Santa Ynez Mountains Research Articles

Stratigraphy and Structure of Mountains Northeast of Santa Barbara, California

The district discussed in this paper includes parts of the Santa Ynez and San Rafael ranges near the coast of Southern California. The oldest rocks belong to the Franciscan group (Jurassic?) and consist chiefly of structurally disorganized dark shale with isolated bodies of sandstone, contorted chert, and other types of rock. The stratigraphic section is remarkable for its great thickness (more than 28,000 feet) of Cretaceous and Eocene sandstone and shale. These sediments, which are marine but only scantily fossiliferous, greatly predominate over the other rocks in areal extent. In this paper the Cretaceous strata are divided into three formations: the Undifferentiated Cretaceous shale, the Debris Dam sandstone, and the Pendola shale, the two latter formations being newly named. Lower Eocene rocks are lacking. There is an important angular unconformity at the base of the middle Eocene section. The well known Sierra Blanca limestone of middle Eocene age locally comprises the basal unit of the Eocene rocks. It is overlain by the thick Juncal formation (middle Eocene shale and sandstone) which is here defined for the first time. Above this are the Matilija sandstone, Cozy Dell shale, and Coldwater sandstone,--all upper Eocene in age, and all previously described by others. The Oligocene is represented by the non-marine Sespe formation, and the Miocene rocks include Temblor sandstone and Monterey shale. At the base of the Miocene section, there is a striking angular unconformity. The Santa Ynez fault, which extends east and west across the area (and beyond), is the most important structural feature. It is a steeply dipping fault of Quaternary age, probably with both a reverse and a strike-slip component of displacement. North of this fault the rocks are folded along northwest-southeast axes in accordance with the general pattern of California Coast Range structure. South of the fault, however, the formations in general strike east-west in harmony with the Transverse Ranges, of which the Santa Ynez Mountains are a member. The rocks of the Santa Ynez Range in this area comprise a locally overturned limb of a large syncline whose trough lies south of the mountains. On the north the limb may have once been shared by an anticline, but the Santa Ynez fault now occupies the supposed axial region. Near the fault the Cretaceous and Eocene beds are interrupted and truncated by a body of Franciscan rocks which, although mainly sedimentary, have apparently been forced upward in the manner of an intrusive mass. The writers describe other structural features and give a chronology of tectonic events. End_Page 1727------------------------------

Santa Maria Region: ABSTRACT

The Santa Maria province is a roughly triangular area in the California coastal belt which is bounded on the west by the Pacific Ocean, on the south by the Santa Ynez Mountains, and on the north and northeast by the Santa Lucia Range. The province consists of several more or less isolated structural basins with similar sedimentary histories and related types of objective zones and traps. Many types of rocks underlie the zones of present and prospective production. The term, basement, as used in this paper, refers to rocks older than Eocene that consist of Jurassic metamorphics and basic intrusives and Cretaceous and Jurassic sediments that have undergone various degrees of alteration. The Santa Maria province has an area of 2,126 square miles, of which 1,824 square miles are underlain by objective sediments. The volume of unaltered sediments is estimated at 1,112 cubic miles and the maximum depth to basement rocks is approximately 16,000 feet. About 400 exploratory wells have been drilled in the province, resulting in the discovery of 14 productive areas with a cumulative production to December 31, 1949, of slightly more than 300 million barrels of oil. Production is largely from Miocene sands, shales, and cherts. Significant amounts of oil have been produced from lower Pliocene sands and in one area from fractured sandstones of Jurassic age. This Jurassic production is considered to have migrated from overlapping Miocene beds. End_Page 2383------------------------------ Prospective sediments range in age from Eocene to Pliocene. They are marine, with the exception of minor amounts of lower Miocene non-marine beds near basement highs and a veneer of upper Pliocene and Pleistocene continental beds in the central portion of the province. Commercial oil production comes from anticlinal closures and stratigraphic and fault traps. It is probable that substantial undiscovered reserves of heavy crude exist in this province, and that lighter oils may be found in parts of the stratigraphic section or in areas not before subjected to intensive search. Stratigraphic and structural studies may well be expected to yield important discoveries. End_of_Article - Last_Page 2384------------

Eocene Stratigraphy in Western Santa Ynez Mountains, Santa Barbara County, California

This paper describes the critical Eocene section at Canada de Santa Anita, Santa Barbara County, California. The formation of early workers is subdivided into the Anita shale (new name), Matilija sandstone, Cozy Dell shale, Sacate formation (new name), and Gaviota formation in ascending stratigraphic order. Detailed study was confined to the Eocene strata below the type Gaviota formation. The general east-west trending anticlinal structure is complicated by strike faulting. Foraminifers in the Anita shale, which is disconformable on Cretaceous beds, suggest a middle Eocene age for the formation. The molluscan faunule in the Matilija is believed to belong in Clark and Vokes' (1936) Transition stage below the Tejon and above the Domengine. Of particular sign ficance are faunules from the Cozy Dell; these belong in Laiming's (1940) Zones A-1 and A-2. The upper member of the Sacate formation contains a Turritella related to T. variata, the abundant Gaviota species.

Wheatland formation and its relation to Early Tertiary andesites in the Sierra Nevada

Research Article| June 01, 1938 Wheatland formation and its relation to Early Tertiary andesites in the Sierra Nevada B. L. CLARK; B. L. CLARK Search for other works by this author on: GSW Google Scholar C. A. ANDERSON C. A. ANDERSON Search for other works by this author on: GSW Google Scholar GSA Bulletin (1938) 49 (6): 931–956. https://doi.org/10.1130/GSAB-49-931 Article history received: 22 Jun 1937 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation B. L. CLARK, C. A. ANDERSON; Wheatland formation and its relation to Early Tertiary andesites in the Sierra Nevada. GSA Bulletin 1938;; 49 (6): 931–956. doi: https://doi.org/10.1130/GSAB-49-931 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract INTRODUCTIONGENERAL STATEMENTMarine fossils were recently discovered east of Marysville, California, by Theo Crook, in a conglomerate resting on the bedrock of the lower western slopes of the Sierra Nevada. Crook kindly turned over his collections to the University of California and suggested that the writers make a more complete examination. Additional fossils have been collected and the local stratigraphy has been studied, resulting in the recognition of a new formation, herein called the Wheatland formation. On the basis of the fauna, the formation is correlated with the lower portion of the Gaviota formation of the Santa Ynez mountains, California, and with the Gries Ranch beds of southwestern Washington. These are tentatively considered of Upper Eocene age, but they may be Lower Oligocene.This formation is of importance for two reasons: (1) it is the first record of a marine invasion in this area in Upper Eocene or possibly . . . This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not currently have access to this article.

Structural Evolution of Southern California: The San Rafael and Santa Ynez Mountains (Part of Compilation by Reed and Hollister for AAPG, Dec. 1936)

Structural Evolution of Southern California: The San Rafael and Santa Ynez Mountains (Part of Compilation by Reed and Hollister for AAPG, Dec. 1936)

Significance of the Matilija Overturn

Introduction 2 The Matilija overturn is on the southern margin of the Santa Ynez Mountains, 30 miles east of Santa Barbara and 80 miles northwest of Los Angeles, in Ventura County, California. The name is taken from a station on the Ventura-Ojai Branch of the Southern Pacific Railroad and from Matilija Springs, on Matilija Creek, 3 miles north of the station. The area in which the principles illustrated by the overturn may be considered significant embraces the coastal district inland from the Santa Barbara Channel. It is a somewhat irregular area beginning 20 miles or more northwest of Los Angeles and extending northwestward to Point Conception (figure 1). The conclusions given in this paper are based on detailed maps prepared during parts of the years 1926, 1927, and 1928 and on several published reports on parts of the area. The structural characteristics of the region near Matilija may be . . .