cliffs and range fronts in the Black (Mohave County), Superstition, Kofa, Eagletail, Galiuro, and Chiricahua Mountains. This unit includes regionally extensive ash-flow tuffs, such as the Peach Springs tuff of northwestern Arizona and the Apache Leap tuff east of Phoenix. Most volcanic rocks are 20-30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona, but this unit includes some late Eocene rocks near the New Mexico border in east-central Arizona. (11-38 Ma)
Middle Proterozoic sedimentary rocks (Middle Proterozoic): Red-brown shale and sandstone, buff to orange quartzite, limestone, basalt, black shale, and sparse conglomerate. This unit includes the Grand Canyon Supergroup, Apache Group, and Troy Quartzite. These rocks were deposited in shallow marine, coastal nonmarine, and fluvial settings. (700-1300)
Moenkopi Formation (Early and Middle(?) Triassic): Dark red sandstone and mudstone; includes gypsum beds in northwestern Arizona; deposited on a low-relief coastal plain. (230-245 Ma)
Permian to Pennsylvanian sedimentary rocks (Pennsylvanian to Permian): Interbedded sandstone, shale, and limestone usually characterized by ledgy outcrops. Orange to reddish sandstone forms cliffs near Sedona. This unit includes Supai Group and Hermit Shale in northern Arizona and Naco Group in southern Arizona. It was deposited in coastal-plain to shallow-marine settings during time of variable and changing sea level. Rocks of this map unit in southern Arizona may be in part equivalent to Permian rocks of map unit P in central and northern Arizona. (280-310 Ma)
Pliocene to late Miocene basaltic rocks (Late Miocene to Pliocene): Mostly dark, inconspicuously flat, low-lying or mesa-forming basalt deposited as lava flows. Rocks included in this unit are located almost entirely in the large volcanic fields south and west of Flagstaff, in smaller fields in northwesternmost Arizona, and in the Hopi Buttes volcanic field on the Navajo and Hopi Indian Reservations north of Holbrook. Original volcanic landforms have been obscured by erosion. (4-8 Ma)
Pliocene to middle Miocene volcanic rocks (Middle Miocene to Pliocene): Rhyolite to andesite deposited as lava flows and related rocks associated with basaltic rocks of map units Tby and Tb. (2-12 Ma)

California

Carboniferous marine rocks, unit 6 (Northeastern Sierra Nevada) (Mississippian to Early Permian): Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Eocene marine rocks (Paleocene to Oligocene): Shale, sandstone, conglomerate, and minor limestone; in part Oligocene and Paleocene.
Miocene marine rocks and Franciscan schist (Cretaceous(?) to Miocene)
Miocene nonmarine rocks (Oligocene to Pleistocene): Sandstone, shale, conglomerate, and fanglomerate; in part Pliocene and Oligocene.
Oligocene nonmarine rocks, unit 2 (Central and Southern California) (middle Eocene to early Miocene): Sandstone, shale, and conglomerate; in part Miocene and Eocene.
Paleozoic marine rocks, undivided, unit 4 (Western Sierra Nevada) (Ordovician to Triassic): Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Plio-Pleistocene and Pliocene loosely consolidated deposits (Miocene to Pleistocene): Pliocene and/or Pleistocene sandstone, shale, and gravel deposits; in part Miocene.
Quaternary pyroclastic and volcanic mudflow deposits, unit 3 (Sutter Buttes) (Quaternary (1.5-2.5 Ma)): Quaternary pyroclastic and volcanic mudflow deposits.
Quaternary volcanic flow rocks, unit 1 (Cascade Volcanic Field) (Quaternary): Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.
Quaternary volcanic flow rocks, unit 1, questionably identified (Cascade Volcanic Field) (Quaternary): Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.
Quaternary volcanic flow rocks, unit 4 (Sutter Buttes) (Quaternary (1.5-2.5 Ma)): Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.
Silurian and/or Ordovician marine rocks, unit 4 (Northern Sierra Nevada) (Ordovician to Devonian): Sandstone, shale, conglomerate, chert, slate, quartzite, hornfels, marble, dolomite, phyllite; some greenstone
Tertiary nonmarine rocks, undivided (Paleocene to Pliocene): Undivided Tertiary sandstone, shale, conglomerate, breccia, and ancient lake deposits.
Tertiary pyroclastic and volcanic mudflow deposits, unit 3 (Pinnacles-Neenach) (Tertiary (22-24 Ma)): Tertiary pyroclastic and volcanic mudflow deposits.
Tertiary pyroclastic and volcanic mudflow deposits, unit 4 (Tranquillon-Obispo) (Tertiary (16-18 Ma)): Tertiary pyroclastic and volcanic mudflow deposits.
Tertiary pyroclastic and volcanic mudflow deposits, unit 5 (Southern California Basin) (Tertiary (8-25 Ma)): Tertiary pyroclastic and volcanic mudflow deposits.
Tertiary pyroclastic and volcanic mudflow deposits, unit 6 (Jacumba) (Tertiary (12-19 Ma)): Tertiary pyroclastic and volcanic mudflow deposits.
Tertiary pyroclastic and volcanic mudflow deposits, unit 7 (Southern Mojave Desert) (Tertiary (8-28 Ma)): Tertiary pyroclastic and volcanic mudflow deposits.
Tertiary pyroclastic and volcanic mudflow deposits, unit 8 (Northern Mojave Desert) (Tertiary (4-22 Ma)): Tertiary pyroclastic and volcanic mudflow deposits.
Tertiary volcanic flow rocks, unit 13 (Plush Ranch-Vasquez-Diligencia) (Tertiary (19-23 Ma)): Tertiary volcanic flow rocks; minor pyroclastic deposits.
Tertiary volcanic flow rocks, unit 14 (Tranquillon-Obispo) (Tertiary (16-18 Ma)): Tertiary volcanic flow rocks; minor pyroclastic deposits.
Tertiary volcanic flow rocks, unit 17 (Cascade Range) (Tertiary (2-24 Ma)): Tertiary volcanic flow rocks; minor pyroclastic deposits.
Tertiary volcanic flow rocks, unit 1 (Quien Sabe-Burdell Mountain) (Tertiary (9.5-13 Ma)): Tertiary volcanic flow rocks; minor pyroclastic deposits.
Tertiary volcanic flow rocks, unit 8 (Southern California Basin) (Tertiary (8-25 Ma; most near 15)): Tertiary volcanic flow rocks; minor pyroclastic deposits.
Upper Cretaceous marine rocks, unit 2 (Klamath Mountains) (late Early to Late Cretaceous): Upper Cretaceous sandstone, shale, and conglomerate

Colorado

Basalt flows and associated tuff, breccia, and conglomerate of late-volcanic bimodal suite (Phanerozoic | Cenozoic | Tertiary): Includes basalts of Hinsdale Fm in San Juan Mountains - Servilleta Fm in San Luis Valley and many other occurrences
Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates (Phanerozoic | Cenozoic | Tertiary): Includes several named units
South Park Fm (Phanerozoic | Cenozoic | Tertiary): Arkosic sandstone and shale, volcaniclastic conglomerate, and andesite flows and breccia

Connecticut

Talcott Basalt (Lower Jurassic): Talcott Basalt - Greenish-gray to black (weathers bright orange to brown), fine- to medium-grained, grading from basalt near contacts to fine-grained gabbro in the interior, composed of pyroxene and plagioclase with accessory opaques and locally olivine or devitrified glass. Pillows in many places; volcanic breccia with fragmentary pillows in others.

Idaho

Dacite to rhyolite (or rhodacite) ignimbrites; Eocene rhyodacitic cauldron complex; east-central Idaho, central Challis volcanic field (Eocene): Eocene mixed silicic and basaltic volcanic ejecta, flows and reworked debris.
Rhyolite, andesite, dacite, quartz latite; Oligocene to Eocene volcanics; northern Idaho; (Paleogene, possibly Oligocene): Lower Tertiary, possibly Oligocene, flows and tuffs of northern Idaho.
Rhyolite ot trachyte ignimbrites and flows; Pliocene felsic volcanics; eastern Snake River Plain and vicinity (Pliocene): Pliocene silicic welded tuff, ash, and flow rock; most common in southwestern Idaho.
Rhyolitic domes, flows, pyroclastic debris, and basalt flows; Early Pleistocene subvolcanic to volcanic features; eastern Snake River Plain (Early Pleistocene): Lower Pleistocene to Pliocene silicic volcanic units near the Snake Plain.
Trachyandesite, latite, trachybasalt flows, dikes, and volcaniclastic debris; Eocene intermediate volcanics; central Idaho, southern Challis volcanic field (Eocene): Eocene mixed silicic and basaltic volcanic ejecta, flows and reworked debris.

Illinois

Middle Devonian (Devonian): Middle Devonian
Upper Valmeyeran (Aux Vases, Ste. Genevieve, St. Louis) Series (Mississippian): Upper Valmeyeran (Aux Vases, Ste. Genevieve, St. Louis) Series

Massachusetts

Belchertown Complex (Devonian): Belchertown Complex (intrudes De) - Intrusive breccia, mafic and ultramafic fragments in quartz diorite matrix.
Mattapan Volcanic Complex (Proterozoic Z or younger): Mattapan Volcanic Complex - Rhyolite, melaphyre, agglomerate, and tuff. Mattapan Volcanic Complex is found in west and southwest part of Boston basin and beyond, and to the south in Blue Hills. Similar in lithology to Lynn Volcanic Complex. Both units consist largely of partly porphyritic rhyolite and rhyodacite flows, welded ash-flow tuffs, vitric tuff, lapilli tuff, lithic tuff, flow breccias, breccia pipes, and extrusion domes. Mattapan's rhyolite and rhyodacites are thinner and less varied in composition and texture than Lynn's, and volcanic breccias are absent in Lynn. Both units are reported to lie nonconformably on Dedham Granite and unnamed plutonic-volcanic complex of eastern MA; however, Mattapan has been observed as dikes and stocks cutting Dedham Granite (Billings, 1976; Kaye and Zartman, 1980; Chute, 1966), and other workers have pointed out evidence that some of Mattapan may be penecontemporaneous with younger phases of Dedham batholith. Westwood Granite may be intrusive equivalent of Mattapan. Mattapan is conformably and fairly continuously overlain by Roxbury Conglomerate of Boston Bay Group. LaForge (19832) cautioned against identifying rocks interbedded within Mattapan that look like Roxbury, but are still part of Mattapan. Metavolcanic rocks in Blue Hills resembling Mattapan are assigned to Mattapan on State bedrock map (Zen and others, 1983); for years they were considered to be either Silurian and Devonian, or Carboniferous; however, they are chemically and mineralogically distinct from Ordovician and Silurian Blue Hills [sic] Granite Porphyry. Author follows usage of Chute (1966) who could find no difference between volcanic rocks in Blue Hills area and Mattapan rocks, and thus these rocks are assigned to Mattapan. Proterozoic Z age is based on U-Th-Pb zircon date of 602 +/-3 Ma (Zartman, in Kaye and Zartman, 1980). Although Billings (1979) questions reliability of zircon ages from volcanic rocks, discovery of Proterozoic Z acritarchs in overlying Cambridge Argillite indicates zircon age is appropriate (Goldsmith, 1991).
Silicified fault-breccia or strongly silicified metamorphic rocks (Lower Jurassic): Silicified fault-breccia or strongly silicified metamorphic rocks.

Maine

Cretaceous intrusive breccia (Cretaceous ): Cretaceous intrusive breccia
Ordovician Shin Brook Formation (Ordovician): Ordovician Shin Brook Formation

Montana

Devonian, undifferentiated (Phanerozoic | Paleozoic | Devonian): Devonian, undifferentiated: comprises Three Forks formation consisting of carbonaceous and calcareous shale with some sandstone and limestone, Jefferson limestone, and unnamed units of Devonian age.

New Hampshire

Moat Volcanics (Middle Jurassic?): Moat Volcanics - Bedded and ignimbritic tuffs, flows, and breccias; also porphyritic rhyolite and minor trachyte.

Nevada

Dolomite (Silurian to Early Devonian): DOLOMITE-Includes units such as Laketown and Lone Mountain Dolomites. Locally includes rocks of Early Devonian age at top.

Oregon

Fisher and Eugene Formations and correlative rocks (Oligocene and upper Eocene) (Late Eocene to Oligocene): Thin to moderately thick bedded, coarse- to fine-grained arkosic and micaceous sandstone and siltstone, locally highly pumiceous, of the marine Eugene Formation; and coeval and older andesitic lapilli tuff, breccia, water-laid and air-fall silicic ash of the continental Fisher and Colestin Formations; upper parts of the Fisher Formation apparently lap onto and interfinger with the Eugene Formation. Megafauna in the Eugene Formation were assigned an Oligocene age by Vokes and others (1951) and foraminifers have been assigned to the upper part of the lower Refugian Stage (McDougall, 1980), or of late Eocene age. Basalt lava flows in the Fisher Formation have yielded isotopic ages as old as 40 Ma (Lux, 1982), and south of the latitude of Cottage Grove the Fisher is overlain by a welded tuff in unit Tu dated at about 35 Ma. North of Eugene, rocks of this unit are overlain unconformably by continental volcanogenic rocks of unit Tu, including an ash-flow tuff with a K-Ar age of 30.9 +/- 0.4 Ma
Mafic vent complexes (Miocene) (Miocene): Intrusive plugs and dike swarms and related near-vent flows, breccias, cinders, and agglutinate of basaltic andesite, basalt, and andesite; commonly in the form of eroded piles of red, iron-stained thin flows, cinders, and agglutinate cut by mafic intrusions
Siletz River Volcanics and related rocks (middle and lower Eocene and Paleocene) (Paleocene to Middle Eocene): Aphanitic to porphyritic, vesicular pillow flows, tuff-breccias, massive lava flows and sills of tholeiitic and alkalic basalt. Upper part of sequence contains numerous interbeds of basaltic siltstone and sandstone, basaltic tuff, and locally derived basalt conglomerate. Rocks of unit pervasively zeolitized and veined with calcite. Most of these rocks are of marine origin and have been interpreted as oceanic crust and seamounts (Snavely and others, 1968). Foraminiferal assemblages referred to the Ulatisian and Penutian Stages (Snavely and others, 1969); K-Ar ages range from 50.7 +/- 3.1 to 58.1 +/- 1.5 Ma (Duncan, 1982); includes the lower part of the Roseburg Formation of Baldwin (1974), which has yielded K-Ar ages as old as 62 Ma

Rhode Island

Scituate Igneous Suite - volcaniclastic rock (Devonian): Scituate Igneous Suite - volcaniclastic rock - Dark-gray, pink, greenish, and purplish tuff and epiclastic rock (sandstone, breccia, conglomerate) containing abundant volcanic detritus. Tuff may include ignimbrite and ash-flow tuff. Fiamme common in some rock mapped formerly as Spencer Hill Volcanics.

Texas

Chinati Mountains caldera volcanic rocks, including Chinati Mountains Group, Mitchell Mesa Ignimbrite, and type area of Petan Basalt (Phanerozoic | Cenozoic | Tertiary | Oligocene): Chinati Mountains caldera volcanic rocks, including Chinati Mountains Group, Mitchell Mesa Ignimbrite, and type area of Petan Basalt
Eagle Mountains caldera volcanic rocks (Phanerozoic | Cenozoic | Tertiary | Oligocene): Eagle Mountains caldera volcanic rocks
South Rim Formation from Pine Canyon Caldera (Phanerozoic | Cenozoic | Tertiary | Oligocene): South Rim Formation from Pine Canyon Caldera
Van Horn Mountains caldera volcanic rocks (Phanerozoic | Cenozoic | Tertiary | Eocene): Van Horn Mountains caldera volcanic rocks
Vieja Group, including Bracks Rhyolite, Chambers and Colmena Tuffs and Gill Breccia (Phanerozoic | Cenozoic | Tertiary | Eocene Oligocene): Vieja Group, including Bracks Rhyolite, Chambers and Colmena Tuffs and Gill Breccia

Virginia

Interlayered Mafic and Felsic Metavolcanic Rocks - Foliated felsite (Cambrian): Interlayered Mafic and Felsic Metavolcanic Rocks - Foliated felsite
Newark Supergroup; Breccia, mixed clasts (Upper Triassic): Breccia, mixed clasts

Vermont

Bascom Formation, and undifferentiated Luke Hill, Naylor Ledge and Hastings Creek Limestones (Ordovician): Bascom Formation, and undifferentiated Luke Hill, Naylor Ledge and Hastings Creek Limestones - Interbedded dolomite, limestone or marble, calcareous sandstone, quartzite and limestone breccia; irregular dolomitic layers, thin sandy laminae, and slaty or phyllitic partings characterize limestone and marble of lower, middle, and upper parts of the Bascom, respectively; south of West Rutland it includes some of the Chipman formation. The combined Luke Hill, Naylor Ledge, and Hastings Creek, east of Philipsburg thrust, are stratigraphically equivalent to the Bascom.

Washington

Cambrian limestone and dolomite (Early Cambrian-Middle Ordovician): Mostly massive dolomite, with a basal unit of gray to dark-gray limestone interbedded with limy shale, and an upper unit of fine-grained massive limestone with some marble; Pend Oreille and northern and central Stevens Counties. Three-fold division less evident in Colville area. Dolomite, with minor basal unit of interbedded limestone and phyllite in the Addy-Dunn Mountain area of Stevens County. Marble, dolomite, limestone, and limy slate in Hunters' district. Dolomitic marble in southern Stevens and northern Lincoln Counties. Middle Cambrian fossils near base in Metaline district, and Bathyuriscus-Elrathina fauna in lower unit in Leadpoint district. Phosphatic brachiopods in upper unit in Leadpoint district tentatively assigned to Middle and Upper Cambrian.
Lower upper Eocene marine and nonmarine rocks (Eocene): Predominantly massive to well-bedded tuffaceous marine siltstone with interbedded arkosic and basaltic sandstone. Includes conglomerate in King County and along north side of Olympic Peninsula. Minor lava flows and breccia in western Lewis County and eastern Grays Harbor County. Coal seams in central Lewis County and north-central Pierce County.
Oligocene nonmarine rocks (Oligocene): Andesite conglomerate, tuff beds, and mudflow material. Includes some interbedded andesite flows in Columbia River Gorge. Lake sediments with Oligocene flora in Republic area in Ferry County. Massive tuffaceous sandstone and siltstone with beds of coal and high-alumina clay in Castle Rock-Toledo coal district in Cowlitz and Lewis Counties; include local interbedded basalt flows and some marine and late Eocene rocks.
Oligocene volcanic rocks (Oligocene): Andesite and rhyodacite flows, tuff, and tuffaceous sandstones of northern Lincoln County and southwestern Stevens County.
Tertiary nonmarine rocks, undivided (Tertiary; mostly Eocene): Sandstone, shale, conglomerate, agglomerate, and tuff; includes some lava flows. Massive conglomerate, sandstone, siltstone, and ferruginous shale in northwestern Whatcom County.