Geologic and bathymetric reconnaissance overview of the San Pedro shelf region, southern California

This report presents a series of maps that describe the
bathymetry and late Quaternary geology of the San Pedro shelf
area as interpreted from seismic-reflection profiles and 3.5-kHz
and multibeam bathymetric data. Some of the seismic-reflection profiles
were collected with Uniboom and 120-kJ sparker during surveys conducted
by the U.S. Geological Survey (USGS) in 1973 (K-2-73-SC), 1978
(S-2-78-SC), and 1979 (S-2a-79-SC). The remaining seismic-reflection
profiles were collected in 2000 using Geopulse boomer and minisparker
during USGS cruise A-1-00-SC. The report consists of seven oversized
sheets:

1. Map of 1978 and 1979 uniboom seismic-reflection and 3.5-kHz
tracklines used to map faults and folds on San Pedro Shelf.

2. Maps of multibeam shaded bathymetric relief with faults and folds,
and bathymetric contours.

3. Isopach map of unconsolidated sediment, seismic-reflection
profile across the San Pedro shelf, seismic-reflection profile
across San Gabriel paleo-valley.

4. Seismic-reflection profiles across the Palos Verdes Fault Zone.

5. Geologic map and samples of Uniboom and 120-kJ sparker
seismic-reflection profiles used to make the map.

6. Map showing thickness of uppermost (Holocene?) sediment layer.

7. Map of San Gabriel Canyon paleo-valley and associated
drainage basins.

For more information on the seismic surveys see http://walrus.wr.usgs.gov/infobank/a/a100sc/html/a-1-00-sc.meta.html

These data are also available via GeoMapApp (http://www.geomapapp.org/) and Virtual Ocean (http://www.virtualocean.org/) earth science exploration and visualization applications.

本报告呈现了一系列基于地震反射剖面、3.5 kHz与多波束测深数据解译得到的圣佩德罗陆架（San Pedro shelf）水深与晚第四纪地质图件。部分地震反射剖面由美国地质调查局（U.S. Geological Survey，USGS）于1973年（航次K-2-73-SC）、1978年（航次S-2-78-SC）及1979年（航次S-2a-79-SC）的调查中，采用Uniboom震源与120 kJ电火花震源采集所得；剩余地震反射剖面则由USGS在2000年的航次A-1-00-SC中，使用Geopulse boom震源与minisparker震源采集完成。
本报告共包含7张超大幅图纸：
1. 用于解译圣佩德罗陆架断裂与褶皱的1978年、1979年Uniboom地震反射剖面与3.5 kHz测线分布图。
2. 标注断裂与褶皱的多波束阴影水深起伏图，以及水深等值线图。
3. 未固结沉积物等厚图、横穿圣佩德罗陆架的地震反射剖面图、横穿圣盖博古河谷（San Gabriel paleo-valley）的地震反射剖面图。
4. 横穿帕洛斯弗迪斯断裂带（Palos Verdes Fault Zone）的地震反射剖面图。
5. 用于编图的Uniboom与120 kJ电火花震源地震反射剖面的地质图与采样点位图。
6. 最上部（全新世？）沉积层厚度分布图。
7. 圣盖博峡谷古河谷（San Gabriel Canyon paleo-valley）及其相关流域盆地分布图。
如需了解地震调查的更多细节，请访问：http://walrus.wr.usgs.gov/infobank/a/a100sc/html/a-1-00-sc.meta.html
上述数据还可通过GeoMapApp（http://www.geomapapp.org/）与Virtual Ocean（http://www.virtualocean.org/）这两款地球科学探索与可视化应用获取。