Marine geological data from the Roman Rock area in False Bay, South Africa

A 12 km2 area off Simon's Town in NW False Bay, South Africa, was surveyed using side-scan sonar and a single-beam echosounder, revealing six distinct patterns of acoustic reflectivity:

Facies 1 -- Outcrops of Cape Peninsula Granite characterized by irregular blocky patterns.
Facies 2 -- Stationary, long-crested wave ripples, oriented WSW-ENE.
Facies 3 -- Patchy veneer of calcareous sediment overlying quartzose sand.
Facies 4 -- Larger 'Cloud-like' and 'tongue-like' windows in the veneer of calcareous sediment revealing underlying rippled sand.
Facies 5 -- Rippled fine-grained quartzose sand in the deeper eastern area.
Facies 6 -- Medium-gray patches within Facies 5, possibly indicating weathered granite or calcareous sediment.

The Facies were ground-truthed using sediment sample data and diver observations. The sub-tidal environment is predominantly calm, with occasional high-energy conditions due to southeasterly gales influencing sediment movement. Analysis of sediment samples shows that the calcareous and quartzose sediments mix according to the Folk & Ward (1957) sediment-mixing model. Quartzose sands probably originate from Late Pleistocene regressive dunes reworked during the Holocene transgression. Modern calcareous sediments originate from carbonate-secreting organisms either attached to granite outcrops or unattached on the seafloor surface.

This repository contains spatial and sedimentological data from the survey and contextual data from other sources.

位于南非西北部虚假湾西蒙镇海域的12平方公里区域，通过侧扫声呐和单波束回声探测仪进行了调查，揭示了六种不同的声学反射模式：

facies 1 -- 开普半岛花岗岩的露头，以不规则块状图案为特征。
facies 2 -- 静止的、长波纹的波痕，方向为西西南-东东北。
facies 3 -- 在石英砂上的钙质沉积层薄层，分布不均。
facies 4 -- 在钙质沉积层薄层中出现的较大“云状”和“舌状”窗口，揭示了其下的波痕砂。
facies 5 -- 深东部区域中细粒石英砂的波痕。
facies 6 -- 在facies 5中出现的灰白色斑点，可能指示风化的花岗岩或钙质沉积。

通过沉积样本数据和潜水员观察对facies进行了实地验证。亚潮汐环境以平静为主，偶尔由于东南风的影响而出现高能量条件，导致沉积物运动。沉积样本分析显示，钙质和石英砂质沉积物按照Folk & Ward（1957）的沉积混合模型混合。石英砂质沉积物可能源自更新世晚期的退潮沙丘，在全新世海侵期间重新塑造。现代钙质沉积物源自附着在花岗岩露头或海床表面的碳酸盐分泌生物。

本存储库包含调查中的空间和沉积学数据，以及其他来源的背景数据。