203287 TP Final Vol 2.Ai
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4.7 Cultural Resources 4.7 Cultural4.7 4. WSIP Facility Projects – Setting and Impacts 4.7 Cultural Resources Cultural resources include paleontological resources, archaeological resources, historical resources, and human remains. This section provides a program-level assessment of potential WSIP impacts on historical, paleontological, or archaeological resources that might be present in the vicinity of the WSIP projects and/or historic water system facilities. Programmatic mitigation measures to reduce or eliminate potentially significant impacts on these cultural resources are identified in this section and presented in detail in Chapter 6. This analysis does not identify specific cultural resources at each of the 22 WSIP facility project sites, although some previously identified cultural resources are located at or near those project sites. Site-specific analysis will be conducted as part of separate, project-level CEQA review for individual WSIP projects. 4.7.1 Setting and Resource Types Paleontological Setting Paleontological resources within the WSIP study area consist of the fossilized remains of plants and animals, including vertebrates (animals with backbones) and invertebrates (e.g., starfish, clams, ammonites, and coral marine). Fossils of microscopic plants and animals, or microfossils, are also considered in this analysis. The age and abundance of fossils depend on the location, topographic setting, and particular geologic formation in which they are found. The geologic formations containing the majority of fossils in the WSIP study area are considered geologically young; the oldest fossil-bearing formation dates to the Paleocene epoch (65 million years old). Most of the fossil-bearing geologic units in the WSIP study area were formed in ancient marine environments such as inland embayments, coastal areas, and extensive inland seas. However, in the eastern portion of the study area, some vertebrate fossils have been found in non-marine formations consisting of sand, gravel, and mudflow deposits. San Joaquin Region Paleontological resources in the San Joaquin Region are most prevalent in geologic formations located along the western margin of the San Joaquin Valley. These formations include the marine sandstone, mudstone, siltstone, and shale of the San Pablo Formation (including units of the Neroly Sandstone, Cierbo Sandstone, and Briones Sandstone); various undivided conglomerate, sandstone, and siltstone units (including the Carbona and Oro Loma Formations); and the Moreno Formation. The Moreno Formation, which is present along the western margin of the Great Valley as an elongated and continuous, northwest-trending unit, consists of shale, sandstone, and siltstone that were once deposited in a deep-marine environment. The Moreno Formation contains abundant fossils, including a variety of marine reptiles, fish skeletons, and various marine invertebrates; plant remains such as wood, leaves, and needles; and the remains of dinosaurs (USFWS/CDFG, 2006). Dinosaurs are rarely found in California, but many of the plesiosaurs and mosasaurs found in the state come from the Moreno Formation (USFWS/CDFG, 2006). SF Planning Department Case No. 2005.0159E 4.7-1 PEIR on SFPUC Water System Improvement Program / 203287 4. WSIP Facility Projects – Setting and Impacts 4.7 Cultural Resources The University of California Museum of Paleontology Collections Database lists 81 fossil localities in San Joaquin County; the majority of these sites are along the western boundary of the San Joaquin Valley. Several fossil localities are grouped in the San Pablo and Moreno Formations west of Vernalis near the Tesla Portal of the Hetch Hetchy Aqueduct (UCMP, 2006). These fossils include an extinct horse, mammoth, and boney fish dating to the Pleistocene epoch, about 1.8 million years ago. The Collections Database includes a fossil locality at the Hetch Hetchy Tunnel (Locality No. 3315), which is listed as a discovery site for a prehistoric camel (up to 1.8 million years old). Only a few fossil localities have been identified in the younger alluvial deposits throughout the central portion of the San Joaquin Valley. Fossil localities appear again on the east side of the San Joaquin Valley near Oakdale, where the Hetch Hetchy Aqueduct extends through the Mehrton Formation, a non-marine formation ranging in age from 24 to 5 million years old (Miocene). Fossils found at sites in the Mehrten Formation near Oakdale include early (Miocene age) turtles, tortoises, kangaroo rats, single-hoofed horses, and mammoths. Sunol Valley and Bay Division Regions Many fossil localities in the Sunol Valley and Bay Division Regions occur in marine and non-marine deposits ranging in age from 10,000 to 5.3 million years old.1 These geologic formations include non-marine sediments of the Santa Clara Formation, Livermore Gravels, and Irvington Gravels. Marine fossil-bearing geologic deposits include the Cierbo Sandstone found in the San Pablo, Monterey, Santa Margarita, and Panoche Formations, and in the older (55 to 34 million years old) Domengine Formation. The majority of the fossils found in the Sunol Valley and Bay Division Regions are vertebrate fossils, including extinct bison, camels, boney fish, mammoths, and horses, although some localities contain marine invertebrate fossils such as bivalves (clams). A fossil of a mastodon from the Pleistocene epoch was discovered in Sunol (Locality No. 6535), while an unidentified vertebrate fossil was discovered in the vicinity of Calaveras Dam (Locality No. 3937) (UCMP, 2006). The distribution of fossil localities and the location of corresponding geologic units indicate that most of the paleontological resources in the Sunol Valley Region are east and south of Interstate 680 in the upland foothills of the Diablo Range. Fossil localities diminish west of Interstate 680, towards the Santa Clara Valley and the central portion of the Bay Division Region, because the Santa Clara Valley and the south San Francisco Bay margin is underlain by much younger alluvial and basin deposits that do not contain abundant fossil remains. There are 280 fossil localities in Alameda County, but only 36 in Santa Clara County (UCMP, 2006). Some of the fossil localities in Santa Clara County contain vertebrate fossils, including a bison and another mammal that appears to be an ancient descendant of an elephant or sea cow. 1 The age range of these deposits is referred to as the Plio-Pleistocene, which is the period of time that spans the Pliocene epoch (5.3 to 1.8 million years ago) and the Pleistocene epoch (1.8 million to 10,000 years ago). SF Planning Department Case No. 2005.0159E 4.7-2 PEIR on SFPUC Water System Improvement Program / 203287 4. WSIP Facility Projects – Setting and Impacts 4.7 Cultural Resources Peninsula and San Francisco Regions There are few fossil localities in the Peninsula and San Francisco Regions. Most fossils are found along the Pacific Coast in the younger (Pliocene, 5.3 to 1.8 million years ago) marine units, such as the Purisima Formation, Monterey Formation, Butano Formation, Colma Formation, and Merced Formation, and in locations within the outcropping marine units in the Santa Cruz Mountains, west of the WSIP regions. Fossils found along the coast include vertebrates (e.g., extinct camels, horses, and sea mammals) and invertebrates (e.g., clams and corals). Fossil localities diminish along the eastern flank of the Santa Cruz Mountains, likely due to the presence of chaotically mixed and severely fractured Franciscan Complex bedrock and geologically younger alluvial deposits in the upland foothills.2 No fossil localities were identified in the Crystal Springs Reservoir or San Andreas Reservoir areas. The lack of fossil localities is partly due to the Franciscan Complex bedrock surrounding the reservoirs and the degree of fracturing in this bedrock unit caused by the San Andreas Rift Zone. The closest fossil locality south of the WSIP study area is an extinct sea mammal, an ancestor of the sea lion (UCMP, 2006). To the north, the closest fossil locality to the study area is an extinct horse from the Pleistocene epoch (1.8 million to 10,000 years ago). Archaeological / Prehistoric-Period Setting Both prehistoric and historic resources are considered archaeological resources. This discussion of prehistoric archaeology addresses cultural patterns in the WSIP study area through the time of European contact. Historic archaeological resources, starting with the Mission era, are discussed below under “Historic-Period Setting.” Numerous prehistoric archaeological sites have been identified in a variety of environments within the WSIP study area. In many cases, these sites are buried by alluvial deposits at or near former or existing wetland boundaries, along seasonal and perennial watercourses and other sources of fresh water such as springs, at the base of foothills, or at or near vegetation ecotones (i.e., a region between two neighboring but dissimilar plant communities). Many of the sites are deposits of stone tools, while others are large habitation sites that represent years of layered subsurface material or residues that chronicle the behavior of the inhabitants. Efforts to reconstruct the prehistoric period into broad cultural stages (e.g., the Windmiller, Berkeley, and Augustine Patterns, as discussed below) allow researchers to describe a wide variety of sites with similar cultural patterns during a given period of time, thereby creating a regional chronology. In some cases, regional patterns in material culture are reflected in areas that are broader than the WSIP regions. For example, the greater San Francisco Bay Area is often discussed as a single region in terms of archaeological sequences (Moratto, 1984). As a result, a broad discussion of the region that encompasses the Bay Area would include the Bay Division, Peninsula, and San Francisco Regions, in addition to elements of the Sunol Valley Region, 2 Fossils are rarely found in the Franciscan Complex bedrock of the Coast Range Province; any fossil remains originally present in the rock would not likely remain because the Franciscan Complex in this area is a chaotically mixed and fragmented mass of rock in a sheared matrix.