Dolan Fire Monterey Ranger District Los Padres N.F. October 9, 2020

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Burned Area Emergency Response (BAER) Assessment FINAL Specialist Report – GEOLOGIC HAZARDS

Jonathan Yonni Schwartz – Geomorphologist/Geologist, Los Padres NF

Introduction: The Dolan Fire started on August 18, 2020 and was 98% contained as of October 8, 2020. The fire burned on the Monterey Ranger District of the Los Padres NF, as well as across the Fort Hunter Liggett military reserve camp, State Parks, County and private properties. Out of a total of 124,327 acres, 82,311 acres burned on National Forest Lands, 29,063 acres burned on the Fort Hunter Liggett military camp lands, 1,880 acres were burn on State Park lands and 11,074 acres burned on private lands. Out of a total of 124,327 acres, 12,362 acre were high soil burn severity (10%), 56,257 acres were moderate soil burn severity (45%), 45,047 acres were low soil burn severity (36%) and 10,688 acres were very low soil burn severity or unburned (9%). The unburned acres refer to unburned areas within the fire perimeter (Figure 1). This report describes and assesses the increase in risk from geologic hazards within the Dolan Fire burned area.

1. Objectives: When evaluating Geologic Hazards, the objectives of the “Geology” function on a BAER Team are identifying the geologic conditions and geomorphic processes that have helped shape and alter the watersheds and landscapes, and assessing the impacts from the fire on those conditions and processes that potentially could affect downstream values at risk (VAR’s). The fire removed vegetation that helps keep slopes and drainages intact, changed the structure and erosiveness of the soil, and altered the stability of the landscape. Using the understanding of rock types and characteristics, geomorphic processes, and distribution of geologic hazards helps predict how the watersheds will respond to and be impacted by upcoming storms.

2. Initial Concerns:

Human Life and Safety: • People living, working, traveling or recreating through and below burned areas – Loss of life or injury could take place as a result of debris slides, debris flows, rock- fall, or flooding in and downstream of the burn area.

Property: • Forest Service roads, trails and campgrounds, CA Hwy 1, State Parks roads, trails and other facilities, County roads, private access roads – As a result of the fire, excessive runoff and flows are expected, stability of slopes over roads, trails and other facilities is compromised. Debris slides, debris flows, rock-fall, and flooding could cause damage to these systems. • Residential houses and other structures, water systems, and other properties - As a result of post-fire conditions, excessive runoff and sheet flows are expected, stability of slopes is compromised. Debris flows, rock-fall, and flooding could cause damage to this infrastructure.

Natural Resources: • The Wildlife- Fisheries BAER Assessment evaluated risks to four federally-listed fish and wildlife Values at Risk which could potentially be impacted by the fire or by post-fire effects; 1) California condors, 2) SCCC Steelhead DPS and designated critical habitat, 3) California red-legged frog and designated critical habitat, and 4) Smith’s blue butterfly. It was determined that the fire could potentially impact all of these species in various ways. • Landslides, debris flows, and mass wasting events have potential to impact populations of steelhead and California red-legged frogs and their critical habitat either directly or indirectly. Direct impacts could include injury or mortality, while indirect effects include degraded suitable or critical habitat conditions, degraded water quality, or habitat alteration resulting from increased sediment loads deposited in the creek channels by debris flows or landslides. • Smith’s blue butterfly are likely at greater risk of direct or indirect impacts to individuals or habitat due to landslides or mass wasting events. Suitable habitat for the species occurs along the western slope of the frontal range of mountains, on both sides of Hwy 1, and may be negatively impacted by mass wasting and landslides which are common in this steep terrain following wildfires. • Risks to condors are primarily related to direct effects from the fire itself, and the cumulative impacts of large recurring wildfires on roosting habitat. They are unlikely to be impacted by geological-related events.

Cultural Resources: • The burn area is prehistorically attributed to the Salinan and Esselen tribes who occupied the area prior to European contact and settlement. In the mid-eighteenth century this area began to be influenced by Spaniards and later Euro- Americans. Mission San Antonio de Padua (1771), is located only 1 mile from the fires most eastern extent.

• Initial concerns include adverse effects to numerous site types representing both prehistoric and historic periods. Most site types are prehistoric and include rock art, intact midden deposits, lithic production sites, milling stations, and habitation sites. Historic era sites are represented by the Spanish mission period and early homesteading with associated grazing and agriculture as well as early forest preserve and forest service management.

• Of immediate concern is identifying cultural resources at risk resulting from a reduction in surface vegetation and compromised soil structure by deteriorated post-fire conditions. Surface and subsurface cultural depositional context that has vital scientific or interpretation values may be altered or lost by increased runoff, erosion, and debris flows during inclement weather within deteriorated watersheds. Increase in runoff and debris, can also expose cultural resources, subjecting them to risk from vandalism and theft.

Figure 1: Soil Burn Severity map of the Dolan Fire area

3. Resource Condition Assessment:

Resource Setting –

Physiology and climate: The Dolan Fire occurred in the Santa Lucia Mountain Range, within the Coast Ranges geomorphic province. The Santa Lucia Mountain Range is about 140 miles long, extending from Carmel in the north (Monterey County) to the Cuyama River in the south (San Luis Obispo County). The physiography of the Santa Lucia mountains is characterized by northwest-trending, steep-sided, sharp-crested ridges that paralleling the numerous faults that transect the area and are separated by youthful V-shaped valleys (Pearson and Fillo, 1967). All associated watersheds flow directly or indirectly into the Pacific Ocean. The topography is complex, reflecting active uplift and deformation, a variety of lithological types, rapidly incising stream networks and highly unstable slopes. Stream channels and hillslopes are very steep, with average hillslope gradients exceeding 60% in some sub-watersheds. The coastal side of the range rises directly from the shoreline, with oceanfront ridges rising directly 4,000 to 5,000 feet to the crest ridge.

The climate gradient in the range is likewise extreme, reflecting the coastal position and steepness of the range. The coastal ridge may exceed 100 inches of rainfall during the winter wet season, while the eastern portions of the area may average less than 20 inches of annual precipitation. This drastic climate gradient is due to the rain shadow effect of the range, which blocks the prevailing southwesterly approach of most Pacific cyclonic storms. Little to no precipitation occurs throughout the range during the dry summer and fall seasons under the prevailing Mediterranean climate.

Bedrock Geology and Structure: The basement rocks of the Santa Lucia Range, within the burned area are predominately comprised of Paleozoic Salinia Block (“Salinian Block”) metamorphics. Other rocks in the area, to a lesser degree, include: Cretaceous Great Valley Group, Mesozoic Franciscan rocks, and alluvium (Figure 2).

The Salinian block is made up of highly fractured, and deeply weathered meta-sediments, especially biotite schist and gneiss, intruded by plutonic (granitic) rocks such as quartz diorite and granodiorite.

The Great Valley Group is an ancient forearc system that is comprised of mudrock, sandstone, and conglomerate that preserve a record of Farallon-North American plate convergence throughout the Cretaceous period (Surpless, 2014).

The Franciscan complex is composed of greywacke sandstone and greenstone, with serpentinite bodies and other ultramafics present. Isolated areas of marble and limestone form resistant outcrops that are prominent landscape features, usually white to light gray in color.

Surficial Geology: Steep slopes within the metamorphic rocks indicate that the un-weathered rock beneath the surface soils is not deeply weathered. However, within the granitic rocks, the slopes can be very steep even though the underlying granitic bedrock is deeply weathered. Road cuts in these granitics can usually be cut very steep, such as 1/4:1 to vertical without becoming unstable. Quaternary to recent landslide scarps and deposits are common in many areas within the burned area. Alluvial or debris flow deposits are preserved in a few areas, although little valley-fill has accumulated in the steep, narrowly incised canyons. In many drainages, deposits from previous floods and debris flows have been washed of finer sediments, leaving large boulders and cobbles exposed.

The burned area has been disrupted and tectonically slivered by Quaternary motion on the San Andreas fault zone. The Sur, McWay, Coast Ridge, Nacimiento, Junipero Serra and Arroyo Seco faults are prominent Quaternary features influencing the linear NW/SE alignment of primary drainages. These and most other smaller faults create a NW-SE trend to the predominant topography, paralleling the larger and controlling Rinconada and San Andreas faults to the NE. When rain saturated soils are shaken by earthquake activity, the cumulative effect can result in liquefaction and additional slope movements, including rotational and translational landslides and debris flows.

Geomorphic Processes and Landforms

Numerous “landslide” features are mapped on the geologic map of the burned area, however most of those are mostly old rotational slide features which are not likely to re-mobilize. Numerous more recent debris slides surface failures and thin soil slips were observed during the helicopter flights (Photo 1). Movement downslope of “dry ravel” increased over background levels immediately after slopes burned (Photo 2) in many areas, prior to any precipitation. Those slope movements contribute excess stored (loose) material on steep slopes and on roads and trails, available to contribute to further erosion and bulking of debris flows, flood events and stream channels.

Debris flows are the most frequent and destructive mass movements which will impact the downstream reaches of this fire. Recent debris flow deposits were observed in some of the canyons draining directly into the Pacific Ocean (crossing Hwy 1), and in some drainages crossing the Indians – Arroyo Seco road (Photo 3). It is important to consider how recently and how frequently past fires have occurred, and when possible, how soon after those fires major storms or wet periods have occurred. In general, the more frequently an area experiences a significant burn, the more likely that surface soils are thinner and have less material available for transport downslope and downstream. Numerous debris flows were reported following the 1972 Molera Fire, the Marble Cone Fire of 1977, the Basin/Indians Complex of 2008, and the 2016 Soberanes Fire. Debris flows

can occur within any of the geologic formations/rock types, but are most likely to occur where slopes are steep, soil and rock material is loose, supporting vegetation has been removed, burn severity is high, abundant rock material is available for transport, soils are saturated, and storm events are intense.

Rockfall is another common destructive form of mass movement which will be exacerbated by the effects of fire. Many of the steep granitic slopes of this fire area are deeply weathered with few outcrops of solid rock. However, some of the steeper slopes denuded of vegetation by the Dolan Fire now reveal rocky slopes which can create hazardous rockfall. Immediately after the burn occurred and since then, numerous roads have been impacted by rockfall, including Hwy 1, the Nacimiento – Fergusson road and other interior roads (Photo 4).

Figure 2: Geology map of the Dolan Fire area Detail legend for the Geology Map is in Appendix A

Photo 1 – Surface failures / erosion along Hwy 1

Photo 2 – Post fire ‘dry ravel’ loading channels and impacting roads 7

Photo 3 – Debris Flow deposit along the Indians - Arroyo Seco road

Photo 4 – Post fire rock-fall impacting the Indians - Arroyo Seco road

Burned Area Reconnaissance –

Reconnaissance of the burn area was rapid and included for the most case ground surveys and a flight recon. Ground surveys were mostly focused on watershed burned on the west end of the fire along Hwy 1 and in some interior areas along the Indians – Arroyo Seco road. Assessment of these areas included identification of Values At Risk (VAR’s) in and downstream of the burn area, identification of pre-fire slope failures and pre-fire slope and channel failure deposits, measurements of slopes, identification of geological units, field verification of soil burn severity, notes of observations and photography. In addition to ground and air reconnaissance, a review of published geologic maps and articles and study of aerial photography imagery was conducted.

USGS Debris Flow Assessment:

In order to assess the probability and potential volumes of debris flows in the burned area the assistance of the US Geological Survey (USGS) - Landslide Hazards Program was obtained. Their ongoing research has developed empirical models for forecasting the probability and the likely volume of such debris flow events. To run their models, the USGS uses geospatial data related to basin morphometry, burn severity, soil properties, and rainfall characteristics to estimate the probability and volume of debris flows that may occur in response to a design storm (Staley, 2013). Estimates of probability, volume, and combined hazard are based upon a design storm with a peak 15-minute rainfall intensity of 12 – 40 millimeters per hour (mm/h) rate. After receiving the final Dolan Fire burn severity map, the USGS conducted a debris flow assessment of the fire area that presented debris flow hazard classes, probability of occurrence, and volumes of materials occurring for multiple precipitation events. We selected a design storm of a peak 15-minute rainfall intensity of 24 millimeters per hour (mm/h) rate to evaluate debris flow potential and volumes, since based on the NOAA Atlas 14 Point Precipitation Frequency Estimates, this magnitude of storm seems likely to occur in any given year.

Debris flow probability and volume were estimated for each basin in the burned area as well as along the upstream drainage networks, where the contributing area is greater than or equal to 0.02 km², with the maximum basin size of 8 km².

Kean et al. (2013) and Staley et al. (2016) have identified that rainfall intensities measured over durations of 60 minutes or less are best correlated with debris-flow initiation. It is important to emphasize that local data (such as debris supply) influence both the probability and volume of debris flows. Unfortunately, local specific data are not presently available at the spatial scale of the post-fire debris-flow hazard assessment done by the USGS. As such, local conditions that are not constrained by the model may serve to dramatically increase or decrease the probability and (or) volume of a debris flow at a basin outlet.

Findings of the On-The-Ground Survey -

Watersheds that were impacted by the Dolan Fire include: eight (8) HUC 7 coastal watersheds on the west side of the burn area, all flowing directly to the Pacific Ocean and three (3) HUC 6 inland watershed flowing east. The 8- HUC 7 coastal watersheds located on the west side of the burn area include: McWay Canyon Frontal, Hot Springs Canyon Frontal, Big Creek North Fork, Devils Canyon, Vicente Creek, Limekiln Creek/Hare Canyon Frontal, Mill Creek Frontal and Prewitt Creek Frontal. The 3- HUC 6 inland watersheds on the east side of the burn area include: Arroyo Seco River, San Antonio River and Nacimiento River (Figure 3).

Figure 3: Watersheds in the Dolan Fire area

During ground surveys and a flight recon, evidence of widespread mass wasting, rock-fall and landslides, were observed throughout the burned area. From a flight recon and on-the-ground observations it is evident that some slopes and drainages within the Dolan Fire burned area are loaded with unsorted, unconsolidated materials available to be transported, while other slopes and drainages lack surface rocky materials. Depending on the parent material / geological unit, some

slopes and drainages are loaded with a thick layer of mostly fine sediments, while other slopes and drainages are loaded with unsorted / unconsolidated materials comprised of rocks of all sizes including boulders, cobbles, gravel and fine sediments. In addition to the fact that many of the burned slopes in the fire area experienced a moderate to high soil burn severity (see Figure 1), many of these same slopes are very steep (60+%) slopes (Figure 4).

Figure 4: Slope in percentage (%) map of the Dolan Fire area

Based on our surveys, Values At Risk (VAR’s) that were identified in and downstream of the burn area included:  Forest Service roads: 19S09 (Indians – Arroyo Seco rd.), 20S05 (North Coast Ridge rd. & Cone Peak rd.), 22S01 (Nacimiento – Fergusson rd.), 22S04 (Prewitt Ridge rd.), and 22S05 (South Coast Ridge rd.).  Forest Service recreation trails: Seventeen (17) system trails where identified within or near the Dolan Fire perimeter.

 Forest Service developed and primitive back-country campsites, include: Seventeen (17) primitive back-country camps, six developed campgrounds, and one developed day use area, which include the Nacimiento Campground, Ponderosa Campground, Escondido Campground and the Arroyo Seco Day Use Area.  Natural Resources include for the most case four federally listed fish and wildlife species that were impacted by the fire or might be impacted by post fire conditions negatively impacting their habitat.  Cultural Resources including adverse effects to numerous site types representing both prehistoric and historic periods.

Other VAR’s off Forest Service lands, in and down-stream of the burn area include:  State, County and private roads: Among them Hwy #1, the Nacimiento – Fergusson road and many private roads accessing homes and other private properties.  State Parkes: infrastructure and trails in the Julia Pfeifer Burns State Park and the Limekiln State Park.  Private properties and infrastructure including the Big Creek Reserve, private properties, homes and infrastructure.

Depended on the specific location of these VAR’s, some of these VAR’s might be impacted by various types of slope failures as landslides and/or rock-fall, while others might be impacted by hyper-concentrated flows and/or debris flows.

Based on an air recon and ground surveys it is evident that this country is naturally unstable, subject to failure even in the absence of wildfires and other human activities. Now that this area has been burned, the probability of slope failures, debris-flows and hyper-concentrated flows has considerably increased.

Based on USGS debris flow modeling regarding a peak 15-minute rainfall intensity of 24 millimeters per hour (0.95 inch/hr.), it seems like probabilities of debris flow initiation in the burn area are relatively high (60-100%) in large portions of the burn landscape, which mostly corresponds to areas that experienced a moderate to high soil burn severity (Figure 5). Other areas of the burn landscape that are either relatively flat and/or experienced low soil burn severity present lower probabilities (0-40%) of initiation of debris flows. Regarding predicted volumes of debris flows in the burn area, much of this landscape is predicted to produce debris flows ranging from <1,000 – 10,000 cubic meters (Figure 6). Relatively few drainages are predicted to produce larger debris flows of 10,000-100,000 cubic meters, but un-fortunately some of these could impact some major VAR’s, as portions of the Julia Pfeifer Burns State Park and the Limekiln State Park, portions of the Big Creek Reserve and some major road infrastructure. Examining the combined hazard maps presented by the USGS debris flow models, reveals large areas of the burn landscape presenting a moderate to high combined hazard, once again, corresponding to areas that

12 experienced a moderate to high soil burn severity (Figure 7). Other areas that present a low combined hazard represent for the most case areas that experienced a low soil burn severity and/or low gradient slopes or relatively flat areas.

Figure 5: Debris Flow Probability based on a peak 15-minute rainfall intensity storm of 24 mm/h rate storm

Highest concern of direct impact from debris flows are areas where people might be traveling through, working or recreating. These locations can occur in any drainage that might produce a debris flow regardless if it is in an area of high concentration of drainages which are predicted to produce a debris flow with high probabilities or if it is in an area of a single drainage which end up delivering a debris flow.

Figure 6: Debris Flow Estimated Volume based on a peak 15-minute rainfall intensity storm of 24 mm/h rate storm

4. Emergency Determination:

The emergency to VARs from geologic hazards caused by the fire includes adverse effects to the health and safety of people, FS, State, County and private properties, and facilities, roads, trails, and natural and cultural resources. Risk of loss of life and limb is of particular concern.

5. Treatments to Mitigate the Emergency:

Treatments to mitigate the emergencies include warning notifications and signs, administration closures, and road stormproof treatments. The objective of these treatments is to save life, limb and property. Further detailed treatments can be found in Appendix B.

Figure 7 - Debris Flow Combined Hazard based on a peak 15-minute rainfall intensity storm of 24 mm/h rate storm

6. Discussion/Summary/Recommendations:

Within the burned area of the Dolan Fire, evidence of mass wasting as debris slides, debris flows and rock fall are widespread. Based on our observations, it appears that numerous slopes and drainages in the burn area have large amounts of stored material, significant drainage areas, defined channels and steep gradients. Based on the steep burn slopes, the soil burn severity and the amounts of stored sediments in some drainages, it is our estimate that as a result of high intensity storms (>20 mm/hr.) that tend to initiate/trigger debris flows, the probabilities of debris flows and/or hyper-concentrated flows are very high especially in watershed that experienced a moderate to high soil burn severity. In addition, based on ground surveys and air recon, landslides and rock- fall are very likely along numerous steep burned slopes within the burn area of the Dolan Fire. Of particular concerns are steep burn slopes above Hwy 1 and above the Nacimiento – Fergusson road.

Now, as a result of the removal of vegetation by the fire, soils are exposed and have become weakened, hydrophobicity conditions have changed and rocks on slopes have lost their supporting vegetation. Due to these post-fire new conditions, roads, trails and water systems are at risk from numerous geological hazards as rolling rocks, debris flows, debris slides and hyper-concentrated floods. Risks to human life, infrastructure, facilities, roads, trails, and water systems, natural and cultural resources is elevated in most areas in and downstream of the Dolan Fire.

The conclusion of our field observations is that whether the primary post-fire process is rock-fall, debris slides, debris flows or sediment laden flooding, the cumulative risk of various types of slope instability, sediment bulking, and channel flushing is high along a majority of slopes and drainages in and below the burn area following the Dolan Fire. Based on the above, special attention and caution is recommended in areas where people are living or traveling through, working or recreating in or below the burned areas during and after storm events.

In order to reduce risk to life, it is our recommendation to coordinate warning notifications with the National Weather Service, post warning signs and enforce administration closures.

Beyond threats to life and property, as a result of the fire, excessive sedimentation and debris could adversely affect the quality and capacity of streams and other critical habitats for Federally & State Listed Species in and below the burn area, in addition to adversely impacting cultural resources.

7. References –

Pearson, R.C., Fillo, R.V., 1967, Mineral resources of the Ventana Primitive Area, Monterey County, California: U.S. Geological Survey Bulletin 1261-B, 42 p.

Kean, J.W., McCoy, S.W., Tucker, G.E., Staley, D.M., Coe, J.A., 2013, Runoff‐generated debris flows: Observations and modeling of surge initiation, magnitude, and frequency, Journal of Geophysical Research Earth Surface, 118(4), p. 2190-2207.

NOAA Atlas 14 Point Precipitation Frequency Estimates. https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html?bkmrk=ca

Surpless, K., 2014, Geochemistry of the Great Valley Group: An integrated provenance record. International Geology Review. 57. 10.1080/00206814.2014.923347

Staley, DM, Kean JW, Cannon SH, Schmidt KM, Laber JL, 2013, Objective definition of Rain- fall intensity–duration thresholds for the initiation of post-fire debris flows in Southern California. Landslides 10:547–562

Staley, D.M., Negri, J.A., Kean, J.W., Tillery, A.C., Youberg, A.M., 2016, Updated logistic regression equations for the calculation of post-fire debris-flow likelihood in the western United States: U.S. Geological Survey Open-File Report 2016-1106, 20 p., available at https://pubs.er.usgs.gov/publication/ofr20161106

Staley, DM, Negri JA, Kean JW, Laber JL, Tillery AC, Youberg AM (2017) Prediction of spatially explicit rainfall intensity–duration thresholds for post-fire debris-flow generation in the Western United States. Geomorphology 278:149–162

Appendix A: Unit Description Age Qg Stream channel gravel pebble cobble gravel of stream channels Holocene Qa Alluvium alluvial gravel, sand and clay of valleys, undissected Holocene Qls Landslide rubble of local rock units, landslide debris Holocene-Pleistoce Qoa Older alluvium, undivided pebble cobble gravel and younge, lower terraces, older surficial sediments Pleistocene Tpe unnamed sandstone marine, light tan arkosic sandstone Paleocene Tss unnamed marine strata hard, arkosic sandstone, includes interbedded conglomerate and micaceous clay shale Paleocene Tm Monterey Formation deep marine biogenic, white weathering, platy siliceous shale Late Miocene Tsm Santa Margarita Formation shallow marine white sandstone, friable, fossiliferous Miocene upper Tmc Mint Canyon Formation terrestrial pink sandstone, claystone Miocene upper Tml Monterey Formation deep marine biogenic, cream-white-weathered platy siliceous to fissile shale, calcareous sMiocene middle Tvq Vaqueros Sandstone marine transgressive, light-gray semi-hard to friable; Saucesian-Zemorrian Stage Miocene lower Tr Rincon Shale deep marine gray clay shale, crumbly; includes thin beds with rusty yellow concretions Miocene lower Tcc Church Creek Formation marine shale and sandstone Oligocene Tl Reliz Canyon Formation marine, gray clay shale; Lucia Shale Eocene middle Tjs Reliz Canyon Formation marine transgressive, hard light gray sandstone, locally pebbly; Junipero Sandstone Eocene lower? Kss unnamed marine strata similar to Tss and Kcss Cretaceous upper a gr Granitic rocks leucocratic (light colored) granitic rocks, probably youngest plutonic intrusives Cretaceous +/- 90 m qm Quartz Monzonite similar to unit gr, but gray-white, somewhat less coherent, with up to about 10% biotite flaCretaceous +/- 90 m qd Quartz Diorite gray, medium-grained, semi-coherent, massive to gneissoid; composed of sodic plagioclasCretaceous +/- 110 Kcg unnamed marine strata similar to Tscg and Kccg Cretaceous upper a Ksh unnamed marine strata similar to Tsh and Kcsh Cretaceous upper a sp Serpentinite serpentinite formed from hydrothermal alteration of mafic rocks, intrusive, into FranciscanCretaceous ? KTs Toro Formation marine, olive brown graywacke Cretaceous lower gb Gabbro hornblende and pyroxine gabbro, small intrusions of plutonic rocks Mesozoic hd Hornblende diorite-gabbro dark gray to black, medium to locally coarse-grained, massive coherent; composed of hornMesozoic ms schist micaceous schist to gneiss, includes some quartzite and calc-silicate hornfels in some localMesozoic or older ml Marble white marble, medium to coarse grained vaguely bedded, much fractured, metamorphosed from lMesozoic or older fg Franciscan Assemblage greenstone, massive, aphanitic, greenish black, weathers brown; metamorphosed from basalt lavCretaceous and Jur