Cai Yan is used. The UK and Isle of Man have been extensively mapped by the British Geological Survey (BGS) since 1835; a separate Geological Survey of Northern Ireland (drawing on BGS staff) has operated since 1947. Two 1:625,000 scale maps cover the basic geology for the UK. More detailed sheets are available at scales of 1:250,000, 1:50,000 and 1:10,000. The 1:625,000 and 1:250,000 scales show both onshore and offshore geology (the 1:250,000 series covers the entire UK continental shelf), whilst other scales generally cover exposures on land only. Sheets of all scales (though not for all areas) fall into two categories	Geologic map
26651216	: The maps are superimposed over a topographic map base produced by Ordnance Survey (OS), and use symbols to represent fault lines, strike and dip or geological units, boreholes etc. Colors are used to represent different geological units. Explanatory booklets (memoirs) are produced for many sheets at the 1:50,000 scale. Small scale thematic maps (1:1,000,000 to 1:100,000) are also produced covering geochemistry, gravity anomaly, magnetic anomaly, groundwater, etc. Although BGS maps show the British national grid reference system and employ an OS base map, sheet boundaries are not based on the grid. The 1:50,000 sheets originate from earlier 'one inch to 	Geologic map
26651217	the mile' (1:63,360) coverage utilising the pre-grid Ordnance Survey One Inch Third Edition as the base map. Current sheets are a mixture of modern field mapping at 1:10,000 redrawn at the 1:50,000 scale and older 1:63,360 maps reproduced on a modern base map at 1:50,000. In both cases the original OS Third Edition sheet margins and numbers are retained. The 1:250,000 sheets are defined using lines of latitude and longitude, each extending 1° north-south and 2° east-west. United States. In the United States, geologic maps are usually superimposed over a topographic map (and at times 	Geologic map
26651218	over other base maps) with the addition of a color mask with letter symbols to represent the kind of geologic unit. The color mask denotes the exposure of the immediate bedrock, even if obscured by soil or other cover. Each area of color denotes a geologic unit or particular rock formation (as more information is gathered new geologic units may be defined). However, in areas where the bedrock is overlain by a significantly thick unconsolidated burden of till, terrace sediments, loess deposits, or other important feature, these are shown instead. Stratigraphic contour lines, fault lines, strike and dip symbols, are 	Geologic map
26651219	represented with various symbols as indicated by the map key. Whereas topographic maps are produced by the United States Geological Survey in conjunction with the states, geologic maps are usually produced by the individual states. There are almost no geologic map resources for some states, while a few states, such as Kentucky and Georgia, are extensively mapped geologically. Geologic map A geologic map or geological map is a special-purpose map made to show various geological features. Rock units or geologic strata are shown by color or symbols. Bedding planes and structural features such as faults, folds, are shown with 	Geologic map
26651220	Joseph Hofmann Joseph Hofmann Joseph Hofmann or Josef Hofmann (the surname spelled with a single f) may refer to: Joseph Hofmann Joseph Hofmann or Josef Hofmann (the surname spelled with a single f) may refer to: 	Joseph Hofmann
26651221	Cai Yan Cai Yan Cai Yan ( 178 – post 206; or 170–215; or died  249), courtesy name Wenji, was a Chinese composer, poet, and writer who lived during the late Eastern Han dynasty of China. She was the daughter of Cai Yong. Her courtesy name was originally Zhaoji, but was changed to Wenji during the Jin dynasty to avoid naming taboo because the Chinese character for zhao" in her courtesy name is the same as that in the name of Sima Zhao, the father of the Jin dynasty's founding emperor, Sima Yan. She spent part of her life as a captive of  the Xiongnu until 207, when the warlord Cao Cao, who controlled the Han central government in the final years of the Eastern Han dynasty, paid a heavy ransom to bring her back to Han territory. Life. Cai Yan was the daughter of Cai Yong, a famous Eastern Han dynasty scholar from Yu County (), (), which is around present-day Qi County, Kaifeng, Henan. She was married to Wei Zhongdao () in 192 but her husband died shortly after their marriage and they did not have any children. Between 194 and 195, when China entered a period of chaos, the Xiongnu nomads intruded  into Han territory, captured Cai, and took her back as a prisoner to the northern lands. During her captivity, she married the Xiongnu chieftain (the "Wise Prince of the Left") and bore him two sons. 12 years later, the Han Chancellor, Cao Cao, paid a heavy ransom in the name of Cai's father for her release. After Cai was freed, she returned to her homeland but left her children behind in Xiongnu territory. The reason Cao Cao wanted her back was that she was the sole surviving member of her clan and he needed her to placate the spirits  of her ancestors. After that, Cai married again, this time to Dong Si (), a local government official from her hometown. However, when Dong Si committed a capital crime later, Cai pleaded with Cao Cao for her husband's acquittal. At the time, Cao Cao was hosting a banquet to entertain guests, who were stirred by Cai's distressed appearance and behaviour. She asked him if he could provide her with yet another husband. He pardoned Dong Si. Later in her life, she wrote two poems describing her turbulent years. Romance of the Three Kingdoms. Cai Yan briefly appears in chapter  71 of the novel, Romance of the Three Kingdoms, a historical novel of 14th century which romanticizes previous events and during the Three Kingdoms period of China. Cao Cao was on a march to battle with Liu Bei during the Hanzhong Campaign when he passed by Cai Yan's residence. Cao Cao came to the gates with a few attendants. Upon hearing who the guest was, Cai Yan hurriedly raced to meet them, and after Cao Cao took a seat in the household, he noticed a tablet which contained mix-matched eight words that he couldn't interpret. Cai Yan  pointed out that her father wrote it after hearing a specific tale. Yang Xiu, one of the men whom Cao Cao brought along, declared he knew the riddle on the tablet. Cao Cao and his subordinates later left the house and Yang Xiu mentioned what the eight words meant using wordplay. Legacy. Like her father, Cai Wenji was an established calligrapher of her time, and her works were often praised along with her father's. Her poems were noted for their sorrowful tone, which paralleled her hard life. The famous guqin piece "Eighteen Songs of a Nomad Flute" is traditionally  attributed to her, although the authorship is a perennial issue for scholarly debate. The other two poems, both named "Poem of Sorrow and Anger" (), were known to be written by her. The following is an excerpt from the "Poem of Sorrow and Anger" in five-character form (): In addition to her surviving poems, a volume of "Collective Works of Cai Wenji" was known to have survived until as late as the Sui dynasty but had been lost by the Tang dynasty. Cai Wenji inherited some 4,000 volumes of ancient books from her father's vast collection. However, they were destroyed  in the ravages of war. At Cao Cao's request, Cai recited 400 of them from memory and wrote them on paper. Literary and artistic tributes. The stories of Cai reverberate primarily with feelings of sorrow, and inspired later artists to keep portraying her past. Her return to Han territory has been the subject of numerous paintings titled "Cai Wenji Returns to Her Homeland" () by various painters since the Tang dynasty, as well as renderings in traditional Beijing opera. In popular culture. Guo Moruo wrote a play on her life in 1959. In 1976, a crater on Mercury was named  Ts'ai Wen-Chi after Cai Wenji, citing her as "Chinese poet and composer". In 1994, a crater on Venus was named Caiwenji after Cai Wenji, citing her as "Chinese poet". Cai Wenji appears as a playable character in Koei's "Dynasty Warriors: Strikeforce 2" and "Dynasty Warriors 7" (her debut as a playable character in North American and European ports). She also appears in Koei's "Romance of the Three Kingdoms" video game series and in "" as a non-playable character. She is also a playable character in "Warriors Orochi 3" and "Warriors Orochi 4". Her fighting style relies on  casting energy balls and shock waves by strumming her harp. Cai Yan Cai Yan ( 178 – post 206; or 170–215; or died  249), courtesy name Wenji, was a Chinese composer, poet, and writer who lived during the late Eastern Han dynasty of China. She was the daughter of Cai Yong. Her courtesy name was originally Zhaoji, but was changed to Wenji during the Jin dynasty to avoid naming taboo because the Chinese character for "zhao" in her courtesy name is the same as that in the name of Sima Zhao, the father of the Jin dynasty's founding emperor, Sima Yan